Brote de legionelosis asociado a un balneario

Abstract

The start of seasonal activity at a spa in Guipuzcoa coincided with the detection of an associated legionnaire outbreak in 1998. This led to the closure of the premises and to the carrying out of opportune environmental and epidemiological studies. The latter included case - control study. A case was defined as a person who, either during his stay or in a period of 10 days thereafter, developed pneumonia or a clinical sindrome compatible with that of Pontiac fever (EIC-9). The environmental study included spa and surrounds, and samples of the sanitary water systems and all water therapy elements. 12.5% of the 278 people surveyed in the Basque Autonomous Community matched the case definition. 9 had pneumonia and 27 Pontiac fever. The epidemic curve began on May 7th, peaked on May 14th and 15th, and finalized on the 20th. The risk of illness adjusted according to age, sex and tobacco consumption was associated with the length of stay at the spa (RR=118.5, 95% C.I.: 18.7-750.2) and with swimming-pool use. Serogroup 1 L. pneumophila was detected in counts above 103 ufc/l at different points in the water therapy system and in the shower in the room of one patient. The pulsed field gel eletrophoresis analysis of one of the biological samples and environmental samples allowed genotypic confirmation. The establishment was reopened to the public after emergency treatment was carried out and confirm that after 15 days no L. pneumophila had been detected in the environmental samples