Comment réduire l'incidence de listériose humaine? (Bilan de 30 ans de surveillance épidémiologique en France)

La surveillance de la listériose en France s est construite par étapes depuis les années 1980 sur deux piliers, la microbiologie et l épidémiologie. Grâce à la création du Centre National de Référence des Listeria et à la mise au point de techniques de typage performantes, l Institut Pasteur assure une surveillance microbiologique depuis 1987. Une surveillance épidémiologique initiée entre 1984 et 1992 par le Laboratoire National de la Santé, a été développée par le Réseau National de Santé Publique de 1993 à 1999, puis amplifiée par l Institut de Veille Sanitaire à partir de 2000. Le premier objectif de cette thèse est de décrire les différentes phases de la construction de cette surveillance afin d analyser leurs contributions respectives au cours de ces 30 dernières années. Cette construction s est faite en 4 phases : 1. L étape fondatrice de 1982 à 1992 a été la reconnaissance et la prise en compte du rôle des aliments dans la transmission de la maladie et dans la survenue d épidémies. 2. La deuxième phase de 1993 à 2000 a été l édification d un système de surveillance opérationnel pour détecter et investiguer les épidémies en France. 3. La troisième phase de 2000 à 2005 a permis de consolider le système de surveillance et de le perfectionner en ajoutant un volet complémentaire avec des prélèvements alimentaires.4. Depuis 2005, nous sommes dans la quatrième phase avec comme objectif l optimisation du système. Cette optimisation repose sur l adaptation des outils de surveillance et d alerte aux connaissances. Ainsi, après avoir montré que la durée d incubation de la maladie varie selon la forme clinique de la maladie, nous avons proposé d intégrer cette variation pour déterminer la période d évaluation des expositions alimentaires à risque. L analyse des performances du système a permis à deux reprises de proposer de nouveaux seuils de signalement plus spécifiques afin d optimiser cette surveillance tout en réduisant son coût. Le deuxième objectif de cette thèse est de montrer la contribution des données de surveillance à une politique de santé publique. Un premier travail a consisté à mettre en perspective les variations temporelles d incidence observées avec les différentes sources de données disponibles afin d en analyser les déterminants. La phase de décroissance de 1987 à 1997 a été concomitante des mesures de contrôles prises par l industrie agro-alimentaire et de la réduction de la contamination des aliments. La phase d augmentation en 2006-2007 semble multifactorielle. L augmentation de la prescription de traitements de réduction de l acidité gastrique par des inhibiteurs de la pompe à protons pourrait être l un des déterminants majeurs de cette augmentation.Dans une deuxième analyse, nous avons hiérarchisé les groupes à risque de listériose sur la base de l estimation du taux d incidence de listériose et de sa mortalité dans ces groupes. Cela a permis d identifier les groupes les plus vulnérables : hémopathies, certains cancers (digestifs, cérébral et pulmonaire), maladie de Horton, cirrhose hépatique, les dialysés rénaux, les greffés, et les femmes enceintes. Une analyse épidémiologique des listérioses materno-néonatales (MN) a montré une association entre les régions avec une incidence plus faible de listérioses materno-néonatales et les régions où la séroprévalence toxoplasmique des femmes enceintes est la plus faible, ce qui suggère un effet positif des recommandations contre la toxoplasmose pour la prévention de la listériose MN.Listeriosis surveillance was built up stage by stage in France since the 1980s on a twofold basis: microbiology and epidemiology. Thanks to the creation of the Listeria National Reference Centre (Centre National de Référence des Listeria), the Pasteur Institute has been doing microbiological surveillance since 1987. Epidemiological surveillance was initiated by the National Health Laboratory, then conducted by the National Health Network and further developed by the National Institute of Health Surveillance. This thesis aims first of all to describe the different stages in the setting up of this surveillance system in order to analyze their respective inputs during these last thirty years. The four stages are:1. From 1982 to 1992: awareness and recognition of the role of food in the transmission of listeriosis and as the source of outbreaks. 2. From 1993 to 2000: building a reliable surveillance system in order to detect and investigate outbreaks in France. 3. From 2000 to 2005: strengthening and perfecting the surveillance system by taking additional measures, such as food sampling.4. Since 2005, we have reached the fourth stage, designed to optimize the surveillance system. This optimization involves adapting surveillance and early warning tools to new knowledge and information. For instance, having established that listeriosis incubation periods vary according to the clinical form of the illness, we suggested the integration of the variation of exposure period factor when interviewing patients with the food questionnaire. On two separate occasions, analysis of the surveillance system performance results made it possible to modify the criteria for early warning so as to optimize surveillance by increasing its specificity whilst reducing costs.The second aim of this thesis is to illustrate how surveillance data can contribute to public health policies. A first study analyzed temporal trends, using all available data in order to give some explanation as to major trends. The first trend was a reduction of incidence from 1987 to 1997 that was concomitant with control measures by the food industry and a drop in food contamination. The increased trend observed in 2006-2007 appears to be due to several factors. The increased rate of sales of proton pump inhibitors medication could be the major factor in this increase. In a second study, we ranked groups at risk of acquiring listeriosis based on the incidence of listeriosis and its lethality in each group. This enabled us to identify the most vulnerable groups : hematological malignancy, some cancers (digestive, lung, and brain cancer), dialysis, cirrhosis, organ transplantation and pregnancy. Epidemiological analysis of listeriosis cases associated with pregnancy indicated an association between regions with low rate listeriosis associated with pregnancy and regions where toxoplasmosis prevalence of pregnant women is low. This suggests that recommendations for avoiding toxoplasmosis have a positive effect on preventing listeriosis during pregnancy.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

VEB-1 Extended-Spectrum β-lactamase–producing Acinetobacter baumannii, France1

VEB-1 extended-spectrum β-lactamase–producing Acinetobacter baumannii was responsible for an outbreak in hospitals in France. A national alert was triggered in September 2003 when 4 hospitals reported clusters of A. baumannii infection with similar susceptibility profiles. Case definitions and laboratory guidelines were disseminated, and prospective surveillance was implemented; strains were sent to a single laboratory for characterization and typing. From April 2003 through June 2004, 53 hospitals reported 290 cases of A. baumannii infection or colonization; 275 isolates were blaVEB-1-positive and clonally related. Cases were first reported in 5 districts of northern France, then in 10 other districts in 4 regions. Within a region, interhospital spread was associated with patient transfer. In northern France, investigation and control measures led to a reduction of reported cases after January 2004. The national alert enabled early control of new clusters, demonstrating the usefulness of early warning about antimicrobial drug resistance

Campylobacter infections in human : results of threeyears of surveillance 2001 - 2003

The frequency of Campylobacter infections in human, their potential severity, and the existence of preventive measures warrant the creation of a surveillance system. A Campylobacter surveillance system based on private laboratories (PL) was set up in France in 2002 to complement the hospital laboratory-based system(HL). Since 1 January 2001 (for HL), 1 April 2002 (for PL) and 31 December 2003, the Campylobacter National reference Centre analyzed 3 698 strains. Initially thought to be 3.4/100,000, the overall isolation rate was grossly underestimated, as the latest figure is 14/100,000 among children under 5 years old. The strains were mainly C. jejuni (76.9%), followed by C. coli (17.0%) and C. fetus (5.4%). Resistance rates were 41% for ampicillin and 28% for nalidixic acid. Surveillance must be maintained to collect more data on Campylobacter epidemiology in France and to estimate its incidence in the general population.La fréquence des infections humaines à Campylobacter, leur gravité potentielle et l'existence de mesures de prévention justifient une surveillance. En France, un système de surveillance des infections à Campylobacter a été mis en place en avril 2002, à partir des laboratoires de ville (LABM), en complément de celui du réseau des laboratoires hospitaliers (LH) existant depuis 1986. Entre le 1/01/01 (pour les LH), le 1/04/02 (pour les LABM) et le 31/12/03, le Centre National de Référence des Campylobacter a expertisé 3698 souches. Le taux global d'isolement de 3,4/100000 était très largement sous-estimé : il était de 14/100000 pour les enfants âgés de moins S ans. C. jejuni représentait 76,9% des souches, suivi de C. coli (17,0 %) et de C. fetus (5,4%). Le taux de résistance à l'ampicilline était de 41 % et à l'acide nalidixique de 28%. Les efforts pour la surveillance doivent être poursuivis, afin de mieux connaître les caractéristiques épidémiotogiques des infection à Campylobacter en France et de faire des estimations d'incidence en population générale

Studies Needed to Address Public Health Challenges of the 2009 H1N1 Influenza Pandemic: Insights from Modeling

In light of the 2009 influenza pandemic and potential future pandemics, Maria Van Kerkhove and colleagues anticipate six public health challenges and the data needed to support sound public health decision making.The authors acknowledge support from the Bill & Melinda Gates Foundation (MDVK, CF, NMF); Royal Society (CF); Medical Research Council (MDVK, CF, PJW, NMF); EU FP7 programme (NMF); UK Health Protection Agency (PJW); US National Institutes of Health Models of Infectious Disease Agent Study program through cooperative agreement 1U54GM088588 (ML); NIH Director's Pioneer Award, DP1-OD000490-01 (DS); EU FP7 grant EMPERIE 223498 (DS); the Wellcome Trust (DS); 3R01TW008246-01S1 from Fogerty International Center and RAPIDD program from Fogerty International Center with the Science & Technology Directorate, Department of Homeland Security (SR); and the Institut de Veille Sanitaire Sanitaire funded by the French Ministry of Health (J-CD). The funders played no role in the decision to submit the article or in its preparation

Campylobacter Antimicrobial Drug Resistance among Humans, Broiler Chickens, and Pigs, France

We describe isolates from human Campylobacter infection in the French population and the isolates' antimicrobial drug resistance patterns since 1986 and compare the trends with those of isolates from broiler chickens and pigs from 1999 to 2004. Among 5,685 human Campylobacter isolates, 76.2% were C. jejuni, 17.2% C. coli, and 5.0% C. fetus. Resistance to nalidixic acid increased from 8.2% in 1990 to 26.3% in 2004 (p<10-3), and resistance to ampicillin was high over time. Nalidixic acid resistance was greater for C. coli (21.3%) than for C. jejuni (14.9%, p<10-3). C. jejuni resistance to ciprofloxacin in broilers decreased from 31.7% in 2002 to 9.0% in 2004 (p = 0.02). The patterns of resistance to quinolones and fluoroquinolones were similar between 1999 and 2004 in human and broiler isolates for C. jejuni. These results suggest a potential benefit of a regulation policy limiting use of antimicrobial drugs in food animals

Introduction of SARS in France, March–April, 2003

We describe severe acute respiratory syndrome (SARS) in France. Patients meeting the World Health Organization definition of a suspected case underwent a clinical, radiologic, and biologic assessment at the closest university-affiliated infectious disease ward. Suspected cases were immediately reported to the Institut de Veille Sanitaire. Probable case-patients were isolated, their contacts quarantined at home, and were followed for 10 days after exposure. Five probable cases occurred from March through April 2003; four were confirmed as SARS coronavirus by reverse transcription–polymerase chain reaction, serologic testing, or both. The index case-patient (patient A), who had worked in the French hospital of Hanoi, Vietnam, was the most probable source of transmission for the three other confirmed cases; two had been exposed to patient A while on the Hanoi-Paris flight of March 22–23. Timely detection, isolation of probable cases, and quarantine of their contacts appear to have been effective in preventing the secondary spread of SARS in France

Studies Needed to Address Public Health Challenges of the 2009 H1N1 Influenza Pandemic: Insights from Modeling

In light of the 2009 influenza pandemic and potential future pandemics, Maria Van Kerkhove and colleagues anticipate six public health challenges and the data needed to support sound public health decision making

A national cross-sectional study among drug-users in France: epidemiology of HCV and highlight on practical and statistical aspects of the design

<p>Abstract</p> <p>Background</p> <p>Epidemiology of HCV infection among drug users (DUs) has been widely studied. Prevalence and sociobehavioural data among DUs are therefore available in most countries but no study has taken into account in the sampling weights one important aspect of the way of life of DUs, namely that they can use one or more specialized services during the study period. In 2004–2005, we conducted a national seroepidemiologic survey of DUs, based on a random sampling design using the Generalised Weight Share Method (GWSM) and on blood testing.</p> <p>Methods</p> <p>A cross-sectional multicenter survey was done among DUs having injected or snorted drugs at least once in their life. We conducted a two stage random survey of DUs selected to represent the diversity of drug use. The fact that DUs can use more than one structure during the study period has an impact on their inclusion probabilities. To calculate a correct sampling weight, we used the GWSM. A sociobehavioral questionnaire was administered by interviewers. Selected DUs were asked to self-collect a fingerprick blood sample on blotting paper.</p> <p>Results</p> <p>Of all DUs selected, 1462 (75%) accepted to participate. HCV seroprevalence was 59.8% [95% CI: 50.7–68.3]. Of DUs under 30 years, 28% were HCV seropositive. Of HCV-infected DUs, 27% were unaware of their status. In the month prior to interview, 13% of DUs shared a syringe, 38% other injection parapharnelia and 81% shared a crack pipe. In multivariate analysis, factors independently associated with HCV seropositivity were age over 30, HIV seropositivity, having ever injected drugs, opiate substitution treatment (OST), crack use, and precarious housing.</p> <p>Conclusion</p> <p>This is the first time that blood testing combined to GWSM is applied to a DUs population, which improve the estimate of HCV prevalence. HCV seroprevalence is high, indeed by the youngest DUs. And a large proportion of DUs are not aware of their status. Our multivariate analysis identifies risk factors such as crack consumption and unstable housing.</p