CAMPYLOBACTERIOSIS IN NEW-ZEALAND - RESULTS OF A CASE-CONTROL STUDY

Study objective-To identify and assess the contributions of major risk factors for campylobacteriosis in New Zealand. Design-Case-control st udy. Home interviews were conducted over nine months using a standardi sed questionnaire to assess recent food consumption and other exposure s. Setting-Four centres in New Zealand with high notification rates of campylobacter infections-Auckland, Hamilton, Wellington, and Christch urch. Participants-Case patients were 621 people notified between 1 Ju ne 1994 and 28 February 1995 as having campylobacter infection. Contro l subjects were selected randomly from telephone directories, and were matched 1:1 with case patients in relation to sex, age group, and hom e telephone prefix. Results-Risk of campylobacteriosis was strongly as sociated with recent consumption of raw or undercooked chicken (matche d odds ratio 4.52, 95% confidence interval 2.88, 7.10). There was also an increased risk with chicken eaten in restaurants (matched odds rat io 3.85; 2.52, 5.88). Recent consumption of baked or roasted chicken s eemed to be protective. Campylobacteriosis was also associated with re cent overseas travel, rainwater as a source of water at home, consumpt ion of raw dairy products, and contact with puppies and cattle, partic ularly calves. Conclusions-Improperly cooked chicken seems to be assoc iated with a large proportion of campylobacteriosis in New Zealand. Th orough cooking of chicken in homes and restaurants could reduce consid erably the incidence of this disease.