Yersinia Enterocolitica Infection Associated With Brucella Agglutinins

The clinical pictures of 24 patients having high agglutinin titres against both Brucella abortus and Yersinia enterocolitica type IX are described. Clinical, serological and epidemiological evidence is presented suggesting that the causative agent is Yersinia enterocolitica type IX in the majority if not in all instances. Fever, diarrhoea and abdominal pain were the dominant symptoms. However, the series includes some atypical cases: one with Reiter's syndrome; one with signs resembling collagen diseases, but which could have been a septicaemic form of Yersinia enterocolitica infection; and one with recurrent fever and muscular pain resembling brucellosis or polymyalgia rheumatica.