Abstract

Seventy nine cases of sporadic, community acquired legionnaires' disease have been reviewed. Annual and seasonal variation in incidence was noted. The mean age of the patients was 53 years and 50 (63%) were male. Pre-existing chronic diseases were present in only 23 (29%), including two patients receiving immunosuppressive treatment. Common symptoms included unproductive cough, dyspnoea, chest pain, headache, confusion, nausea, vomiting, and diarrhoea. Respiratory symptoms were absent, however, in 17 (22%). Localising chest signs were present in 74 (95%) cases. Frequent laboratory findings included lymphopenia, high erythrocyte sedimentation rate, hyponatraemia, raised urea and creatinine concentrations, abnormal liver function, hypophosphataemia, hypoalbuminaemia, proteinuria, and haematuria. Thirteen patients died (16%), including nine of 20 who received assisted ventilation. The mortality rate in patients treated with erythromycin (11%) was lower than in those who received other antibiotics (23%), but this difference was not statistically significant. Of the features noted on admission, only a high plasma urea concentration was significantly associated with death. Sporadic community acquired legionnaires' disease is a not uncommon disorder, which with appropriate treatment has a prognosis similar to that of other forms of community acquired pneumonia.