Eurosurveillance - Volume 15, Issue 42, 21 October 2010

During August and September 2010, an outbreak comprising 22 cases of Legionnaires' disease was identified by the public health service in Wales. The cases are distributed over a wide geographical area in South East Wales. There are two space-time clusters centred on the upper Rhymney Valley and the lower Cynon Valley respectively. Epidemiological investigations are compatible with cooling towers in each location as the potential source, but environmental inspections were satisfactory and microbiological investigations are inconclusive.

Pandemic H1N1 influenza virus is of global health concern and is currently the predominant influenza virus subtype circulating in the southern hemisphere 2010 winter. The virus has changed little since it emerged in 2009, however, in this report we describe several genetically distinct changes in the pandemic H1N1 influenza virus. These variants were first detected in Singapore in early 2010 and have subsequently spread through Australia and New Zealand. At this stage, these signature changes in the haemagglutinin and neuraminidase proteins have not resulted in significant antigenic changes which might make the current vaccine less effective, but such adaptive mutations should be carefully monitored as the northern hemisphere approaches its winter influenza season.

Campylobacter infection is the most common cause of bacterial gastroenteritis worldwide. This study examines the association between campylobacteriosis incidence and degree of urbanicity in Hesse, Germany, by age and Campylobacter species. During a one-year period (July 2005-June 2006), Hessian local health authorities provided information on municipality of residence for 3,315 campylobacteriosis cases. We calculated age- and Campylobacter species-specific incidences for six levels of urbanicity, as defined by population density and accessibility of centres. For children under five years old, living in inner rural areas (incidence rate ratio (IRR): 2.9; 95% confidence interval (CI): 1.9 to 4.4) and for children aged 5-14 years living in inner rural (IRR: 2.1; 95% CI: 1.3 to 3.1) or intermediate areas (inner intermediate area IRR: 1.8; 95% CI: 1.2 to 2.7; outer intermediate area IRR: 2.1; 95% CI: 1.3 to 3.3) was associated with a statistically significantly higher campylobacteriosis risk (reference category: inner urban area). Calculations by Campylobacter species showed a higher risk of gastroenteritis due to C. coli for inhabitants (all ages) of non-urban areas. This study suggests that differences in risk factors by age, Campylobacter species and degree of urbanicity do exist. For children contact with animals or the environment may be responsible for a substantial proportion of sporadic Campylobacter infections.