An outbreak of Salmonella reactive arthritis in Northern Ireland.

During a five month period in the summer of 1987, seven cases of reactive arthritis were seen at Musgrave Park Hospital, Belfast. Of the seven patients, five were male and two female. Their ages ranged from 13 to 44 (mean: 26 +/- 4) years. Five patients gave a preceding short history of diarrhoea which was usually mild. All patients presented with acute inflammatory oligoarthritis which predominantly affected the lower limbs. The knees were involved in 100%, the ankles in 70% with enthesopathy in 30% of cases. The diagnosis was confirmed in all cases by positive serology for Salmonella enteritidis. In three patients, stool cultures grew a particular strain of Salmonella enteritidis (phage type 4). Six patients were HLA-B27 positive. It is not possible to estimate the prevalence of reactive arthritis in this outbreak because there were different sources of infection and the total number of gastroenteritis cases was unknown. However, gut infections with Salmonella enteritidis are becoming increasingly common in this community and throughout the Western world. Over the past two years, in our area, there has been an almost thirty-fold increase in the number of recorded cases of infections due to this organism. By far the commonest source of infection appears to be poultry and egg products.