Objective: To determine all cases of leptospirosis in the Netherlands in 1991-1995 that were confirmed by serological investigation or culturing.
Design: Descriptive, retrospective.
Setting: Department of Biomedical Research, Royal Tropical Institute, Amsterdam, the Netherlands, and Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands.
Method: Using data of the Reference Laboratory for Leptospirosis, the number of leptospirosis cases in 1991-1995 was determined and compared with the data of 1986-1990. Additional information was obtained about patients with confirmed leptospirosis or who had been hospitalized because of leptospirosis.
Results: The number of confirmed cases dropped from 229 in 1986-1990 to 159 in 1991-1995. This decrease could be attributed mainly to a marked decrease of the number of dairy farm fever (hardjo) cases. There was a clear increase of the number of infections acquired during travel in foreign countries, notably outside Europe. Thus, leptospirosis in the Netherlands shifted from an occupational disease towards a disease due to recreational activities. In about 10% of the patients the disease ran a severe course with Weil's syndrome (icterus, renal failure, and haemorrhages). Eight patients (5%) died. Clinical data of 5 of these 8 patients indicated that they had suffered from Weil's syndrome.