Eurosurveillance - Volume 16, Issue 20, 19 May 2011

Hospital-acquired listeriosis cases are not commonly reported but remain a significant public health problem. We report on three cases in patients with underlying conditions occurring during one week in February 2011. The cases had common exposure to pre-packed sandwiches and salads manufactured in compliance with regulations. Breaches in cold chain and shelf life controls at hospital level were identified as key contributing factors. Rigorous hospital food management systems remain important for patient safety.

Following the 2010/11 influenza season, we determined the age- and location-specific seroprevalence of antibodies against the influenza A(H1N1)2009 virus in Scotland. Samples were analysed by microneutralisation assay. Age/seropositivity profiles varied significantly between cities. The increases in seroprevalence relative to the previous influenza season (2009/10) were similar across age groups and geographic locations. However, the increased seropositivity in older adults appeared to be driven by exposure to vaccination, indicating significantly lower levels of infection than in younger age groups.

The Florida Department of Health, Florida, United States, is investigating a Vibrio cholerae O75 outbreak. Ten cases with disease onsets from 23 March to 13 April 2011, presented with gastrointestinal symptoms of diarrhoea, nausea, vomiting, cramps, chills, and/or fever, after consuming raw or lightly cooked oysters harvested from Apalachicola Bay, Florida. Symptoms were milder than those during outbreaks of epidemic (serogroup O1 and O139) Vibrio cholerae; no case required rehydration treatment or hospitalisation.

A pneumococcal conjugate vaccine (PCV7) was introduced into the United Kingdom's childhood immunisation schedule in September 2006. Evaluation of its impact on the incidence of invasive pneumococcal disease (IPD) as assessed by routine reports of laboratory-confirmed cases should take into account possible long-term trends due to factors like changes in case ascertainment. To this end, we compared pre-PCV7 trends in reported IPD incidence in England and Wales identified by blood culture with those for two other bacteraemias, Escherichia coli and non -pyogenic streptococci, for which there has not been any public health intervention. While no trend was detected in the age group 65 years and older, there was an annual increase of 3% and 11% in those aged under five years and between five and 64 years, respectively, which was similar for IPD and the other two pathogens. After PCV7 introduction, a continuing trend was only found for non-pyogenic streptococci in under five year-olds. These trends in the incidence for bacteraemias for which there has been no intervention could suggest that there have been changes in case ascertainment because of increased reporting or blood culturing. Accounting for them will improve the evaluation of the impact of PCV7 on IPD.