Epidemiology of food-borne disease outbreaks in the French armed forces: a review of investigations conducted from 1999 to 2009.

OBJECTIVE: Aim of this study was to describe the main characteristics of food-borne disease outbreaks (FBDOs) in the French armed forces from 1999 to 2009. METHODS: FBDOs are reported to the military epidemiological surveillance system, which concerns all active military personnel. Investigation reports published from 1999 to 2009 were reviewed. RESULTS: Among the 180 FBDOs reported, 48.3% occurred overseas. The mean reporting rate was 2.4 outbreaks p.100,000 in France and 26.7 p.100,000 overseas, reaching to 39.3 p.100,000 in Africa. Digestive symptoms were predominant among cases. Laboratory analyses on cases were positive in 29.4% of FBDOs. The most frequently isolated agents were shigella (15.4%). Laboratory analyses on food samples were positive in 18.9% of outbreaks, the most frequently isolated agent being Clostridium perfringens (15.7%). Only 7 FBDOs were documented by concordant analyses in both patients and food samples. CONCLUSIONS: The reporting rate was much higher among military deployed overseas, which can be the consequence of a lack of hygiene due to operational imperatives and the consumption of local food which does not meet safety standards. In operational settings, laboratory evidence may be difficult to obtain and a timely epidemiological investigation in some cases proves valuable to identify the likely vehicle of infection and to guide targeted intervention measures.

Novel influenza A(H1N1) outbreak among French armed forces in 2009: results of Military Influenza Surveillance System.

OBJECTIVES: An outbreak of novel A(H1N1) virus influenza, detected in Mexico in April 2009, spread worldwide in 9 weeks. The aim of this paper is to present the monitoring results of this influenza outbreak among French armed forces. STUDY DESIGN: The period of monitoring by the Military Influenza Surveillance System (MISS) was 9 months, from May 2009 to April 2010. METHODS: The main monitored events were acute respiratory infection (ARI), defined by oral temperature ≥38.5 °C and cough, and laboratory-confirmed influenza. Weekly incidence rates were calculated by relating cases to the number of servicepersons monitored. RESULTS: In continental France, the incidence of ARI increased from September 2009, with a weekly maxima of 401 cases per 100,000 in early December 2009 according to MISS. Estimations of the incidence of consultations which could be related to novel A(H1N1) influenza ranged from 48 to 57 cases per 100,000. CONCLUSIONS: The trends observed by MISS are compatible with French national estimations. The incidence of consultations which could be related to A(H1N1) influenza at the peak of the epidemic (194 cases per 100,000) was much lower than the national estimate (1321 cases per 100,000). This may be due to servicepersons who consulted in civilian facilities and were not monitored. Other explanations are the healthy worker effect and the younger age of the military population.

[A(H1N1) influenza surveillance in the French armed forces: adapting the surveillance systems to the pandemic setting]. / Surveillance épidémiologique de la grippe A(H1N1) 2009 dans les armées françaises: adaptation des systèmes de surveillance au contexte pandémique.

OBJECTIVES: An outbreak of A(H1N1) virus influenza, detected in Mexico during April 2009, spread around the world in nine weeks. French armed forces had to adapt their epidemiological surveillance systems to this pandemic. Our aim was to present surveillance results. DESIGN: There are two influenza surveillance systems in French armed forces: one permanent throughout the year and one seasonal, the Military influenza surveillance system (SMOG). The pandemic threat led to an early reactivation of SMOG, before the initiation of a daily surveillance system specifically dedicated to A(H1N1) influenza. RESULTS: In metropolitan France, the increase of respiratory infections was observed as of September 2009, with a maximum of 401 cases for 100,000 at the beginning of December according to SMOG. The estimated rate of consultations related to A(H1N1) influenza ranged between 46 and 65 cases for 100,000. For military units operating outside of metropolitan France, a peak of incidence was observed in August (400 cases for 100,000). CONCLUSION: The trends observed by influenza military surveillance networks were compatible with French ones. Concerning French forces in operations, the increase of incidence observed in August was the consequence of the influenza outbreak in the Southern hemisphere. Estimations of consultations rate related to A(H1N1) influenza, ranged between 127 and 194 cases for 100,000 at the beginning of December, lower than the national rate (1321 cases for 100,000), a consequence of the age pyramid in the military population.

Molecular epidemiology or bovine rotaviruses from the Charolais area. / Epidémiologie moléculaire des rotaviroses bovines en région charolaise.

Molecular epidemiology of bovine rotavirus from the Charolais area (France). Faecal samples from 164 diarrhoeic calves under 60 days of age were collected from the Charolais area of France during winter of 1998. The samples were tested by an enzyme-linked immunosorbent assay (ELISA) to detect the presence of rotavirus antigen. Of 164 dairy calves tested, 45.1% were positive for rotavirus antigen. The presence of rotavirus was confirmed by electrophoresis of genomic segments. Genomic segment 9 coding for the surface glycoprotein VP7 was amplified by RT-PCR using amplimeres corresponding to a conserved sequence located at the 5' and 3' ends. Nucleotides of the region 29 to 320-560 (average 427) was determined by the Taq dye deoxynucleotide cycle sequencing method. By comparison to the 175 sequences of gene 9 previously published, sequence analysis demonstrated that all of the isolates from the present study belong to the genotype G6. This result confirms previously published data indicating the prevalence of rotavirus G6 in bovine, and suggests that a monovalent vaccine based on G6 antigen would be sufficient to elicit a good protection.

Serologic evidence for bovine immunodeficiency virus infection in France.

We report herein on the first serologic detection of antibodies to bovine immunodeficiency virus (BIV) in France. Serum samples from dairy and beef cattle from southwestern and western France (Landes and Vendée) were tested using a western blot assay with a recombinant 53 kDa gag precursor derived from the Louisiana BIV R29 isolate. We performed our study on the oldest animals from 37 different herds that were under serologic follow up for previous bovine leukemia virus infection. Overall, 398 selected bovine sera were assayed and 15 serum samples from 8 herds reacted with the recombinant 53 kDa BIV R29 gag. Interestingly, reactions obtained with French sera were weaker than with positive Louisiana sera, a finding that may indicate the occurrence of distinct French and Louisiana BIV variants.

Natural mode of horizontal transmission of bovine leukemia virus (BLV): the potential role of tabanids (Tabanus spp.).

In order to evaluate the potential role of hematophagous insects in the natural spreading of bovine leukemia virus (BLV) infection in cattle, a 2-year survey was carried out involving sequential serological tests on 3328 cattle in three different areas. A parallel entomological study was run over the same period, using continuous trapping, in order to determine both the density and variations of horsefly (Tabanus spp.) populations in the close vicinity of the herds. After statistical analysis, this space-time study showed that: (1) There is a significant positive geographical correlation between the rate of incidence of BLV infection and the density of the horsefly population. (2) Seasonal variations in the incidence rate exist; the highest rates are generally observed during summer (from July of September), and the lowest during winter, spring and early summer (from November to mid-July). (3) There is a time link between the rate of sero-conversion and the variations in activity of the horsefly population. All these data combined would appear to indicate that tabanids play a considerable role in the spread of BLV under natural conditions.