Eurosurveillance - Volume 13, Issue 38, 18 September 2008

Several influenza B outbreaks occurred in closed settings late in the 2007/08 influenza season (October to mid-May) in the United Kingdom (UK), with implications for public health management. Influenza B viruses usually circulate late in the season and cause a milder disease than influenza A viruses [1]. Epidemics of influenza B usually occur every two to three years with the burden of disease falling predominantly on school-aged children [2].

The number of reported cases of Chlamydia trachomatis infections has increased in Sweden in the last decade, as in many other European countries [1]. After a temporary fall in the number of cases reported in Sweden in 2006, due to the spread of a new variant that was not detectable with some of the test methods used at the time, 2007 showed a record high of over 47,000 reported cases [2].

During June and July 2008, five cases of Legionnaires' disease (LD) were reported to the local health authorities and the Norwegian Institute of Public Health (NIPH). The patients all lived in the industrial twin cities Sarpsborg and Fredrikstad in southeast Norway. In the same area, a large outbreak of LD with 56 cases and 10 deaths had occurred in 2005. The source at the time had been traced to an industrial air scrubber at the factory of one of the world's leading suppliers of wood-based chemicals (company A). During this outbreak patients were infected up to 10km away from the source [1]. .

Wet cooling systems are often associated with large outbreaks of Legionnaires' disease. Several European countries have legislation for registering such systems. The authors aimed to obtain an overview of the situation in Europe. A questionnaire survey was sent to 35 of the countries that collaborate in the European Working Group for Legionella Infections. In two countries it was passed to a regional level (to three regions in both Belgium and the United Kingdom), so that 39 countries or regions were sent the survey; 37 responded. Nine countries stated having legislation for the registration of wet cooling systems. Separate legislation exists at a regional level for two regions in Belgium and all three regions in the UK, giving a total of twelve countries/regions with legislation. In nine of these countries/regions, the legislation has been introduced since 2001. All of these countries/regions require periodic microbiological monitoring between twice a year and weekly; in nine, the legislation requires periodic inspection of the systems. Regulations for the registration of wet cooling systems should be required by public health authorities. During an outbreak of legionellosis, a register of wet cooling systems can speed up the investigation process considerably. The authors believe that the European Centre for Disease Prevention and Control (ECDC) should take the initiative to propose European Community (EC) regulations for all Member States.

We describe an outbreak of Legionnaires' disease in 2006 in Amsterdam, the Netherlands. Comparisons with the outbreak that took place in 1999 are made to evaluate changes in legionella prevention and outbreak management. The 2006 outbreak was caused by a wet cooling tower. Thirty-one patients were reported. The outbreak was detected two days after the first patient was admitted to hospital, and the source was eliminated five days later. The 1999 outbreak was caused by a whirlpool at a flower show, and 188 patients were reported. This outbreak was detected 14 days after the first patient was admitted to hospital, and two days later the source was traced. Since 1999, the awareness of legionellosis among physicians, the availability of a urinary antigen tests and more efficient early warning and communication systems improved the efficiency of legionellosis outbreak management. For prevention, extensive legislation with clear responsibilities has been put in place. For wet cooling towers, however, legislation regarding responsibility and supervision of maintenance needs to be improved. .

An action plan for a new animal health strategy for the European Union (2007-2013), where “prevention is better than cure”, was recently published by the European Commission and is now available online.