Dissertations / Theses on the topic 'Malaria morbidity'

A study was undertaken in Debre Zeit sector, central Ethiopia to identify the most important determinants of malaria transmission with a specific purpose of assessing whether global warming was the main cause of increased morbidity and mortality ascribed to malaria in the highlands of Ethiopia. Both retrospective and prospective methods were employed to conduct the study in 430 localities with a total population of 406,891. Some nine data sets were collected including altitude, malaria incidence and prevalence, hospital morbidity and mortality, outbreaks of malaria, vector control, climate patterns and in-vivo drug resistance mostly on a monthly basis with varying time periods ranging from 1951 to 1993. Morbidity analysis revealed a 67-fold increase in monthly incidence of malaria in about two decades. Mortality patterns showed a 13-fold increase in deaths ascribed to malaria in the last decade alone. Furthermore, highland communities living in localities lying between 2,000 and 2,200 metres were affected by P. falciparum transmission for the first time since 1986. Time series analysis of climate patterns revealed a trend of increased climatic warming in both day-time and night-time temperature especially since 1988, at which time a coincident peak in the incidence rate of malaria was also observed despite a decrease in total rainfall. Each °C rise in monthly mean night-time temperature was associated with up to 64% and 58% estimated rise in monthly incidence of falciparum malaria two and three months later respectively. The historic epidemic of malaria in which 150,000 people were estimated to have died among 3 million cases of malaria in Ethiopia in 1958 was associated with abnormally high ambient temperature and rainfall. This year also saw a very strong El Niño event. A simultaneous peak was seen in incidence of malaria, hospital admissions and hospital deaths ascribed to malaria together with an abnormal rise in mean night-time temperature in 1988. Based on current data it is concluded that epidemics of malaria in the highlands of Ethiopia that were observed during the past decade were mainly due to an increase in night-time temperature. The coincident peak in both malaria and ambient temperature together with statistical evidence suggested that global warming was the main cause of the rise in incidence of highland malaria. This appeared to be the cause of new foci of transmission at high altitude localities while also increasing both the rate and duration of transmission in previously known epidemic-prone areas from highly seasonal to perennial transmission. Furthermore, non-climatic biological and human conditions such as chloroquine resistant falciparum malaria, decreased vector control efforts and large scale population migration were also identified as important factors amplifying the impact of global warming on morbidity and mortality ascribed to highland malaria by affecting more distal parts of the causal pathway.

Includes bibliographical references (leaves 135-147).
This thesis presents the findings of a research on the economic burden of malaria morbidity to rural households in Mtoko district of North-East Zimbabwe. The main objective of this study was to ascertain the household level impacts of direct costs (medical costs, consultation costs, transport costs and other related costs) and indirect costs (lost productive time by malaria sufferers whilst sick, lost time by caretakers whilst caring for the sick) due to malaria sickness. A cross sectional study with both descriptive and analytical features was carried out and the main finding from the research was that the economic costs of seeking malaria care were regressive. In other words the poor were using a higher percentage of their income whilst seeking malaria care. In addition, access to care was very limited for the poor as they either could not afford to access the care because of prohibitive costs or they were geographically too far away from sources of care to easily access it. Furthermore, indirect costs were far higher than direct costs as they constituted a greater percentage of total malaria costs. It was concluded that measures meant to exempt the poor from paying for malaria treatment and care were needed to limit the economic burden of malaria morbidity on poor households. The need to ensure that cheap affordable malaria drugs were available to the affected rural people is imperative.

Plasmodium vivax malaria threatens nearly half the world’s population. This relapsing disease may be more severe than previously recognised and is proving refractory to current malaria control measures. This thesis aimed to describe the burden of anaemia and mortality attributable to vivax malaria in Southern Papua, Indonesia, an area endemic for multidrug-resistant P. vivax and P. falciparum, and to determine the potential of currently available antimalarial drugs to reduce transmission of P. vivax in co-endemic regions. Approximately 0.5 million uniquely identified clinical records from patients presenting to Mitra Masyarakat Hospital between April 2004 and May 2009 were matched with corresponding laboratory and pharmacy data in order to determine the burden of anaemia in the hospital setting and the effectiveness of primaquine prescription for preventing P. vivax relapses. Clinical information extracted from patient notes was used to clarify the contribution of P. vivax malaria to a series of deaths detected by an active hospital-based surveillance system. Additional secondary sources of data used in this thesis included a large house-to-house survey and multiple clinical trials of antimalarial therapy from both Southern Papua and Northwestern Thailand. In Southern Papua, P. vivax malaria is an important cause of haematological morbidity both in the hospital and community setting. This morbidity is most significant in the first year of life when P. vivax infection accounts for 23% of all severe anaemia (haemoglobin <5g/dL) in the hospital and approximately 28% of all moderate-to-severe anaemia (haemoglobin <7g/dL) in the community. In this region concomitant P. vivax infection accentuates haematological impairment associated with P. falciparum malaria. Plasmodium vivax in Southern Papua rarely causes death directly but rather indirectly contributes to mortality through exacerbation of comorbid conditions. In Northwestern Thailand, 53.8% of patients with falciparum malaria who were treated with a rapidly eliminated drug between 1991 and 2005 had a recurrence of vivax malaria within two months making P. vivax infection the most common cause of parasitological failure in these individuals. Slowly eliminated artemisinin combination therapies (ACT) provided the greatest protection against recurrent P. vivax parasitaemia during 63 days of follow-up. In three randomised controlled trials from Papua and Thailand, P. vivax gametocytaemia was shown to mirror asexual parasitaemia closely and to have the same characteristics in acute and recurrent infections. This emphasises that the most important chemotherapeutic means of blocking P. vivax transmission is prevention of future relapse. Primaquine is recommended for this purpose but analyses in this thesis suggest that in Southern Papua, unsupervised primaquine at a dose of 0.5mg/kg/day for 14 days, does not reduce the risk of subsequent relapse (Adjusted Hazard Ratio = 1.01 [95% confidence interval 0.95-1.07]). Plasmodium vivax malaria should not be neglected. High priority must be given to new hypnozoitocidal drug discovery. In the interim, optimising the safety and effectiveness of primaquine and adoption of a unified ACT-based blood schizontocidal treatment strategy for malaria of any parasitological cause in co-endemic regions will be crucial for controlling P. vivax malaria.

In tropical Africa, fever is commonly associated with malaria. However, there are many other illnesses presenting with fever. Non-malaria febrile illnesses (NMFIs) may be attributable to multiple etiologic agents including viral, bacterial and parasitic infections in malaria-endemic resource-poor countries. NMFIs pose challenges to peripheral health systems such that they are clinically under-diagnosed while malaria remains over-diagnosed. Misdiagnoses of a febrile condition may lead to wrong prescription that delays treatment and increases expenditure on health-care and also leads to increased morbidity and mortality. In Sierra Leone, dealing with infections other than malaria remain a serious problem, starting from diagnosis to providing care. Several factors make it difficult to test and treat for NMFIs. Fewer febrile people report their fevers to healthcare centers and there are fewer resources generally which include: fewer laboratories, insufficiently trained laboratory technicians, inadequate standardized infrastructure and unsuitable equipment, epileptic power supplies as well as poor cold-chain storage conditions for reagents among others. The primary goal of this Ph.D. study was to investigate the prevalence/incidence of NMFIs in Bo, Sierra Leone, using a tiered laboratory analyzes method. The specific objectives were to: investigate the types and etiology of non-malarial febrile illnesses in Bo, Sierra Leone; determine the prevalence/incidence of non-malarial pathogens causing febrile illnesses, and investigate the distribution of NMFIs. The study started with a baseline and syndromic survey of all households in the study community (n=882 households with 5410 persons). A total cohort of 1403 persons was recruited and followed for a period of one year. After obtaining informed-consent, bio-samples were obtained from febrile subjects and used for laboratory analyses involving three tiers. The first tier (T1) included the use of rapid, lateral flow assays (RLFAs). T1 tests were: chikungunya, malaria, typhoid fever, syphilis, HIV, hepatitis A, B and C, dengue fever, leptospirosis, influenza A and B, RSV and Streptococcus aureus. Subsequent tests at Tier 2 included singleplex and multiplex PCR and bacterial culture; with resequencing pathogen microarray at Tier 3. From the initial survey 882 households with 5410 individuals and 76.6% reported having malaria in a month prior to the study. About 1402 (25.9%) of persons in participating households were reported to have had a fever within the past six months. The rate of fever reported differed by age group and sex, with young children having the highest rate (p<0.001) and females reporting more fevers than males (p<0.001). Viral infections detected included; 46% chikungunya (95%CI 43.5-48.7), 24.2 human rhino virus/enterovirus (95%CI: 17.4-32.6), 19.2% corona virus (95%CI: 13.1-27.1), 9.7% HIV (95%CI: 8.2-11.4), 8.5% hepatitis B(HbSAg) (95%CI: 7.1-10.1), 8.7%HAV(IgG)(95%CI:7.3-10.3), 8.3% influenza B (95%CI:4.6-14.7 ), 5% adenovirus(95%CI: 2.1-11.0), 4.7% hepatitis C(95%CI: 3.7-5.9), 2.8% dengue fever (95%CI: 2.0-3.8), 1.7% parainfluenza virus and 1.7% influenza A(H1N1) (95%CI: 0.5-5.9), 0.8% cytomegalovirus (95%CI: 0.04-5.2) and 0.2 % human coxsackie virus A24 and A22(95%CI: 0.07-0.6). Bacterial infections detected included: 16.9% of Escherichia. coli (95%CI: 11.6-23.9); 12.6% of Klebsiella pneumonia (95%CI: 8.2-19.2); 12% of Citrobacter freundii (95%CI: 7.6-18.3); 8.5% of Enterobacter cloacae (95%CI: 4.9-14.2), 7.5% Haemophilus influenzae (95%CI: 3.7-14.2), 5%Chlamydophila pneumonia (95%CI: 2.9-11.6), 4.7% Burkholderia pseudomallei (95%CI: 3.7-5.9), 3.3% Moraxella catharrhalis (95%CI: 1.3-8.3), 2.8% Kluyvera spp. and 2.8% Serratia plymuthica /marcescens (95%CI: 1.1-7.0), 2.5% Mycoplasma pneumonia (95%CI: 0.9-7.1), 1.6% Treponema pallidum (95%CI: 1.1-2.5) and 0.7% Enterobacter intermedium, 0.7 Enterobacter aerogenes and 0.7% Escherichia hermannii (95%CI: 0.1-3.9) ), 1.1% Yersinia pestis(95%CI 0.7-1.8). Helminths detected included: 19.3% Ascaris lumbricoides (95% CI: 14.2-25.8); 10.8% hookworms (95% CI: 7.0-16.3); 6.3% Schistosoma mansoni (95% CI: 3.5-10.8); 1.1% had Schistosoma haematobium; 1.2% Strongyloides stercoralis (95% CI: 0.3-4.1); and 2.8% had Trichuris trichiura (95% CI: 1.2-6.5). It is worthy to note that these helminthes are collectively neglected tropical diseases and also known as diseases of poverty. Though malaria remains endemic, the results provide evidence of several other pathogens in circulation in Bo, Sierra Leone, one of which, Chikungunya, has a higher prevalence (46%) than malaria (23%). Among the bacteria, Salmonella enterica serotype Typhi is of importance as the population antibody levels has risen such that three-fifth of the study population had up to 1:120 titers of both Anti-O and Anti-H antibodies. A new cut-off point for the Widal test at about 1:160 or above is recommended to prevent over prescription of antibiotics for cases not related to typhoid. This study demonstrates the need to prioritize diagnosis and treatment of NMFIs in Sierra Leone.

Background: Intermittent preventive treatment in infants (IPTi) with sulphadoxine-pyrimethamine (SP) for the prevention of malaria has shown encouraging results in recent trials. However, resistance to SP is rising and alternative drugs for IPTi need to be evaluated. Objectives: To evaluate the safety and efficacy of different drugs for IPTi and to better understand the role of treatment vs. prophylactic effect of IPTi by comparing short and long-acting antimalarials.

Background Malaria remains a serious epidemic threat in the Lowveld region of Mpumalanga Province. In order to appropriately target interventions to achieve substantial reductions in malaria morbidity and mortality, there is a need to assess the impact of current control interventions such as indoor residual spraying (IRS) for vector control. This study aimed to assess long-term changes in the burden of malaria in Mpumalanga Province during the past eight years (2001-2009) and whether IRS and climate variability had an effect on these changes. Methods All malaria cases and deaths notified to the Malaria Control Programme, Department of Health was reviewed for the period 2001 to 2009. Data were retrieved from the provincial Integrated Malaria Information System (IMIS) database. Climate and population data were obtained from the South Africa Weather Service and Statistics South Africa, respectively. Descriptive statistics were computed to determine any temporal changes in malaria morbidity and mortality. Autoregressive integrated moving average (ARIMA) models were developed to assess the effect of climatic factors on malaria. Results Within the eight-year period of the study, a total of 35,191 cases and 164 deaths-attributed to malaria were notified in Mpumalanga Province. There was a significant decrease in the incidence of malaria in Mpumalanga Province from 385 in 2001/02 to 50 cases per 100,000 population in 2008/09 (P < 0.005). The overall incidence and case fatality rates were 134 cases per 100,000 and 0.54%, respectively. Malaria incidence and case fatality rate by gender showed significant differences, higher in males than in L.M. Ngomane University of Pretoria, 2012 iv females (166.9 versus 106.4; P < 0.001; CFR 0.41% versus 0.55%). The incidence of malaria increased from age 5-14 years (70), reaching a peak at age 25-34 years (190), declining thereafter (50 in those >65 years). Mortality due to malaria was higher in those >65 years, the mean CFR reaching a 2.1% peak. Almost half (47.8%) of the notified cases originated from Mozambique and Mpumalanga Province itself constituted 50.1%. The distribution of malaria varied across the districts, highest in Ehlanzeni district (96.5%), lowest in Nkangala (<1%) and Gert Sibande (<1%). A notable decline in malaria case notification was observed following the increased IRS coverage from 2006/07 to 2008/09 malaria seasons. A distinct seasonal transmission pattern was found to be significantly related to changes in rainfall patterns (P = 0.007). Conclusion Decades of continuous IRS with insecticides have proved to be successful in reducing the burden of malaria morbidity and mortality in Mpumalanga Province between 2001 and 2009. A decline of above 50% in malaria morbidity and mortality was observed following expanded IRS coverage. These results highlight the need to continue with IRS together with other control strategies until interruption in local malaria transmission is completely achieved and alternative vector control strategies implemented. Efforts need to be directed towards the control of imported cases, interruption of local transmission and focus on research into sustainable and cost-effective combination of control interventions.
Dissertation (MSc)--University of Pretoria, 2012.
School of Health Systems and Public Health (SHSPH)
Unrestricted

ContexteSi l’efficacité de la stratégie de prise en charge du paludisme au niveau communautaire n’est pas remise en cause à Madagascar, la mise en place de la nouvelle politique nationale incluant le remplacement de la chloroquine par la combinaison artésunate plus amodiaquine et l’introduction des tests de diagnostic rapide (TDR) dans la prise en charge des fièvres chez les enfants de moins de cinq ans suscite plusieurs inquiétudes. ObjectifsLe principal objectif de notre travail a été d’évaluer la stratégie de prise en charge des fièvres chez les enfants de moins de 5 ans au niveau communautaire. Pour évaluer la stratégie de prise en charge,trois objectifs spécifiques ont été abordés, à savoir, (i) l’étude de l’efficacité thérapeutique de la combinaison fixe « artesunate-amodiaquine » dans la prise en charge des fièvres chez les enfants de moins de 5 ans au niveau communautaire, (ii) l’évaluation des performances des tests de diagnostic rapide utilisés au niveau communautaire et (iii) la description de la situation épidémiologie du paludisme au niveau communautaire et l’évaluation de l’impact des stratégies de lutte actuellement mises en œuvre.MéthodologiesDeux études longitudinales ont été mises en place. La première étude (objectifs 1 & 2) a été conduite de février 2008 à février 2010 (24 mois) chez les enfants de moins de 5 ans en zone de transmission stable (district de Manakara) et en zone de transmission instable (district de Moramanga). La deuxième (objectif 3) s’est déroulée entre février 2009 et mars 2011 en zone de transmission stable (district de Manakara). Résultats & ConclusionObjectif 1 : les données obtenues lors de notre étude, nous permettent d’affirmer l’excellente efficacité thérapeutique de la combinaison fixe « artesunate-amodiaquine ». Nous avons observé que le taux de guérison clinique global était de 98,4% au bout de 28 jours et 97,9% au bout de 42 jours. La compliance au traitement a été estimée à 83,4%. Aucun effet indésirable grave n'a été observé. : Objectif 2 : Cette étude a permis de confirmer que les performances diagnostiques des agents de santé communautaire utilisant les TDR en termes de sensibilité, spécificité, VPP et VPN étaient supérieures à 85%, que la concordance entre les résultats de la microscopie et des TDRs, estimée par la valeur Kappa était excellente (83%) et que les TDR étaient stable même conservés au niveau communautaire. L’introduction des TDR au niveau communautaire semble être une stratégie efficace pour améliorer la prise en charge des malades fébriles, pour réduire la surconsommation d’antipaludiques (et donc le coût des traitements inutilement utilisés) et pour réduire la pression de sélection exercée par cette surconsommation. Objectif 3 : Nous avons pu démontrer que les mesures de prévention et de traitement prises au niveau communautaire étaient efficaces avec la mesure objective de la réduction de la prévalence du paludisme. Nous avons également mis en évidence une variation importante de la prévalence du paludisme inter-villages dans une même commune de quelques kilomètres carrés, suggérant des interventions ciblées en fonction des risques liés à la situation géographique, agricole, et climatique. Ce travail a permis de proposer une première approche méthodologique qu’il serait souhaitable d’étendre pour collecter les données de prévalence et d’incidence dans les autres communes, et préciser ainsi les besoins ciblés en TDR et ACTs à Madagascar
Context:One should think back of the effectiveness of malaria case management strategy at the community level Otherwise, questions will remain unanswered on the setting up of the new national Policy including the replacement of the chloroquine with combination artesunate and amodiaque and the introduction of rapid diagnostic test (RDT) for fever case management among children under five.Objective:The principal goal of our essay is to assess fever case management strategy among children under five years old at the community level. To proceed to the assessment, three specific objectives were tackled: (i) Therapeutic effectiveness of the fixed combination (artesunate-amodiaque) in fever case management among children under five at the community level. ii)the assessment of RDT performances used at the community level and iii) description of malaria epidemiological situation at the community level and the assessment of the impact of the fight against malaria strategies implementedMethodology: Two long depth studies were applied. The first study (Objective 1 and 2) was conducted in February 2008 to February 2010 (24 months) among children under five years old in stable transmission area (Manakara district) and in changeable transmission area (Moramanga district). The second study (objective 3) was held in February 2009 and March 2011 in stable transmission area (Manakara).Outputs and Conclusion:Objective 1: Data collected during our study enabled us to confirm the excellent therapeutically effectiveness of the fixed combination “artesunate-amodiaque”. We have noticed that the global clinical recovery rate is 98.4% after 28 days and 97.9% after 42 days of treatment. Compliance with the treatment was estimated at 83.4%. Not any adverse effect was noticed.Objective 2: This study enabled us to confirm the diagnostic performances of community health workers using RDT in terms of sensitiveness, specification. VPP and VPN were more 85% than the reliability between microscopic results and the RDTs estimated by the kappa value was excellent (83%) and RDTs were stable even kept at the community level. The introduction of RDT at the community level seems to be an effective strategy to improve sick people case management, to reduce overconsumption of products anti-malaria (and so reduce the cost of treatments used uselessly) and to reduce the selection pressure from this overconsumption.Objective 3: We could prove that prevention and treatment measures at the community level were effective with the objective measure of reducing malaria rate. We could bring to evidence an important variation of malaria rate between villages of one same commune from few kilometers of distance, suggesting targeted interventions depending on the risks linked to the geographic, agricultural and climate situations. This work enabled us to suggest a first methodological approach that is better to extend to collect prevalence data and in adverse circumstances in other communes and to mention the RDT targeted needs and ACTs in Madagascar

En Afrique tropicale, là où le paludisme est fortement endémique, la plupart des individus sont semi-immuns et les infections asymptomatiques sont très répandues. Ainsi la détection de parasites dans le sang de malades fébriles n'est pas un critère suffisant pour distinguer le paludisme des autres causes de fièvre. A Dielmo, un village du Sénégal d'environ 500 habitants en 2010, un suivi épidémiologique continu très étroit du paludisme a débuté en 1990. Dans ce village où la transmission est pérenne, la mise en place de moyens de lutte et de prévention contre le paludisme de plus en plus efficaces a profondément transformé l'épidémiologie du paludisme. Dans ce travail, nous analysons l'impact de ces interventions sur les prévalences parasitaires, les densités parasitaires et les critères diagnostiques du paludisme et nous mesurons l'évolution du paludisme clinique à Plasmodium falciparum, P. malariae et P. ovale de juin 1990 à décembre 2010. Les données parasitologiques et cliniques ont été analysées par régression logistique à effet aléatoire pour étudier la relation entre les densités parasitaires et le risque de fièvre. Les prévalences parasitaires des trois espèces plasmodiales ont considérablement diminué lors de l'abandon de la chloroquine en traitement de première ligne et de son remplacement par des combinaisons thérapeutiques, puis sont devenues presque nulles après la mise en place de moustiquaires imprégnées d'insecticides à longue durée d'action. Les seuils pyrogéniques calculés nous ont permis de mesurer la densité d'incidence des accès palustres et d'étudier l'impact des mesures de lutte sur la morbidité palustre dans la population
In tropical Africa, where malaria is highly endemic, most people are semi-immune and asymptomatic infections are widespread. Thus, the detection of malaria parasites in the blood of febrile patients is not a sufficient criterion for distinguishing malaria from other causes of fever. In Dielmo, a Senegalese village of about 500 inhabitants in 2010, a very closely continuous epidemiological monitoring of malaria began in 1990. In this village where the transmission is perennial, the establishment of more effective means of control and prevention against malaria have profoundly changed the epidemiology of malaria. In this work, we analyze the impact of these interventions on the parasite prevalences, the parasite densities and the malaria diagnostic criteria and we measure the evolution of Plasmodium falciparum, P. malariae and P. ovale clinical malaria from June 1990 to December 2010 in Dielmo. Parasitological and clinical data are analyzed in a random effect logistic regression to investigate the relationship between parasite density and fever risk. The prevalence of the three Plasmodium species decreased dramatically with the abandonment of chloroquine as first line treatment and his replacing with the combination therapies and became almost zero after the introduction of long lasting insecticidal nets. Pyrogenic thresholds calculated enabled us to measure the incidence density of malaria and to study the impact of intervention methods on malaria morbidity in the population

Malaria and anaemia are the leading cause of morbidity and mortality in children worldwide (WHO, 1986) and are the main disease burdens in sub-Saharan Africa. Severe malaria and anaemia are often fatal, while moderate anaemia in childhood is associated with impaired physical and mental development. One promising approach to the prevention of malaria is the administration of intermittent preventive treatment (IPT) to infants (IPTi) or to children under five years old (IPTc). This involves administration of a predefined number of treatment courses of antimalarial drugs at specified time intervals. Although IPTi has been shown to be efficacious in reducing the incidence of malaria in infants, this strategy may not be adequate to reduce the burden of malaria in children because in many parts of Africa the burden of malaria is high in children under five years of age not just in infants. Furthermore, in highly seasonal transmission areas of West Africa targeting IPT during the high transmission season is more appropriate than administering IPT throughout the year. There is now some evidence from Mali and Senegal that seasonal IPTc can reduce the burden of malaria substantially in Sahelian West Africa. The IPTc studies done so far have been carried out in areas with an intense but short transmission season. Furthermore resistance to SP, the drug commonly used for IPT is increasing. Thus, there is a need to assess the efficacy of IPTc in an area of intense transmission with a prolonged seasonal peak of malaria transmission and to find alternative drugs or drug combinations for IPTc. Hence, a randomised, controlled trial of amodiaquine plus artesunate (AQ+AS), given at two different intervals (monthly or bimonthly), SP alone bimonthly or placebo to children aged 3- 59 months during the high malaria transmission season was conducted in Ghana in 2005-2006. The protective efficacy of IPTc against malaria and anaemia was assessed during the intervention period and one year post intervention period to determine if there was any rebound in the incidence of malaria or anaemia after stopping IPTc. A total of 2451 children were enrolled from 30 villages and randomly assigned to four arms. The number of children assigned to each arm and followed up to six months was 650 to placebo, 613 to SP bimonthly, 562 to AQ+AS bimonthly and 626 to AQ+AS monthly. The follow up rate was high (range 92%-95%) and was comparable between groups. IPTc provided protection against clinical malaria and anaemia in children less than five years of age. Monthly AQ+AS IPTc reduced the incidence of malaria by 75% (95% Cl: 65%-83%) and anaemia 58% (95% Cl: 33%-74%), bimonthly SP reduced the incidence of malaria 35% (95% Cl: 17%-49%) and anaemia 45% (95% Cl: 15%-65%) and bimonthly AQ+AS reduced the incidence of malaria 30% (95% Cl: 11%-46%) and anaemia 24% (95% Cl: 14%-50%) compared to placebo. Episodes of hospital admissions with severe malaria were reduced by 62% (95% Cl: 5%-86%) in the AQ+AS monthly, 39% in SP bimonthly (95% Cl: -36%-74%) and 58% in the AQ+AS bimonthly group (95% Cl: 5%-85). There was no significant increase in the incidence of clinical malaria with any parasitaemia or high density parasitaemia in the dry and rainy seasons following IPTc intervention in older children (12-59 months). However, there was a slight increase in the incidence of clinical malaria with any parasitaemia or high density parasitaemia in infants (3-11months) in the rainy season following IPTc intervention. IPTc using any of the three treatment regimens was cost effective and scaling up to cover more children reduced cost drastically. The intervention was found to be acceptable to the community. We conclude that IPTc is safe and efficacious even in areas with a prolonged intense transmission season. IPTc, when combined with other interventions such as the use of insecticide treated bednets and home management of malaria, will reduce the burden of malaria in West Africa.

It has been generally recognised that sick children have an increased risk on malnutrition. An activated immune system requires more nutrients while illness is often associated with a lower absorption and decreased consumption because of lack of appetite. When these increased needs are not balanced with an adequate availability of nutrients, the sick child is at higher risk of developing malnutrition.Médecins Sans Frontières investigated the question whether this process is mitigated by simple short term nutritional supplementation given to sick children alongside medical treatment. Three Randomised Controlled Trials (RCT’s) were conducted. The first, in Democratic Republic of Congo, was a pilot; 180 children with malaria were randomised in 2 arms: 1 group receiving 2 weeks of ready to use therapeutic food (RUTF) and a control group. The children were followed for a period of 4 weeks. Children in the RUTF group showed a higher weight gain in the first 14 days compared to the control group, at day 28 the weight gain in both groups was similar.Thereafter, 2 RCT’s were implemented in Uganda and Nigeria using a similar methodology. Children with malaria, lower respiratory tract infection or diarrhoea (sample size of 2202) were randomised in three groups: supplemented with 2 weeks of RUTF, supplemented with 2 weeks of micronutrient powder (MNP), and not receiving supplementation after each disease episode. The incidence of malnutrition was compared after an observation period of 6 months. The trial in Uganda showed a reduction in malnutrition in the RUITF group with 31%, while in Nigeria, there was no significant reduction in the RUTF group. The MNP group did not show reduction in malnutrition in any site. In the group of moderate malnourished children the RUTF and MNP supplementations were not effective in preventing deterioration to severe malnutrition. However, when the studies were combined the RUTF group showed a lower mortality compared to the MNP group.Multi-variate analysis did not show a reduction of incidence of malnutrition in the supplementation groups. A strong association with morbidity was found. A higher frequency of diarrhoea was associated with an increased incidence of malnutrition. The association with malaria episodes was mixed; it was associated with a higher incidence of malnutrition in Kaabong, but in Goronyo a higher frequency of malaria decreased the incidence of malnutrition. In addition, a more frequent monitoring of the children and treatment of their illnesses was associated with a decreased incidence of malnutrition.The difference in effectiveness of supplementation between the sites can be explained by differences in food security and level of morbidity. It is argued that the fragile food security in Kaabong limits the supply of nutrients, and therefore supplementation with RUTF was effective. In Goronyo the high frequency of morbidity limits convalescence and therefore supplementation was not effective.It is likely that malnutrition is more effectively prevented when several interventions are combined like water and sanitation to prevent diarrhoea, malaria chemoprophylaxis and preventative and curative health and nutrition interventions.This dissertation will present the background, the methods of the trials and the results, followed by a discussion on the implications for programming and research.
Doctorat en Santé Publique
info:eu-repo/semantics/nonPublished

Cette thèse se donne pour objectif de contribuer à la compréhension des tendances démographiques en Afrique subsaharienne par l’examen de l’influence de la mortalité infantile sur les comportements de fécondité. Dans le premier chapitre, j’examine la relation entre mortalité infantile et fécondité à l’échelle micro-économique. Des modèles de données de comptage sont utilisés pour analyser les déterminants de la fécondité complète de femmes d’une communauté rurale sénégalaise. Je montre que l’effet global de la mortalité infantile est positif tant sur la fécondité totale que sur la fécondité nette. De plus, j’identifie une relation en U inversé entre mortalité infantile et fécondité nette. Dans le second chapitre, j’analyse les effets de la mortalité infantile sur les comportements reproductifs dans un modèle de fécondité endogène où la survie infantile est stochastique. J’adopte une forme fonctionnelle de coût des enfants englobant quatre scénarios différents, chacun représentant un contexte socio-économique distinct. Mon modèle peut prédire des réponses positives et négatives de la fécondité, selon que les enfants sont respectivement “intensifs en temps” ou “pourvoyeurs en temps”. Finalement, le troisième chapitre analyse les effets de la mortalité et de la morbidité infantiles sur le processus de décision de fécondité des femmes rurales sénégalaises. J’estime des modèles dynamiques non linéaires de données de panel. Je montre que la mortalité et la morbidité palustres à l’échelle de la communauté, ont un effet positif sur les décisions ultérieures de fécondité. Cet effet est d’autant plus fort que la maladie est létale pour les enfants infectés
This dissertation attempts to contribute to the understanding of current demographic trends in sub-Saharan Africa by examining the role of child mortality in shaping fertility behavior. In the first chapter of this dissertation, I examine the relationship between child mortality and fertility at the micro level. Count data models are employed to investigate the determinants of completed fertility of women from a Senegalese rural community. The global effect of child mortality on total and net fertility is found to be positive. I also identify an inverted-U shaped relationship between child mortality and net fertility. In the second chapter of this dissertation, I analyze the effects of child mortality changes on fertility behaviors in an endogenous fertility model where child survival is stochastic. I adopt a functional form for the cost of children that allows for four different scenarios, each of which is representative of a particular socio-economic setting. My model can predict both positive and negative fertility responses to child mortality depending on whether children are “time-intensive” or “time-supplying”, respectively. Finally, the third chapter analyzes the effects of childhood mortality and morbidity on the fertility decision-making process among rural Senegalese women. I estimate nonlinear dynamic panel data models of fertility behavior. I find that community child mortality and morbidity attributable to malaria exert a joint influence on fertility behaviors. Community-level malaria incidence among children has a positive effect on subsequent fertility choices, and this positive effect is stronger the more the disease is fatal to children who are infected

En France, l'usage des bases de données médico-administratives dans le cadre épidémiologique est récent comparativement à d'autres pays d'Europe, du fait notamment de leur complexité, liée à leur développement initial mené dans une optique comptable. Les travaux menés ont porté sur l'apport de ces bases de données à l'étude de la prise en charge et de la morbidité évitable dans l'asthme et dans l'ostéoporose. Dans un premier temps, nous avons montré que ces bases de données permettaient au travers d'algorithmes d'identifier des nourrissons asthmatiques et leurs exacerbations, et que la prise en charge de ces nourrissons n'était pas optimale en France, avec une forte consommation d'antibiotiques et de corticoïdes oraux. Nous avons prolongé ces recherches par la description de la prise en charge des asthmatiques enfants/adolescents et adultes, et les constats ont été les mêmes. Une surconsommation des traitements de crise a pu être mise en évidence, ainsi que des sous-groupes de patients à risque d'exacerbation sévère. Ces résultats nous ont amené à nous intéresser tout particulièrement à l'adhésion aux traitements de fond. Dans une étude menée sur 5 000 patients asthmatiques, le taux de couverture par un traitement de fond était en moyenne de 51%, et seuls 24% des patients avaient un taux de couverture supérieur ou égal au taux minimal recommandé (80%). Enfin, concernant l'ostéoporose, nous nous sommes attachés à décrire la prise en charge des patients ostéoporotiques sur une période de 6 ans, en nous concentrant particulièrement sur les changements de stratégies thérapeutiques
Anglais In France, the use of claims data in the epidemiological context is recent compared to other European countries, in particular because of their complexity, linked to their initial development for accounting purposes. This work was focused on the contribution of these databases to study disease management and unmet needs in asthma and osteoporosis. First, we showed that it was feasible, through algorithms, to identify in these data infants with asthma and their exacerbations, and we noted that management of these infants was not optimal, with high use of antibiotics and oral corticosteroids. We extended this research by describing the treatment of asthmatic children/adolescents and adults, with similar findings. Overuse of reliever therapy was observed, beyond the identification of subgroups at risk of serious exacerbation. These results led us to focus on adherence to controller therapy. In a study including 5,000 asthma patients, the coverage by controller therapy was 51%, and only 24% of patients had a higher coverage than the recommended minimum (80%). Finally, regarding osteoporosis, we described the treatment of osteoporotic patients over 6 years, with a particular focus on treatment switches

Malgré les progrès dans la lutte contre le paludisme au Burkina Faso, il reste la plus importante maladie à transmission vectorielle dans le pays. P. falciparum est le plus répandu et le plus mortel au Burkina Faso. Les facteurs liés à ce fardeau élevé sont l’inaccessibilité (financière et géographique) aux soins de santé, l’insuffisance dans le diagnostic et la prise en charge adéquate et précoce des cas de paludisme. La réalisation de l'Objectif du Développement Durable 3 au Burkina Faso repose sur une mise en œuvre réussie d'un ensemble d'interventions de prévention, de gestion des cas et de surveillance épidémiologique du paludisme. L'objectif de réduire le taux de létalité lié au paludisme à 1 % en 2020 n'a pas été atteint, il est donc nécessaire de réaliser une évaluation de l’efficacité des programmes de lutte antipaludique (utilisation des MILDA, utilisation des CTA, la politique de gratuité des soins de santé) surtout au niveau infranational, utile pour orienter la prise de décision à des échelles géographiques plus petites. Les données cliniques sur le paludisme collectées en routine peuvent fournir des informations indispensables pour l’évaluation de la variation inter et intra mensuelle/annuelle de l’effet des interventions de lutte antipaludique et du risque de paludisme à l'échelle nationale et infranationale chez les enfants de moins de cinq ans. Au Burkina Faso, une quantité importante de données a été régulièrement collectée par le biais du système de transmission des données en ligne via le « District Health Information System 2 (DHIS2) ». Toutefois, leur utilisation pour évaluer l’effet des interventions de lutte sur la dynamique spatio-temporelle du risque de paludisme à l’échelle locale (district) reste limitée au Burkina Faso. Dans cette recherche, nous avons développé des modèles spatiaux et spatio-temporels implémentés dans un cadre hiérarchique bayésien pour (I) évaluer l’effet des interventions de lutte sur la dynamique spatio-temporelle de la morbidité et de la létalité dues au paludisme sur la période 2013-2018 chez les enfants de moins de 5 ans au Burkina Faso et (II) détecter les districts sanitaires (spatio-temporelle) qui ne parviennent pas à atteindre les objectifs du PNLP en termes de morbidité/létalité. Ces modèles utilisent l’Approximation Intégrée de la Laplace (INLA), un algorithme déterministe qui est une méthode appropriée pour analyser les données de routine du paludisme corrélées à la fois dans l’espace et dans le temps. Nous avons observé que la mise en œuvre de la politique de gratuité des soins de santé était significativement associée à une augmentation du nombre de cas rapportés de paludisme testés et confirmés par rapport à la période précédant sa mise en œuvre. Cet effet était cependant hétérogène dans les districts de santé. De plus, nous avons constaté que le taux mensuel de létalité du paludisme était en baisse au cours de la période 2013-2018. Cette réduction était significativement associée à la disponibilité des tests de diagnostic rapide du paludisme et du traitement. Aussi, nous avons observé que le risque de décéder du paludisme chez les enfants de moins de 5 ans était plus faible au cours de la période suivant la mise en œuvre de cette politique par rapport à la période précédente. Nous avons également identifié des districts sanitaires avec un taux de létalité du paludisme élevé dans les parties nord, nord-ouest et sud-ouest du pays. Nos résultats appellent à un effort soutenu et renforcé pour tester tous les cas suspects afin que, parallèlement à l’amélioration de la prise en charge précoce des cas, le fardeau du paludisme chez les enfants de moins de cinq ans soit connu avec précision (voir l'hippopotame presque entièrement). De plus, ils ont mis en évidence les districts sanitaires qui ont le plus besoin d'interventions ciblées et la nécessité de maintenir et de renforcer les programmes de santé en cours pour réduire davantage les décès dus au paludisme au Burkina Faso.
Despite progress in the fight against malaria in Burkina Faso, malaria remains the most important vector-borne disease in the country, and P. falciparum is the most widespread and deadly pathogen in the area. The factors linked to this high burden are the inaccessibility (financial and geographical) to health care, insufficient diagnoses, and inadequate/late management of malaria cases. The achievement of Sustainable Development Goal 3 in Burkina Faso is based on the successful implementation of a set of interventions for the prevention, case management, and epidemiological surveillance of malaria. The objective of reducing the case fatality rate linked to malaria to 1% by 2020 has not been reached. It is, therefore, necessary to carry out an evaluation of the effectiveness of malaria control programs (the use of long-lasting insecticidal nets, the use of Artemisinin-based combination therapy, and free health care policies), especially at the sub-national level, which will be useful for guiding decision-making at smaller geographic scales. Routinely collected clinical data on malaria can provide essential information for the assessment of inter- and intra-monthly/annual variation in the effects of malaria control interventions and the risk of malaria at the national and subnational levels among children under five. In Burkina Faso, a significant amount of data is regularly collected through the online data transmission system via the “District Health Information System 2 (DHIS2)”. However, the use of these data to assess the effects of control interventions on the spatio-temporal dynamics of malaria risk at the local (district) level remains limited in Burkina Faso. In this research, we developed spatial and spatio-temporal models implemented in a Bayesian hierarchical framework to (i) assess the effects of control interventions on the spatio-temporal dynamics of morbidity and lethality due to malaria in the period of 2013–2018 in children under 5 in Burkina Faso and (ii) detect health districts (spatio-temporal) that fail to achieve the PNLP objectives in terms of morbidity/lethality. These models use Laplace Integrated Approximation (INLA), a deterministic algorithm that provides an appropriate method for analyzing routine malaria data correlated in both space and time. We observed that the implementation of the free health care policy was significantly associated with an increase in the number of reported cases of malaria tested and confirmed compared to the period before its implementation. This effect was, however, heterogeneous in the health districts. In addition, we found that the monthly malaria case fatality rate declined during the period of 2013–2018. This reduction was significantly associated with the availability of rapid diagnostic tests for malaria and treatments. We also observed that the risk of dying from malaria in children under 5 years old was lower during the period following the implementation of this policy compared to the previous period and identified health districts with a high case fatality rate from malaria in the northern, northwestern, and southwestern parts of the country. Our results call for a sustained and strengthened effort to test all suspected cases so that, along with improving early case management, the burden of malaria in children under five can be known with precision. In addition, our results highlight the health districts in greatest need of targeted interventions, as well as the need to maintain and strengthen ongoing health programs to further reduce malaria deaths in Burkina Faso.
Doctorat en Sciences de la santé Publique
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Les données épidémiologiques montrent une association inverse entre les taux de HDL-cholestérol (HDL-C) et le risque d'évènements cardiovasculaires. Des traitements ayant montré une augmentation significative du HDL-C, comme les inhibiteurs de la protéine de transfert des esters de cholestérol, devraient donc permettre de réduire le risque cardio-vasculaire. En utilisant différentes techniques de modélisation, nous avons tenté de quantifier l'efficacité attendue sur les événements cardiovasculaires de l'un d'entre eux, le dalcétrapib, ne disposant que de données pharmacocinétiques et pharmacodynamiques. Tout d'abord, afin d'établir la relation pharmacocinétique / pharmacodynamique entre les concentrations et la modification de HDL-C, nous avons analysé les données individuelles des patients dyslipidémiques par une approche de population. Une hausse moyenne de HDL-C de 26.4 % par rapport au placebo était alors anticipée. Nous avons ensuite tenté de corréler l'effet observé sur l'HDL-C et l'effet clinique à partir de données d'autres études par méta-régression des essais évaluant l'effet des principaux hypolipémiants en prévention secondaire. Cette modélisation n'a pas permis de montrer de corrélation entre le changement de l'HDL-C (P5 P95 :-3.0 et 36 %) et la réduction du risque cardiovasculaire. Une analyse de sensibilité par type de traitement suggère qu'une même hausse de HDL-C entre deux classes thérapeutiques pourrait se traduire par un effet clinique dissemblable, indiquant que HDL-C ne peut pas être utilisé comme critère intermédiaire puisqu'il ne serait pas un prédicteur indépendant du risque cardiovasculaire

Afin de modéliser l'évolution de l’infection par le chikungunya (CHIK), son impact, et les facteurs pronostiques de chronicité, nous avons travaillé en trois parties. L'impact à long terme de l’épidémie de CHIK en 2005-2006 à la Réunion a été estimé en calculant la proportion de patients en phase chronique au cours du temps et la charge globale de morbidité du CHIK par la méthode des années de vie ajustées sur l'invalidité (méthode DALY de l’OMS, qui prend en compte les années de vie perdues en raison de la mortalité prématurée et des années de vie vécues avec une incapacité). Ainsi entre 51,2 et 65,3% des patients étaient estimés symptomatiques après 1 an et 0% à15,2% après 5 ans. Le total d’années de vie en bonne santé perdues à la Réunion a été estimé à 65-73/1000 personnes, 55,5% des pertes concernant la population active (les 20 à 60 ans), et 86% étant dues à la persistance de rhumatismes post-CHIK (phase chronique). Les facteurs pronostiques de la persistance de rhumatismes et de l’altération de la qualité de vie (QdV) à long terme (30 mois) ont été étudiés dans une cohorte des gendarmes dont 25% étaient infectés (CHIK+). Etre CHIK+, avoir des comorbidités et un moral déprimé pendant la phase aiguë étaient prédictifs de la persistance d’arthrite comme d’arthralgies. De plus, la présence d’arthralgies ou arthrite à six mois était très prédictive de la persistance des mêmes rhumatismes à 30 mois
To model the evolution of chikungunya virus (CHIK) infection, its impact and the prognostic factors of post-CHIK rheumatism and quality of life, we worked in three parts. The long-term impact of the 2005-2006 CHIK outbreaks in Reunion Island was estimated by calculating the proportion of chronic patients over time and the global burden of CHIK using the Disability Adjusted Life Years (DALY) method. This method sums the years of life lost due to premature mortality and the years lived with disability. Between 51.2 and 65.3% of patients were estimated chronic after 1 year and 0%-15.2% after 5 years. The global disease burden of CHIK was estimated 65-73 DALYs/1000 persons, 55.5% concerning the active population (20-60 years old), and 86% due to persistence of post-CHIK rheumatisms. Prognostic factors of the long-term (30 months) rheumatisms and impaired quality of life (QoL) were studied in a cohort of French army policemen (25% CHIK infected: CHIK+). Being CHIK+, suffering of comorbidity and having depressed mood during the acute stage were predictive for both persistent arthritis and arthralgias at 30 months. In addition, suffering of either arthralgias or arthritis at six months was predictive of the same symptoms at 30 months. Determinants of impaired QoL were CHIK infection and comorbidity, in addition to older age, work-stoppage during the acute infection and arthritis at 6 months for the QoL physical component, and depressed mood at 6 months for the mental health component.Association between the severity of initial CHIK-stages and recovery were studied using multiple correspondence analysis (MCA)

Master of Science in Epidemiology and Biostatistics
Background Malaria is one of the primary public health concerns in the world and an important cause of morbidity and mortality in sub-Saharan Africa. Malaria morbidity is associated with poverty and vulnerability as it is not easy for the poor people to access preventive treatment and protective measures. In Rwanda, malaria prevention has become a major problem against the double-barrelled burden of an overstretched health system and strained financial resources. Methods This research was a cross-sectional survey study design based on data from Rwanda collected in 2010 through the Malaria Indicator Survey as part of the Demographic and Health Survey. The primary outcome variable was an ordinal variable with these three categories; no malaria, probable malaria, and confirmed malaria cases. The outcome variable was formulated by combining rapid malaria test and confirmatory blood smear laboratory test. Statistical analysis was done using survey ordinal logistic regression modelling adjusting for random effects for direct effects and generalised structural equation modelling (G-SEM) to obtain total (direct and indirect) effects of malaria morbidity. Results The 11,865 participants had a mean age of 22 years, and two-thirds of the participants were females (67%). Household related variables (socio-economic status, health insurance, age in years) showed a significant total effect on malaria infection. Socioeconomic status had the greatest total effect which was a sum of the direct and indirect effects influenced indirectly by education, health insurance and the number of rooms for sleeping. Conclusion Poverty is still the core issue to the morbidity patterns driving the malaria epidemic in Rwanda. Access to health insurance has a high positive impact on decreasing disease as such a special focus on some regions can be an effective intervention strategy. A better understanding of the drivers of morbidity directly and/or indirectly can better target interventions to be more efficient in those affected areas.
MT2017

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand in partial fulfilment of the requirements for the Degree of Masters in Epidemiology in the field Biostatistics and Epidemiology May, 2018.
Background: Malaria and anaemia pose significant public health challenges to most developing countries. Sub-Saharan Africa continues to carry a disproportionately high share of the global malaria burden. Recent WHO (2015) global estimates on disease burden shows the African region accounted for 88% of the 214 million new malaria cases in 2015. This statistic further highlighted that the region accounted for 90% of malaria deaths in 2015. Similarly, anaemia, defined as low hemoglobin concentration, is estimated to globally affect 43% of children under five years of age. Anemia prevalence is very high among Ghanaian children under 5 years of age. The objectives of this study were to determine the prevalence and spatial distribution of malaria morbidity in children under age 5 years in Ghana in 2014, to ascertain the prevalence and spatial distribution of childhood anaemia morbidity in Ghanaian children under age 5 years in 2014, to determine the spatial distribution of factors associated with malaria morbidity in Ghana in 2014, and to determine the spatial distribution of factors associated with anaemia morbidity in Ghana in 2014. Objectives: The aim of the study is to determine spatial distribution and factors associated with malaria and anaemia morbidity among Ghanaian children under 5 years of age in 2014. Methods: This study analysed malaria and anaemia morbidity and prevalence using data from the Ghana 2014 Demographic and Health Survey. These data captured malaria related information on children under 5 years. Survey logistic and ordered logistic multivariable regression was done to determine associations between the singular outcomes malaria and anaemia and several explanatory variables. The regression models were employed and results thereof were used to produce maps illustrating the predicted risk of malaria and anaemia occurrence. The generalized linear mixed model was used to simultaneously identify the risk factors of malaria and anaemia of children under five years and how these are spatially distributed. Multilevel survey adjusted logistic and ordinal logistic regression models with non-spatial random effects were fitted for malaria and anaemia respectively. A Bayesian approach was employed to further adjust for spatial random effects on the convolution models for the two main outcomes. Results: The sample in this study was made up of 2727 children under age 5 years, of which 783 tested positive for malaria and 1873 had anaemia, resulting in an observed malaria and anaemia prevalence of 28.71% and 68.68% respectively. Spatially adjusted significant variables were: Child’s age; type of place of residence; mother’s highest education level, wealth index; child’s altitude adjusted haemoglobin level; cluster altitude; severe anaemia vomiting; severe anaemia extreme weakness. Children from the Western, Central, Greater Accra, Eastern, and Brong Ahafo regions were more likely to have malaria compared to northern region. Malaria was 1.46 times more likely to occur among children residing in rural than urban areas [OR=1.46, (95% CI: 1.02-2.16); p=0.05]. Vomiting as well as extreme weakness were 6.37 [OR=6.37 (95% CI: 2.16- 18.75); p<0.001] and 7.63 [OR=7.63 (95% CI: 3.02-19.22); p<0.001] times more likely to have anaemia than those without these symptoms. Children residing at higher altitude were 0.98 times less likely to have anaemia compared to those at lower altitude [OR=0.98 (95% CI: 0.97-0.99); p=0.01]. Conclusion: Recent reports in Ghana indicate that malaria and anaemia related deaths in children under age 5 years are on the ascendancy. In spite of this, there is a dearth of empirical research that establishes our understanding on the prevalence of malaria and anaemia in the endemic regions of Ghana. Understanding the prevalence of malaria and anaemia in terms of spatial risk factors, will provide more insight and practical guidelines to the formulation of policies aimed at fighting the spread of malaria and anaemia. Hence, directing health interventions to higher risk areas and ensuring nationwide coverage are promising strategies for promoting equity and reducing risk of malaria and anaemia. This study showed that Brong Ahafo, Eastern, Northern, Western, Volta and Upper East regions were the hotspot zones with greatest disease burden. Keywords: Ghana, Anaemia morbidity, Malaria morbidity, Malaria Indicator Survey (MIS), Demographic and Health Survey (DHS), spatial mapping, West Africa.
LG2018

A quantitative, explorative, descriptive contextual study was conducted to determine to what extent the malaria control measures proposed by the Tanzanian government had been implemented by parents of children between the ages 0-5 years who lived in Bukumbi village. Structured interviews were conducted with 40 parents of children who had been admitted for malaria treatment during 2007, and the data analysed by computer. Although respondents had a basic knowledge of preventive measures they did not implement actions preventing the anopheles mosquitoes’ breeding in this tropical area. The vicious cycle of poverty, malaria episodes and lack of proper malaria health education hampered the implementation of control measures such as the spraying of houses with insecticides. Although the government of Tanzania subsidises insecticide treated bed nets the respondents did not maintain these nets and did not renew the insecticide treatment of these nets. The incidence of malaria is unlikely to decline in the Bukumbi village unless all identified factors are addressed.
Health Studies
M.A.

RESUMO: Introdução: O contexto atual de aumento exponencial em viagens internacionais, crescente mobilidade humana e progressivo encurtamento temporal de distâncias desafia a saúde pública global. Nesta dissertação pretendeu-se contribuir para o conhecimento na área da saúde relacionada com viagens internacionais e sua vigilância, uma área emergente, muito aflorada, mas pouco explorada em Portugal, sendo um ponto de partida para equacionar um modelo de vigilância em saúde baseado no viajante. Nela exploram-se fontes de dados, instrumentos e métodos de análise usadas pela primeira vez em Portugal, nomeadamente em vigilância e saúde do viajante. A relações bidirecionais entre Portugal e os países africanos e a recente vaga de expatriação civil para Angola e Moçambique motivaram a exploração da vigilância de importação de malária e a exploração das características, problemas e necessidades em saúde dos viajantes portugueses para estes destinos, com ênfase no viajante de longa duração e no expatriado, com objetivo profissional. Métodos: Foram desenvolvidos 3 estudos. O primeiro consistiu num estudo retrospetivo sobre malária importada em Portugal, com internamento hospitalar, (2000-2012), recorrendo à Base de dados Nacional das Doenças de Declaração Obrigatória (DDO) e à Base de dados Nacional de Morbilidade Hospitalar ou dos Grupos de Diagnósticos Homogéneos (GDH). Foram selecionados, respetivamente, as notificações consecutivas de malária (ICD-10, códigos B50-B54: 606 notificações) e episódios consecutivos de hospitalização por malária (ICD-9 CM, códigos 084* e 647.4: 2465 casos), procedendo-se ao cruzamento das duas bases de dados. Foi estudado o impacto da malária importada. Foram analisados, respetivamente, por regressão linear múltipla e regressão logística múltipla, o tempo de internamento e a letalidade intra-hospitalar. Foram quantificadas as sensibilidades de ambas as fontes de dados, através do método de captura-recaptura. O segundo estudo, de desenho transversal, traçou um perfil demográfico e de saúde de viajante português para Angola, assim como o seu conhecimento, atitude e práticas em relação à malária, por questionário, no Aeroporto Internacional de Lisboa, numa amostra de conveniência de viajantes portugueses adultos com destino a Angola (N=404). O conhecimento, a atitude e a prática em relação à prevenção de malária, foram estudados por regressão linear múltipla. No terceiro, foi estudado o estado de saúde geral e a morbilidade em expatriados adultos portugueses em Angola e Moçambique, por questionário, numa amostra de conveniência (N=352), que incluiu o GHQ-12 para medir nível de bem estar psicológico. Confirmada a fiabilidade (Cronbach alpha 0,83) e a adequação a análise fatorial (KMO 0,85; teste Bartlett p <0,001) do GHQ-12, procedeu-se a analise fatorial exploratória e confirmatória. O nível de bem estar psicológico, a ocorrência auto-referida de novos problemas de saúde e de sintomas psicológicos foram estudadas por regressão logística múltipla. O nível de significância considerado foi 0,05. Foram utilizados o Excel Microsoft Office, o IBM SPSS Statistics version 21 e o IBM SPSS Amos.
ABSTRACT: Introduction: The current context of exponential increase in international travel, increasing human mobility and progressive temporal shortening of distances challenges global public health. This dissertation aimed at increasing baseline awareness in international travel and health surveillance, an emerging area that is little explored in Portugal, so as to evolve towards integrated traveller centred approaches. It explores data sources, tools and methods of analysis used for the first time in Portugal in traveller’s health surveillance. The bidirectional migration between Portugal and African countries and the recent increased civil expatriation to Angola and Mozambique motivated research in imported malaria surveillance and in the ascertainment of the characteristics, health problems and needs of the Portuguese travellers to these destinations, with an emphasis on occupational long-term traveller and expatriates. Methods: Three studies were developed. The first was a retrospective study on imported malaria requiring hospitalization in Portugal (2000-2012), using the National Database of Notifiable Diseases (DDO) and the National Database of Hospital Morbidity (GDH). Consecutive malaria notifications (ICD-10, B50-B54 codes, N=606 cases) and hospitalizations (ICD-9 CM codes 084 * and 647.4, N=2465 cases), respectively, were selected, and linkage of both databases was carried out. Disease burden and trends were studied. In hospital length of stay and mortality were analysed with multiple linear and logistic regression methods. Database completeness was quantified by the capture-recapture method. The second study had a cross-sectional airport survey design and drew a demographic and health profile of the Portuguese traveller to Angola, as well as their knowledge, attitude and practices towards malaria (N = 404). Knowledge, attitude and practice towards malaria prevention were studied by multiple linear regression. In the third study, the general health and morbidity in Portuguese adult expatriates in Angola and Mozambique were studied, by a web based questionnaire (N = 352). It included the GHQ-12 to measure level of psychological well-being. GHQ-12 reliability (Cronbach's alpha 0.83) and suitability for factor analysis (KMO 0.85, Bartlett test p <0.001) were determined and exploratory and confirmatory factor analysis was carried out. The level of psychological well-being, self-reported new health problems and psychological symptoms were studied by multiple logistic regression. The significance level was 0.05. Excel Microsoft Office IBM SPSS version 21 and IBM SPSS Amos were used.

This thesis comprises three essays on “The Economic impact of adult mortality and morbidity on smallholder farm households in Malawi.” The first essay estimates the levels of technical efficiency of AIDS-affected and non-affected smallholder farm households, and examines the technical efficiency differentials. The study uses time-varying and timeinvariant inefficiency models of production. The results show that among both female and male headed households, for both affected and non-affected households, fertilizer and seeds are the only variables that contribute significantly towards technical efficiency. The mean efficiency levels of affected and non-affected households are statistically not different. The second essay examines the maize production differentials between AIDS-affected and nonaffected farm households using the difference in difference estimation method. The results show that, for both affected and non-affected households, the mean maize production levels are higher during 2006/07 compared to 2004/05 However, the difference between the mean maize production levels of affected and non-affected households over the 2004/05 and 2006/07 period is not statistically significant. The third essay examines the coping strategies used by households facing food security problems. The results from the multinomial logistic model show that during 2004/05 and 2006/07, the most dominant coping strategy used by both AIDS-affected and non-affected households facing food security problems, is buying food from market. This is followed by casual labour, obtaining food from relatives and friends, eating unripe maize before harvest, and irrigation farming. The results from logistic discriminant analysis function indicate that, for all households, ordinary coping strategies are dominant among food-insecure households with a total score of close to 80 percent, much higher than survival strategies at around 20 percent during 2004/05.
Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

Il est généralement reconnu, par la communauté́ scientifique, que le risque de morbidité́ augmente lors des vagues de chaleur. On retrouve néanmoins des différences importantes en ce qui a trait à la vulnérabilité́ des populations au stress thermique. L'effet de la température sur la morbidité́ diffère selon plusieurs facteurs, dont l’âge. Pour des raisons physiologiques et comportementales, les enfants sont l’un des groupes les plus vulnérables aux vagues de chaleur (Hutter et al., 2007; Thompson et al., 2012). La présente étude vise à analyser l’influence de la vulnérabilité́ différentielle face aux problèmes de santé chez les enfants lors des vagues de chaleur à Ouagadougou. L’analyse de la vulnérabilité́ aux risques environnementaux rend compte des conditions de fragilité́ des individus pouvant mener à des expériences de souffrance et de dépendance à autrui. Ceci influence conséquemment la capacité à faire face aux catastrophes et à se rétablir (Becerra, 2012; Muttarak et al., 2015). Les données utilisées ont été́ recueillies par l’Observatoire de Population de Ouagadougou (OPO) de mars à mai 2017 lors d’une enquête sur la vulnérabilité́ et la capacité d'adaptation de la population de l'OPO aux vagues de chaleur. Ces données transversales regroupent un sous-échantillon aléatoire de 332 enfants de cinq ans et moins, habitant dans cinq quartiers de la périphérie nord de Ouagadougou. Nous les analysons tout d’abord à l’aide de tableaux croisés, de tests de chi-2 et d’une analyse factorielle. Des régressions logistiques ordinales permettent ensuite d’étudier la force et la significativité des associations entre la prévalence des symptômes lors des vagues de chaleur et les variables associées à la vulnérabilité climatique. L’analyse permet de relever des associations inattendues entre la prévalence de certains symptômes chez l’enfant lors des vagues de chaleur et plusieurs variables indépendantes. Par exemple, lorsque nous étudions les effets bruts des variables indépendantes sur la variable dépendante, nous constatons que les enfants dont la mère n’a pas tendance à apporter de l’aide supplémentaire aux très jeunes enfants lors des périodes de très forte chaleur sont plus susceptibles de ne pas présenter de symptôme(s) que de présenter des symptômes (OR = 0,60* (0,36 ; 1,01), à la limite du significatif de 10%), comparativement aux enfants ayant une mère apportant de l’aide supplémentaire. Nous notons également que les enfants dont le toit de chambre est isolé ou construit avec du ciment / béton (dalle) sont plus susceptibles de manifester des symptômes lors des vagues de chaleur que de ne pas en manifester (OR = 1,68* (0,97 ; 2,91), à la limite du significatif de 10%), en comparaison aux enfants dont le toit de chambre est fait de tôle galvanisée / métal / fer-blanc / zinc. Néanmoins, ces résultats sont très faiblement significatifs (seuil de 10%) à partir d’un échantillon de petite taille. Ainsi, le fait que les résultats sont à la limite du significatif à 10% nous amène à interpréter de manière prudente l’existence des liens entre ces variables. Dans l’explication de ces résultats, nous soupçonnons la présence de biais dans l’auto-déclaration des symptômes. Les limites des données incluent l’auto-déclaration des symptômes, la petite taille de l’échantillon, la nature transversale des données ainsi que la présence de biais de rappel liée aux problèmes de mémoire. Compte tenu de ces limites méthodologiques, il serait nécessaire de confirmer les résultats obtenus dans de futures recherches. Néanmoins, ces résultats pourront contribuer à orienter de futures recherches sur l’effet des vagues de chaleur chez les enfants au Sahel.
It is generally recognized by the scientific community that the risk of morbidity increases during heatwaves. However, there are important differences in regard to the vulnerability of populations to increased temperatures. The effect of temperature on morbidity differs depending on several factors, including age. Children are one of the most vulnerable groups when it comes to heatwaves due to physiological and behavioral reasons (Hutter et al., 2007; Thompson et al., 2012). This study aims to analyze the influence of differential vulnerability on children’s health during heatwaves in Ouagadougou. The analysis of vulnerability on environmental risks takes into account the fragile conditions of individuals that can lead to experiences of suffering and dependence on others. Consequently, it influences the capacity to cope with and recover from disasters (Becerra, 2012; Muttarak et al., 2015). The data used were collected by the Ouagadougou Population Observatory (OPO) from March to May 2017 during a survey on the vulnerability and adaptability of the OPO population to heatwaves. The cross-sectional data brings together a random subsample of 332 children aged five and under, living in five neighborhoods in the northern outskirts of Ouagadougou. We first analyze them using crosstabs, chi-2 tests and factor analysis. Ordinal logistic regressions are then performed to study the strength and significance of the associations between the prevalence of symptoms during heatwaves and the variables associated with climatic vulnerability. Descriptive analysis reveals unexpected associations between the prevalence of certain symptoms in children during heatwaves and several independent variables. An in-depth analysis carried out with the use of ordinal logistic regressions shows that the results do not support our initial hypotheses. For example, when we study the gross effects of the independent variables on the dependent variable, we found that children with mothers who do not tend to provide extra help to very young children during intense periods of heat are more likely to be symptom-free than to have symptoms (OR = 0.60 * (0,36 ; 1,01), at the significant limit of 10%), compared to children with mothers who provide extra help. We also note that children whose room roof is insulated or built with cement / concrete (slab) are more likely to show symptoms during heat waves than to not show symptoms (OR = 1.68 * (0,97 ; 2,91), at the significant limit of 10%), compared to children whose room roof is made of galvanized sheet metal / metal / tinplate / zinc. Nevertheless, these results are very weakly significant (10% threshold) from a small sample size. Thus, the fact that the results are at the limit of significance at 10% leads us to interpret the existence of links between these variables cautiously. In an attempt to explain these results, we suspect that there is a bias in the self-reported symptoms. Data limitations include self-reporting of symptoms, small sample size, the cross-sectional nature of the data, and the presence of recall bias related to memory problems. Given these methodological limitations, it would be necessary to confirm our results with those obtained in future research. However, the results obtained may help guide future research about the effect of heatwaves on children’s health in Sahel.

Le présent projet doctoral a pour objectif d'évaluer l'effet des troubles de l'humeur et anxieux sur la sensibilité de certaines méthodes d'investigation cardiovasculaire, ainsi que sur la morbidité cardiaque et la mortalité générale. Plus spécifiquement, la présente thèse sert à évaluer l'impact des troubles anxieux sur les résultats d'examens diagnostiques de l'ischémie myocardique, obtenus à l'aide de deux méthodes d'investigation différentes. Elle permet également d'évaluer si la présence d'anxiété influence la performance des patients lors de leur test à l'effort, ainsi que la réactivité cardiovasculaire de ces patients en réponse à l'activité physique. Dans un deuxième temps, cette thèse a pour but l'examen des relations prospectives des troubles de l'humeur et des troubles anxieux avec l'occurrence des événements cardiovasculaires majeurs et avec la mortalité générale. De façon à mettre en contexte et à rendre compte du travail effectué et des résultats obtenus, la thèse est divisée en cinq chapitres. Le premier chapitre sert à situer le lecteur par rapport à la problématique relative aux maladies cardiovasculaires et à faire état des résultats antérieurement rapportés, pertinents aux objectifs de recherche. Les limites attribuables à ces études antérieures, les objectifs, ainsi que les hypothèses de la thèse y sont également exposés. Le deuxième chapitre relate quant à lui les méthodologies exhaustives utilisées aux fins des deux études dont il est par la suite question aux chapitres trois et quatre. Finalement, une discussion générale concernant les principaux résultats de la thèse, les implications cliniques associées, les forces et faiblesses des deux études effectuées, l'état des connaissances quant au traitement des troubles de l'humeur et anxieux chez les patients cardiaques et des pistes de recherches futures constituent le cinquième et dernier chapitre. De façon globale, les résultats exposés dans le premier article indiquent que la présence des troubles anxieux, lors de l'ajustement du modèle statistique en fonction des troubles de l'humeur, n'influencerait pas le dépistage de l'ischémie myocardique à l'aide de l'ECG. Aussi, les patients anxieux performeraient de façon équivalente aux patients sans trouble d'anxiété lors du test à l'effort. Les troubles anxieux seraient toutefois associés à une réactivité cardiovasculaire amoindrie et ce, même lors de l'ajustement du modèle en fonction de la présence des troubles de l'humeur. Considérés de façon globale, les résultats antérieurement présentés par notre équipe, ainsi que ceux présentés de la cadre du premier article permettent de penser que les pratiques de référence des patients à des fins d'investigation cardiovasculaire devraient être adaptées en fonction de la présence des troubles de l'humeur chez les patients concernés, alors que la présence des troubles anxieux importerait peu. Ils suggèrent également que les troubles anxieux seraient associés à un dérèglement au niveau du système nerveux autonome. Les intervenants médicaux devraient donc considérer à la fois le traitement des atteintes psychiatriques et autonomes lors du choix des méthodes d'intervention curatives et/ou préventives au niveau cardiovasculaire. Quant aux résultats rapportés dans le cadre du deuxième article, ils suggèrent de façon générale que les patients présentant un trouble de l'humeur seraient significativement plus à risques de mortalité au cours des neuf années suivant leur évaluation psychiatrique, que les patients non dépressifs au niveau de base. De plus, les troubles de l'humeur seraient particulièrement nocifs pour les patients sans MCV au niveau de base, puisqu'ils augmenteraient leurs risques de mortalité générale de plus de quatre fois et ce, indépendamment de la présence des troubles anxieux et d'autres importants facteurs de risques non traditionnels des maladies chroniques telles que le cancer et les MCV. De leur côté, les troubles anxieux considérés en ajustant le modèle d'analyse en fonction des troubles de l'humeur ne constitueraient pas un facteur de risque significatif quant à l'incidence de la mortalité et ce, peu importe le statut cardiaque des patients. Ceci suggère que le dépistage et la prise en charge des troubles de l'humeur, plutôt que des troubles anxieux, doivent impérativement être améliorés et faire partie intégrante des pratiques médicales en contexte de soins primaires et tertiaires. Ainsi, à la fois les professionnels médicaux et les professionnels de la santé mentale se doivent de travailler de façon conjointe afin d'être en mesure d'identifier les patients présentant un risque médical élevé et surtout, afin d'être en mesure de fournir à ces patients les services préventifs et curatifs appropriés. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Troubles de l'humeur, Troubles anxieux, Dépistage, Ischémie myocardique, ECG, SPECT, Morbidité cardiovasculaire, Mortalité, Maladie coronarienne artérielle