A low-cost, community-based measles outbreak investigation with follow-up action.

An outbreak of measles in Kampala, Uganda, in 1990 raised concern about the effectiveness of the measles vaccine that was used. The Uganda EPI programme and the medical office of the Kampala City Council therefore conducted a community-based investigation, with door-to-door interviews in two selected communities. They revealed 68 measles cases ranging in age from 5 months to 12 years; the highest age-specific attack rate (32%) was found in children aged 12 to 23 months. BCG immunization coverage was high (85%), but measles immunization coverage was moderate (48%). One community, served by a mobile clinic, presented a vaccine efficacy of only 55%. Responses by mothers revealed that many had failed to have their children completely immunized because of a lack of information, and not because of difficulties in access to the service. In a follow-up, community leaders initiated monthly checking of immunization cards of both children and mothers. The low vaccine efficacy found in one of the communities resulted in a thorough assessment of the city's cold chain. This community-based approach proved to be cost-effective and practical for identifying the obstacles to effective immunization delivery.