Eurosurveillance - Volume 16, Issue 34, 25 August 2011

Between 16 July and 21 August 2011, 31 cases of West Nile neuroinvasive disease were reported from four regions in Greece. Of these, 17 occurred in districts that had not been affected in 2010. The reoccurrence of human cases in two consecutive years (following the large 2010 outbreak) and the spread of the virus in new areas suggest that West Nile virus is established in Greece, and its transmission may continue to occur in the future.

We report on a salmonellosis-outbreak due to Salmonella Enteritidis phage type 14b resistant to nalidixic acid (S. Enteritidis PT14b Nx) among residents and employees of a student residence in Austria, September 2010. The outbreak was described and analysed by a retrospective cohort study, and microbiological environmental investigations were conducted to identify the outbreak source(s) and the reservoir of the outbreak strain. A total of 66 persons fulfilled the outbreak case definition including 14 laboratory-confirmed cases. Food specific cohort-analyses by day revealed that consumption of potato salad (RR: 1.65, 95%CI: 1.35-2.01, p=0.001) and a cheese-sausage cold plate (RR: 2.24, 95%CI: 1.29-3.88, p=0.002) on 14 September was associated with being an outbreak case. We hypothesised that cross-contamination with S. Enteritidis PT14b Nx positive eggs had occurred during preparation of the potato salad and cold plate as a result of preparing in parallel egg-containing breaded cutlets on 14 September. A traced laying hen holding in eastern Austria was identified as the sole source of the consumable eggs in the student residence. By applying the legally mandated sampling method for epidemiological-related laying hen farms (one pooled dust sample à 150g, two paired boot swabs cultured separately), the outbreak strain could not be detected. Our findings, that legally required sampling methods for laying hen farms failed to detect the causative pathogen in a laying hen holding, despite an epidemiological link, underline the request stated by the European Food Safety Authority Panel on Biological Hazards for a more sensitive sampling plan in epidemiologically-associated laying hen flocks. .

We describe the epidemiology and characteristics of hepatitis A among men who have sex with men (MSM) who had been hospitalised due to the infection in Warsaw, Poland, from September 2008 to September 2009. A total of 50 men were analysed; their median age was 28 years (range: 17-43). None had travelled to hepatitis A-endemic regions during the six months before hospitalisation nor had they been vaccinated against hepatitis A. Of the 50 men, 40 had been tested before hospitalisation or on admission for the presence of anti-HIV antibodies: six were coinfected with HIV. The six HIV-positive MSM were significantly older than those who were HIV negative - median age: 37 years (range: 26-43) versus 28 years (range: 17-43); p=0.02. No difference in disease severity or the duration of hospitalisation was observed, however, between the two groups. Our study underlines the need to screen MSM for hepatitis A and to vaccinate them against hepatitis A. Given the ages of the MSM in our study, we recommend that this be carried out in Poland when the MSM are aged 20-35 years. This should apply not only to MSM with multiple casual partners but also to those in monogamous relationships. .