An outbreak investigation of cryptosporidiosis in the Netherlands
Een epidemische verheffing van cryptosporidiose in Nederland
Asperen IA van , Stijnen C , Mank T , Boer A de , Groot JF , Medema GJ , Ham P ten , Sluiters JF , Borgdorff MW
RIVM Report 215700001
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.