V Vaillant

Novel Chikungunya Virus Variant in Travelers Returning from Indian Ocean Islands

Aedes albopictus may cause epidemics when infected persons travel to areas where vectors are prevalent.

Incidence of Listeriosis and Related Mortality Among Groups at Risk of Acquiring Listeriosis

BACKGROUND Listeriosis is a foodborne disease of significant public health concern that primarily affects persons with recognized underlying conditions or diseases that impair cell-mediated immunity. The degree of risk posed by the different underlying conditions is crucial to prioritize prevention programs that target the highest risk populations. METHODS We reviewed cases of listeriosis reported in France from 2001 to 2008. Numbers of cases and deaths were tabulated by age and underlying condition. Measures of the impact of specific underlying conditions on the occurrence of listeriosis were calculated. For estimating the total number of persons living with specific diseases, we applied prevalence estimates of these diseases to the French population. Underlying conditions were ranked by the degree to which they increased the risk of listeriosis. RESULTS From 2001 to 2008, 1959 cases of listeriosis were reported in France (mean annual incidence 0.39 per 100,000 residents). Compared with persons <65 years with no underlying conditions, those with chronic lymphocytic leukemia had a >1000-fold increased risk of acquiring listeriosis, and those with liver cancer; myeoloproliferative disorder; multiple myeloma; acute leukemia; giant cell arteritis; dialysis; esophageal, stomach, pancreas, lung, and brain cancer; cirrhosis; organ transplantation; and pregnancy had a 100-1000-fold increased risk of listeriosis. CONCLUSIONS To be effective and acceptable to physicians and patients, listeriosis prevention strategies should be targeted based on evidence of increased risk. Stringent dietary guidance, to avoid specific foods with a high risk for Listeria contamination, should be targeted to pregnant women and to others at highest risk of listeriosis.

Outbreak of Shiga Toxin–Producing Escherichia coli O104:H4 Associated With Organic Fenugreek Sprouts, France, June 2011

BACKGROUND On 22 June 2011, 8 patients with hemolytic uremic syndrome (HUS) or bloody diarrhea were reported in France. All 8 were attendees of a community center event on 8 June near Bordeaux. Three Escherichia coli cases were confirmed by isolation of Shiga toxin-producing E. coli O104:H4 stx2 aggR producing a cefotaximase (CTX-M) β-lactamase (STEC O104:H4); the same rare serotype caused the outbreak in Germany in May-July 2011. An investigation was initiated to describe the outbreak, identify the vehicle for infection, and guide control measures. METHODS We conducted a retrospective cohort study among all adults attending the event, including food handlers. A standardized questionnaire was administered to participants. A case was an attendee who developed HUS or diarrhea between 8 and 24 June. Cases were confirmed by isolation of STEC O104:H4 or O104 serology. Relative risks (RRs) and 95% confidence intervals (CIs) by exposure were calculated using a Poisson regression model. RESULTS Twenty-four cases were identified (14% attack rate). Of these, 18 (75%) were women, 22 (92%) were adults, 7 (29%) developed HUS, 5 (21%) developed bloody diarrhea, and 12 (50%) developed diarrhea. Ten (42%) cases were confirmed. Fenugreek was the only sprout type with an independent association to illness (RR, 5.1; 95% CI, 2.3-11.1) in multivariable analysis. CONCLUSIONS This investigation identified a point-source STEC O104:H4 outbreak associated with consumption of fenugreek sprouts. Comparison of results from French and German STEC O104:H4 outbreak investigations enabled identification of a common food vehicle, fenugreek sprouts, and resulted in implementation of Europe-wide control measures in July 2011.

Molecular Epidemiology of Caliciviruses Detected in Sporadic and Outbreak Cases of Gastroenteritis in France from December 1998 to February 2004

ABSTRACT We compiled sequence and epidemiological data from 172 caliciviruses detected in France from December 1998 to February 2004 in sporadic and outbreak cases. The results showed a cocirculation of strains with a majority of genogroup II (GII) noroviruses. Three groups of noroviruses, not detected before in our laboratory, emerged and spread during the period: the recombinant GGIIb and Norwalk-related strains not amplified in the polymerase gene in 2000 and a new Lordsdale variant in 2002. We observed that (i) GII-4 noroviruses were predominant in nursing home and hospital outbreaks but rare in oyster- and water-related outbreaks despite continuous circulation in the population; (ii) at the opposite, genogroup I strains were detected in the majority of environmental outbreaks; (iii) several strains were frequently found in oyster- and water-linked outbreaks (up to seven), whereas one single strain was detected when transmission was from person to person; and (iv) whereas GII noroviruses were predominant in sporadic cases where patients were under 15 years of age, GI strains were more frequent in outbreaks occurring in this age group. Finally, from a methodology point of view, this compilation shows that detection and characterization in the polymerase gene are not adequate in a significant number of cases and should be completed by amplification and sequencing in the capsid gene.

Surveillance of listeria infections in Europe.

In addition to the economic consequences and threats associated with outbreaks, listeriosis remains of great public health concern, as it has one of the highest case fatality rates of all the foodborne infections (20%-30%), and has common source epidemic potential. Changes in the way food is produced, distributed and stored have created the potential for diffuse and widespread outbreaks involving many countries. In 2002, a survey was carried out to assess the need for and the feasibility of a European network on listeria infections in humans. Data on surveillance systems and laboratory methods were collected through two postal surveys sent to the national Centres for communicable disease surveillance and to the listeria reference laboratories. Surveillance systems for listeria infections were in operation in 16 out of the 17 countries surveyed, and 16 countries had a national reference laboratory (NRL). All countries based their case definition of listeriosis on the isolation of Listeria monocytogenes. Fourteen NRLs performed at least one typing method on human strains. At least 13 countries already carried out or expressed willingness to carry out characterisation of isolates by pulsed field gel electrophoresis (PFGE) of L. monocytogenes strains isolated from human cases following a standard protocol. The participants concluded that there was a clear added value to having a European surveillance network for listeria infections, particularly for outbreak detection and investigation, and that a surveillance network based on the existing national surveillance systems was feasible.

Role of Sex, Age, Previous Valve Lesion, and Pregnancy in the Clinical Expression and Outcome of Q Fever after a Large Outbreak

BACKGROUND Q fever is a zoonosis caused by Coxiella burnetii. After a large outbreak occurred in the Chamonix Valley in the French Alps in 2002, an extensive surveillance was conducted, to describe the variations in the clinical expression of acute Q fever according to host factors, as well as to monitor the risk of evolution of acute Q fever to chronic Q fever in patients at risk. METHODS Three groups of patients with risk factors for evolution of acute Q fever to chronic Q fever were considered: 376 pregnant women, 19 immunocompromised patients, and 91 patients with valvular or vascular abnormalities. A group of 578 people without risk factors for evolution of acute Q fever to chronic Q fever was also tested. Diagnosis of Q fever was based on serologic testing by immunofluorescence assay. RESULTS Between 30 August 2002 and 31 July 2003, a total of 1946 serum samples obtained from 1064 persons were tested. A total of 101 patients (9.3%) had acute Q fever diagnosed, and 5 patients (0.5%) had chronic Q fever diagnosed. A diagnosis of acute Q fever was established for 11 pregnant women (2.6% of 379 pregnancies), 5 patients with valvular disease (5.5%), and 85 people without risk factors (14.7%) (71 [27.9%] of 254 symptomatic patients and 14 [4.3%] of 324 asymptomatic patients). A new pregnancy in a woman with negative results of serologic tests for Q fever exposes the woman to a new risk for acute Q fever able to evolve to chronic Q fever. The rates of clinical expression were 90.6% in adult men, 75% in adult women, and 33.3% in children, and they were significantly lower (9.1%) in pregnant women. Evolution to chronic Q fever was observed in 5 patients. CONCLUSION This study emphasizes the importance of active surveillance in postepidemic conditions, especially among patients at risk, as well as the importance of systematic serologic testing during pregnancy.

Influenza vaccination coverage against seasonal and pandemic influenza and their determinants in France: a cross-sectional survey

BackgroundFollowing the emergence of the influenza A(H1N1)2009 virus, the French ministry of health decided to offer free vaccination against pandemic influenza to the entire French population. Groups of people were defined and prioritised for vaccination.MethodsWe took a random sample of the population of mainland France and conducted a retrospective cross-sectional telephone survey to estimate vaccination coverage against seasonal and pandemic influenza and to identify determinants of these vaccinations.Results10,091 people were included in the survey. Overall seasonal influenza vaccination coverage (IVC) remained stable in the population from the 2008-2009 season to the 2009-2010 season reaching 20.6% and 20.8% respectively. Overall pandemic IVC in the French population is estimated to be 11.1% (CI95%: 9.8 - 12.4). The highest pandemic IVC was observed in the 0-4 years age group. For individuals with health conditions associated with higher risk of influenza, pandemic IVC was estimated to be 12.2% (CI95%: 9.8 - 15.1). The main determinants associated with pandemic influenza vaccine uptake were: living in a household with a child < 5 years ORadj: 2.0 (CI95%: 1.3 - 3.1) or with two children < 5 years or more, ORadj: 2.7 (CI95%: 1.4 - 5.1), living in a household where the head of the family is university graduate (>2 years), ORadj: 2.5 (CI95%: 1.5 - 4.1), or has a higher professional and managerial occupation, ORadj: 3.0 (CI95%: 1.5 - 5.5) and being vaccinated against seasonal influenza, ORadj: 7.1 (CI95%: 5.1 - 10.0). Being an individual with higher risk for influenza was not a determinant for pandemic influenza vaccine uptake. These determinants are not the same as those for seasonal influenza vaccination.ConclusionsOverall A(H1N1)2009 influenza vaccine uptake remained low, particularly among individuals with higher risk for influenza and was lower than that observed for seasonal influenza. The reasons behind peoples reluctance to be vaccinated need to be investigated further.

What is the incubation period for listeriosis

BackgroundListeriosis is a foodborne infection with a low incidence but a high case fatality rate. Unlike common foodborne diseases, the incubation period can be long. The first incubation periods were documented during a large listeriosis outbreak published in 1987 by Linnan and al. in the New England Journal of Medicine (range: 3 days to 70 days). Data on the incubation period of listeriosis are scarce. Our study aim was to estimate precisely the incubation period of listeriosis using available data since 1987.MethodsWe estimated the incubation period of listeriosis using available published data and data from outbreak investigations carried out by the French National Institute for Public Health Surveillance. We selected cases with an incubation period calculated when a patient had a single exposure to a confirmed food source contaminated by Listeria monocytogenes.ResultsWe identified 37 cases of invasive listeriosis (10 cases with central nervous system involvement (CNS cases), 15 bacteraemia cases and 12 pregnancy-associated cases) and 9 outbreaks with gastroenteritis. The overall median incubation period of invasive listeriosis was 8 days (range: 1–67 days) and differed significantly by clinical form of the disease (p<0.0001). A longer incubation period was observed for pregnancy-associated cases (median: 27.5 days; range: 17–67 days) than for CNS cases (median: 9 days; range: 1–14 days) and for bacteraemia cases (median: 2 days; range: 1–12 days). For gastroenteritis cases, the median incubation period was 24 hours with variation from 6 to 240 hours.ConclusionsThis information has implications for the investigation of food borne listeriosis outbreaks as the incubation period is used to determine the time period for which a food history is collected. We believe that, for listeriosis outbreaks, adapting the exposure window for documenting patients’ food histories in accordance with the clinical form of infection will facilitate the identification of food products as the source of contamination. We therefore propose to take an exposure window of 14 days before the diagnosis for CNS and bacteraemia cases, and of 6 weeks before the diagnosis, for pregnancy-associated cases.

Autochthonous case of dengue in France, October 2013.

In October 2013, autochthonous dengue fever was diagnosed in a laboratory technician in Bouches-du-Rhone, southern France, a department colonised by Aedes albopictus since 2010. After ruling out occupational contamination, we identified the likely chain of local vector-borne transmission from which the autochthonous case arose. Though limited, this second occurrence of autochthonous dengue transmission in France highlights that efforts should be continued to rapidly detect dengue virus introduction and prevent its further dissemination in France.

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.