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An outbreak investigation of cryptosporidiosis in the Netherlands

Een epidemische verheffing van cryptosporidiose in Nederland


Two studies have been carried out during an outbreak of cryptosporidiosis in the Netherlands in the late summer of 1995. A Cryptosporidium prevalence study was conducted in five laboratories in the country among 1495 patients who consulted a general practitioner for complaints of gastroenteritis. At the same time a case-control study was carried out among 71 cases of cryptosporidiosis and 138 matched controls in the Spijkenisse/Rotterdam area and the Haarlem area. Cryptosporidium was isolated in 5-14% of stool specimens in the five laboratories in the late summer of 1995. The prevalence was highest in the youngest age-groups ; sex differences were not observed. Cryptosporidiosis was associated with household contact with a person with diarrhoea (odds ratio (OR) 3.7), swimming in a swimming pool (OR 2.5), recurrent gastrointestinal disease (OR 3.2) and attendance of day care centres in the Haarlem area (OR 3.6). These results suggest that person-to-person transmission has played a major role in the observed increase in cryptosporidiosis in the late summer of 1995. An increase of cryptosporidiosis may occur every summer ; however, the increase in the summer of 1995 appears to have been extreme. It is recommended to incorporate Cryptosporidium-specific testing in the routine examinations of diarrhoeal stool specimens in selected laboratories, in order to study trends in the prevalence of cryptosporidiosis.

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