Objective: To study reactive symptoms following an outbreak of Salmonella enteritidis that occurred after a dinner party held January 15, 1999, in Copenhagen, Denmark. An epidemiological study pointed toward a dish of minced raw salmon, in which one of the constituents was unboiled eggs as the likely cause of the outbreak. Remnants of this dish were not available for bacteriological exam.
Method: All 94 guests and kitchen staff members were mailed a questionnaire about gastrointestinal, joint, and eye symptoms. Nonrespondents were contacted by telephone. Thirty-five individuals delivered blood samples for serological analysis mean 90 days (range 60-186) after the exposure.
Results: Answers were obtained from all participants and 91 were regarded as Salmonella exposed. Male/female ratio was 40/51, mean age 49 years. Fifty-two reported diarrhea (57%), 49 abdominal pain (54%), 33 fever (36%), and 12 vomiting (13%). Eight (9%) delivered stool samples, and all were positive for S. enteritidis. Seventeen fulfilled predefined criteria of reactive arthritis/arthralgia (ReA), and of these 13 had had enterocolitis. Joint pain from knees and ankles was most frequently reported. The mean duration of diarrhea among the patients reporting joint symptoms was 7.5 days, while in the group of patients with enterocolitis without joint symptoms it was 4.1 days (p = 0.00047). Three participants, all from the ReA group, reported ocular redness and irritation compatible with conjunctivitis. Although there was a trend to higher IgG anti-Salmonella antibody levels among the patients with ReA the difference was not significant.
Conclusion: Reactive joint symptoms after food-borne Salmonella infection may be more frequent than previously thought. The duration of diarrhea is strongly correlated with the occurrence of joint symptoms.