E Espié

Surveillance of hemolytic uremic syndrome in children less than 15 years of age, a system to monitor O157 and non-O157 Shiga toxin-producing Escherichia coli infections in France, 1996-2006.

Background: Since the 1980s, Shiga toxin-producing Escherichia coli (STEC), especially E. coli O157:H7, has been an important cause of food borne disease in industrial countries. In France, as there was no routine screening for STEC in clinical laboratories, enhanced surveillance of hemolytic uremic syndrome (HUS) in children less than 15 years of age was established in 1996 to monitor trends in the incidence of STEC infections. Methods: The surveillance system was based on a voluntary national network of pediatricians of 31 pediatric nephrology units in public hospitals. Results: From 1996 to 2006, the mean annual incidence of HUS was 0.71 cases per 100,000 children less than 15 years of age and 1.87 cases per 100,000 children less than 5 years of age. STEC infections were confirmed in 66% of patients; STEC O157 was the most common serogroup identified in STEC-related HUS (83%). In this 11-year period, 96% of HUS cases were sporadic and only 2 outbreaks caused by STEC O157 and by a dual infection of STEC O26 and O80 were detected. Conclusions: An evaluation of the surveillance of pediatric HUS showed that it is a simple and useful system for monitoring trends in STEC infections in France. It provides the information needed to measure the impact of new and changing vehicles of STEC transmission, and evaluate the effectiveness of prevention measures.

Chromosomal Integration of the Extended-Spectrum β-Lactamase Gene blaCTX-M-15 in Salmonella enterica Serotype Concord Isolates from Internationally Adopted Children

ABSTRACT We report the emergence of Salmonella enterica isolates of serotype Concord (and its monophasic variant 6,7:l,v:-) producing the extended-spectrum β-lactamases (ESBLs) SHV-12 and CTX-M-15 in France and Norway between 2001 and 2006 (43 in France and 26 in Norway). The majority of these isolates were from adopted children from Ethiopia, most of whom were healthy carriers. Several symptomatic secondary cases were found in the adoptive families and health care facilities in France. Serotype Concord isolates collected before 2003 produced SHV-12 encoded on a 340-kb conjugative plasmid of replicon IncI1. Isolates collected after 2003 produced CTX-M-15. We detected two conjugative plasmids carrying blaCTX-M-15. One plasmid, approximately 300 kb in size, was positive for the IncHI2 replicon and the plasmid-mediated quinolone resistance gene qnrA1. The other plasmid, from one of the earliest CTX-M-15-producing isolates collected, was a fusion plasmid with IncY and IncA/C2 replicons and was 200 kb in size. However, we showed, using Southern hybridization of I-CeuI-digested chromosomal DNA and S1 nuclease analysis of plasmid DNA, that most isolates had a blaCTX-M-15 gene located on chromosomal DNA. Analysis of the flanking regions of the chromosomally located blaCTX-M-15 gene by cloning revealed an ISEcp1 truncated by an intact IS26 upstream from the blaCTX-M-15 gene and a truncated orf477 gene downstream from blaCTX-M-15. We found regions beyond the IS26 and the orf477 genes that were derived from IncA/C2 plasmids, suggesting the chromosomal integration of part of the blaCTX-M-15-carrying IncY and IncA/C2 fusion plasmid from early CTX-M-15-producing isolates.

Two consecutive large outbreaks of Salmonella enterica serotype Agona infections in infants linked to the consumption of powdered infant formula.

Background: An increase of isolation of Salmonella Agona was observed in January through February 2005 among infants in France. Methods: Case–control study, food trace-back and microbiologic investigations were promptly carried out. Results: A total of 141 confirmed cases <12 months of age were identified. Most had diarrhea (99%; bloody 56%) and fever (75%) and 36% were hospitalized for 5 days on average and none died. In the case–control analysis, all 23 cases and none of the 23 controls had consumed powdered formula of brand A (P < 10−5). Active follow up of all cases showed that after the withdrawal of formula A, cases that had consumed formula A decreased rapidly, but new cases had consumed another formula (brand B). The trace-back found that 5 batches of formula B had been manufactured on the same production line as formula A. Forty-four cases were linked to formula A and 92 to formula B. All routine controls performed by the producers were negative for Salmonella. However, enhanced microbiologic investigations yielded S. Agona in one of 176 samples of formula A, in 4 of 27 tins of formula B consumed by cases and in 6 of 420 environmental swabs from the production line. All clinical, food and environmental isolates were of the same pulsed-field gel electrophoresis profile. Conclusions: Powdered infant formulas are not sterile products and may contain low levels of Salmonella. Routine microbiologic controls are insufficient to detect a low-grade contamination, which may cause serious illness and outbreaks among infants.

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.

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.

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.

Undercooked ground beef and person-to-person transmission as major risk factors for sporadic hemolytic uremic syndrome related to Shiga-toxin producing Escherchia coli infections in children in France.

In a prospective matched case-control study of sporadic pediatric hemolytic uremic syndrome related to Shiga-toxin producing Escherichia coli infection in France, eating undercooked ground beef, contact with a person with diarrhea, and drinking well water during the summer period were identified as risk factors. Prevention efforts in France should focus on reducing not only food-borne but also person-to-person transmission.

A Bayesian Evidence Synthesis for Estimating Campylobacteriosis Prevalence

Stakeholders making decisions in public health and world trade need improved estimations of the burden-of-illness of foodborne infectious diseases. In this article, we propose a Bayesian meta-analysis or more precisely a Bayesian evidence synthesis to assess the burden-of-illness of campylobacteriosis in France. Using this case study, we investigate campylobacteriosis prevalence, as well as the probabilities of different events that guide the disease pathway, by (i) employing a Bayesian approach on French and foreign human studies (from active surveillance systems, laboratory surveys, physician surveys, epidemiological surveys, and so on) through the chain of events that occur during an episode of illness and (ii) including expert knowledge about this chain of events. We split the target population using an exhaustive and exclusive partition based on health status and the level of disease investigation. We assume an approximate multinomial model over this population partition. Thereby, each observed data set related to the partition brings information on the parameters of the multinomial model, improving burden-of-illness parameter estimates that can be deduced from the parameters of the basic multinomial model. This multinomial model serves as a core model to perform a Bayesian evidence synthesis. Expert knowledge is introduced by way of pseudo-data. The result is a global estimation of the burden-of-illness parameters with their accompanying uncertainty.