A vaccination survey using the EPI methodology to evaluate the impact of a child health outreach programme in an urban area of South Africa

ABSTRACT

A community-based survey of the vaccination status of children aged 12-23 months was conducted to evaluate the impact of a child health outreach programme on vaccination coverage in Alexandra township, South Africa. The EPI cluster sampling technique was adapted for this purpose. The sample size, including the number of clusters and the number of units per cluster, was increased to permit stratification of the data and comparison of the results with those obtained in a study conducted prior to the introduction of the outreach services in 1988. At the time of the survey interview, 67% of the children were fully vaccinated (78% against measles) and by 1 year of age, 58% were fully vaccinated (69% against measles). The increase in coverage since the introduction of the programme was statistically significant only for measles (Student's t-test, P < 0.01). A total of 75% of children living in formal dwellings, compared with 51% living in informal dwellings, were fully vaccinated by interview (Fisher's exact test, two tailed, P < 0.0001). Mothers from informal dwellings had a 1.88 times greater chance of not knowing about the outreach services (P < 0.001). Children whose mothers knew where vaccinations were given, attended postnatal clinics, used the outreach services, possessed a road-to-health card from the Alexandra Health Centre, and who resided in a formal dwelling all had a higher chance of being vaccinated