An outbreak of parvovirus B19 infection; a study of clinical manifestations and the incidence of fetal loss.

Eighty-five cases of B19 infection were diagnosed in Northern Ireland from 1984 to 1989; 65 of these occurred during 1989, the outbreak year. Of the total 85 cases, 15 had a rash, 21 had arthralgia, 47 had a rash and arthralgia, and 2 had aplastic crisis. The age range was 4-63 years with a mean of 26.9 years. Thirty cases (35%) were referred to hospital; 25 of these had arthralgia and 2 had aplastic crisis. Two thousand four hundred pregnant women at 12 weeks gestation in 1989 were screened for anti-B19 IgM; 8 were positive. Of these 8 patients, 7 progressed to delivery of a normal fetus and one had an intra-uterine death at 26 weeks gestation; no congenital abnormalities were noted in any fetus. The incidence of fetal involvement in maternal B19 infection in this study was therefore 12.5%.