Campylobacter infection, the most commonly reported bacterial food-borne disorder in the western world, affects more than 2 million people each year in the United States and more than 50,000 people each year in England and Wales. For each case that is reported and cultured, another 7 cases are estimated to remain unreported (0.5% to 1.0% of the total U.K. population). Infection causes a mild, self-limiting illness but cases of Guillain-Barré syndrome (1 in 1000) and death (1 in 20,000) have been reported.

In this retrospective study of cases in the Cardiff area of the United Kingdom during 2001, 1444 patients with negative fecal samples were compared with 213 patients positive for Campylobacter. History of food intake, animal contact, foreign travel, leisure activities, health, and medicine use were recorded. Eating chicken, restaurant fried chicken, and salad vegetables other than lettuce; drinking bottled water (but not milk); and direct contact with cattle were independently associated with Campylobacter infections in nearly 70% of cases. Chicken remains a major risk factor in the United Kingdom, but neither salad vegetables nor bottled water has previously been recognized as a risk factor. Drinking untreated bottled or filtered water has been previously identified as a possible risk factor, but drinking tap water was protective. Cross-contamination during food preparation may be a contributing factor. Even healthy beef and dairy cattle excrete Campylobacter. More studies are needed on the microbiologic quality of natural mineral waters and to identify what interventions would be most effective at reducing food-handling risk.

COMMENTARY: The current controversy suggesting that treatment of poultry with fluoroquinolones makes campylobacter a resistant organism is still raging. Finding new risk factors widens public health concerns. More studies are needed to determine how campylobacter is transmitted and how it can be prevented as well as the role of fluoroquinolones.

Hazards of healthy living: bottled water and salad vegetables as risk factors for Campylobacter infection. Evans MR, Ribeiro CD, Salmon RL. EMERG INFECT DIS 9:1219-1225, 2003.