An outbreak of Legionnaire's disease among visitors to a fair in Belgium in 1999.

This paper describes an outbreak of Legionnaire's disease at Kapellen in Belgium among visitors of the annual fair. The investigation started on 13th November 1999 after a respiratory physician notified the health authorities of the province of Antwerp of presumptive cases of legionellosis. The annual commercial fair at Kapellen, a small town in northern Belgium, was held 10 days previously and attracted 50,000 visitors. Stand employees (professionals or volunteers), technical staff of the hall and visitors at the fair were affected cases. An exploratory case-control study was conducted to trace the source of the epidemic. To complete the inventory study and to evaluate other risk factors, a cohort study of exhibitors and staff was conducted. Ninety-three people met the case definition, 41 of whom were considered as confirmed, 14 as presumptive cases and 38 as possible/clinical cases. Five people died. Further testing at the reference laboratory confirmed all strains to be Legionella pneumophila serogroup 1. The sensitivity for culture was low (29.2%), and sensitivity for seroconversion was high (90.9%). For urinary antigen test, a sensitivity with Biotest EIA of 65.6% was found, and the sensitivity of polymerase chain reaction (PCR) was 85.7%. In all cases, the individual had visited the fair. Those individuals working in the central areas of the tent, near the aerosol-producing devices, were at higher risk of disease. Legionella was detected by PCR on swabs of the surfaces of the whirlpool. Although not fully proven, an aerosol-producing device was the most probable source of the outbreak.

Carbon monoxide load in indoor carting.

Personal experience and reports of colleagues made the authors aware of a possible problem of carbon monoxide exposure in indoor carting arenas. Symptoms such as nausea, headache and altered coordination are not uncommon. This prompted us to register carbon monoxide levels in 15 healthy volunteers in a recreational carting event in a random arena. After two sessions of 10 min and a finale of 20 min we measured a clear increase in carboxyhaemoglobin levels, up to a 16.5-fold increase. The mean rise in the carboxyhaemoglobin level (expressed as a percentage) was 2.06 (mean start carboxyhaemoglobin 0.49%, mean end carboxyhaemoglobin 2.55%). Nausea was noted in 53% of the drivers, headache and altered coordination in 33%, and 13% had a vague abdominal pain. The effects of carbon monoxide exposure during indoor carting should thus not be underestimated, and healthcare workers should be aware of the possible risks.

An outbreak of legionnaire s disease among visitors to a fair in Belgium, 1999.

Ninety-three cases of legionnaires disease (43 confirmed, 12 presumptive, and 38 possible/ clinical) were identified in an outbreak associated with a trade fair in Kapellen, Belgium in November 1999. Five cases died. Epidemiological investigation showed