Epidemic Reiter's syndrome following an outbreak of shigellosis.

We prospectively studied the occurrence of Reiter's syndrome (RS) or reactive arthritis (ReA) in 205 of 349 cruise-ship passengers who attended a buffet ashore and developed Shigella flexneri 2a enteritis. Five passengers probably had RS/ReA and 16 were possible or doubtful cases of RS/ReA. HLA-B27 was identified in 4 of 5 probable RS cases, but was not present in any of the 16 possible or doubtful cases nor in any of 20 passengers (controls) without any symptoms of RS/ReA. There was no statistically significant difference in the frequency of B7-Creg antigens in persons with possible or doubtful RS/ReA (9/16) compared to controls (8/20).