Wet cooling systems as a source of sporadic Legionnaires' disease: a geographical analysis of data for England and Wales, 1996-2006.

BACKGROUND: The source of infection for most sporadic cases of Legionnaires' disease remains unknown. This study aims quantify the relationship between cases and wet cooling systems (WCS), a potential source of aerosolised legionella bacteria. METHODS: The study analysed data on 1163 sporadic, community-acquired cases of Legionnaires' disease in England and Wales with onset between 1996 and 2006, and 11630 postcode controls randomly sampled in proportion to population size and matched on region, age group and sex. The relationship between risk of Legionnaires' disease and distance from a WCS was analysed by conditional logistic regression. RESULTS: Cases and controls had a mean age of 56.3 years; 79.3% were male. Cases lived appreciably closer to WCS than their controls (mean distance of cases=2.11 km, controls=2.58 km; mean difference 0.47 km (95% CI 0.28 to 0.65)). The OR for disease within 1 km of a WCS compared with over 6 km (a distance taken to reflect background rates of Legionnaires' disease) was 1.59 (95% CI 1.26 to 2.01) when adjusted for socio-economic deprivation, and 1.33 (95% CI 1.04 to 1.71) when additionally adjusted for population density. The results suggest that residential proximity to a WCS may account for 19.6% of sporadic community-acquired cases. CONCLUSIONS: WCS may be an important source of sporadic, community-acquired cases of Legionnaires' disease, an observation that has important implications for health protection, especially given the likely increase in such systems as a component of strategies to improve energy efficiency in buildings.

From development to success: the European surveillance scheme for travel associated Legionnaires' disease.

BACKGROUND: EWGLINET, the European surveillance scheme for travel associated Legionnaires' disease, was established in 1987 following the identification of the disease in 1976. In 1998, the European Commission's Decision 2119/98/EC provided a legal framework for EWGLINET's operation, and its aims and objectives were formalised. Since its inception, the scheme has encountered a number of challenges which have influenced its development as a Disease Specific Network. The solutions to these challenges, and their successes, may be of interest to similar schemes. AIM: This article traces the development of the scheme and its responses to the challenges it has encountered. RESULTS: One especially significant document developed by the scheme is the European Guidelines for Control and Prevention of Travel Associated Legionnaires' Disease;(1) its history is explored. In addition, EWGLINET's relationship with collaborating centres and other groups such as tour operators is highlighted. CONCLUSIONS: Despite changing over time, the collaborations and partnerships have been maintained and continue to ensure a close cooperation, maximizing public health effects.