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1
Ball, Frank, and Tom Britton. "An epidemic model with infector-dependent severity." Advances in Applied Probability 39, no. 4 (2007): 949–72. http://dx.doi.org/10.1239/aap/1198177234.
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A stochastic epidemic model is defined in which infected individuals have different severities of disease (e.g. mildly and severely infected) and the severity of an infected individual depends on the severity of the individual he or she was infected by; typically, severe or mild infectives have an increased tendency to infect others severely or, respectively, mildly. Large-population properties of the model are derived, using branching process approximations for the initial stages of an outbreak and density-dependent population processes when a major outbreak occurs. The effects of vaccination are considered, using two distinct models for vaccine action. The consequences of launching a vaccination program are studied in terms of the effect it has on reducing the final size in the event of a major outbreak as a function of the vaccination coverage, and also by determining the critical vaccination coverage above which only small outbreaks can occur.
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Ball, Frank, and Tom Britton. "An epidemic model with infector-dependent severity." Advances in Applied Probability 39, no. 04 (2007): 949–72. http://dx.doi.org/10.1017/s0001867800002184.
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A stochastic epidemic model is defined in which infected individuals have different severities of disease (e.g. mildly and severely infected) and the severity of an infected individual depends on the severity of the individual he or she was infected by; typically, severe or mild infectives have an increased tendency to infect others severely or, respectively, mildly. Large-population properties of the model are derived, using branching process approximations for the initial stages of an outbreak and density-dependent population processes when a major outbreak occurs. The effects of vaccination are considered, using two distinct models for vaccine action. The consequences of launching a vaccination program are studied in terms of the effect it has on reducing the final size in the event of a major outbreak as a function of the vaccination coverage, and also by determining the critical vaccination coverage above which only small outbreaks can occur.
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Sanchez, Emily, Ryan Simpson, Lauren Sallade, Yutong Zhang, and Elena Naumova. "Foodborne Illness Outbreak Severity Across Geographic and Supply Chain Contamination Locations in the United States, 2009–2019." Current Developments in Nutrition 6, Supplement_1 (2022): 946. http://dx.doi.org/10.1093/cdn/nzac067.066.
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Abstract Objectives In 2009, the Centers for Disease Control and Prevention's National Outbreak Reporting System (NORS) began collecting supply chain contamination data as part of foodborne outbreak (FBO) traceback investigations. We created an integrated FBO severity score measure and examined differences in FBO severity by geographic and supply chain contamination locations. We used 9,407 NORS records between 2009–2019 to demonstrate the utility of the proposed methodology. Methods The severity scores were composed of 11 metrics based on outbreak intensity and duration characteristics and metrics’ completeness. Metrics were normalized (with natural log-transformation), calibrated (to 0–1 scale), and weighed (by completeness) across all recorded outbreaks. Individual outbreak scores ranged from 0 (lowest severity) to 1 (highest severity). We compared averages of severity scores across geographic (i.e., multistate and single state exposure outbreak) and supply chain contamination locations (i.e., suspected or confirmed before preparation, preparation, unknown and missing) using tobit-regression models. Results All FBOs reported the state of exposure; 5,500 (58.5%) reported supply chain contamination location. Multistate exposure FBOs had higher median severity scores than single state outbreaks (0.54 [0.44, 0.67] vs 0.28 [0.16, 0.41], P < 0.001). FBOs with reported point of contamination that occurred before preparation had higher median severity scores than all other stages (0.36 [0.27, 0.49] vs 0.26 [0.15, 0.41], 0.25 [0.13, 0.39], and 0.29 [0.16, 0.43], P < 0.001, for preparation, unknown and missing stages respectively). Conclusions Understanding an FBO's severity by geographic and supply chain contamination location helps to quantify supply chain vulnerability and improve monitoring of food safety. Identification of supply chain contamination at high level granularity and completeness is critical for developing foodborne outbreak (FBO) prediction analytics aimed to reduce both the volume and severity of outbreaks and illnesses. Funding Sources DoD, ODNI, NIFA, NSF, USIAD.
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Mattner, Frauke, Lutz Mattner, Hans Ulrich Borck, and Petra Gastmeier. "Evaluation of the Impact of the Source (Patient Versus Staff) on Nosocomial Norovirus Outbreak Severity." Infection Control & Hospital Epidemiology 26, no. 3 (2005): 268–72. http://dx.doi.org/10.1086/502538.
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AbstractObjective:To study the dependence of infection risk and outbreak size on the type of index case (ie, patient or staff).Methods:Nosocomial outbreaks were reviewed and categorized into those started by patients and those started by staff. Infection risks and outbreak sizes were evaluated taking into account the index case category.Results:Of the 30 nosocomial outbreaks of norovirus with person-to-person transmission, 20 (67%) involved patients as the index cases. Patient-indexed outbreaks affected significantly more patients than did staff-indexed outbreaks (difference in means, 16.25; 95% confidence interval [CI95], 5.1 to 27.0). For the numbers of affected staff, no dependence on the index case category was detectable (difference in means, -1.05; CI95, -9.0 to 6.9). For patients exposed during patient-indexed outbreaks, the risk of acquiring a norovirus infection was approximately 4.8 times as high as the corresponding risk for patients exposed during staff-indexed outbreaks (odds ratio [OR], 4.79; CI95,1.82 to 8.28). The infection risk for exposed staff during patient-indexed outbreaks was approximately 1.5 times as high as the corresponding risk during staff-indexed outbreaks (OR, 1.51; CI95, 0.92 to 2.49).Conclusions:Patient-indexed norovirus outbreaks generally affect more patients than do staff-indexed outbreaks. Staff appear to be similarly affected by both outbreak index category groups. This study demonstrates the importance of obtaining complete outbreak data, including the index case classification as staff or patient, during norovirus outbreak investigations. Such information may be useful for further targeting prevention measures.
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Duncombe, Tamara, Matthew Garrod, Wang Xuetao, et al. "Risk factors associated with SARS-CoV-2 transmission, outbreak duration, and mortality in Fraser Health acute-care settings." Antimicrobial Stewardship & Healthcare Epidemiology 2, S1 (2022): s38—s39. http://dx.doi.org/10.1017/ash.2022.129.
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Background: Transmission of SARS-CoV-2 in acute-care settings affects patients, healthcare workers, and the already-burdened healthcare system. An analysis of risk factors associated with outbreak severity was conducted to inform prevention strategies. Methods: This study was a cross-sectional analysis of COVID-19 outbreaks at Fraser Health (FH) acute-care sites between March 2020 and March 2021. Outbreak severity measures included COVID-19 attack rate, outbreak duration, and 30-day case mortality. Covariates at patient, outbreak, unit level, and facility level were included (Table 1). Generalized linear models with generalized estimation equations were used for all outcome measures, with outbreak duration and 30-day case mortality using multivariate negative binomial distributions, and attack rate using Gaussian distribution. A P value of .05 indicated statistical significance. Analyseswere performed using SAS version 3.8 software, R version 4.1.0 software, and Stata version 16.0 software. Results: Between March 2020 and March 2021, 54 COVID-19 outbreaks were declared in FH acute-care sites involving 455 SARS-CoV-2–positive patients. The average outbreak duration was 23 days, the average attack rate was 28%, and the average 30-day all-cause mortality per outbreak was 2 deaths. The results of the full models are shown in Table 1. Discussion: We identified an inverse relationship between increased hand hygiene compliance during outbreaks and all 3 severity measures. Paradoxically, hand hygiene rates in the year prior to the pandemic were positively associated with duration and mortality. Increased unit age was also associated with increases in each of the severity measures. Comorbidity total factor was correlated with outbreak attack rate and duration, demonstrating the importance of individual patient characteristics in an outbreak. Conclusions: Our findings highlight the importance of hand hygiene practices during an outbreak. Additionally, it is important to understand the difficulties faced by older facilities, many of which face infrastructural challenges. This study reinforces the need to incorporate infection control standards into healthcare planning and construction.Funding: NoneDisclosures: None
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Patterson, Kaitlin, Erin McGill, Demy Dam, Anna Bellos, Cameron Mark Coulby, and Rachel McCormick. "Characterising COVID-19 school and childcare outbreaks in Canada in 2021: a surveillance study." BMJ Public Health 2, no. 1 (2024): e000248. http://dx.doi.org/10.1136/bmjph-2023-000248.
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BackgroundIn January 2021, the Public Health Agency of Canada launched the Canadian COVID-19 Outbreak Surveillance System to monitor outbreaks by setting. Schools and childcare centres were identified as settings of interest, as children play a key role in the transmission chain of other respiratory illnesses. This paper describes outbreak trends observed in school and childcare settings from January to December 2021 when many public health measures were in place.MethodsSchool and childcare outbreak data from five jurisdictions were included, representing 76% of the total Canadian population. Epidemiological curves were generated, trends in outbreak settings and cases’ age distribution over time were examined and descriptive statistics on outbreak size were calculated.ResultsIn 2021, most school and childcare outbreaks were in primary schools (42%). Severity was low in school and childcare settings (0.40% of outbreak cases hospitalised, <0.01% of outbreak cases deceased). Most school and childcare outbreaks reported fewer than 10 cases per outbreak. During the start of the 2021–2022 school year (September 2021), there were fewer outbreaks in secondary schools and fewer cases among those aged 12+ years compared with January–June of 2021.ConclusionDuring the study period, there was no observed association between an increase in school and childcare outbreaks and an increase in incidence rates in community case data. Children remain a population of interest for SARS-CoV-2; however, severity in paediatric populations remained low throughout 2021 and the risk of transmission in Canadian schools was low.
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Talucci, Anna C., Garrett W. Meigs, Anders Knudby, and Meg A. Krawchuk. "Fire severity and the legacy of mountain pine beetle outbreak: high-severity fire peaks with mixed live and dead vegetation." Environmental Research Letters 17, no. 12 (2022): 124010. http://dx.doi.org/10.1088/1748-9326/aca2c1.
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Abstract Bark beetle outbreaks and wildfires are two of the most prevalent disturbances that influence tree mortality, regeneration, and successional trajectories in western North American forests. Subboreal forests have experienced broad overlaps in these disturbances, and recent wildfires have burned through landscapes with substantial tree mortality from prior outbreaks. This study investigated how fuel conditions associated with mountain pine beetle outbreaks influence the probability of high burn severity (i.e. stand-replacing fire) across a range of fire weather conditions in subboreal forests of central interior British Columbia, Canada. We focused on three large fires that occurred in 2012, 2013, and 2014. We characterized outbreak severity, outbreak-influenced prefire vegetation, and subsequent burn severity using Landsat spectral vegetation indices, high-resolution imagery, and field observations. Substantial portions of the prefire landscape contained mixtures of live and dead vegetation created by variable beetle damage and vegetation response—spatial patterns that are related to, but distinct from, peak outbreak severity. We evaluated drivers—fuels, weather, and topography—of high-severity fire under ‘extreme,’ ‘moderate,’ and ‘benign’ fire weather conditions (i.e. burning conditions) using Boosted Regression Trees. While fire weather was a primary driver in most cases, prefire vegetation was an influential predictor variable across all burning conditions, and the probability of high-severity fire was highest when prefire vegetation was a mixture of tree mortality from bark beetles and live vegetation. Thus, while weather and drought are important drivers of wildfires in subboreal forests, bottom-up drivers of elevation and vegetation, including the fuel legacies of bark beetle outbreaks, are crucial factors influencing high-severity burning. The legacy of recent bark beetle outbreaks will continue for decades on these landscapes, affecting fuel structures, future wildfires, forest dynamics, and the broader social-ecological systems of the region.
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Bouchard, Mathieu, and David Pothier. "Spatiotemporal variability in tree and stand mortality caused by spruce budworm outbreaks in eastern Quebec." Canadian Journal of Forest Research 40, no. 1 (2010): 86–94. http://dx.doi.org/10.1139/x09-178.
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We evaluated spruce budworm ( Choristoneura fumiferana (Clem.)) outbreak effects in nine study areas (60–86 ha each) located in the boreal forest of eastern Quebec (Canada). In each area, spruce budworm outbreak effects were measured from vegetation plots, dominant canopy and understory tree age structures, retrospective analysis of aerial photographs, defoliation records, and host tree growth reductions (dendrochronology). Large-scale synchronous outbreaks were detected across the region around the years 1880, 1915, 1950, and 1980. Overall, contrarily to what was expected for a region where host species (balsam fir ( Abies balsamea (L.) Mill.), Picea spp.) content is relatively high, these spruce budworm outbreaks seemed to have a relatively minor influence on stand dynamics, with the exception of the most recent outbreak (1980). This outbreak resulted in major stand mortality in the southern part of the region and favored the establishment of extensive tracts of young even-aged stands with few residual mature trees. This very abrupt increase in outbreak severity compared with earlier outbreaks, perhaps due to climatic or random factors, suggests that historical trends in successive outbreak severity should be extrapolated very cautiously and that the study of several outbreak cycles is needed to establish a range of natural variability that can be used to develop an ecosystem forest management strategy.
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Vanderhoof, M., C. A. Williams, Y. Shuai, D. Jarvis, D. Kulakowski, and J. Masek. "Albedo-induced radiative forcing from mountain pine beetle outbreaks in forests, south-central Rocky Mountains: magnitude, persistence, and relation to outbreak severity." Biogeosciences 11, no. 3 (2014): 563–75. http://dx.doi.org/10.5194/bg-11-563-2014.
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Abstract. Mountain pine beetle (MPB) outbreaks in North America are widespread and have potentially persistent impacts on forest albedo and associated radiative forcing. This study utilized multiple data sets, both current and historical, within lodgepole pine stands in the south-central Rocky Mountains to quantify the full radiative forcing impact of outbreak events for decades after outbreak (0–60 yr) and the role of outbreak severity in determining that impact. Change in annual albedo and radiative forcing peaked at 14–20 yr post-outbreak (0.06 ± 0.006 and −0.8 ± 0.1 W m−2, respectively) and recovered to pre-outbreak levels by 30–40 yr post-outbreak. Change in albedo was significant in all four seasons, but strongest in winter with the increased visibility of snow (radiative cooling of −1.6 ± 0.2 W m−2, −3.0 ± 0.4 W m−2, and −1.6 ± 0.2 W m−2 for 2–13, 14–20 and 20–30 yr post-outbreak, respectively). Change in winter albedo and radiative forcing also increased with outbreak severity (percent tree mortality). Persistence of albedo effects are seen as a function of the growth rate and species composition of surviving trees, and the establishment and growth of both understory herbaceous vegetation and tree species, all of which may vary with outbreak severity. The establishment and persistence of deciduous trees was found to increase the temporal persistence of albedo effects. MPB-induced changes to radiative forcing may have feedbacks for regional temperature and the hydrological cycle, which could impact future MPB outbreaks dynamics.
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Vanderhoof, M., C. A. Williams, Y. Shuai, D. Jarvis, D. Kulakowski, and J. Masek. "Albedo-induced radiative forcing from mountain pine beetle outbreaks in forests, south-central Rocky Mountains: magnitude, persistence, and relation to outbreak severity." Biogeosciences Discussions 10, no. 7 (2013): 11935–68. http://dx.doi.org/10.5194/bgd-10-11935-2013.
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Abstract. Mountain pine beetle (MPB) outbreaks in North America are widespread and have potentially-persistent impacts on forest albedo and associated radiative forcing. This study utilized multiple datasets, both current and historical, within lodgepole pine stands in the south-central Rocky Mountains to quantify the full radiative forcing impact of outbreak events for decades after outbreak (0 to 60 yr) and the role of outbreak severity in determining that impact. Change in annual albedo and radiative forcing peaked at 14–20 yr post-outbreak (0.06 ± 0.006 and −0.8 ± 0.1 W m−2, respectively) and recovered to pre-outbreak levels by 30–40 yr post-outbreak. Change in albedo was significant in all four seasons, but strongest in winter with the increased visibility of snow (radiative cooling of −1.6 ± 0.2 W m−2, −3.0 ± 0.4 W m−2, and −1.6 ± 0.2 W m−2 for 2–13 yr, 14–20 yr and 20–30 yr post-outbreak, respectively). Change in winter albedo and radiative forcing also increased with outbreak severity (percent tree mortality). Persistence of albedo effects are seen as a function of the growth rate and species composition of surviving trees, and the establishment and growth of both understory herbaceous vegetation and tree species, all of which may vary with outbreak severity. The establishment and persistence of deciduous trees was found to increase the temporal persistence of albedo effects. MPB induced changes to radiative forcing may have feedbacks for regional temperature and precipitation, which could impact future MPB outbreaks dynamics.
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Lynch, Ann M., Nurjan S. Mukhamadiev, Christopher D. O’Connor, Irina P. Panyushkina, Nursagim A. Ashikbaev, and Abay O. Sagitov. "Tree-ring Reconstruction of Bark Beetle Disturbances in the Picea schrenkiana Fisch. et Mey. Forests of Southeast Kazakhstan." Forests 10, no. 10 (2019): 912. http://dx.doi.org/10.3390/f10100912.
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Ips hauseri Reitter is the most important bark beetle on Picea schrenkiana in southeast Kazakhstan, but its biology, ecology, and outbreak dynamics are poorly known. We dendrochronologically reconstructed a 200-year history of disturbances in the Kazakh Tien Shan P. schrenkiana forests. Only localized, low-severity bark beetle events occurred during the reconstructed period, indicating that extensive high-severity bark beetle outbreaks have not occurred historically in the Tien Shan spruce forest, unlike bark beetle outbreaks in spruce forests in North America, Europe, and Russia. Disturbance frequency doubled after about 1965, probably due to warming climate. Results, combined with the failure of an outbreak to fully develop after blowdown events associated with hurricane-force windstorms in 2011, indicate that prolonged drought may be necessary to sustain I. hauseri outbreaks, or that year-to-year variation in the Tien Shan weather prevents outbreak development. I. hauseri is probably less aggressive than I. typographus, at least on their natural hosts within their natural ranges.
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Hadley, Keith S., and Thomas T. Veblen. "Stand response to western spruce budworm and Douglas-fir bark beetle outbreaks, Colorado Front Range." Canadian Journal of Forest Research 23, no. 3 (1993): 479–91. http://dx.doi.org/10.1139/x93-066.
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The montane forests (i.e., below ca. 2900 m) of the Colorado Front Range have experienced repeated outbreaks of western spruce budworm (Choristoneuraoccidentalis Free.) and Douglas-fir bark beetle (Dendroctonuspseudotsugae Hopk.), both of which locally attack Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). In this study we examine the effects of historically documented outbreaks of these insects on succession, stand structure, and radial growth of host and nonhost species in Rocky Mountain National Park. The most recent budworm (1974–1985) and bark beetle (1984–present) outbreaks resulted in the most severe and widespread disturbance of these forests since the late 1800s. Stand response to these outbreaks is primarily a function of stand structure and age characteristics of Douglas-fir prior to an outbreak. Young, vigorous postfire stands show minimal budworm defoliation, and in these stands only remnant trees from the prefire generation appear susceptible to beetle-caused mortality. Dense stands exhibit higher budworm-induced mortality, which hastens the natural thinning process and shifts dominance towards the nonhost species. The stands most severely disturbed by the combined insect agents are multistoried stands with high host densities and a wide range of stem sizes. The stand response to these disturbances include the growth release of shade-intolerant, seral species, and in some cases, a higher survivorship among midsized individuals of the host Douglas-fir. The net result of the combined insect outbreaks is the temporary slowing of the successional trend towards a steady-state Douglas-fir forest. Fire suppression, by increasing the density of suppressed Douglas-fir, has previously been shown to favor increased outbreak severity of western spruce budworm in the northern Rockies. However, in the Front Range, recent increases in outbreak severity and their synchroneity may also be the result of large areas of forest, burned during the late 19th century during European settlement, simultaneously entering structural stages susceptible to insect outbreak.
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Volney, W. Jan A. "Analysis of historic jack pine budworm outbreaks in the Prairie provinces of Canada." Canadian Journal of Forest Research 18, no. 9 (1988): 1152–58. http://dx.doi.org/10.1139/x88-177.
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The annual Forest Insect and Disease Survey reports of the Canadian Forestry Service were used to develop a jack pine budworm (Choristoneurapinus Freeman) defoliation severity index for a 50-year span. The region covered was the western half of the host's (Pinusbanksiana Lamb.) range. An interpretation of this record permitted the construction of an annual time series of the total area moderately to severely or severely defoliated. The area of outbreaks has increased over the period. This trend was removed from the data to obtain a stationary time series. Analyses of the time series showed that there was a statistically significant periodicity to the size of outbreaks. An examination of the sample autocorrelation function revealed that only the past year's outbreak area was significantly correlated with that of the current year's outbreak. The model identified by applying the Box–Jenkins methodology to these results was inadequate, indicating that the series itself does not contain sufficient information for predictions. Outbreak area and the total area burned in Manitoba and Saskatchewan 4–7 years previously were highly correlated. Despite the crudity of the data, these relations could be exploited to develop predictors of outbreak size and occurrence. The significance of these results for forest management in the region is discussed.
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Taylor, Sarah L., and David A. MacLean. "Legacy of Insect Defoliators: Increased Wind-Related Mortality Two Decades After a Spruce Budworm Outbreak." Forest Science 55, no. 3 (2009): 256–67. http://dx.doi.org/10.1093/forestscience/55.3.256.
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Abstract Effects of spruce budworm (Choristoneura fumiferana Clem.) outbreaks on growth and survival of balsam fir (Abies balsamea [L.] Mill.) and spruce (Picea spp.) are well documented, but few studies extend beyond 10 years after defoliation ceased. We used inventory data from 106 permanent sample plots in &gt;50-year-old balsam fir stands in northern New Brunswick, Canada, to determine legacy effects of the 1969–1993 budworm outbreak on stand development up to 29 years after defoliation ceased. Defoliation data were from annual aerial surveys from 1945 to 1993 and plot ground sampling from 1985 to 1993. Plots were stratified into net stand volume development categories (decreasing, stable, and increasing 1985–2005 stemwood volume) and related to outbreak phases (outbreak, direct 1–10 years after defoliation ceased, and legacy &gt;10 years), outbreak severity (1–4 [low], 5–8 [medium], and 9–12 [high] years of defoliation), and stand age (mature and overmature). Stand age was an important factor influencing outbreak severity (e.g., r2 = 0.383, P &lt; 0.01). Trend and rate of volume development over time were related to past outbreak severity and increased rate of postoutbreak wind-related mortality, which peaked at 11 m3/ha/yr 11–15 years after defoliation ceased. Results indicate that aging postoutbreak stands are more vulnerable to wind disturbance events, effecting rapid stand decline.
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Welsh, Cedar, Kathy J. Lewis, and Alex J. Woods. "Regional outbreak dynamics of Dothistroma needle blight linked to weather patterns in British Columbia, Canada." Canadian Journal of Forest Research 44, no. 3 (2014): 212–19. http://dx.doi.org/10.1139/cjfr-2013-0387.
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Dothistroma needle blight (DNB) has caused extensive mortality in plantations of lodgepole pine in northwestern British Columbia, Canada, and even mature pine trees in natural forests are succumbing. We examined a number of explanatory models to determine which temperature or precipitation variable is most important in explaining DNB outbreak occurrence. We compared a multicentury tree-ring outbreak reconstruction with mean monthly temperature and total monthly precipitation during the individual and seasonal spring (April, May, June) and summer (July, August, September) months. A trend towards increased August minimum temperatures appears to be an important climate factor contributing to the spread of the disease. Graphical comparisons of total April precipitation reveal that periods of above-average precipitation coincided with periods of outbreak increase. Decreases in August minimum temperature also correspond to decreases in outbreak severity. Even more pronounced was a spike in spring precipitation and its association with the current epidemic. The correspondence of past outbreaks with periods of wet and warm conditions suggests that regional climate trends drive DNB behavior. The extent and severity of the current disease epidemic raises the possibility that the key factors that drive outbreaks have become more frequent, enabling the emergence of DNB as a serious disease.
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Gray, David R. "The influence of forest composition and climate on outbreak characteristics of the spruce budworm in eastern Canada." Canadian Journal of Forest Research 43, no. 12 (2013): 1181–95. http://dx.doi.org/10.1139/cjfr-2013-0240.
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The spruce budworm (Choristoneura fumiferana Clemens) is perhaps the single most important disturbance agent in Canada’s eastern forests. Climate and forest composition are dominant factors in spruce budworm outbreak dynamics through their direct influences on the pest, its natural enemies, and its hosts, and through their influence on the multitrophic interactions that are important in outbreak dynamics. A combination of four climate variables, three forest composition variables, and one location variable explained 60% of the multivariate variability in outbreak characteristics (duration and severity) in eastern Canada. Outbreak duration was most strongly influenced by April–May accumulation of degree-days; outbreak severity was most strongly influenced by the extreme maximum temperatures of April–May. The basal area of balsam fir had a stronger influence than that of black spruce on duration and on severity. Both outbreak characteristics declined in more northerly locations. Under a projected future (2011–2040) climate scenario the largest increases in outbreak duration and severity are predicted to occur on the Gaspé Peninsula and the north shore of the St. Lawrence River (Quebec). The largest decreases in duration and severity are predicted to occur in southern Ontario and along the Bay of Fundy in New Brunswick and Nova Scotia. The predicted average change in outbreak duration is around –1.3 years. The predicted average change in outbreak severity is only slightly different from zero (around –1.5% defoliation).
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KOOLHOF, I. S., S. BETTIOL, and S. CARVER. "Fine-temporal forecasting of outbreak probability and severity: Ross River virus in Western Australia." Epidemiology and Infection 145, no. 14 (2017): 2949–60. http://dx.doi.org/10.1017/s095026881700190x.
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SUMMARYHealth warnings of mosquito-borne disease risk require forecasts that are accurate at fine-temporal resolutions (weekly scales); however, most forecasting is coarse (monthly). We use environmental and Ross River virus (RRV) surveillance to predict weekly outbreak probabilities and incidence spanning tropical, semi-arid, and Mediterranean regions of Western Australia (1991–2014). Hurdle and linear models were used to predict outbreak probabilities and incidence respectively, using time-lagged environmental variables. Forecast accuracy was assessed by model fit and cross-validation. Residual RRV notification data were also examined against mitigation expenditure for one site, Mandurah 2007–2014. Models were predictive of RRV activity, except at one site (Capel). Minimum temperature was an important predictor of RRV outbreaks and incidence at all predicted sites. Precipitation was more likely to cause outbreaks and greater incidence among tropical and semi-arid sites. While variable, mitigation expenditure coincided positively with increased RRV incidence (r2 = 0·21). Our research demonstrates capacity to accurately predict mosquito-borne disease outbreaks and incidence at fine-temporal resolutions. We apply our findings, developing a user-friendly tool enabling managers to easily adopt this research to forecast region-specific RRV outbreaks and incidence. Approaches here may be of value to fine-scale forecasting of RRV in other areas of Australia, and other mosquito-borne diseases.
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Valentyna, Meshkova, Nazarenko Serhii, and Kolienkina Maryna. "Diprion pini L. (Hymenoptera, Symphyta, Diprionidae) population dynamics in the Low Dnieper region." FOLIA FORESTALIA POLONICA, SERIES A – FORESTRY 61, no. 1 (2019): 22–29. https://doi.org/10.2478/ffp-2019-0002.
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Pine sawflies (Hymenoptera, Symphyta, Diprionidae) are the most spread foliage browsing insects of pine forests in Europe, especially monovoltinous European pine sawfly<em> Neodiprion sertifer</em> (Geoffroy, 1785) and common pine sawfly <em>Diprion pini</em> (Linnaeus, 1758), which develops in one or two generations per year depending on weather. The outbreaks of both pine sawflies are the most frequent and intensive in the Steppe zone of Ukraine, especially in the Low Dnieper region, where pine forest (<em>Pinus sylvestris</em> Linnaeus and <em>Pinus pallasiana</em> D. Don) was planted on moving sands in the sixties of the 20th century. This research is aimed at the evaluation of the parameters for <em>D. pini </em>outbreak dynamics in the Low Dnieper region. Outbreak severity, specific foci area and mean score of stand threat by <em>D. pini </em>were evaluated from the regional statistical reports. In the regional scale for 1979–2017, notable outbreaks of <em>D. pini </em>were registered in 1982, 1993, 2002, 2006 and 2017. An interval between maximums was from 4 to 11 years, in average 9 years. The growth of foci area in 1979–1998 as compared to 1999–2017 as well as correlation between pine stand area and annual area of this pest’s foci in different forests was not statistically significant. Graphical analysis of dynamics of <em>D. pini </em>focal area for 2010–2017 was done based on individual threat levels. Our study confirms the fact of three outbreaks for this period in three forest and hunting enterprises (FHE), two outbreaks in one FHE and one outbreak in one FHE. An interval between the outbreaks makes three or six years. The causes of such shortening of interval are discussed.
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Skretting, Tristan, Laura Chasmer, Christopher J. Watson, Patrick M. A. James, Ivan Townshend, and Daniel D. B. Perrakis. "Forest fuel structure and loading along a gradient of gray-phase mountain pine beetle severity in Jasper National Park, Alberta, Canada." Canadian Journal of Forest Research 55 (January 1, 2025): 1–14. https://doi.org/10.1139/cjfr-2024-0319.
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Wildland fire fuels within the gray-phase of mountain pine beetle ( Dendroctonus ponderosae Hopkins) outbreak (4–10 years post mortality) are treated as homogenous despite potential variability. To assess if proportion of mortality due to mountain pine beetle in gray-phase stands significantly affects fuel structure, composition, and loading, detailed fuel measurements were collected across a range of severity in Jasper National Park, Alberta, Canada, by coincidence 1–3 years before a major wildfire. These were categorized based on outbreak severity thresholds of Light (<35%), Moderate (36%–65%), and Severe (>65%) beetle-induced pine mortality defined as the proportion of killed trees within a stand. The canopy fuels of both mature and small tree cohorts were significantly reduced with increasing outbreak severity. Severely affected stands showed a 49% reduction in mature tree canopy bulk density from original loading but increased herbaceous vegetation. Moderately affected stands had higher coarse woody debris loading (mean = 3.21 kg m– 2; SE = 0.49 kg m–2). These severity ratings can be used to quantify canopy fuel loss and signal potential shifts to other surface fuel types, barring fire. This is one of the first studies to showcase variability within gray-phase outbreak fuels, despite their prevalence in western Canada, and discuss the potential influences on fire behaviour.
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Stephens, Patrick R., N. Gottdenker, A. M. Schatz, J. P. Schmidt, and John M. Drake. "Characteristics of the 100 largest modern zoonotic disease outbreaks." Philosophical Transactions of the Royal Society B: Biological Sciences 376, no. 1837 (2021): 20200535. http://dx.doi.org/10.1098/rstb.2020.0535.
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Zoonotic disease outbreaks are an important threat to human health and numerous drivers have been recognized as contributing to their increasing frequency. Identifying and quantifying relationships between drivers of zoonotic disease outbreaks and outbreak severity is critical to developing targeted zoonotic disease surveillance and outbreak prevention strategies. However, quantitative studies of outbreak drivers on a global scale are lacking. Attributes of countries such as press freedom, surveillance capabilities and latitude also bias global outbreak data. To illustrate these issues, we review the characteristics of the 100 largest outbreaks in a global dataset ( n = 4463 bacterial and viral zoonotic outbreaks), and compare them with 200 randomly chosen background controls. Large outbreaks tended to have more drivers than background outbreaks and were related to large-scale environmental and demographic factors such as changes in vector abundance, human population density, unusual weather conditions and water contamination. Pathogens of large outbreaks were more likely to be viral and vector-borne than background outbreaks. Overall, our case study shows that the characteristics of large zoonotic outbreaks with thousands to millions of cases differ consistently from those of more typical outbreaks. We also discuss the limitations of our work, hoping to pave the way for more comprehensive future studies. This article is part of the theme issue ‘Infectious disease macroecology: parasite diversity and dynamics across the globe’.
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Bell, N. L., R. J. Townsend, A. J. Popay, C. F. Mercer, and T. A. Jackson. "Black beetle: lessons from the past and options for the future." NZGA: Research and Practice Series 15 (January 1, 2011): 119–24. http://dx.doi.org/10.33584/rps.15.2011.3193.
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An outbreak of the pasture insect pest black beetle began in the Waikato and Bay of Plenty in 2007/8 and has persisted. The extent and severity of damage caused by black beetle during the current outbreak has focused farmer and researcher attention on methods to maintain persistent pasture now and in future outbreaks. This paper reviews previous research in combination with data from the current outbreak and relates these to current pasture management practice. The possibility of being able to predict the distribution, occurrence and duration of black beetle outbreaks is explored while actual and potential means of controlling black beetle are outlined. We conclude that there are methods available to successfully renew pastures in the presence of black beetle but that outbreak situations increase risks and may limit subsequent pasture persistence. There are fewer readily available options to maintain an existing pasture and more research is urgently needed to provide these options. Keywords: Heteronychus arator, paspalum, pasture, pasture renewal, pest resistance, pest tolerance, ryegrass
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Liu, Eric Ye, Van A. Lantz, David A. MacLean, and Chris Hennigar. "Economics of Early Intervention to Suppress a Potential Spruce Budworm Outbreak on Crown Land in New Brunswick, Canada." Forests 10, no. 6 (2019): 481. http://dx.doi.org/10.3390/f10060481.
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We investigated the potential economic impacts of future spruce budworm (Choristoneura fumiferana Clem.) (SBW) outbreaks on 2.8 million ha of Crown land in New Brunswick, Canada and compared an early intervention strategy (EIS) with foliage protection approaches. We coupled the Spruce Budworm Decision Support System (SBW DSS) with a Computable General Equilibrium (CGE) model to assess the impacts of EIS and foliage protection on 0%, 5%, 10%, and 20% of susceptible Crown (publicly owned) forest, under moderate and severe SBW outbreak scenarios. Cumulative available harvest supply from 2017 to 2067 was projected to be reduced by 29 to 43 million m3, depending upon SBW outbreak severity, and a successful EIS approach would prevent this loss. These harvest reductions were projected to reduce total economic output by $25 billion (CAD) to $35 billion. Scenarios using biological insecticide foliage protection over 20% of susceptible Crown forest area were projected to reduce losses to 6–17 million m3 and $0.5–4.1 billion. Depending upon SBW outbreak severity, EIS was projected to have benefit/cost ratios of 3.8 to 6.4 and net present values of $186 million to $353 million, both higher than foliage protection strategies. Sensitivity analysis scenarios of ‘what if’ EIS partially works (80% or 90%) showed that these produced superior timber harvest savings than the best foliage protection scenario under severe SBW outbreak conditions and generally superior results under moderate outbreak scenarios. Overall, results support the continued use of EIS as the preferred strategy on economic grounds to protect against SBW outbreaks on Crown land in New Brunswick.
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Gautam, Pragati, VP Goswami, Ila Bajpai, Salil Sakalle, and Sanjay Dixit. "An Epidemiological Investigation of Cholera Outbreak in a Residential School for differently abled children and adolescents in Central India." Indian Journal of Community Health 37, no. 1 (2025): 130–36. https://doi.org/10.47203/ijch.2025.v37i01.022.
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Background: Migration, inadequate sanitation, congestion, and disease ignorance make cholera a major public health issue in emerging nations like India. The increase in diarrhea and dehydration cases at an NGO Residential School for differently abled children and adolescents in Indore, M.P., India, demanded quick investigation to avert future morbidity and mortality. Objectives: To investigate diarrhea and dehydration outbreak at an NGO Residential School for differently abled children and adolescents in urban Indore, M.P., India; determine the etiological agents, outbreak’s severity and recommend control strategies. Materials and Methods: A cross-sectional study with pre-defined case definition, followed line-listing and collection of stool, food, and water samples. Symptomatic cases were referred and treated. A comprehensive epidemiological report with recommendations and inclusive action plan was submitted to the district health authorities. Results: Out of 94 suspected cases, 31 tested positive for cholera. Most affected individuals (72.34%) were aged 10–19 years, with an equal male-to-female ratio. The case fatality rate was 4.3%, while attack rate was 32.98%. Contaminated drinking water and poor hygiene were identified as the main causes of the outbreak. Conclusion: Contaminated water and poor hygiene were identified as key factors responsible for cholera outbreak. Water treatment and hygiene education helped control the outbreak. Periodic supervision suggested to prevent future outbreaks.
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Schafer, Chad M., and Charles A. Doswell III. "Multivariate Index for Ranking." E-Journal of Severe Storms Meteorology 5, no. 1 (2021): 1–39. http://dx.doi.org/10.55599/ejssm.v5i1.21.
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In previous work, severe weather outbreaks have been classified either as major tornado outbreaks or as primarily nontornadic outbreaks, but the large majority of such events are of a mixed character. This study proposes a reproducible method for ranking all types of severe weather outbreaks from the period 1960-2006. Numerous nonmeteorological artifacts exist in the severe weather reports archived during this period, and many of the variables used to formulate the multivariate indices had to be detrended to reduce the effect of secular trends. The resulting outbreak rankings indicate that the methodology presented herein is able to distinguish the most significant severe weather outbreaks from intermediate outbreak days and days with a large amount of geographic scatter in the severe reports. The rankings of the most severe outbreaks and those outbreak days with a large degree of spatial scatter exhibit only limited variability when the selection of parameters and their weights are modified, but a relatively high degree of volatility is noted with the intermediate cases. This result suggests there is relatively little difference in the severity of these intermediate events. However, the particular modes of severe weather in these events can be quite different. A k-means cluster analysis of the outbreak days, using a four-dimensional representation of the multivariate indices developed, indicates that outbreak days can be separated into five groups: major tornado, wind-dominated, hail-dominated, multi-modal, and days with considerable spatial scatter of the severe reports.
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Huber, Caroline, Lyn Finelli, and Warren Stevens. "The Economic and Social Burden of the 2014 Ebola Outbreak in West Africa." Journal of Infectious Diseases 218, Supplement_5 (2018): S698—S704. http://dx.doi.org/10.1093/infdis/jiy213.
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Abstract Background The 2014 Ebola virus disease (EVD) outbreak in West Africa was more devastating than all previous EVD outbreaks combined; however, many estimates of its economic burden did not capture its significant social costs. This study aimed to review all currently available estimates, identify social components missed by these estimates, and generate a comprehensive cost of the 2014 EVD outbreak. Methods We conducted a systematic review of the grey (reports produced by nonprofit or nongovernmental organizations, government, or industry) and published literature to identify current estimates of the burden of the outbreak. Based on the findings of this review, we identified 6 key areas absent or underestimated from previous estimates and calculated the underestimated social costs using estimates from the literature and extrapolation. Results Current estimates of the economic burden of the outbreak range from $2.8 to $32.6 billion in lost gross domestic product. We estimated the comprehensive economic and social burden from the 2014 EVD outbreak to be $53.19 billion (2014 USD). The most significant component, $18.8 billion, was deaths from non-Ebola causes. Conclusions A more complete understanding of the burden of the 2014 EVD outbreak underscores the value of interventions that can mitigate or reduce the severity of future outbreaks.
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Kulakowski, Dominik, and Thomas T. Veblen. "The effect of fires on susceptibility of subalpine forests to a 19th century spruce beetle outbreak in western Colorado." Canadian Journal of Forest Research 36, no. 11 (2006): 2974–82. http://dx.doi.org/10.1139/x06-182.
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In the subalpine forests of the Colorado Rocky Mountains, research on disturbances that have occurred over the past several decades has shown that prior occurrence of disturbances can alter the extent and severity of subsequent disturbances. In the current study, we consider how fire history affected stand susceptibility to a mid-19th century spruce beetle (Dendroctonus rufipennis Kirby 1837) outbreak. Twenty-one sites were randomly located in an Engelmann spruce – subalpine fir (Picea engelmannii Parry ex Engelm. – Abies lasiocarpa (Hook.) Nutt.) forest across ~2000 km2 of the Grand Mesa area, Colorado. At each site, dendrochronological methods were used to reconstruct the history of severe fires and beetle outbreak. Stand-origin dates were estimated by collecting increment cores from 20–27 of the largest trees at each sample site. The beetle outbreak was reconstructed based on coincident releases among nonhost trees that survived the outbreak. Forest stands originated following severe fires in ca. 1790, ca. 1740, and ca. 1700. The 1840's outbreak affected 67% of these stands. Stands that initiated following the ca. 1790 fire were less susceptible to the outbreak than older stands. These findings indicate that stand-replacing fires have mitigated susceptibility to outbreaks of spruce beetles not only during recent outbreaks, but also over the past centuries.
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Bilal, Muhammad, Muhammad Imran Khan, Muhammad Shahzad Nazir, Ishtiaq Ahmed, and Hafiz M. N. Iqbal. "Coronaviruses and COVID-19 – Complications and Lessons Learned for the Future." Journal of Pure and Applied Microbiology 14, suppl 1 (2020): 725–31. http://dx.doi.org/10.22207/jpam.14.spl1.09.
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Despite the earlier two Coronavirus outbreaks, this appearance of the third Coronavirus outbreak has brought several complications and now emerged as a human-health related pandemic issue. The wide geographical spread and transmissibility of newly emerged novel-Coronavirus (2019-nCoV) and severity of coronavirus disease 2019 (COVID-19) raised serious concerns about the future trajectory of the 2019-nCoV/COVID-19 outbreak. Herein, we have briefly covered some important aspects of the 2019-nCoV/COVID-19 outbreak to highlight the need to learn lessons for a safer future. First, an epidemiological comparison of respiratory viral infections with particular reference to 2019-nCoV is given with relevant examples. Following that, considering the earlier two Coronavirus outbreaks, the emergence of another new 2019-nCoV is given. Finally, the lesson learned, so far, and key concerns for pandemic impact assessment at large and COVID-19, in particular, are discussed for future considerations.
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Mannes, Trish, Leena Gupta, Adam Craig, et al. "Large point-source outbreak of Salmonella Typhimurium phage type 9 linked to a bakery in Sydney, March 2007." Communicable Diseases Intelligence 34 (March 31, 2010): 41–48. https://doi.org/10.33321/cdi.2010.34.6.
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This report describes the investigation and public health response to a large point-source outbreak of salmonellosis in Sydney, Australia. The case-series investigation involved telephone interviews with 283 cases or their guardians and active surveillance through hospitals, general practitioners, laboratories and the public health network. In this outbreak 319 cases of gastroenteritis were identified, of which 221 cases (69%) presented to a hospital emergency department and 136 (43%) required hospital admission. This outbreak was unique in its scale and severity and the surge capacity of hospital emergency departments was stretched. It highlights that foodborne illness outbreaks can cause substantial preventable morbidity and resultant health service burden, requiring close attention to regulatory and non-regulatory interventions. Commun Dis Intell 2010;34(1):40–47.
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Welsh, Cedar, Kathy Lewis, and Alex Woods. "The outbreak history of Dothistroma needle blight: an emerging forest disease in northwestern British Columbia, Canada." Canadian Journal of Forest Research 39, no. 12 (2009): 2505–19. http://dx.doi.org/10.1139/x09-159.
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Native pathogens are normally limited in the damage they cause by host resistance and (or) environmental conditions that limit one or more phases of the disease cycle. Changes to host or environmental conditions can relax these limits and result in disease emergence. Until recently, Dothistroma needle blight (Dothistroma), caused by Dothistroma septosporum (Dorog.) Morelet, has had only minor impacts on native forest trees in western North America. Over the past decade in the forests of northwestern British Columbia, Canada, Dothistroma has caused extensive mortality in managed plantations of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.), and even mature pine trees are succumbing. We used dendrochronological techniques to reconstruct the temporal patterns of past Dothistroma outbreaks in the area using tree-ring series from sites with documented outbreaks. We found that Dothistroma outbreaks in northwest British Columbia have occurred periodically over the last 174 years, with an increase in outbreak incidence and extent since the 1940s. The most distinct change observed in the outbreak history has been the greater severity and synchrony among the sites affected during the current outbreak. A recently observed climate change trend over the study area may represent an environmental trigger that synchronized the current outbreak causing the widespread emergence of the disease.
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Sanchez, Emily, Ryan B. Simpson, Yutong Zhang, Lauren E. Sallade, and Elena N. Naumova. "Exploring Risk Factors of Recall-Associated Foodborne Disease Outbreaks in the United States, 2009–2019." International Journal of Environmental Research and Public Health 19, no. 9 (2022): 4947. http://dx.doi.org/10.3390/ijerph19094947.
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Earlier identification and removal of contaminated food products is crucial in reducing economic burdens of foodborne outbreaks. Recalls are a safety measure that is deployed to prevent foodborne illnesses. However, few studies have examined temporal trends in recalls or compared risk factors between non-recall and recall outbreaks in the United States, due to disparate and often incomplete surveillance records in publicly reported data. We demonstrated the usability of the electronic Foodborne Outbreak Reporting System (eFORS) and National Outbreak Reporting System (NORS) for describing temporal trends and outbreak risk factors of food recalls in 1998–2019. We examined monthly trends between surveillance systems by using segmented time-series analyses. We compared the risk factors (e.g., multistate outbreak, contamination supply chain stage, pathogen etiology, and food products) of recalls and non-recalls by using logistic regression models. Out of 22,972 outbreaks, 305 (1.3%) resulted in recalls and 9378 (41%) had missing recall information. However, outbreaks with missing recall information decreased at an accelerating rate of ~25%/month in 2004–2009 and at a decelerating rate of ~13%/month after the transition from eFORS to NORS in 2009–2019. Irrespective of the contaminant etiology, multistate outbreaks according to the residence of ill persons had odds 11.00–13.50 times (7.00, 21.60) that of single-state outbreaks resulting in a recall (p < 0.001) when controlling for all risk factors. Electronic reporting has improved the availability of food recall data, yet retrospective investigations of historical records are needed. The investigation of recalls enhances public health professionals’ understanding of their annual financial burden and improves outbreak prediction analytics to reduce the likelihood and severity of recalls.
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GARVEY, P., A. CARROLL, E. McNAMARA, and P. J. McKEOWN. "VerotoxigenicEscherichia colitransmission in Ireland: a review of notified outbreaks, 2004–2012." Epidemiology and Infection 144, no. 5 (2015): 917–26. http://dx.doi.org/10.1017/s0950268815002034.
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SUMMARYVerotoxigenicEscherichia coli(VTEC) are significant for their low infectious dose, their potential clinical severity and the frequency with which they generate outbreaks. To describe the relative importance of different outbreak transmission routes for VTEC infection in Ireland, we reviewed outbreak notification data for the period 2004–2012, describing the burden and characteristics of foodborne, waterborne, animal contact and person-to-person outbreaks. Outbreaks where person-to-person spread was reported as the sole transmission route accounted for more than half of all outbreaks and outbreaks cases, most notably in childcare facilities. The next most significant transmission route was waterborne spread from untreated or poorly treated private water supplies. The focus for reducing incidence of VTEC should be on reducing waterborne and person-to-person transmission, by publicizing Health Service Executive materials developed for consumers on private well management, and for childcare facility managers and public health professionals on prevention of person-to-person spread.
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Shafer, Chad M., Andrew E. Mercer, Michael B. Richman, Lance M. Leslie, and Charles A. Doswell. "An Assessment of Areal Coverage of Severe Weather Parameters for Severe Weather Outbreak Diagnosis." Weather and Forecasting 27, no. 4 (2012): 809–31. http://dx.doi.org/10.1175/waf-d-11-00142.1.
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Abstract The areal extent of severe weather parameters favorable for significant severe weather is evaluated as a means of identifying major severe weather outbreaks. The first areal coverage method uses kernel density estimation (KDE) to identify severe weather outbreak locations. A selected severe weather parameter value is computed at each grid point within the region identified by KDE. The average, median, or sum value is used to diagnose the event’s severity. The second areal coverage method finds the largest contiguous region where a severe weather parameter exceeds a specified threshold that intersects the KDE region. The severe weather parameter values at grid points within the parameter exceedance region are computed, with the average, median, or sum value used to diagnose the event’s severity. A total of 4057 severe weather outbreaks from 1979 to 2008 are analyzed. An event is considered a major outbreak if it exceeds a selected ranking index score (developed in previous work), and is a minor event otherwise. The areal coverage method is also compared to Storm Prediction Center (SPC) day-1 convective outlooks from 2003 to 2008. Comparisons of the SPC forecasts and areal coverage diagnoses indicate the areal coverage methods have similar skill to SPC convective outlooks in discriminating major and minor severe weather outbreaks. Despite a seemingly large sample size, the rare-events nature of the dataset leads to sample size sensitivities. Nevertheless, the findings of this study suggest that areal coverage should be tested in a forecasting environment as a means of providing guidance in future outbreak scenarios.
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Robert, Louis-Etienne, Daniel Kneeshaw, and Brian R. Sturtevant. "Effects of forest management legacies on spruce budworm (Choristoneura fumiferana) outbreaks." Canadian Journal of Forest Research 42, no. 3 (2012): 463–75. http://dx.doi.org/10.1139/x2012-005.
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The “silvicultural hypothesis” of spruce budworm ( Choristoneura fumiferana Clem.) dynamics postulates that increasing severity of spruce budworm outbreaks over the last century resulted from forest conditions created by past management activities. Yet, definitive tests of the hypothesis remain elusive. We examined spruce budworm outbreak dynamics (synchrony, periodicity, and intensity) in the 20th century using historical reconstruction from tree-ring chronologies sampled within 19 sites in a large ecoregion located on the border of Minnesota and Ontario. The study encompassed three areas affected by contrasting management legacies: a fine-grained area (Minnesota, six sites, average cut size = 17 ha), a coarse-grained area (Ontario, six sites, average cut size 10 times that of Minnesota), and a conservation zone (seven sites) with little recent harvest activity overlapping the border. Results suggest important differences in outbreak dynamics between the forest management zones that cannot be explained by differences in climate among sample sites. Budworm outbreaks within the conservation zone were more synchronous, with more trees per site affected and less frequent outbreaks than sites sampled within fine-scale managed areas. Outbreak dynamics within forests managed at coarser scales suggest a mixture of the conservation and fine-scale management zone outbreak patterns. Potential factors affecting differences in the observed outbreak patterns include forest pattern, composition, and age. Our study generally supports the silvicultural hypothesis and emphasizes that management legacy effects on spruce budworm dynamics should be observable at landscape scales, as well as at local scales.
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Thawillarp, Supharerk, Carlos Castillo-Salgado, and Harold P. Lehmann. "Evaluation of Early Aberration Reporting System for Dengue Outbreak Detection in Thailand." Outbreak, Surveillance, Investigation & Response (OSIR) Journal 11, no. 4 (2018): 1–6. http://dx.doi.org/10.59096/osir.v11i4.263047.
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Thailand is one of the highest-burden countries for dengue infections in the South-East Asia Region of the World Health Organization. The 5-year median is normally used for outbreak detection; however, studies assessing the performance of this indicator against other detection methods are lacking. We, therefore, conducted a descriptive ecological study from a dataset comprised of patient visits to public hospitals for dengue treatment that were reported to the Ministry of Public Health. The aim was to evaluate the performance of an early aberration reporting system (EARS) in detecting dengue outbreaks, compared to using the 5-year median method. During 2003-2015, there were 1,014,201 patient visits and seven reported dengue outbreaks, with the largest occurring in 2013, and six seasonal peaks. The EARS was able to detect all seven dengue outbreaks and six seasonal peaks, including one outbreak that occurred in 2014 which was undetected by the 5-year median. However, EARS cannot provide information on trends, outbreak severity and issues noise signals. Our recommendation was to combine the EARS with the 5-year median method to reduce the number of false positive signals, or use the 5-year median method as a confirmatory tool.
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Garg, Ishan, Rahul Shekhar, Abu Baker Sheikh, and Suman Pal. "Impact of COVID-19 on the Changing Patterns of Respiratory Syncytial Virus Infections." Infectious Disease Reports 14, no. 4 (2022): 558–68. http://dx.doi.org/10.3390/idr14040059.
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Seasonal epidemics of respiratory syncytial virus (RSV) is one of the leading causes of hospitalization and mortality among children. Preventive measures implemented to reduce the spread of SARS-CoV-2, including facemasks, stay-at-home orders, closure of schools and local-national borders, and hand hygiene, may have also prevented the transmission of RSV and influenza. However, with the easing of COVID-19 imposed restrictions, many regions are noticing a delayed RSV outbreak. Some of these regions have also noted an increase in severity of these delayed RSV outbreaks partly due to a lack of protective immunity in the community following a lack of exposure from the previous season. Lessons learned from the COVID-19 pandemic can be implemented for controlling RSV outbreaks, including: (1) measures to reduce the spread, (2) effective vaccine development, and (3) genomic surveillance tools and computational modeling to predict the timing and severity of RSV outbreaks. These measures can help reduce the severity and prepare the health care system to deal with future RSV outbreaks by appropriate and timely allocation of health care resources.
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Branda, Francesco, Massimo Ciccozzi, and Fabio Scarpa. "Epidemiology and Genetic Characterization of Distinct Ebola Sudan Outbreaks in Uganda." Infectious Disease Reports 17, no. 3 (2025): 44. https://doi.org/10.3390/idr17030044.
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Background. Sudan virus (SUDV) has caused multiple outbreaks in Uganda over the past two decades, leading to significant morbidity and mortality. The recent outbreaks in 2022 and 2025 highlight the ongoing threat posed by SUDV and the challenges in its containment. This study aims to characterize the epidemiological patterns and phylogenomic evolution of SUDV outbreaks in Uganda, identifying key factors influencing transmission and disease severity. Methods. We conducted a retrospective observational study analyzing epidemiological and genomic data from SUDV outbreaks in Uganda between 2000 and 2025. Epidemiological data were collected from official sources, including the Ugandan Ministry of Health and the World Health Organization, supplemented with reports from public health organizations. Genomic sequences of SUDV were analyzed to investigate viral evolution and identify genetic variations associated with pathogenicity and transmissibility. Results. The 2022 outbreak involved 164 confirmed cases and a case fatality rate (CFR) of 33.5%, with significant geographic variation in case distribution. The 2025 outbreak, still ongoing, was first detected in Kampala, with evidence of both nosocomial and community transmission. Phylogenomic analysis revealed the presence of two main genetic groups, representing Sudan and Uganda, respectively. The genetic variability of the Ugandan cluster is higher than that observed in Sudan, suggesting a greater expansion potential, which aligns with the current outbreak. Epidemiological findings indicate that human mobility, weaknesses in the health system, and delays in detection contribute to the amplification of the outbreak. Conclusions. Our findings underscore the importance of integrated genomic and epidemiological surveillance in understanding SUDV transmission dynamics. The recurrent emergence of SUDV highlights the need for improved outbreak preparedness, rapid response mechanisms, and international collaboration. Strengthening real-time surveillance and enhancing healthcare system resilience are critical to mitigating the impact of future outbreaks.
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Kerr, Eleanor M., Laura A. Vonnahme, and Neela D. Goswami. "Impact of Targeted Local Interventions on Tuberculosis Awareness and Screening Among Persons Experiencing Homelessness During a Large Tuberculosis Outbreak in Atlanta, Georgia, 2015-2016." Public Health Reports 135, no. 1_suppl (2020): 90S—99S. http://dx.doi.org/10.1177/0033354920932644.
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Objectives Tuberculosis (TB) outbreaks disproportionately affect persons experiencing homelessness (PEH) in the United States. During 2014-2016, a resurgent TB outbreak occurred among PEH in Atlanta, Georgia. To control the outbreak, citywide policies and educational interventions were implemented in January 2015. Policy changes standardized and enforced TB screening requirements for PEH in homeless shelters. Educational campaigns informed PEH of the outbreak and encouraged TB screening. We evaluated factors associated with, and the effect policy changes and educational interventions had on, TB screening and awareness among PEH in Atlanta. Methods Questions related to TB screening and awareness of the outbreak were added to an annual US Department of Housing and Urban Development survey of PEH in Atlanta in 2015 (n = 296 respondents) and 2016 (n = 1325 respondents). We analyzed the 2016 survey data to determine characteristics associated with outcomes. Results From 2015 to 2016, reported TB screening increased from 81% to 86%, and awareness of the TB outbreak increased from 68% to 75%. In 2016, sheltered PEH were significantly more likely than unsheltered PEH to report being evaluated for TB in the previous 6 months (prevalence odds ratio [pOR] = 3.18; 95% confidence interval [CI], 2.28-4.47) and to report being aware of the TB outbreak (pOR = 4.00; 95% CI, 2.89-5.55). Conclusions Implementation of required TB screening and educational interventions may reduce the incidence and severity of TB outbreaks among PEH in other communities. Furthermore, the annual survey of PEH offers an opportunity to collect data to better inform practices and policies.
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Chatterjee, Ananya, Uttaran Bhattacharjee, Rudrak Gupta, et al. "Genomic Expedition: Deciphering Human Adenovirus Strains from the 2023 Outbreak in West Bengal, India: Insights into Viral Evolution and Molecular Epidemiology." Viruses 16, no. 1 (2024): 159. http://dx.doi.org/10.3390/v16010159.
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Understanding the genetic dynamics of circulating Human Adenovirus (HAdV) types is pivotal for effectively managing outbreaks and devising targeted interventions. During the West Bengal outbreak of 2022–2023, an investigation into the genetic characteristics and outbreak potential of circulating HAdV types was conducted. Twenty-four randomly selected samples underwent whole-genome sequencing. Analysis revealed a prevalent recombinant strain, merging type 3 and type 7 of human mastadenovirus B1 (HAd-B1) species, indicating the emergence of recent strains of species B in India. Furthermore, distinctions in VA-RNAs and the E3 region suggested that current circulating strains of human mastadenovirus B1 (HAd-B1) possess the capacity to evade host immunity, endure longer within hosts, and cause severe respiratory infections. This study underscores the significance of evaluating the complete genome sequence of HAdV isolates to glean insights into their outbreak potential and the severity of associated illnesses.
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MANDILARA, G., C. M. VASSALOS, A. CHRISOSTOMOU, et al. "A severe gastroenteritis outbreak of Salmonella enterica serovar Enteritidis PT8, with PFGE profile XbaI.0024 and MLVA profile 2-9-7-3-2 following a christening reception, Greece, 2016." Epidemiology and Infection 146, no. 1 (2017): 28–36. http://dx.doi.org/10.1017/s0950268817002667.
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SUMMARYIn June 2016, a Salmonella enterica serovar Enteritidis outbreak (n = 56) occurred after a christening reception in Central Greece, mainly affecting previously healthy adults; one related death caused media attention. Patients suffered from profuse diarrhoea, fever and frequent vomiting episodes requiring prolonged hospitalisation and sick leave from work, with a 54% hospital admission rate. The majority of cases experienced serious illness within <12 h of attending the party. We investigated the outbreak to identify the source(s) of infection and contributing factors to the disease severity. From the retrospective cohort study, the cheesy penne pasta was the most likely vehicle of infection (relative risk 7·8; 95% confidence interval 3·6–16·8), explaining 79% of the cases. S. enterica ser. Enteritidis isolates were typed as phage-type PT8, pulsed-field gel electrophoresis type XbaI.0024, multiple locus variable-number tandem repeat analysis-type 2-9-7-3-2. The strain did not share the single-nucleotide polymorphism address of the concurrent European S. enterica ser. Enteritidis PT8 outbreak clusters. Following five consecutive years with no documented S. enterica ser. Enteritidis outbreaks in Greece, this outbreak, likely associated with a virulent strain, prompted actions towards the enhancement of the national Salmonella molecular surveillance and control programmes including the intensification of training of food handlers for preventing similar outbreaks in the future. Advanced molecular techniques were useful in distinguishing unrelated outbreak strains.
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Inizan, Catherine, Marine Minier, Matthieu Prot, et al. "Viral evolution sustains a dengue outbreak of enhanced severity." Emerging Microbes & Infections 10, no. 1 (2021): 536–44. http://dx.doi.org/10.1080/22221751.2021.1899057.
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JONES, RODERICK C., SUSAN I. GERBER, PAMELA S. DIAZ, et al. "Intensive Investigation of Bacterial Foodborne Disease Outbreaks: Proposed Guidelines and Tools for the Collection of Dose-Response Data by Local Health Departments." Journal of Food Protection 67, no. 3 (2004): 616–23. http://dx.doi.org/10.4315/0362-028x-67.3.616.
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Local health departments that investigate foodborne disease outbreaks do not have adequate guidelines for collecting data that could be used to estimate dose-response relationships, a key component of hazard characterization in quantitative microbial risk assessment. To meet this need, criteria and a questionnaire template for the collection of appropriate dose-response data in the context of outbreaks were developed and applied in the investigation of a point-source outbreak linked to Salmonella serotype Enteritidis in a salmon entrée in February 2000. In this outbreak, the attack rate and risk of hospitalization increased with the amount of salmon entrée consumed, and detailed data were obtained on illness severity measures and host susceptibility factors. Local health departments might consider broadening investigations to include the collection of additional data when investigating outbreaks that have met a specific set of conditions. These data could provide information needed by federal regulatory agencies and other organizations for quantitative microbial risk assessment. Intensive investigations of outbreaks could prevent future illnesses by providing information needed to develop approaches to minimizing risk.
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Soliman, Tarek, Andrew Barnes, and Irmelin Slettemoen Helgesen. "The hidden carbon impact of animal disease." PLOS ONE 18, no. 10 (2023): e0292659. http://dx.doi.org/10.1371/journal.pone.0292659.
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Livestock production is under scrutiny for its impact on greenhouse gas (GHG) emissions. Animal disease outbreaks will have economic effects on producers and the indirect cost of an animal disease outbreak is the result of shifts in consumption across commodities. This shift in demand for meat products will also positively or negatively affect carbon emissions. We explore the indirect costs and subsequent carbon impact of four potential exotic disease outbreaks, namely African swine fever, sheep pox, bluetongue, and foot and mouth disease. The indirect costs are quantified under different severities of outbreak using a vector error correction model and by estimating the changes in revenues of livestock and feed markets. By associating subsequent consumption switches with emission factors, we quantify the hidden carbon impact of these livestock disease outbreaks. The indirect costs vary based on severity and type of disease outbreak. Similarly, the net reduction in supply and subsequent consumption impacts result in averting between 0.005 and 0.67 million tonnes of CO2 eq. for these sectors. A foot and mouth disease outbreak has the highest indirect costs and largest reduction in GHG emissions as it decreases the production of cattle as consumers switch to lower emitting meat commodities. Conversely, African swine fever has the smallest reduction in GHG emissions, reflecting the more industrialised nature of pig farming. Our modelling approach opens a provocative debate around how compensation to producers supports restocking and how this relates to commitments to net zero farming. Overall, an exotic disease outbreak may trigger an opportunity to switch to lower emitting breeds or species if a more holistic, joined up approach were taken by Government.
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Chasteen, Manda B., and Steven E. Koch. "Multiscale Aspects of the 26–27 April 2011 Tornado Outbreak. Part II: Environmental Modifications and Upscale Feedbacks Arising from Latent Processes." Monthly Weather Review 150, no. 2 (2022): 337–68. http://dx.doi.org/10.1175/mwr-d-21-0014.1.
Full textAbstract:
Abstract One of the most prolific tornado outbreaks ever documented occurred on 26–27 April 2011 and comprised three successive episodes of tornadic convection that culminated with the development of numerous long-track, violent tornadoes over the southeastern United States during the afternoon of 27 April. This notorious afternoon supercell outbreak was preceded by two quasi-linear convective systems (hereinafter QLCS1 and QLCS2), the first of which was an anomalously severe nocturnal system that rapidly grew upscale during the previous evening. Here in Part II, we use a series of RUC 1-h forecasts and output from convection-permitting WRF-ARW simulations configured both with and without latent heat release to investigate how environmental modifications and upscale feedbacks produced by the two QLCSs contributed to the evolution and exceptional severity of this multiepisode outbreak. QLCS1 was primarily responsible for amplifying the large-scale flow pattern, inducing two upper-level jet streaks, and promoting secondary surface cyclogenesis downstream from the primary baroclinic system. Upper-level divergence markedly increased after QLCS1 developed, which yielded strong isallobaric forcing that rapidly strengthened the low-level jet (LLJ) and vertical wind shear over the warm sector and contributed to the system’s upscale growth and notable severity. Moreover, QLCS2 modified the mesoscale environment prior to the supercell outbreak by promoting the downstream formation of a pronounced upper-level jet streak, altering the midlevel jet structure, and furthering the development of a highly ageostrophic LLJ over the Southeast. Collectively, the flow modifications produced by both QLCSs contributed to the notably favorable shear profiles present during the afternoon supercell outbreak. Significance Statement The tornado outbreak that impacted the United States on 26–27 April 2011 was part of an extended outbreak that produced 343 tornadoes and numerous fatalities. This paper is Part II of a study that describes the meteorological factors supporting such a prolific event. Herein we investigate the convectively forced environmental modifications that occurred during a 36-h period encompassing three successive convective episodes. The first two episodes collectively altered the upper-level flow pattern and markedly enhanced low-level winds throughout the warm sector. These modifications served as upscale feedbacks that contributed to the first episode’s exceptional severity and to the remarkable vertical shear profiles that supported numerous long-track and violent tornadoes during the final episode on the afternoon of 27 April.
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Chasteen, Manda B., and Steven E. Koch. "Multiscale Aspects of the 26–27 April 2011 Tornado Outbreak. Part II: Environmental Modifications and Upscale Feedbacks Arising from Latent Processes." Monthly Weather Review 150, no. 2 (2022): 337–68. http://dx.doi.org/10.1175/mwr-d-21-0014.1.
Full textAbstract:
Abstract One of the most prolific tornado outbreaks ever documented occurred on 26–27 April 2011 and comprised three successive episodes of tornadic convection that culminated with the development of numerous long-track, violent tornadoes over the southeastern United States during the afternoon of 27 April. This notorious afternoon supercell outbreak was preceded by two quasi-linear convective systems (hereinafter QLCS1 and QLCS2), the first of which was an anomalously severe nocturnal system that rapidly grew upscale during the previous evening. Here in Part II, we use a series of RUC 1-h forecasts and output from convection-permitting WRF-ARW simulations configured both with and without latent heat release to investigate how environmental modifications and upscale feedbacks produced by the two QLCSs contributed to the evolution and exceptional severity of this multiepisode outbreak. QLCS1 was primarily responsible for amplifying the large-scale flow pattern, inducing two upper-level jet streaks, and promoting secondary surface cyclogenesis downstream from the primary baroclinic system. Upper-level divergence markedly increased after QLCS1 developed, which yielded strong isallobaric forcing that rapidly strengthened the low-level jet (LLJ) and vertical wind shear over the warm sector and contributed to the system’s upscale growth and notable severity. Moreover, QLCS2 modified the mesoscale environment prior to the supercell outbreak by promoting the downstream formation of a pronounced upper-level jet streak, altering the midlevel jet structure, and furthering the development of a highly ageostrophic LLJ over the Southeast. Collectively, the flow modifications produced by both QLCSs contributed to the notably favorable shear profiles present during the afternoon supercell outbreak. Significance Statement The tornado outbreak that impacted the United States on 26–27 April 2011 was part of an extended outbreak that produced 343 tornadoes and numerous fatalities. This paper is Part II of a study that describes the meteorological factors supporting such a prolific event. Herein we investigate the convectively forced environmental modifications that occurred during a 36-h period encompassing three successive convective episodes. The first two episodes collectively altered the upper-level flow pattern and markedly enhanced low-level winds throughout the warm sector. These modifications served as upscale feedbacks that contributed to the first episode’s exceptional severity and to the remarkable vertical shear profiles that supported numerous long-track and violent tornadoes during the final episode on the afternoon of 27 April.
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Lesmanawati, Dyah A. S., Patrick Veenstra, Aye Moa, Dillon C. Adam, and Chandini Raina MacIntyre. "A rapid risk analysis tool to prioritise response to infectious disease outbreaks." BMJ Global Health 5, no. 6 (2020): e002327. http://dx.doi.org/10.1136/bmjgh-2020-002327.
Full textAbstract:
Epidemics are influenced by both disease and societal factors and can grow exponentially over short time periods. Epidemic risk analysis can help in rapidly predicting potentially serious outcomes and flagging the need for rapid response. We developed a multifactorial risk analysis tool ‘EpiRisk’ to provide rapid insight into the potential severity of emerging epidemics by combining disease-related parameters and country-related risk parameters. An initial set of 18 disease and country-related risk parameters was reduced to 14 following qualitative discussions and the removal of highly correlated parameters by a correlation and clustering analysis. Of the remaining parameters, three risk levels were assigned ranging from low (1) moderate (2) and high (3). The total risk score for an outbreak of a given disease in a particular country is calculated by summing these 14 risk scores, and this sum is subsequently classified into one of four risk categories: low risk (<21), moderate risk (21–29), high risk (30–37) and extreme risk (>37). Total risk scores were calculated for nine retrospective outbreaks demonstrating an association with the actual impact of those outbreaks. We also evaluated to what extent the risk scores correlate with the number of cases and deaths in 61 additional outbreaks between 2002 and 2018, demonstrating positive associations with outbreak severity as measured by the number of deaths. Using EpiRisk, timely intervention can be implemented by predicting the risk of emerging outbreaks in real time, which may help government and public health professionals prevent catastrophic epidemic outcomes.
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MacLean, David A. "Forest management strategies to reduce spruce budworm damage in the Fundy Model Forest." Forestry Chronicle 72, no. 4 (1996): 399–405. http://dx.doi.org/10.5558/tfc72399-4.
Full textAbstract:
Spruce budworm (Choristoneura fumiferana) outbreaks cannot be prevented, but the amount of damage that occurs can be managed. Tree species, stand age, hardwood content, and drainage class, as well as the outbreak severity and length, determine the amount of tree mortality during budworm outbreaks. Silviculture and forest management can be used to reduce the incidence of the most damaged stand types across the landscape. The amount of defoliation in mixed balsam fir-hardwood stands is strongly negatively related to hardwood content, especially with hardwoods > 40%. The Spruce Budworm Decision Support System (DSS) links models of stand and forest response to budworm outbreaks and inventory interpretation to a GIS, and can be used to evaluate effects of outbreaks and management on forest structure and timber supply. An example using the Spruce Budworm DSS for a portion of the Fundy Model Forest indicated that losses from a future budworm outbreak could be reduced 34% by directing harvesting and silviculture towards conversion of one-half of the most vulnerable stand types into low susceptibility or non-susceptible species. Key words: decision support system, vulnerability, silviculture, insect damage
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Medeiros, Daniele Barbosa de Almeida, Juarez Antônio Simões Quaresma, Raimunda do Socorro da Silva Azevedo, et al. "Case Series of Adverse Pregnancy Outcomes Associated with Oropouche Virus Infection." Viruses 17, no. 6 (2025): 816. https://doi.org/10.3390/v17060816.
Full textAbstract:
The Oropouche virus (OROV) is an arbovirus (Peribunyaviridae: Orthobunyavirus) that traditionally causes febrile outbreaks in Latin America’s Amazon region. Previously, OROV was not associated with severe pregnancy outcomes. During the 2022–2024 outbreak in Brazil, OROV expanded geographically, revealing links to adverse pregnancy outcomes. This study describes six cases with varied fetal outcomes, including miscarriage, antepartum, intrauterine fetal demise (IFD), and normal development, correlating with maternal symptoms but not symptom severity. Vertical transmission was confirmed by detecting OROV through RT-qPCR, ELISA, and immunohistochemistry in fetal tissues. Genome sequencing from an IFD case identified a novel reassortment pattern reported in the 2022–2024 outbreak. Severe encephalomalacia, meningoencephalitis, vascular compromise, and multi-organ damage were evident, underscoring the significant risk OROV poses to fetal development and emphasizing the need for further investigation.
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Pelz, Kristen, Charles Rhoades, Robert Hubbard, and Frederick Smith. "Severity of Overstory Mortality Influences Conifer Recruitment and Growth in Mountain Pine Beetle-Affected Forests." Forests 9, no. 9 (2018): 536. http://dx.doi.org/10.3390/f9090536.
Full textAbstract:
The severity of lodgepole pine mortality from mountain pine beetle outbreaks varies with host tree diameter, density, and other structural characteristics, influencing subcanopy conditions and tree regeneration. We measured density and leader growth of shade-intolerant lodgepole pine, shade-tolerant Engelmann spruce, and very shade-tolerant subalpine fir regeneration beneath stands that experienced moderate and high overstory lodgepole pine mortality (average 40% and 85% of total basal area) a decade earlier. Lodgepole comprised >90% of the overstory basal area and mature spruce and fir were present in both mortality levels, though live basal area and disturbance history differed. Post-beetle outbreak recruitment was high in both mortality levels, but there were more lodgepole in high than moderate mortality plots (1140 stems ha−1 vs. 60 stems ha−1) and more subalpine fir in moderate than high mortality plots (4690 stems ha−1 vs. 2870 stems ha−1). Pine advance regeneration, established prior to outbreak, was more dense in high mortality than moderate mortality sites (930 stems ha−1 vs. 310 stems ha−1), but the trend was generally the opposite for the other conifers. Lodgepole recruitment increased and subalpine fir decreased with greater forest floor light availability. All species grew faster in high mortality areas than their counterparts in moderate mortality areas. However, in high mortality areas pine grew faster than the more shade tolerant species, and in moderate mortality areas spruce and fir grew faster than pine. These species-specific responses to the degree of overstory mortality will influence future stand composition and rate of forest recovery after mountain pine beetle outbreaks.
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Poldrugovac, Mircha, Sara Barsanti, Emiliano Pardini, Niek S. Klazinga, and Dionne S. Kringos. "Relation between pre-existing quality management measures and prevention and containment of COVID-19 outbreaks in 159 nursing homes in Tuscany: a mixed methods study." BMJ Open Quality 13, no. 2 (2024): e002560. http://dx.doi.org/10.1136/bmjoq-2023-002560.
Full textAbstract:
BackgroundNursing homes were often the focus of COVID-19 outbreaks. Many factors are known to influence the ability of a nursing home to prevent and contain a COVID-19 outbreak. The role of an organisation’s quality management prior to the pandemic is not yet clear. In the Italian region of Tuscany nursing home performance indicators have been regularly collected since before the pandemic, providing the opportunity to better understand this relationship.ObjectivesTo test if there is a difference in the results achieved by nursing homes in Tuscany on 13 quality management indicators, when grouped by severity of COVID-19 outbreaks; and to better understand how these indicators may be related to the ability to control COVID-19 outbreaks, from the perspective of nursing homes.MethodsWe used a mixed methods sequential explanatory design. Based on regional and national databases, 159 nursing homes in Tuscany were divided into four groups by outbreak severity. We tested the significance of the differences between the groups with respect to 13 quality management indicators. The potential relation of these indicators to COVID-19 outbreaks was discussed with 29 managers and other nursing homes’ staff through four group interviews.ResultsThe quantitative analysis showed significant differences between the groups of nursing homes for 3 of the 13 indicators. From the perspective of nursing homes, the indicators might not be good at capturing important aspects of the ability to control COVID-19 outbreaks. For example, while staffing availability is seen as essential, the staff-to-bed ratio does not capture the turn-over of staff and temporary absences due to positive COVID-19 testing of staff.ConclusionsThough currently collected indicators are key for overall performance monitoring and improvement, further refinement of the set of quality management indicators is needed to clarify the relationship with nursing homes’ ability to control COVID-19 outbreaks.
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Rojas, Alejandra, John Shen, Fátima Cardozo, et al. "Characterization of Dengue Virus 4 Cases in Paraguay, 2019–2020." Viruses 16, no. 2 (2024): 181. http://dx.doi.org/10.3390/v16020181.
Full textAbstract:
In 2019–2020, dengue virus (DENV) type 4 emerged to cause the largest DENV outbreak in Paraguay’s history. This study sought to characterize dengue relative to other acute illness cases and use phylogenetic analysis to understand the outbreak’s origin. Individuals with an acute illness (≤7 days) were enrolled and tested for DENV nonstructural protein 1 (NS1) and viral RNA by real-time RT-PCR. Near-complete genome sequences were obtained from 62 DENV-4 positive samples. From January 2019 to March 2020, 799 participants were enrolled: 253 dengue (14 severe dengue, 5.5%) and 546 other acute illness cases. DENV-4 was detected in 238 dengue cases (94.1%). NS1 detection by rapid test was 52.5% sensitive (53/101) and 96.5% specific (387/401) for dengue compared to rRT-PCR. DENV-4 sequences were grouped into two clades within genotype II. No clustering was observed based on dengue severity, location, or date. Sequences obtained here were most closely related to 2018 DENV-4 sequences from Paraguay, followed by a 2013 sequence from southern Brazil. DENV-4 can result in large outbreaks, including severe cases, and is poorly detected with available rapid diagnostics. Outbreak strains seem to have been circulating in Paraguay and Brazil prior to 2018, highlighting the importance of sustained DENV genomic surveillance.