A MILK-BORNE CAMPYLOBACTER OUTBREAK FOLLOWING AN EDUCATIONAL FARM VISIT

After a nursery school trip to a dairy farm, 20 (53%) of 38 children a nd 3 (23%) of 13 adult helpers developed gastrointestinal infection. C ampylobacter jejuni was isolated from 15 primary cases and from 3 of 9 secondary household cases. A cohort study of the school party found i llness to be associated with drinking raw milk (relative risk 5.4, 95% confidence interval 1.4-20.4, P = 0.001). There was a significant dos e response relationship between amount of raw milk consumed and risk o f illness (chi(2)-test for linear trend 12.1, P = 0.0005) but not with incubation period, severity of symptoms or duration of illness. All 1 8 human campylobacter isolates were C. jejuni resistotype 02 and eithe r biotype I (number 16) or biotype II (number 2). Campylobacter was al so isolated from samples of dairy cattle and bird faeces obtained at t he farm but these were of different resisto/biotypes. Educational farm visits have become increasingly popular in recent years and this outb reak illustrates the hazard of exposure to raw milk in this setting.