O148 Shiga toxin-producing Escherichia coli outbreak: microbiological investigation as a useful complement to epidemiological investigation.

An outbreak of Shiga toxin-producing Escherichia coli (STEC) O148 infection occurred among wedding attendees in France in June 2002. A retrospective cohort study was performed and ten cases were identified, including two adults with haemolytic uraemic syndrome (HUS). The analytical study revealed that > 80% of affected individuals had eaten lightly roasted mutton and poultry pâté, but only the consumption of pâté tended to be associated with illness (relative risk 3.4; 95% CI 0.8-14.4). Left-overs (cooked mutton and raw offal) and processed foods (pâté) from the same batches as served at the party were sampled. Human, food and environmental samples were examined for the Shiga toxin (stx) gene and virulence traits by PCR. Stx-positive samples were cultured for STEC. HUS cases were tested for serum antibodies against 26 major STEC serogroups. An STEC O26 strain (stx1, eae, ehxA) was isolated from one case with diarrhoea, and an STEC O148 strain (stx2c) from one case of HUS. Serum antibodies against O26 were not detected in either of these patients; antibodies against O148 were not tested. Three STEC strains were isolated from the mutton and the offal (stx2c, O148), and two from the pâté (stx2c, O-X and O-Y). The isolates from the mutton were indistinguishable from the human stx2c isolate, whereas the pâté isolates differed. Although four different STEC strains were identified in patients and foods, the results of molecular subtyping, in conjunction with analysis of food consumption patterns, strongly suggested that this outbreak was caused by mutton contaminated with STEC O148.

[Influenza sentinel surveillance network improvement in Senegal and results]. / Renforcement du réseau de surveillance sentinelle de la grippe au Sénégal et résultats.

Influenza surveillance in Senegal was initially restricted to the identification of circulating strains. The network has recently been enhanced (i) to include epidemiological data from Dakar and other regions and (ii) to extend virological surveillance to other respiratory viruses. Epidemiological data from the sentinel sites is transmitted daily by mobile phone. The data include those for other febrile syndromes similar to influenza-like illnesses (ILI), corresponding to integrated approach. Also, clinical samples are randomly selected and analyzed for influenza and other respiratory viruses. There were 180,192 declared visits to the 11 sentinel sites between week 11-2012 and week 52-2013; 24% of the visits were for fever syndromes and 25% of the cases of fever syndrome were ILI. Rhinoviruses were the most frequent cause of ILI (19%), before adenoviruses (18%), enteroviruses (18%) and influenza A viruses (13%). Co-circulation and co-infection were frequent and were responsible for ILI peaks. In conclusion, it is clear that the greatest advantage of this system is the ease with which it can be implemented, thanks to the availability of mobile phones and mobile phone networks. We recommend this solution for other African countries, because it performs very well and provides rapid benefits in terms of public health decision-making.

Investigation of an outbreak of E. coli O157 infections associated with a trip to France of schoolchildren from Somerset, England.

A retrospective cohort study was conducted after 2 confirmed and 8 probable cases of VTEC 0157 occurred in a schoolgroup from Somerset following a trip to France. The strain of the 2 confirmed cases was vero-cytotoxin type 2, phage type 34. Despite its low statistical power due to small numbers, this study suggested the most likely vehicle of infection was cucumber salad (crude RR=4.3, 95%CI [0.6-29], adjusted OR=107, 95%CI indeterminate, p=0.08). The cucumbers were purchased from Belgium but it was not possible to trace them back to source. The international nature of this outbreak emphasises the importance of close collaboration between organisations in the management of outbreaks, of ensuring international standards in food safety, and of agreeing a common standard in VTEC typing across Europe.

Two outbreaks of Salmonella enteritidis phage type 8 linked to the consumption of Cantal cheese made with raw milk, France, 2001.

Salmonelloses are one are the main causes of foodborne infections in industrialised countries. In France, the incidence of human salmonellosis recorded by the National Reference Centre for Salmonella and Shigella (CNRSS) in 2001 was 21 cases per 100,000 inhabitants, and Salmonella serotype Enteritidis represented 39% of cases (1). This article reports the investigation results of two community outbreaks of salmonellosis that occurred simultaneously in the south west of France, and which were linked to the consumption of cheese made from raw milk.

[Infant botulism in France, 1991-2009]. / Le botulisme infantile en France, 1991-2009.

Infant botulism is caused by the ingestion of spores of Clostridium botulinum and affects newborns and infants under 12 months of age. Ingested spores multiply and produce botulinum toxin in the digestive tract, which then induces clinical symptoms. A single French case was described in the literature prior to 1991. We describe the cases of infant botulism identified in France between 1991 and 2009. All clinical suspicions of botulism must be declared in France. Biological confirmation of the disease is provided by the National reference laboratory for anaerobic bacteria and botulism at the Pasteur Institute. During this period, 7 cases of infant botulism were identified, 1 per year from 2004 to 2008 and 2 in 2009. The median age of affected infants was 119 days and all were female. All infants presented with constipation and oculomotor symptoms. All were hospitalized and required mechanical ventilation. The infants recovered from their botulism. The diagnosis of infant botulism was biologically confirmed for all patients. One 4-month-old infant was treated with a single dose of the human-derived botulism antitoxin specific for infant botulism types A and B (BabyBIG®). The infants all had different feeding habits ranging from exclusive breast feeding to a mix of formula feeding and solid food consumption. The consumption of honey, the only documented risk food for this disease, was reported for 3 of the infants. The honey had been placed on the pacifier of 2 infants and directly in the mouth of the 3rd by the mother. Infant botulism, a form of botulism that was previously rarely recognized in France, has been reported more frequently during the last 6 years. This disease remains rare but nonetheless severe. In light of recent epidemiological data, efforts to raise awareness among parents of infants and health professionals on the danger of infant botulism and particularly, its association with honey consumption seems necessary.

Community-wide outbreak of Escherichia coli O157:H7 associated with consumption of frozen beef burgers.

On 24-25 October 2005 a cluster of five haemolytic uraemic syndrome (HUS) cases was reported in southwest France. An investigation was undertaken to identify the outbreak source and implement control measures. Cases were defined as individuals with HUS or diarrhoea with isolation of Escherichia coli O157:H7 in stools or a positive antibody response to E. coli O157 lipopolysaccharide, resident in southwest France with symptom onset after 19 September 2005. Sixty-nine identified patients had symptom onset between 5 October and 3 November 2005, including 17 cases of HUS. One brand of frozen beef burgers produced on 22 August 2005 was consumed by all patients in the week before symptom onset. E. coli O157:H7 strains from patients, patients' burgers and the manufacturing plant were genetically related. This is the largest community-wide outbreak of E. coli O157:H7 in France to date and the first associated with consumption of contaminated frozen beef burgers.

Evaluation of the impact on human salmonellosis of control measures targeted to Salmonella Enteritidis and Typhimurium in poultry breeding using time-series analysis and intervention models in France.

In France, salmonellosis is the main cause of foodborne bacterial infection with serotypes Enteritis (SE) and Typhimurium (ST) accounting for 70% of all cases. French authorities implemented a national control programme targeting SE and ST in poultry and eggs from October 1998 onwards. A 33% decrease in salmonellosis has been observed since implementation. We designed an evaluation of the impact of this control programme on SE and ST human infections in France. Using monthly Salmonella human isolate reports to the National Reference Centre we defined two intervention series (SE and ST) and one control series comprising serotypes not know to be associated with poultry or eggs. The series, from 1992 to 2003, were analysed using autoregressive moving average models (ARMA). To test the hypothesis of a reduction of SE and ST human cases >0 after the programme started and to estimate its size, we introduced an intervention model to the ARMA modelling. In contrast to the control series, we found an annual reduction of 555 (95% CI 148-964) SE and of 492 (95% CI 0-1092) ST human infections, representing respectively a 21% and 18% decrease. For SE, the decrease occurred sharply after implementation while for ST, it followed a progressive decrease that started early in 1998. Our study, suggests a true relation between the Salmonella control programme and the subsequent decrease observed for the two targeted serotypes. For ST, however, the decrease prior to the intervention may also reflect control measures implemented earlier by the cattle and milk industry.

Association between indicators of cattle density and incidence of paediatric haemolytic-uraemic syndrome (HUS) in children under 15 years of age in France between 1996 and 2001: an ecological study.

Over the past years Shiga-like toxin-producing Escherichia coli (STEC) O157:H7 emerged as an important cause of severe gastrointestinal illnesses and haemolytic-uraemic syndrome (HUS) with up to 10% of children infected with STEC developing HUS. We conducted a geographical ecological study using the district as the statistical unit. For each district, we estimated the incidence of HUS among children <15 years for the period 1996-2001 from national HUS surveillance data and data obtained on cattle density. We used multivariate Poisson regression to quantify the relation, adjusted for covariates, between paediatric HUS incidence and exposure to cattle. In univariate analysis, a positive association was observed between several cattle-density indicators and HUS incidence. In multivariate analysis, HUS paediatric incidence was associated with dairy cattle density and the ratio of calves to children <15 years (P<0.001). Our findings are consistent with previous studies in other countries and support the recommendation to limit exposure of children to dairy cattle and manure to reduce the risk of STEC infection.

Escherichia coli O157 outbreak associated with fresh unpasteurized goats' cheese.

A family cluster of three cases of Escherichia coli O157 infection was identified in France. Two cases developed haemolytic-uraemic syndrome. The source was fresh unpasteurized goats' cheese, produced by an independent producer. Three E. coli O157 strains, isolated from one HUS case and faeces of one cow and one goat, were indistinguishable by toxin type and PFGE pattern.

An outbreak of multidrug-resistant Salmonella enterica serotype Newport infections linked to the consumption of imported horse meat in France.

In 2003, 14 cases of multidrug-resistant Salmonella Newport infections were reported. This is the first documented foodborne outbreak of multidrug-resistant S. Newport in France. The blaCMY gene was present in all isolates. All cases reported having eaten horse meat from a common wholesaler. The country of origin of the imported meat could not be identified.