A SURVEY OF ROUTINE IMMUNIZATION COVERAGE IN OGO OLUWA LOCAL GOVERNMENT AREA OF OYO STATE

Abstract

Inadequate levels and poor routine immunization coverage in Nigeria has led to a large burden of vaccine preventable diseases being borne by children under five years of age. Many causes and factors have been suggested by various researchers which include inequality in the coverage levels especially in rural areas, waxing and waning coverage rates and poorly understood factors due to various peculiarities. This study was carried out to assess the routine immunization coverage of children in Ogo-Oluwa Local Government Area (LGA), a rural community in Oyo state, the timeliness of these vaccines and identify reasons for inadequate immunization.

A descriptive cross sectional survey of children aged 12-23 months in Ogo-Oluwa LGA of Oyo State was conducted in December 2009. Consenting mothers of children in this age group were interviewed utilizing interviewer administered questionnaires. Participants were selected following the World Health Organization’s (WHO) immunization coverage cluster survey design. Vaccination coverage was assessed by vaccination cards. A child was said to be fully immunized if he or she had received all of the following vaccines: a dose of Bacille Calmette Guerin (BCG), four doses of oral polio (OPV), three doses of diphtheria, pertussis and tetanus (DPT), three doses of hepatitis B vaccines (HB) and one dose each of measles and yellow fever vaccines. The vaccination was age appropriate if given within 30 days of the prescribed age. Frequency tables were generated and logistic regression was used to analyze associations between immunization coverage and various factors.

Four hundred and forty mothers were interviewed. The mothers had their immunization cards. Their mean age was 27.9 5.7 years. Sixty six (15.0%) mothers had no formal education and most (76.1%) were married in monogamous family settings. Three hundred and sixteen (71%) women had health facilities offering immunization within a distance of 5km of their homes. Females constituted 228(51.8 %) of the children studied. The mean age of the children studied was 17.33.7 months. Two hundred and thirty two (52.7%) children were delivered in health facilities. One hundred and thirty (29.5%) children were fully immunized and of these only 53.8% were fully immunized by one year of age. Three hundred children had been partially immunized and twenty one (4.8%) had not been immunized at all.
Apart from BCG, OPV0, OPV1, DPT1 and HBV2 all the other vaccines had more than 50% of the children receiving doses that were later than the recommended ages. The drop out rate for DPT1/Yellow fever vaccines was 39% which is almost four times the WHO accepted drop out rate of 10%. The reasons given for non completion of immunization were non availability of vaccines, closely followed by the mother being too busy and mother being unaware of need for subsequent doses of vaccinations. The birth order of children, mothers with formal education, monogamous family type and delivery in a health facility were found to be significant predictors of being fully immunized.

This study showed that immunization coverage rate in this rural area is low with systemic obstacles like non availability of vaccines being contributory factors. Maternal education is also one of the significant predictors of full immunization. It is therefore recommended that more efforts be put into regular provision of vaccines, health education as well as female education.

A SURVEY OF ROUTINE IMMUNIZATION COVERAGE IN OGO OLUWA LOCAL GOVERNMENT AREA OF OYO STATE