Eurosurveillance - Volume 16, Issue 39, 29 September 2011

Until August, 161 cases of tick-borne encephalitis (TBE) were recorded in Sweden for 2011, leading to an incidence of 1.7 per 100,000 population. Fifty to 59 year-olds (24%) were most affected, 55% of the cases were males. An increase in TBE in Sweden has occurred in the last decade and might be explained by enlarged tick populations, more contact between TBE virus infected ticks and man, and also by growing awareness of the disease. Climatic conditions may have contributed to the increase.

As a follow-up of a retrospective survey on tick borne-encephalitis (TBE) in 2008, the European Network for Diagnostics of 'Imported' Viral Diseases launched a new survey in 2010, to collect broader information on TBE prevalence between 2007 and 2009 and to observe possible changes compared to the previous data. A two-part questionnaire was mailed to contact points in all European Union (EU) Member States and four non-EU countries (Bosnia and Herzegovina, Norway, Russia, and Switzerland). The first part was identical to the 2008 survey, requesting information on case definition, diagnostic methods, investigations regarding tick-transmitted diseases, endemic foci mapping, vaccination programmes, and recommendations for travellers. The second newly added part, inquired about geographic and seasonal distribution of TBE cases, imported cases, TBE subtypes, animal cases, and prevalence in ticks and wildlife hosts. Of 28 participat-ing countries, 16 had TBE as a notifiable disease, as in the first survey. In the 2007-2009 period, the total number of notified cases (17,818) was lower than in 2004-2006 (21,339 cases), also when subtracting Russian cases (8,207 vs 9,073 cases respectively). The highest reported incidence was 18.5 per 100,000 population in Lithuania in 2009. The 2010 study showed that increased numbers of countries used PCR and nucleotide sequencing for particular investigations. Most countries, however, relied on specific antibody detection by enzyme linked immunosorbent assay for TBE laboratory diagnosis. Disparities nevertheless remained across countries regarding case definitions, and surveillance and prevention activities. To understand changing patterns in TBE transmission, surveillance strategies including screening of vector ticks and testing of animal hosts should be harmonised and done more systematically in Europe. Collected data will support rec-ommendations concerning diagnostic and mapping methods, case reporting, vaccination programmes and information campaigns. .

Despite high immunisation coverage, several measles outbreaks occurred in the canton of Geneva between 2003 and 2010, with 161 reported cases (52 in 2003, 16 in 2005 and 93 in 2007-2010). It affected mainly 10-14 year-old children in 2003 (31%), and adults 20 years and older in 2005 (75%) and 2007-2010 (39%). Several cases were imported from neighbouring cantons and countries, as confirmed by the diversity of the genotypes identified (D8, D6, D5, D4 and G3). Infections were mainly transmitted via family (54%) and school (22%) in 2003, hospital (71%) and family (29%) in 2005, and family (55%) and school (26%) in 2007-2010. In 2003, 6% of infected patients were vaccinated, 27% in 2005 and 2% in 2007-2010, none of them with two doses of measles-containing vaccine. Between 2003 and 2008, measles vaccine coverage, particularly for the second dose, increased by 23 percentage points to 91.7% in the 28 month-olds, by 27 points to 92.3% in the 5-6 year-olds, and by 19 points to 86% in the 13-14 year-olds. In a cosmopolitan setting where immunisation coverage is high but not sufficient to eradicate measles, outbreaks can be limited by efficient surveillance and early control measures. Catch-up vaccination needs to be reinforced among teenagers and young adults. .

On 9 September 2011, the Estrel Convention Center in Berlin was the venue for a first clinical symposium on Shiga toxin-producing Escherichia coli / haemolytic uremic syndrome (STEC/HUS) reflecting on the large STEC outbreak in Germany earlier this year. The German Society of Nephrology (DGfN) invited internationally renowned clinical experts and microbiologists to discuss the basic science and diagnostics of STEC infections and the different options for treating an EHEC-associated HUS, including plasmapheresis, antibody therapy with Eculizumab, and extracorporeal immune adsorption.