ROUTINE IMMUNIZATION COVERAGE AND ASSOCIATED FACTORS AMONG CHILDREN AGED 12-23 MONTHS IN ODEDA LOCAL GOVERNMENT AREA, OGUN STATE NIGERIA

Abstract

Vaccine preventable childhood diseases are serious health problems in Nigeria. As a result, programmes have been put in place to improve immunization coverage with a view to reducing their burden across the country. However, available evidence suggests that these diseases contribute significantly to childhood morbidity and mortality in spite of concerted efforts aimed at preventing them through Routine immunization (RI). Furthermore, the status of immunization coverage and the factors which militate against full RI are yet to be fully explored. The study was therefore conducted to assess the status of routine immunization coverage and factors responsible for incomplete coverage in Odeda Local Government Area, Ogun State Nigeria. The cross-sectional survey was carried out among 510 women with children aged 12-23 months. Respondents were selected using the WHO cluster sampling technique. A pre-tested structured questionnaire was used to obtain information on mothers' knowledge about immunization and immunization status of their children aged 12 - 23 months. A child was considered fully immunized if he has received a dose of Bacillus Calmette-Guerin (BCG ). three doses of Oral Polio Vaccine (OPV), three doses of Diphtheria - Pertussis - Tetanus (DPT), three doses of Hepatitis B Vaccine (HBV), and a dose each of Measles and Yellow Fever vaccines by 12 months of age while a partially immunized child would have missed one or more of these doses. A composite knowledge score about immunization was computed for each respondent on a 7 - item scale. Respondents with scores or ≥5 and <5 points were considered to have adequate and inadequate knowledge respectively. Descriptive, Chi-square and logistic regression statistics were used for data analysis at p=0 05. Mean age of the respondents was 28.8 ± 5.4 years, 68% had formal education and 57.3% were employed. The mean age of children was 17.9 ± 3.9 months and 49.2% of them were males. Full immunization coverage was 22.2% while 51.9% were partially immunized and 25.9% were not immunized at all. Full coverage in respect of each of the antigens were BCG (57.5%), OPV (21.7%), DPI (23.8%), HBV (14.6%), measles (59.5%) and yellow fever (60.5%). Majority (68.3%) had adequate knowledge about immunization. Respondents with inadequate knowledge were twice more likely to have their children fully immunized than those with adequate knowledge (OR=0.5, 95% CI=0.3-0.9). Thirty percent of respondents with secondary education had their children fully immunized compared to 17.3% of the non-educated ones. Employed mothers were twice more likely to fully immunize their children than unemployed mothers (OR=2.3. 95% Cl= 1.4-3.8). Inconvenient immunization scheduling (14.4%) lack of social support (12.2%), lack of knowledge about need for additional doses (9.4%) and lack of vaccine (8.1%) were among the reasons for incomplete routine immunization coverage. Full immunization coverage among children aged 12-23 months old in the study area was below the national target of at least 80.0%. Inadequate knowledge of mothers and logistic problems are the major limitations to inadequate coverage. Public enlightenment, social support and ready availability of vaccines are needed to address these challenges