Dissertations / Theses on the topic 'Rapid Diagnostic Tests (RDTs)'

<p> <b>Introduction:</b> The Home-based Management of Malaria (HMM) is a cornerstone of malaria control in sub-Saharan Africa (SSA) and is recommended by WHO to provide prompt access to antimalarial treatment for children in under-served areas. Although HMM has been shown to reduce malaria morbidity and mortality with chloroquine, it has not been examined previously in the era of artemisinin-based combination therapies. The objectives of this study were to determine whether HMM reduced: 1] the time from when a mother or guardian realized her child was ill to the time when the child was brought for treatment and 2] malaria morbidity in children less than 5 years of age.</p><p> <b>Methodology:</b> This cross-sectional retrospective study (2008-2014) was performed in intervention villages (receiving HMM) and control villages (not receiving HMM) to examine the effectiveness of HMM.</p><p> <b>Key Results:</b> More mothers and guardians were informed about the malaria control activities performed (98% vs. 24%) in intervention than control villages (<i>p</i> &lt; 0.001). Consistent with that result, mothers and guardians in intervention villages sought care for their sick children earlier than mothers in control villages (<i>p</i> &lt; 0.001) and were more likely to obtain treatment from community health workers (CHWs) in their home villages. In contrast, more children were referred for malaria treatment to health posts and health centers from control than intervention villages (<i>p</i> &lt; 0.001). Likewise, more children with complicated malaria were referred for treatment from control villages (<i>p</i> &lt; 0.001), although those conclusions were limited by the small numbers of complicated (severe) malaria cases.</p><p> <b>Conclusions:</b> These results indicate HMM shortens the time mothers wait before taking their children to receive treatment. Because more children with uncomplicated or complicated malaria are referred for treatment from control than intervention villages, these results indicate that the availability of HMM treatment in the child&rsquo;s home village reduces morbidity (the risk of severe malarial disease). However, additional studies with larger numbers of subjects will be necessary to determine if HMM reduces mortality. </p>

Les tests de diagnostic rapide (TDR) sont aujourd’hui des outils indispensables pour une réponse urgente en pathologie infectieuse. De nombreux tests sont disponibles pour rechercher différents agents pathogènes (VIH, streptocoque du groupe A, plasmodium …) dans des prélèvements biologiques variés (urine, liquide cérébrospinal ou LCS, sang …). L’avantage de ce mode de diagnostic est leur rapidité, leur simplicité de mise en œuvre, y compris par des non-spécialistes ou à l’extérieur d’une structure de laboratoire, et leur coût raisonnable. Dans ce travail de thèse CIFRE, nous présentons trois TDR que nous avons contribué à développer et à évaluer, basés sur l’immunochromatographie à flux latéral (LFIA). Le premier TDR cible Neisseria meningitidis dans le LCS, bactérie responsable de redoutables épidémies de méningites dans les pays à ressources limitées. Ce TDR est le seul test commercial de type LFIA qui permette de détecter 5 des 6 principaux sérogroupes impliqués dans la maladie (A/C/W/X/Y). Une étude publiée sous l’égide du CNR des méningocoques à l’Institut Pasteur de Paris montre les excellentes performances de ce test sur près de 560 échantillons de LCS provenant de 6 pays. Le deuxième TDR cible Streptococcus pneumoniae dans l’urine et le LCS, également dans le cadre du diagnostic des méningites bactériennes. Ce test, couplé au précédent, fait l’objet d’une étude multicentrique en Afrique de l’ouest sous couvert de l’OMS. Le troisième TDR est un avatar du précédent dédié aux sécrétions respiratoires. Dénommé PneumoResp, il introduit le concept de TDR semi-quantitatif en proposant d’effectuer le test sur sécrétions non diluées et, en cas de résultat positif, sur sécrétions diluées au 1 :100ème. Nous proposons un algorithme (qui fait l’objet d’un brevet en cours d’expertise) qui vise à différencier le portage de l’infection invasive à S. pneumoniae chez l’enfant. Par rapport aux techniques conventionnelles (culture semi-quantitative et qPCR), nous montrons sur quelque 200 échantillons respiratoires une excellente sensibilité et une très bonne valeur prédictive négative de ce test pour exclure ou suspecter une infection active à S. pneumoniae chez l’enfant dès le premier jour<br>Nowadays, Rapid Diagnostic Tests (RDTs) are essential tools for an urgent response in infectious diseases. Many tests are available to search for different pathogens (HIV, group A streptococcus, plasmodium ...) in various biological samples (urine, cerebrospinal fluid or CSF, blood ...). The main advantages of this mode of diagnosis are speed, simplicity of implementation, including by non-specialists or outside a laboratory structure, and reasonable cost. In this “CIFRE” (industrial) thesis, we present three RDTs based on lateral flow immunochromatography (LFIA) that we contributed to develop and evaluate.The first TDR targets Neisseria meningitidis, a bacterium responsible for severe outbreaks of meningitis in resource-limited countries, in CSF samples. This RDT is the only LFIA-type commercial test that can detect 5 of the 6 major serogroups involved in the disease (A/C/W/X/Y). A study published under the authority of the meningococci reference centre at the Institut Pasteur of Paris showed the excellent performances of this test on nearly 560 CSF samples collected from 6 countries including 5 in Africa.The second TDR targets Streptococcus pneumoniae in urine and CSF; it is also intended to the diagnosis of bacterial meningitis. This test, coupled with the previous one, is the object of a multicentric study presently conducted in West Africa under cover of WHO.The third TDR is an avatar of the previous one but was dedicated to respiratory secretions. Called PneumoResp, it introduces the concept of semi-quantitative RDT. It proposes to perform the test on undiluted secretions and, in the case of positive result, on 1:100-diluted secretions. We present an algorithm (which is the object of a patent pending appraisal) that aims to differentiate S. pneumoniae carriage from invasive infection by this germ in children. Compared to conventional techniques (semi-quantitative culture and qPCR assays), the test performed on 196 respiratory specimens showed an excellent sensitivity and a very good negative predictive value, allowing to exclude or suspect an active S. pneumoniae infection as soon as the first day

Diagnosis of schistosomiasis is still widely reliant on traditional parasitological methods, i.e. the Kato-Katz faecal smear for Schistosoma mansoni and urine filtration for S. haematobium. Since these methods are insensitive, relatively laborious and expensive to perform, much effort has been expended into developing alternative ways of diagnosing the disease. Antibody-detection is the best method for diagnosis in areas of low endemicity. It has the merit of high sensitivity and is likely to be useful for schistosomiasis control as programmes are expanded and accelerated towards meeting the WHO's 2020 goals for neglected tropical diseases (NTDs). A rapid diagnostic test (RDT) for use at the point-of-care (POC) is much more likely to be useful in low-middle income countries than the current assays that are available for antibody-detection. Work has therefore begun towards developing such a test that incorporates S. mansoni cercarial transformation fluid (SmCTF) for the detection of anti -schistosome antibodies in human blood. Here it is demonstrated that SmCTF performs equivalently to S. mansoni soluble egg antigens (SmSEA) in an enzyme-linked immunosorbent assay (ELlSA) format for the detection of anti -So mansoni, anti-So haematobium and anti-So japonicum antibodies.

BACKGROUND: Timely diagnosis of influenza is important to administer appropriate antiviral therapy, institute proper infection control measures, and decrease ancillary test usage. While viral culture or reverse-transcriptase polymerase chain reaction (RT-PCR) are considered the most accurate diagnostic tests, a vast array of rapid influenza diagnostic tests (RIDTs) is available and could potentially impact patient management at the point-of-care. OBJECTIVE: To summarize, using meta-analysis, available evidence on the diagnostic accuracy of RIDTs compared to a reference standard in adults and children with influenza-like illness and to evaluate patient and test factors associated with higher accuracy.METHODS: Four databases (MEDLINE, EMBASE, Biosis, Web of Science) were searched up to and including September 2010 for studies on RIDTs' accuracy compared to a reference standard of either RT-PCR (first choice) or viral culture. Sensitivity and specificity were pooled using a bivariate random effects regression model and investigation of heterogeneity was done using subgroup analyses and meta-regression using an extension of the summary receiver operating characteristic curve (SROC) model. RESULTS: A total of 100 articles, comprising 127 studies were identified. The pooled sensitivity of all RIDTs was 64.5% (95% CI: 60.6, 68.6), while the pooled specificity was 98.1% (95% CI: 97.3, 98.6). Sensitivity estimates were highly heterogeneous. Some of this heterogeneity was explained by significantly higher sensitivity in children (71.1%, 95% CI: 65.6, 76.1) than in adults (51.6%, 95% CI: 43.9, 59.1). Virus type also accounted for some of the heterogeneity in sensitivity (68.0%, 95% CI: 62.3, 73.1, for influenza A versus 51.8%, 95% CI: 42.8, 60.6, for influenza B) as well as the circulating strain of influenza A (56.9%, 95% CI: 50.9, 62.6, for influenza A/H1N1/2009 versus 72.8%, 95% CI: 65.9-78.8, for other seasonal influenza A strains). Finally, RIDTs performed better when compared against culture as the reference standard (sensitivity of 71.0%, 95% CI: 65.9, 75.6) than when compared against RT-PCR (sensitivity of 56.0%, 95% CI: 49.7, 62.1). Few studies reported duration of symptoms before testing, but studies that did showed a trend toward better accuracy at 24-48h with a rapid decline thereafter. When a meta-regression was conducted including several study-level covariates, only age remained significant with a relative diagnostic odds ratio (RDOR) of 2.67 (95% CI: 1.17, 6.11) for children versus adults.CONCLUSION: RIDTs have modest sensitivity and high specificity, but heterogeneity in sensitivity is a concern. While they are more accurate in children than adults, and for influenza A compared to influenza B, these factors do not completely explain the heterogeneity in sensitivity. Because of their high specificity, RIDTs may be useful to rule in influenza. However, a negative test cannot be used to rule out influenza and should be confirmed by one of the reference standard tests. Further work is needed to summarize the clinical impact of RIDTs on patient management and patient-important outcomes.<br>INTRODUCTION: Poser rapidement le diagnostic d'influenza permet d'administrer une thérapie antivirale appropriée, de débuter en temps opportun des mesures de prévention des infections et de diminuer le recours à d'autres tests diagnostiques. Bien que la culture virale et le RT-PCR demeurent les outils diagnostiques les plus fiables, il existe une vaste gamme de tests de diagnostic rapide de l'influenza (TDRI) pouvant potentiellement avoir un impact sur la prise en charge des patients. OBJECTIFS: Résumer, par le biais d'une méta-analyse, l'ensemble des données disponibles sur la sensibilité et la spécificité des TDRIs comparés à un test de référence, chez les adultes et les enfants souffrant d'un syndrome d'allure grippal, ainsi qu'évaluer les facteurs liés au test ou au patient qui sont associés à une plus grande fiabilité. MÉTHODES: Nous avons cherché à travers quatre bases de données (PubMed, EMBASE, Biosis, Web of Science), jusqu'en septembre 2010, pour des études sur la fiabilité des TDRIs comparés au RT-PCR (1er choix) ou à la culture virale. Nous avons méta-analysé la sensibilité et spécificité des TDRIs au moyen d'un bivariate random effect regression model et tenté d'expliquer l'hétérogénéité des résultats au moyen d'analyses de sous-groupes et d'une méta-régression, via une extension du modèle SROC (summary receiver operating characteristic curve).RÉSULTATS: Nous avons identifiés 100 articles, comprenant 127 études. La sensibilité globale des TDRIs était de 64.5% (95% CI: 60.6, 68.6), alors que leur spécificité globale était de 98.1% (95% CI: 97.3, 98.6). Par contre, on a retrouvé une grande hétérogénéité au niveau de la sensibilité. Une partie de cette hétérogénéité pourrait être expliquée par une sensibilité significativement plus élevée lorsque le test est utilisé chez les enfants (71.1%, 95% CI: 65.6, 76.1) plutôt que chez les adultes (51.6%, 95% CI: 43.9, 59.1). La sensibilité des TDRIs variait également en fonction du type de virus (68.0%, 95% CI: 62.3, 73.1, pour l'influenza A versus 51.8%, 95% CI: 42.8, 60.6, pour l'influenza B) ainsi que de la souche d'influenza A en circulation (56.9%, 95% CI: 50.9, 62.6, pour l'influenza A/H1N1/2009 versus 72.8%, 95% CI: 65.9-78.8, pour les autres souches saisonnières d'influenza A). Finalement, les TDRIs affichaient une meilleure performance lorsque comparés à la culture virale (sensibilité: 71.0%, 95% CI: 65.9, 75.6) plutôt qu'au RT-PCR (sensibilité: 56.0%, 95% CI: 49.7, 62.1). Peu d'études ont évalué l'effet de la durée des symptômes sur la fiabilité des TDRIs, mais les quelques études qui se sont penchées sur le sujet tendaient à démontrer une meilleure sensibilité 24-48h après le début des symptômes suivi d'un déclin rapide. Lorsque plusieurs de ces variables furent analysées en même temps, au moyen d'une méta-régression, seulement l'âge est demeuré significativement associé à la fiabilité des TDRIs, avec un rapport de cotes diagnostiques de 2.67 (95% CI: 1.17, 6.11) pour les enfants versus les adultes.CONCLUSION: Les TDRIs ont une sensibilité modeste et une bonne spécificité, mais une grande hétérogénéité au niveau de la sensibilité demeure une préoccupation. Bien que les TDRIs soient plus fiables chez les enfants que chez les adultes et pour détecter l'influenza A versus l'influenza B, ces facteurs ne suffisent pas à expliquer l'hétérogénéité notée au niveau de la sensibilité. Puisqu'ils sont très spécifiques, les TDRIs sont utiles pour confirmer le diagnostic d'influenza. Cependant, un TDRI négatif n'est pas suffisant pour infirmer le diagnostic d'influenza et devrait être confirmé au moyen d'un des tests de référence. D'autres études sont nécessaires pour résumer l'impact clinique des TDRIs sur la prise en charge des patients.

Malaria represents one of the oldest documented diseases among humans and even today organisms in the genus Plasmodium kill more people than any other infectious disease, especially in tropical and subtropical areas. The four most common species which infect humans are Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malaria. Of these four species, Plasmodium falciparum and Plasmodium vivax account for 95 percent of infections globally. Microscopy has been used since early days for the diagnosis of malaria because this method is simple, does not require highly equipped facilities, and in most cases enables differentiation among the species causing malaria in humans when performed by skilled microscopy readers. However, this method has been misleading in identifying parasite species, especially in the case of low level parasitemia, a mixed parasite infection, or modification by drug treatment as well as in placental malaria. Malaria rapid diagnostic tests (RDT) have played a major role in malaria management; particularly in providing blood based diagnosis in remote locations where microscopy based diagnosis is unavailable. These diagnostic tests are fast and easy to perform and do not require electricity or specific equipment. As part of strengthening malaria diagnostics in Malawi, the Ministry of Health and Population strongly recommends the use of malaria RDT’s at all levels of the health care delivery system. However, malaria microscopy remains a gold standard test for malaria. All patients (regardless of age) with suspected uncomplicated malaria should have a confirmed diagnosis with malaria RDT before anti-malaria treatment is administered. Based on field performance evaluations that assessed performance, quality control and production capacities of the manufacturing companies of malaria RDT’s, the Ministry of Health and Population recommended two brands of Histidine Rich Protein 2 (HRP-2), RDT’s for use in Malawi. These are SD Bioline malaria Ag Pf and the New Paracheck malaria Ag Pf. All these RDT’s are able to detect only P. falciparum. However, other species have been reported to exist in the country and there is a need to find proper RDT’s which will be able to detect all other species including P. falciparum. The main aim of this study was to evaluate Paramax-3 Pf/Pv/Pan RDT (Zephyr Biomedicals, India), if used in Malawi, could be able to detect and identify the different species of Plasmodium causing malaria in Malawi. The study recruited a total of 250 adult and infants at Bwaila Hospital in Lilongwe, Malawi. Study results showed that the overall sensitivity and specificity of the Paramax-3 RDT used in the study were 100 percent and 83 percent respectively. However, it was observed that the RDT test was not able to identify the P. ovale, and in some cases, the RDT test was positive for P. falciparum when the PCR identified the species as P. ovale. No P. vivax was detected both by RDT and PCR. This study was able to detect and identify the presence of P. malaria and P. ovale in Malawi apart from the P. falciparum. There were no significant differences between microscopy results compared to both the RDT and the PCR, with 94 percent and 98 percent sensitivities of R1 and R2 compared to RDT, as well as 94 percent and 96 percent sensitivities for R1 and R2 compared to PCR respectively. Both R1 and R2 had low specificities for example, R1 had 72 percent and R2 had 80 percent compared to RDT. Comparing R1 and R2 to PCR, the sensitivities were 64.9 percent and 67.2 percent respectively. However, the readers had difficulties differentiating the different species microscopically. The history of anti-malaria treatment had no significant effect on the outcome of the results in both the RDT and PCR.

Introduction We know that translating new knowledge from research into change in health care delivery is not a simple process. This thesis examines this process for a new technology applied to primary health care in tropical countries: including RDTs in clinical guidelines for treating fever in children Method The thesis examines the question: ―does implementing policy of using RDTs to target treatment instead of presumptive treatment of fever result in better quality patient care under experimental conditions as well as in routine practice?‖ Three methodological approaches are used to delineate translation to change in the field. A Cochrane review of randomised trials examines effects on quality of care in a trial, where delivery conditions are usually optimal. An analysis of a dataset from an effectiveness trial from Uganda examines effects of the policy on quality of care delivered within the context of a trial through routine health services. And third, a survey of current practice assesses implementation of an RDT-based guideline when it is introduced into the health system for routine use in selected districts. Across all three components, the thesis examines implementation of the guideline. In addition, both the systematic review and the effectiveness trial measure effects of the intervention on prescribing of antimalarials and antibiotics, and clinical outcomes (primary outcomes).The effectiveness trial evaluates effects of the policy on incremental cost, and the survey of current practice also assesses adequacy of essential health systems inputs and support services. Results The systematic review showed that HWs prescribed antimalarials to as many as 40% to 80% of cases with negative RDTs under experimental conditions. Use of RDTs was associated with 29% decline in prescribing of antimalarial drugs. Prescribing of antibiotics did not change in one trial but increased by 19% in another. Data from the effectiveness trial show that HWs used RDTs and adhered to RDT results almost all the time. This reduced antimalarials usage by 60.2% (high), 48.9% (medium) and by 22.1% (low). The data show no significant change in usage of antibiotics. Both the review and the pragmatic trial detected no significant difference in clinical outcomes between RDT and clinical diagnosis arms. Data from the effectiveness trial shows that use of RDTs is associated with a cost-saving of US$ 0.50 per case of fever (24.5% decline) in low transmission setting, and a cost-saving of US$ 0.33 per case of fever (17.7% decline) in medium transmission. Use of RDTs did not lead to a significant change in cost in high transmission settings: US$ +0.02 (95% CI: US$ -0.97 to US$+1.06). Cost-savings were accrued exclusively in older children and adults. The survey found inadequate implementation of all components of the guideline in both districts. Essential supplies, equipment and in-service training were inadequate in both districts. Discussion and conclusion Antimalarial use is lower when RDTs are used to guide treatment of fever instead of presumptive treatment. This results in savings from drugs costs in older children and adults with fever in low and medium transmission areas. This research does not confirm whether or not use of RDT-based guidelines has any effects on usage of antibiotics or clinical outcomes. A case study of Uganda shows that when delivered through routine services, none of the components of an RDT-based guideline is implemented to acceptable standards. There is insufficient evidence to suggest that the policy is superior to presumptive treatment of fever in terms of clinical outcomes. However, it can save money for medicines in low and medium transmission settings if its use is restricted to older children and adults.

Le paludisme est un problème de santé public dans de nombreux pays. Cinq espèces infectent l'homme : P. falciparum, responsable de la grande majorité des décès, et P. vivax, P. ovale, P. malariae et P. knowlesi qui provoquent des formes bénignes de la maladie. Le diagnostic qui fait partie des moyens de lutte, est une urgence médicale. Les tests de diagnostic rapides (TDRs) dont l'usage est recommandés par l'OMS, sont donc de plus en plus employés. Cependant, la détection et l'identification des espèces non P. falciparum par ces tests est insuffisante. Le besoin en nouveaux couples « antigènes-anticorps » est une nécessité pour améliorer les TDRs. Au cours de ce travail, de nouveaux anticorps anti LDH de P.malariae ont été produits.Une recherche de nouveaux antigènes a également été entreprise. Pour cela, certaines enzymes de la voie de la glycolyse ont été étudiées. Pour la première fois des séquences des enzymes de cette voie ont été obtenues pour P. ovale et P. malariae. Elles ont permis de déterminer de nombreux épitopes cibles potentiels spécifiques et ceux communs à toutes les espèces. Dans un deuxième temps, une recherche en protéomique a été menée pour identifier des biomarqueurs parasitaires. L'étude du culot globulaire et du plasma de patients infectés a permis la sélection de 8 protéines cibles originales. Ces travaux préparent la fabrication et la commercialisation par la société Whidiag d'une nouvelle génération de TDRs pour le paludisme<br>Malaria is a public health problem in many countries. Five species infect humans: P. falciparum, responsible for the vast majority of deaths, and P. vivax, P. ovale, P. malariae and P. knowlesi causing mild forms of the disease. The diagnostic is a means of control and a medical emergency. The rapid diagnostic tests (RDT) whose are recommended by WHO, are increasingly used. However, the detection and identification of not P. falciparum species is insufficient. New "antigen-antibody" couples are a need to improve the RDTs performance. In this work, new anti LDH antibodies from P. malariae were produced. A search for new antigens was also undertaken. For this purpose, some enzyme of glycolysis pathway were studied. For the first time the sequences of the enzymes from this pathway were obtained for P. ovale and P. malariae. We identified many potential target epitopes specific and common to all those species. In a second step, a proteomics approches has been conducted to identify parasites biomarkers. The study of red blood cells and plasma of infected patients has led to the selection of 8 original target proteins. This work prepares the manufacturing and marketing of a new generation of RDTs for malaria by the company Whidiag

Decreased amyloid-ß42 (Aß42), increased total tau (t-tau) and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) reflect histopathological core changes in the most common dementia disorder, Alzheimer’s disease (AD). They discriminate AD from healthy controls and predict conversion to AD with a relatively high accuracy. Memantine, an uncompetitive NMDA-receptor antagonist, is indicated for symptomatic treatment of AD. The first aim of this thesis was to investigate effects of memantine on CSF concentrations of Aβ42, tau and p-tau. Secondly, the aim was to explore the relation between these CSF biomarkers and retention of the amyloid biomarker Pittsburgh compound B using positron emission tomography (PIB PET), regional glucose metabolism measured with 18Fluoro-2-deoxy-d-glucose (FDG) PET and neuropsychological test performance. The third aim was to investigate their possible utility as predictors of future rate of AD dementia deterioration. All patients in the studies were recruited from the Memory Clinic, Uppsala University Hospital. In study I CSF p-tau concentrations in 11 AD patients were reduced after twelve months treatment with memantine, indicating that this compound may affect a key pathological process in AD. Results from study II showed that the concentrations of CSF Aß42 are lower in PIB+ patients than in PIB- patients, and that the PIB retention was stable during 12 months. In study III 10 patients with the diagnoses AD (6 PIB+/4 PIB-) and 8 subjects (1 PIB+/7 PIB-) with frontotemporal dementia were included. PIB+ patients had lower psychomotor speed measured by performance on the Trail Making Test A and impaired visual episodic memory compared to the PIB- patients. The initial clinical diagnoses were changed in 33% of the patients (6/18) during follow-up. Study IV is the first-ever report of an association between high CSF tau and dying in severe dementia. These 196 AD patients were followed up to nine years after baseline lumbar puncture. Moreover, CSF t-tau concentrations above median was associated with an increased risk of rapid cognitive decline (OR 3.31 (95% CI 1.53-7.16), independently of baseline functional stage. Thus, a clear association between high levels of CSF t-tau and p-tau and a more aggressive course of the disease was shown.

Includes bibliographical references (p. 253-265)<br>This study seeks to use the techniques of cost-effectiveness analysis to evaluate, within the context of effective vector control, the change to artemisinin-based combination therapies (ACTs) as first line malaria treatment and to evaluate the relevance of using definitive diagnosis (as opposed to clinical diagnosis) as the basis for initiating malaria treatment, especially when using ACTs for treatment. The cost-effectiveness of ACTs was evaluated in two study sites (i.e. In Kwazulu Natal which switched from SP monotherapy to AL in 2001 and in Mpumalanga which changed from SP monotherapy to AS+SP in 2003) in South Africa. The economic evaluation of use of routine definitive diagnosis as part of malaria case management, using rapid diagnostic tests (ROTs), was undertaken at two districts (Namaacha and Matutuine), in southern Mozambique, where routine use of ROTs and treating malaria patients with an ACT (using artesunate + SP) were implemented at pilot level in 2003.

La dengue est une maladie virale des régions tropicales et subtropicales, transmise par les moustiques du genre Aedes. Le virus de la dengue (DENV) appartient à la famille des Flaviviridae, genre Flavivirus. Si la plupart des infections sont asymptomatiques ou se traduisent par un syndrome fébrile sans gravité, le virus peut aussi causer une maladie plus sévère caractérisée par une fuite plasmatique, avec ou sans hémorragie. Sans prise en charge adéquate, les formes les plus sévères peuvent évoluer vers un syndrome de choc, potentiellement mortel. Il n’existe pas de traitement spécifique de la dengue mais une réhydratation adaptée et débutée précocement permet de réduire la survenue de formes sévères de la maladie. Malheureusement, les symptômes initiaux de la dengue avant la survenue des éventuelles complications ne sont pas spécifiques et seul un diagnostic biologique basé sur la détection du génome viral, de l’antigène NS1 ou des anticorps anti-DENV dans le sang des patients permet de confirmer la nature exacte de l’infection. La dengue constitue à l’heure actuelle un problème majeur de santé publique du fait de son expansion mondiale et de l’augmentation annuelle du nombre de cas sévères. Pour assurer la surveillance épidémiologique et le contrôle de la maladie, il est indispensable de développer des outils diagnostiques performants et faciles à mettre en œuvre, à la fois utilisables par les médecins de toutes les structures médicales, des simples centres de soins de santé primaire aux centres de référence, et utilisables lors d’enquêtes épidémiologiques pour l’investigation de nouvelles épidémies. Le travail de cette thèse a porté sur plusieurs aspects de cette problématique. Dans une première partie, un test commercial de diagnostic rapide (TDR) permettant la détection simultanée de la NS1 et des IgG et IgM anti-DENV, a été évalué, en laboratoire spécialisé et sur le terrain, afin de comparer, à partir des mêmes échantillons, les performances du test dans deux situations différentes. La sensibilité s’est révélée plus faible lors de l’utilisation sur le terrain que lors de l’utilisation en laboratoire de référence. La majorité des discordances a été observées pour la détection des IgG et des IgM. L’impact de la mise à disposition du test sur la prise en charge des patients a également été évalué et il s’est avéré qu’au cours de cette étude les pédiatres cambodgiens ont ignorés les résultats du test rapide et ont préféré suivre leur instinct clinique.Un second volet a porté sur la faisabilité d’utiliser les urines et la salive en remplacement du sang veineux pour les tests employés en routine pour le diagnostic de la dengue. Les urines et la salive sont des fluides biologiques plus faciles à prélever que le sang veineux ce qui présente un avantage majeur pour les enquêtes épidémiologiques mais peut également secourir les médecins lorsqu’un prélèvement de sang veineux est difficile à obtenir, par exemple chez les enfants. Bien que les performances des différentes méthodes de diagnostic ne soient pas aussi bonnes avec de l’urine et la salive qu’avec du plasma, les résultats obtenus par PCR en temps réel et avec les ELISAs de détection des anticorps anti-DENV démontrent l’intérêt potentiel de ces deux fluides biologiques pour détecter les infections par le DENV lorsqu’il est difficile d’obtenir du sang veineux. Plusieurs TDR commerciaux développés pour permettre la détection de la NS1 et des anticorps anti-DENV (IgM, IgG et IgA) dans les urines et la salive ont été évalués mais les performances obtenues se sont révélées peu satisfaisantes.Une dernière partie du travail a été consacrée à l’étude de la protéinurie comme marqueur pronostic potentiel de sévérité de la dengue. Ce marqueur biologique ne s’est pas révélé être utile pour diagnostiquer précocement les formes sévères de la maladie<br>Dengue is a viral disease transmitted by Aedes species mosquitoes, in tropical and subtropical regions. Dengue virus (DENV) belongs to the family Flaviviridae, genus Flavivirus. Although most DENV infections are asymptomatic or result in a self-limited febrile illness, severe diseases characterized by plasma leakage, with or without hemorrhage, can also occur. Patients with a severe dengue can rapidly progress into a life-threatening shock syndrome if no efficient clinical management is provided. There is no specific treatment available for dengue but an accurate and early fluid therapy substantially reduces the occurrence of severe forms of the disease. Dengue symptoms are typically non-specific until or unless complications develop. Only a biologic diagnosis based on DENV genome, NS1 antigen or anti-DENV antibodies detection enables to confirm dengue cases. Dengue is now a major public health problem due to both its geographical spread and the increase in the number of severe cases. New diagnostic tools are necessary to ensure epidemiological surveillance and control of the disease. These tools need to be effective and easy to use in every medical settings, from the smallest primary health centers to the biggest reference centers, and also usable for epidemiologic studies, e.g. for epidemic investigations. The work presented in this thesis was dedicated to this problematic.In a first part of the work, a rapid diagnostic test (RDT), designed to detect NS1 antigen, anti-DENV IgG and IgM, was evaluated, both in a specialized laboratory and in the field, in order to compare the test performances in two different settings, with the same samples. Interestingly, sensitivity was lower when the test was used in the field compared to the sensitivity of the test when performed in the specialized laboratory. Discordances were mainly observed for IgM and IgG detection. Impact of the use of the RDT on clinical management was also assessed during the field study and it revealed that Cambodian pediatricians ignored the results of the RDT and followed their clinical instinct.A second part of the work was dedicated to the assessment of the usefulness of urine and saliva for dengue diagnostic. Dengue diagnostic normally requires a venous blood sample that can be difficult to obtain in certain conditions such as in children or during epidemiological studies. Urine and saliva are easier to collect as the procedure is non-invasive. We showed that, although the performances of the different diagnostic methods were not as good in saliva and urine as in plasma specimens, the results obtained by qRT-PCR and by anti-DENV antibody ELISA could well justify the use of these two body fluids to detect dengue infection in situations when the collection of blood samples is difficult. Performances of commercial RDTs developed for NS1 and anti-DENV antibodies (IgM, IgG and IgA) detection in urine and saliva specimens were not satisfactory.In the last part of the thesis, the potential use of proteinuria as a prognostic marker of severity was assessed but it didn’t prove to be a useful marker for risk prediction

A prospective study was undertaken to assess the diagnostic value of various rapid diagnostic tests for tuberculosis in pleural fluid, and to assess the sensitivity and speed of a radiometric mycobacterial culture system (BACTEC, Johnson Laboratories). Patients presenting to the Department of Medicine at Groote Schuur Hospital with pleural effusions for diagnostic pleural aspiration and biopsy over a 6 month period were entered into the study. Because the incidence of tuberculous effusions was observed to be high in this population (65% of 94 patients), patients from the Department of Radiotherapy with proven malignant disease and the development of new pleural effusions requiring diagnostic or therapeutic aspiration were included in the study in order to increase the number of control patients without tuberculosis. The 111 patients (17 of whom were recruited from the Department of Radiotherapy) were divided into 4 diagnostic categories: tuberculosis - 62 patients, malignant - 28 patients, miscellaneous conditions - 10 patients, and undiagnosed - 11 patients (3 of whom probably had tuberculosis). There were 59 male patients. The racial distribution was 11 whites, 51 of mixed race, and 49 blacks. Exudative pleural effusions were present in 109 patients. Closed pleural biopsies with the Abrams needle were performed on 100 patients using a modified version of the standard technique whereby larger specimens were obtained by stripping pleura off the chest wall. Seven pleural biopsies were reported as inadequate by the pathologist and the diagnostic yield of the procedure was 63%. Tuberculosis was confirmed histologically or by culture in 62 patients. The age distribution of these patients was bimodal, with most cases occuring in the third decade. The presentation was usually acute, with 60% of patients being symptomatic for less than 4 weeks. Granulomata were found on initial pleural biopsy in 52 cases (84%). Pleural biopsy culture was positive in 44 cases (71%). The radiometric culture system tested (12B BACTEC) yielded the same number (14) of positive cultures as conventional mycobacterial culture media in pleural fluid, but was almost twice as fast. Bedside inoculation of pleural fluid into 13A BACTEC bottles more than doubled the yield in the 24 patients tested (11 positive cultures compared with 4 each for conventional and 12B BACTEC media, p=0.046). The rapid diagnostic tests assessed on pleural fluid were adenosine deaminase (ADA), an antigen (BCG) capture enzymelinked immunosorbent assay (ELISA), and a specific DNA probe after amplification with the polymerase chain reaction. ADA was found to have a sensitivity of 0.77 and a specificity of 0.83 in the 109 patients tested, and values were significantly higher in tuberculosis patients compared with the other three diagnostic categories (p< 0.001 ). The ELISA test was performed on 103 patients and showed a sensitivity of only 0.26 and a specificity of 0.72. The DNA probe was performed on 43 patients, and had a sensitivity of 0.93 with a specificity of 0.43. Contamination of samples or latent tuberculous infection may have been responsible for the poor specificity of the DNA probe.

Introduction – La place des tests de diagnostic rapide (TDR) et des règles de décision cliniques (RDC) pour le diagnostic des pharyngites à streptocoque du groupe A (SGA) chez l’enfant varie selon les recommandations internationales en raison de doutes sur la stabilité des performances diagnostiques du TDR et d’une validation insuffisante des RDC. Méthodes – Dans une étude prospective multicentrique (n=17) ambulatoire réalisée au sein du réseau clinique pédiatrique ACTIV de 2009 à 2011, 1776 enfants avec pharyngite ou sains ont été soumis à des prélèvements de gorge pour réaliser un TDR et une mise en culture (test de référence). Nous avons étudié l’effet indépendant de variables liées aux patients et aux médecins sur les performances diagnostiques du TDR, exploré systématiquement les faux-Positifs (FP) du TDR et réalisé une validation externe et une comparaison des RDC existantes. Résultats – La sensibilité du TDR (en moyenne 87%) variait selon la présentation clinique (âge, signes cliniques), l’inoculum bactérien et le phénomène de portage (paramètres aussi liés entre eux), et selon des variables liées aux médecins (dont le type d’activité clinique). La valeur prédictive négative du TDR était élevée (autour de 90%) et stable. Les FP du TDR étaient positifs pour le SGA en PCR. Aucune RDC n’était satisfaisante en termes de calibration et de discrimination. Conclusion – Le TDR est suffisant pour le diagnostic de pharyngite à SGA si les cliniciens évaluent leurs propres performances et les améliorent si besoin. Aucune RDC ne peut être recommandée en pratique clinique en pédiatrie<br>Background – The roles of rapid antigen detection tests (RADT) and clinical prediction rules (CPR) for the diagnosis of group A streptococcus (GAS) in children with pharyngitis vary across international clinical guidelines. This might be related to unstable diagnostic accuracy of RADTs and insufficient validation of CPRs. Methods – In a prospective multicenter (n=17) office-Based study that took place in France within the ACTIV network between 2009 and 2011, 1776 children with pharyngitis or healthy controls underwent throat swabs to perform a RADT and a throat culture (reference standard). We assessed the independent effect of patient- and physician-Level characteristics on the accuracy of a RADT, systematically re-Analyzed RADT false-Positive results, and externally validated and compared existing CPRs. Results – RADT sensitivity (overall 87%) varied according to clinical signs and symptoms, bacterial inoculum size and GAS throat carriage (factors also related to each other), and according to physician-Level characteristics (including type of clinical practice). RADT negative predictive value was high (about 90%) and stable. RADT false-Positives were positive for GAS when using a new PCR technique. No CPR had sufficient performances regarding calibration and discrimination. Conclusions – RADTs are sufficient for diagnosing GAS pharyngitis if clinicians accept diagnostic accuracy monitoring and adequate training when needed. No CPR can be recommended for use in pediatrics

Background and aims: Most respiratory tract infections (RTI) are self-limiting. Despite this, they are associated with high antibiotic prescription rates in general practice in Sweden. The aim of this thesis was to evaluate the management of respiratory tract infections (RTIs) with particular emphasis on acute otitis media (AOM). Methods: Paper I: A prospective, open, randomized study of 179 children presenting with AOM and performed in primary care. Paper II &amp; III: Study of 6 years data from primary care in Kalmar County on visits for RTI, retrieved from electronic patient records. Paper IV: Observational, clinical study of 71 children presenting with AOM complicated by perforation, without initial use of antibiotics. Results: Children with AOM who received PcV had some less pain, used fewer analgesics and consulted less, but the PcV treatment did not affect the recovery time or complication rate (I). Between 1999 and 2005, 240 445 visits for RTI were analyzed (II &amp; III). Antibiotics were prescribed in 45% of visits, mostly PcV (60%) and doxycycline (18%). Visiting rates for AOM and tonsillitis declined by &gt;10%/year, but prescription rates of antibiotics remained unchanged. For sore throat, 65% received antibiotics. Patients tested but without presence of S.pyogenes received antibiotics in 40% of cases. CRP was analyzed in 36% of consultations for RTI. At CRP&lt;50mg/l antibiotics, mostly doxycycline, were prescribed in 54% of visits for bronchitis. Roughly 50% of patients not tested received antibiotics over the years.Twelve of 71 children with AOM and spontaneous perforation completing the trial received antibiotics during the first nine days due to lack of improvement, one child after 16 days due to recurrent AOM and six had new incidents of AOM after 30 days (IV). Antibiotics were used more frequently when the eardrum appeared pulsating and secretion was purulent and abundant. All patients with presence of S.pyogenes received antibiotics. Results: Children with AOM who received PcV had some less pain, used fewer analgesics and consulted less, but the PcV treatment did not affect the recovery time or complication rate (I). Between 1999 and 2005, 240 445 visits for RTI were analyzed (II &amp; III). Antibiotics were prescribed in 45% of visits, mostly PcV (60%) and doxycycline (18%). Visiting rates for AOM and tonsillitis declined by &gt;10%/year, but prescription rates of antibiotics remained unchanged. For sore throat, 65% received antibiotics. Patients tested but without presence of S.pyogenes received antibiotics in 40% of cases. CRP was analyzed in 36% of consultations for RTI. At CRP&lt;50mg/l antibiotics, mostly doxycycline, were prescribed in 54% of visits for bronchitis. Roughly 50% of patients not tested received antibiotics over the years.Twelve of 71 children with AOM and spontaneous perforation completing the trial received antibiotics during the first nine days due to lack of improvement, one child after 16 days due to recurrent AOM and six had new incidents of AOM after 30 days (IV). Antibiotics were used more frequently when the eardrum appeared pulsating and secretion was purulent and abundant. All patients with presence of S.pyogenes received antibiotics.

acase@tulane.edu<br>Introduction: The Home-based Management of Malaria (HMM) is a cornerstone of malaria control in sub-Saharan Africa (SSA) and is recommended by WHO to provide prompt access to antimalarial treatment for children in under-served areas. Although HMM has been shown to reduce malaria morbidity and mortality with chloroquine, it has not been examined previously in the era of artemisinin-based combination therapies. The objectives of this study were to determine whether HMM reduced: 1] the time from when a mother or guardian realized her child was ill to the time when the child was brought for treatment and 2] malaria morbidity in children less than 5 years of age. Methodology: This cross-sectional retrospective study (2008-2014) was performed in intervention villages (receiving HMM) and control villages (not receiving HMM) to examine the effectiveness of HMM. Key Results: More mothers and guardians were informed about the malaria control activities performed (98% vs. 24%) in intervention than control villages (p < 0.001). Consistent with that result, mothers and guardians in intervention villages sought care for their sick children earlier than mothers in control villages (p < 0.001) and were more likely to obtain treatment from community health workers (CHWs) in their home villages. In contrast, more children were referred for malaria treatment to health posts and health centers from control than intervention villages (p < 0.001). Likewise, more children with complicated malaria were referred for treatment from control villages (p < 0.001), although those conclusions were limited by the small numbers of complicated (severe) malaria cases. Conclusions: These results indicate HMM shortens the time mothers wait before taking their children to receive treatment. Because more children with uncomplicated or complicated malaria are referred for treatment from control than intervention villages, these results indicate that the availability of HMM treatment in the child’s home village reduces morbidity (the risk of severe malarial disease). However, additional studies with larger numbers of subjects will be necessary to determine if HMM reduces mortality.<br>1<br>Ibrahima SECK

Yes<br>Background: Tuberculosis (TB) is the highest-mortality infectious disease in the world and the main cause of death related to antimicrobial resistance, yet its surveillance is still paper-based. Rifampicin-resistant TB (RR-TB) is an urgent public health crisis. The World Health Organization has, since 2010, endorsed a series of rapid diagnostic tests (RDTs) that enable rapid detection of drug-resistant strains and produce large volumes of data. In parallel, most high-burden countries have adopted connectivity solutions that allow linking of diagnostics, real-time capture, and shared repository of these test results. However, these connected diagnostics and readily available test results are not used to their full capacity, as we have yet to capitalize on fully understanding the relationship between test results and specific rpoB mutations to elucidate its potential application to real-time surveillance. Objective: We aimed to validate and analyze RDT data in detail, and propose the potential use of connected diagnostics and associated test results for real-time evaluation of RR-TB transmission. Methods: We selected 107 RR-TB strains harboring 34 unique rpoB mutations, including 30 within the rifampicin resistance–determining region (RRDR), from the Belgian Coordinated Collections of Microorganisms, Antwerp, Belgium. We subjected these strains to Xpert MTB/RIF, GenoType MTBDRplus v2.0, and Genoscholar NTM + MDRTB II, the results of which were validated against the strains’ available rpoB gene sequences. We determined the reproducibility of the results, analyzed and visualized the probe reactions, and proposed these for potential use in evaluating transmission. Results: The RDT probe reactions detected most RRDR mutations tested, although we found a few critical discrepancies between observed results and manufacturers’ claims. Based on published frequencies of probe reactions and RRDR mutations, we found specific probe reactions with high potential use in transmission studies: Xpert MTB/RIF probes A, Bdelayed, C, and Edelayed; Genotype MTBDRplus v2.0 WT2, WT5, and WT6; and Genoscholar NTM + MDRTB II S1 and S3. Inspection of probe reactions of disputed mutations may potentially resolve discordance between genotypic and phenotypic test results. Conclusions: We propose a novel approach for potential real-time detection of RR-TB transmission through fully using digitally linked TB diagnostics and shared repository of test results. To our knowledge, this is the first pragmatic and scalable work in response to the consensus of world-renowned TB experts in 2016 on the potential of diagnostic connectivity to accelerate efforts to eliminate TB. This is evidenced by the ability of our proposed approach to facilitate comparison of probe reactions between different RDTs used in the same setting. Integrating this proposed approach as a plug-in module to a connectivity platform will increase usefulness of connected TB diagnostics for RR-TB outbreak detection through real-time investigation of suspected RR-TB transmission cases based on epidemiologic linking.<br>KCN was supported by Erasmus Mundus Joint Doctorate Fellowship grant 2016-1346, and BCdJ, LR, and CJM were supported by European Research Council-INTERRUPTB starting grant 311725.

Os antineoplásicos do grupo das platinas são fármacos essenciais no tratamento da neoplasia do ovário e cólon, e o seu uso continuado/recorrente tem sido associado ao aumento global de reacções de hipersensibilidade (RHS). As RHS podem conduzir à suspensão de terapêuticas críticas, condicionando a sobrevivência de doentes oncológicos. Os testes cutâneos, considerados gold-standard na identificação de sensibilização às platinas, têm sido associados à ocorrência de reacções irritativas locais e risco de contaminação de profissionais de saúde. Investigámos assim o desempenho de testes diagnósticos in vitro/ex vivo que pudessem ser utilizados como complemento/alternativa aos testes cutâneos, em doentes com RHS a platinas. Demonstrámos que a determinação de IgE-específicas (IgE-esp) séricas para platinas é promissora não apenas no diagnóstico, como também na avaliação de reactividade cruzada entre as platinas. A maioria dos doentes sensibilizados à oxaliplatina tinha IgE-esp detectáveis não só para a oxaliplatina, mas também para a carboplatina e cisplatina, apresentando assim, provavelmente, maior risco de RHS a outras platinas. Mostrámos também a elevada sensibilidade do Teste de Activação de Basófilos no diagnóstico de RHS à oxaliplatina, quando utilizado o marcador de activação basofílica CD203c, não tendo o CD63 atingido significado estatístico. Demonstrámos ainda que, na ausência de alternativas terapêuticas igualmente eficazes, a dessensibilização rápida a platinas permite a sua reintrodução eficaz e segura, mesmo quando realizada totalmente em regime de ambulatório. Identificámos também que, na nossa série, níveis elevados de IgE total sérica estão associados de forma independente a maior risco de RHS durante a dessensibilização a platinas. Revelámos que a inclusão de montelucaste e ácido acetilsalicílico no plano de pré-medicação condicionou uma diminuição significativa da frequência e gravidade das RHS durante a dessensibilização a platinas. Na nossa série, a dessensibilização rápida não diminuiu a eficácia terapêutica dos antineoplásicos, não comprometendo assim a sobrevivência de doentes com doença oncológica metastática.<br>Platinum-based chemotherapy regimens remain the cornerstone in the management of ovarian and colon cancer. However, their sustained/recurrent use has led to increasing reports of hypersensitivity reactions (HSR) which may preclude their subsequent use, jeopardizing the overall survival of oncologic patients. Skin testing has been considered the gold standard to identify IgE sensitization to platins, despite the occurrence of local irritative reactions and potential hazard contamination of healthcare workers. We have investigated in vitro/ ex vivo diagnostic tools aimed to complement/substitute skin testing in the evaluation of patients with HSR to platins. We have shown that the quantification of platin-specific IgE (sIgE) in the serum can be used for both diagnosis and assessment of cross-reactivity between different platins. We observed that most oxaliplatin-sensitized patients had quantifiable sIgE, not only for oxaliplatin but also for carboplatin and cisplatin; these patients thus seem to be at higher risk of developing a reaction to other platins. We further found the basophil activation test to be highly sensitive in the diagnosis of HSR to oxaliplatin, when using basophil activation marker CD203c, in comparison with CD63. In addition, we have demonstrated that when no equally effective drugs are available, rapid drug desensitization (RDD) is an effective and safe alternative to maintain the platinum drug to which the patient has reacted, even when performed in an outpatient setting. We have also identified for the first time that, in our cohort, high levels of total serum IgE were independently associated with increased risk for breakthrough HSR during RDD to platins. xv Further, we have demonstrated that acetylsalicylic acid and montelukast were effective in decreasing the number and severity of breakthrough HSR during RDD to platins, when added as premedication. Importantly, we have shown that RDD allows maintained use of critical antineoplastic drugs, without signs of impaired drug efficacy, and thus with no decline of overall survival of oncologic patients.