[Clinical findings and diagnosis of Yersinia enterocolitica infections; a retrospective study in Friesland].

The clinical data of 97 patients with Yersinia enterocolitica infection during 1989 were evaluated. The diagnosis was made by positive culture, serology and/or detection of Yersinia antigens in biopsies. The enteric form (enteritis, abdominal syndrome, pseudo-appendicitis, ileitis and colitis) occurred in 66% of all patients, 10 (10%) had an extramesenteric form, 22 had arthritis and 6 had erythema nodosum. The mean age was 33.6 (SD 19.4) years. Abdominal pain was the syndrome most frequently observed (in 55%), followed by diarrhoea in 44% and malaise in 41%. The duration of the disease was shorter than four weeks in 37% and longer than eight weeks in 34%. Serotype 03 was most frequently isolated. The agglutination reaction was positive in 25%, false-positive in 7% and false-negative in 68%; 91% had specific IgA and IgG antibodies against two or more virulence proteins (Yops).