Measles control in Maputo, Mozambique, using a single dose of Schwarz vaccine at age 9 months

Abstract

In Maputo city, immunization is available at government health facilities, all contacts being used to vaccinate children. Door-to-door mobilization is conducted to identify eligible children and refer them for immunization. Card-documented measles vaccine coverage, estimated by community surveys, rose from 48% in 1982 to 86% in 1986 and 92% in 1992. The median age at measles vaccination was 10.2 months in 1986 and 9.2 months in 1992. The reported measles incidence rates per 100,000 population fell by 92% from 569 in 1977-78 (pre-vaccination) to 44 in 1990-92, and the reported inpatient measles mortality fell from 19.8 to 0.7 per 100,000. Among children whose age at measles onset was known, the proportion of reported measles cases in children under 9 months of age fell from 2162 (20.3% of 10,636 cases) in 1982-85 to 1695 (17.8% of 9501 cases) in 1986-92. The proportion of cases in children aged > or = 5 years increased from 15.2% to 32.8% in the corresponding periods. The global goals for measles control can be achieved by a single dose of Schwarz vaccine at 9 months of age.

PIP: In the attempt to reduce measles mortality by 95% and morbidity by 90% from pre-vaccination levels by 1995, the World Health Organization recommends district-level immunization coverage of greater than 90% and that emphasis be given to measles control in urban areas. This article describes the use of a single dose of Schwarz vaccine administered at nine months of age to control measles in Maputo, Mozambique. Measles vaccine was introduced to the city in early 1979 during a nationwide campaign reaching an estimated 95% of children aged nine months to five years. The national Expanded Program on Immunization was launched in 1981, with vaccination since then delivered daily at well-baby clinics in 18 government health facilities, and since 1991 at another health center once per week. A team of 18 municipal workers also have gone door-to-door since 1983 to identify eligible children and refer them for immunization. Community survey data indicate that card-documented measles vaccine coverage increased from an estimated 48% in 1982 to 86% in 1986 to 92% in 1992. The median age at measles vaccination of 10.2 months in 1986 had declined to 9.2 months by 1992. Moreover, the reported rates of measles incidence per 100,000 population fell from 569 in 1977-78 to 44 in 1990-92, while reported inpatient measles mortality fell from 19.8 to 0.7 per 100,000. Among children whose age at measles onset was known, the proportion of reported measles cases in children under 9 months old fell from 20.3% in 1982-85 to 17.8% in 1986-92, while the proportion of cases among children five years old and older increased from 15.2% to 32.8% in the corresponding periods. These surveillance findings point to the potential for the administration of a single dose of Schwarz vaccine at nine months of age to realize the global goals for measles control.