Reactive arthritis following an outbreak of Salmonella infection in Finland

The incidence and clinical features of reactive arthritis (ReA) following an outbreak of enteritis caused by Salmonella enterica ssp. enterica serovar 4,5,12:b:-were studied in the autumn of 1992. The outbreak occurred in several municipalities and originated from sprouted mung beans. A questionnaire on extra-enteric manifestations such as joint and eye symptoms was mailed 2 to 5 months after the outbreak to all bacteriologically proven cases. Two hundred and forty-six of the 272 (90%) subjects responded to the questionnaire; 224 (91%) reported having had enterocolitis, 22 (9%) were asymptomatic. Sixteen subjects fulfilled the criteria for ReA, and one had irities only. Thus, the incidence of ReA/iritis after S. enterica was 6.9%. Only four of the 155 (3%) subjects aged less than 16 yr developed ReA, as compared with 12 of the 91 (13%) older patients (P < 0.001). The only patient with iritis was also more than 16 yr old. The joint symptoms were oligoarticular in 10 (63%), monoarticular in five (31%) and polyarticular in one (6%). The most frequently affected joints were the wrists, knees and ankles. Joints of upper extremities only were affected in three (19%), of the lower extremities only in six (37%) and of both in seven (44%) subjects. In the majority of the patients ReA was mild. The joint symptoms persisted for less than 1 month in six, 2 to 6 months in five and more than 6 months in five. Thirteen subjects with ReA/iritis were tissue-typed for HLA; four (33%) had HLA-B27.(ABSTRACT TRUNCATED AT 250 WORDS)