Having received a press release referring to Legionella Awareness Day and deciding to look a little more deeply into the issues, I came across a report in the journal Eurosurveillance. Compiled from annual data submitted by 29 EU/EEA countries to the European Legionnaires' Disease Surveillance Network (ELDSNet) - covering 2011 to 2015 - it revealed some interesting facts and trends.

The report's conclusion is that the burden of Legionnaires Disease appears to be growing in Europe, displaying an epidemiology similar to that observed in the US, with a comparable notification rate and similar settings of infection. Four countries, France, Germany, Italy and Spain, accounted for 70.3% of all reported cases, although their combined populations represent only 49.9% of the study population. The 20 lowest-reporting countries make up only 10.2% of all cases, while their combined populations represent 28.8% of the study population.

The main purpose of ELDSNet, is detection of travel-related Legionnaires Disease clusters involving residents of Europe that could not otherwise be detected by any national surveillance scheme. Of the total 30,532 cases reported between 2011 and 2015, 11.5% (3098) were deemed foreign travel-related, 71% (21,618) were community/sporadic, 4.9% (1322) nosocomial, and 8.4% (2259) domestic travel-related. By comparison, 46.3% of confirmed cases in England and Wales residents were deemed to have been foreign travel-related (177 of 387 cases).

In the EU/EEA, although the case fatality rate fell between 2011 (10.4%) and 2015 (8.1%), the age-adjusted notification rate increased steadily to 1.3 cases per 100,000 population - the highest rate ever recorded. The report recommends that: "In countries with persistently low notification rates, ad hoc studies should identify reasons for under-ascertainment and all countries should endeavour to develop and maintain appropriate control measures in man-made water systems to prevent LD cases".

The press release I referred to earlier proved that I don't know as much about how we can contract this disease as I thought I did. For example, it talks about the bacteria being present in soil and advises us to wear gloves when handling soil and compost while gardening - something I never bother to do. That got me thinking about my water butt and what could be lurking in there, as some of the contents will have been sitting there - stagnant - for many months. We're expecting a drought next year so many people will be installing water butts for the first time. Worth reading up on how to stay safe while using them then...