PubMed1991
Legionella infection was recognized as a cause of human disease in 1976, following the occurrence of an epidemic at Bellevue Stratford Hotel, Philadelphia, USA. In the subsequent years, various cases, both sporadic and epidemical, have been reported worldwide. In Italy, the first reports date from 1980. The compulsory notification of the disease was established in February 1983, and a few months later a National Surveillance Programme started operating at the Istituto Superiore di Sanità, Rome. Up to June 30, 1990, 542 confirmed cases of legionellosis were reported. For 249 of them, data of clinical and epidemiological significance are available. The incidence of the disease is higher in males (76% of total cases) and 51.5% of the patients are aged more than 50 years. During the clinical course, the occurrence of hepatic and/or renal dysfunction, cough, dyspnoea, diarrhoea and confusion was documented in a significant proportion of patients. The fatality rate was 12.4%. The disease occurred both sporadically and epidemically. Namely, clusters and outbreaks were detected all over the country, accounting for a total of 97 cases. Hospital patients should be regarded as an important category at risk for infection. The occurrence is also frequent among travellers and tourists, because of the stressing factors that may increase individual susceptibility, as well as the more frequent contact with infective sources. In Italy, the major risk of infection appears connected with water plumbing systems of hotels, residential houses and hospitals, where oxygen bubble-humidifiers have been found to represent an important source of infection. On the contrary, the association of human infection with air conditioning systems has not been evidenced up-to-now.