Gastroenteritis outbreaks in elderly homes in the east of France during winter 2009/10: aetiology research for a series of 37 outbreaks.

Although acute gastroenteritis is a common cause of morbi-mortality in care homes, there is no national surveillance system in France except for food-borne gastroenteritis. Since 2008, a specific surveillance system has been operating in nursing homes in Alsace, a region in eastern French. In the winter season 2009/10 we had the opportunity to study 37 outbreaks, collecting data on attack rate, duration and aetiology as well as epidemic management in nursing homes. We noticed the responsiveness of the institutions, with a mean period of 1.6 days between the onset of first symptoms and the implementation of management measures (95% confidence interval (CI): 1.0­2.2). One or several stool samples were taken in 27 of the 37 described outbreaks. The only pathogen detected was norovirus, and the positive samples were from outbreaks with a very typical pattern: vomiting in 36 of the outbreaks, a high average attack rate of 36.8% (95% CI: 31.5­42.2) and a short average duration of 8.9 days (95% CI: 5.8­7.0). No severe cases, hospitalisations or deaths were reported. The high frequency of norovirus isolation indicated that systematic bacteriological analysis in local laboratories is not cost-effective. Consequently, Cire Est recommends to test for bacteria and viruses only in cases presenting with fever or atypical symptoms. Nevertheless, Cire Est also recommends to continue sending stool samples to the French National Centre for enteric viruses, more for the benefit of the virological surveillance programme than for diagnostic purposes.

The impact of the prevention programme of hepatitis C over more than a decade: the French experience.

To assess the impact of the French national hepatitis C prevention programme initiated in 1999, we analysed trends in hepatitis C virus (HCV) prevalence, testing and characteristics of HCV-infected patient at first referral from 1994 to 2006. We used four data sources: Two national population-based sero-prevalence surveys carried out in 1994 and 2004; two surveillance networks, one based on public and private laboratories throughout France and the other on hepatology reference centres, which aim to monitor, respectively, trends of anti-HCV screening and of epidemiological-clinical characteristics of HCV patients at first referral. Between 1994 and 2004, the anti-HCV prevalence for adults aged 20-59 years decreased from 1.05 (95% confidence interval 0.75-1.34) to 0.71 (0.52-0.97). During the same period, those anti-HCV positive with detectable HCV RNA decreased from 81 to 57%, whereas, the proportion of anti-HCV positive persons aware of their status evolved from 24 to 56%. Anti-HCV screening activity increased by 45% from 2000 to 2005, but decreased in 2006 (-10%), while HCV positivity among those tested decreased from 4.3 to 2.9%. The proportion of cirrhosis at first referral remains around 10% between 2001 and 2006, with many patients with excessive alcohol consumption (34.7% among males) or viral co-infections (HIV seropositivity for 5.2% patients). Our analysis indicates that the national programme had a positive impact at the population level through improved prevention, screening and management. There is still a need to identify timely those at risk for earlier interventions, to assess co-morbidities better and for a multidisciplinary approach to HCV management.

Surveillance of screening for hepatitis C through the laboratory network RENA-VHC, France, 2000-2001.

Over the period 2000-2001, 189 private or hospital laboratories scattered throughout France participated to the laboratory network RENA-VHC. A total of 759 591 serologies (screening tests and validation of screening tests) were performed, revealing an increase of 10% between 2000 and 2001. The rate of the amount of tests to validate screening found positive over the overall amount of tests performed was 1.2% in 2000 and 1.0% in 2001. This suggests that screening covered more people with little risk of acquiring HCV infection. The per-sons confirmed HCV positive were predominantly men (sex ratio 1.5) of which 31% were 30 to 39 years of age.

Measles outbreak in a community with very low vaccine coverage, the Netherlands.

A 1999-2000 measles epidemic in the Netherlands started with an outbreak in an orthodox reformed elementary school with 7% vaccine coverage. The overall attack rate was 37%: 213 clinical cases among the 255 participating pupils (response 62%) and 327 household members. The attack rate ranged from 0% for the oldest groups of pupils to 88% for the youngest, who had not been exposed in previous measles epidemics. None of 25 vaccinated pupils had clinical symptoms. Among pupils with clinical symptoms, the self-reported complication rate was 25%. These data confirm that measles infection causes severe disease and that vaccination is the most effective means of preventing the disease and its complications. The data also show that clusters of persons refraining from vaccination interfere with measles elimination even in populations with very high overall vaccine coverage (96%).