Eurosurveillance - Volume 15, Issue 5, 04 February 2010

We report an outbreak of listeriosis in Austria and Germany due to the consumption of ‘Quargel’ cheese produced by an Austrian manufacturer. At the time of writing this report, the outbreak was known to account for 14 outbreak cases in 2009, including four cases with lethal outcome. On 23 January 2010, the cheese product was voluntarily withdrawn from the market.

The paper describes weekly fluctuations of all-cause mortality observed in eight European countries during the period between week 27 and 51, 2009, in comparison with three previous years. Our preliminary data show that the mortality reported during the 2009 influenza pandemic did not reach levels normally seen during seasonal influenza epidemics. However, there was a cumulative excess mortality of 77 cases (1 per 100,000 population) in 5-14-year-olds, and possibly also among 0-4-year-olds.

We analysed mortality among people aged 65 years or older in Navarre, Spain in 2009 and compared it with the mean for the same period of time in the previous three years. In the pandemic weeks 24 to 52 2009 we observed 4.9% more deaths than expected (p=0.0268). Excess mortality occurred during the circulation of seasonal influenza (8.0%, p=0.0367) and the first wave of pandemic influenza (9.9%, p=0.0079). In the second wave of pandemic influenza there was a non-significant excess of deaths (5.2%, p=0.1166). Surveillance of laboratory-confirmed severe influenza cases detected only one death in this age group.

To study if antibiotic treatment of outpatients had triggered Clostridium difficile infections (CDI), prescription numbers were compared with CDI-affected patient numbers. A strong correlation was observed for ciprofloxacin (R=0.917), suggesting that increased use of ciprofloxacin by outpatients contributed to increased numbers of CDI. These findings deserve further investigation as they may have an impact on future decisions regarding antibiotic prescribing.

Since May 2009, the pandemic influenza A(H1N1) virus has been spreading throughout the world. Epidemiological data indicate that the elderly are underrepresented among the ill individuals. Approximately 1,000 serum specimens collected in Finland in 2004 and 2005 from individuals born between 1909 and 2005, were analysed by haemagglutination-inhibition test for the presence of antibodies against the 2009 pandemic influenza A(H1N1) and recently circulating seasonal influenza A viruses. Ninety-six per cent of individuals born between 1909 and 1919 had antibodies against the 2009 pandemic influenza virus, while in age groups born between 1920 and 1944, the prevalence varied from 77% to 14%. Most individuals born after 1944 lacked antibodies to the pandemic virus. In sequence comparisons the haemagglutinin (HA) gene of the 2009 pandemic influenza A(H1N1) virus was closely related to that of the Spanish influenza and 1976 swine influenza viruses. Based on the three-dimensional structure of the HA molecule, the antigenic epitopes of the pandemic virus HA are more closely related to those of the Spanish influenza HA than to those of recent seasonal influenza A(H1N1) viruses. Among the elderly, cross-reactive antibodies against the 2009 pandemic influenza virus, which likely originate from infections caused by the Spanish influenza virus and its immediate descendants, may provide protective immunity against the present pandemic virus.