K De Schrijver

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

This paper describes an outbreak of Legionnaires 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.

Brote de intoxicación alimentaria por consumo de marisco en Amberes, Bélgica

En Amberes, Belgica, se declararon 403 casos de intoxicacion alimentaria asociados a consumo de marisco tras la ingestion de mejillones azules. Los sintomas incluyeron diarrea, vomitos, dolor abdominal y nauseas. El analisis de muestras de heces de pacientes permitio excluir la presencia de bacterias y virus. Las pruebas en ratones revelaron la presencia de biotoxinas especificas de dinoflagelados, que fueron identificados y cuantificados por LC-MS. Los mejillones se habian importado de Dinamarca y formaban parte de un lote cuya concentracion de acido ocadaico era superior a la permitida por la ley.