SummaryYersinia enterocoliticais a recognized cause of gastroenteritis in northern Europe. During October 1988-January 1990, a prospective case-control study was performed to address risk factors associated with sporadic.Y. enterocoliticainfections in southeastern Norway. Sixty-seven case-patients (mean age 23.4 years, range 8 months-88 years) and 132, age-, sex- and geographically-matched controls were enrolled in the study. Multivariate analysis of the data showed that persons withY. enterocoliticainfection reported having eaten significantly more pork items(3.79v. 2.30 meals,P= 0.02) and sausage (2.84v. 2.20 meals,P= 0.03) in the 2 weeks before illness onset than their matched controls; only one patient had eaten raw pork. Patients were also more likely than controls to report a preference for eating meat prepared raw or rare (47v. 27%,P= 0.01), and to report drinking untreated water (39v. 25%,P= 0.01) in the 2 weeks before illness onset. Each of these factors was independently associated with disease, suggesting a link between yersiniosis and consumption of undercooked pork and sausage products and untreated water. Efforts should be directed towards developing techniques to reduceY. enterocoliticacontamination of pork and educating consumers about (1) proper handling and preparation of pork items and (2) the hazards of drinking untreated water.
Etiology and Factors Associated with Pneumonia in Children under 5 Years of Age in Mali: A Prospective Case-Control Study
