Travel-associated legionnaires' disease.

The outbreak of pneumonia involving delegates to the 1976 American Legion c onvention at a Philadelphia hotel was the first example of travel-associate d legionnaires' disease. Travel is now well known as a common risk factor f or legionnaires' disease. This travel-associated disease is a preoccupation among European countries because of morbidity among citizens of the Europe an Union. The definition of the case of legionellosis is a patient who pres ents an acute lower respiratory tract infection with focal signs of pneumon ia and/or radiological features, and microbiological evidence of Legionella infection. A case is considered to be travel associated if the patient has spent one or more nights away from home during the ten days before becommi ng ill. An European Surveillance Scheme for Travel-Associated Legionnaires' Disease was established in 1987 to identify clusters and outbreaks of cases of the disease. This group centralizes the case reports of twenty-nine collaborat ing centres in twenty-five countries. Outbreaks of legionnaires' disease we re described in hotels, camps or cruise ships. In 1996, the number of trave l-associated cases of legionnaires' disease represented 16% of the total nu mber cases. The increase of the number of reported cases may reflect improv ed surveillance and increased ascertainment. In Europe on 1996 the diagnosi s legionellosis was confirmed by detection of Legionella pneumonia sero-gro up 1 antigen on urine (36%), seroconversion (fourfold rise in antibody titr e, 33%) and culture of the organism (16%). Fifteen per cent of legionellosi s was diagnosed by the identification of a single high antibody titre. In France a coordination between Public Health Institutions (Reseau Nationa l de Sante Public and DDASS), clinicians, laboratories and National Referen ce Centre was established to improve prevention and control of legionnaires ' disease outbreaks. Legislation obliges to report each case. When more two cases in the same area are notified an its eradication allows to prevent n ew cases and outbreaks. Outbreaks of Legionnaires' disease are even now mediatic and this fact lead s to maintain attention for the quality of diagnosis and epidemiology inves tigation due to touristic and economic consequences for the implicated coun tries.