Congo/Crimean haemorrhagic fever in Iraq: a seroepidemiological survey.

A seroepidemiological survey to determine the prevalence of Congo/Crimean haemorrhagic fever virus activity in Iraq was carried out during 1979 and 1980. Sera were collected from 1680 people including contacts of known patients, abattoir workers and animal husbandry workers in various parts of the country. These were tested by complement fixation and agar gel precipitin tests. Among patients' relatives and contacts, 29% had antibodies to Congo/Crimean haemorrhagic fever; 11% of hospital staff, 7% of abattoir workers and 29% of those engaged in animal husbandry had antibodies. Inapparent infections were common in hospital staff caring for patients known to have had the disease. No antibodies were detected in the sera of 151 people who were not believed to have had contact with a known case of the disease.