Factors associated with discrepancies in vaccination and immunization coverage of measles, tetani and hepatitis B among children aged 12-23 months in Narok County, Kenya

The burden of vaccine preventable diseases and mortalities are still unacceptably high in Narok County despite relatively high vaccination coverage. The objective is to determine factors associated with discrepancies in vaccination coverage and immunization coverage among 373 children aged 12-23 months. This was a cross sectional study that entailed determination of vaccination coverage and serosurveillance of Tetanus, Hepatitis B, and Measles using blood serum. A stratified sampling technique was used to sample children in the County. Statistical data analysis was done in SAS-software and regression performed using Pearson-chi. Results378 children aged 12-23 months were sampled. The mean age of children was 15.3 (SD=3.7) months. Out of 378 children, 255 (67.5%) were aged <17 months. 195(51.6%) children were female. Children with normal birth weight ([&ge;]2.5kgs) were 260 (68.8%) while 230 (60.9%) received exclusive breastfeeding in the first six months of life. Up to 225(59.5%) children were fully vaccinated at health facilities while 31(8.2%) children were fully vaccinated at the outreach centers. Up to 127 (33.6%) children lived in houses with poor ventilations and hygiene. Children with acute/chronic infections during vaccination period were 34.1% (129/278) and 119 (31.5%) had helminthes infestation. Up to 249 (83%) children were vaccinated for measles dose one at the appropriate age of 9 month. Up to 119 (31.5%) children had previous hospital admission in the last one year. The Full vaccination coverage was 251(66.4%) while full immunization coverage was 38.1% (144/378). Discrepancies in vaccination coverage and immunization coverage per age and vaccine doses as were follows, respectively: MCV1 202(79.2%) versus 151 (59.2%) among children <17 months and 98 (79.7%) versus 78 (63.4%) among aged [&ge;]17 months; Vaccination coverage for children who received both MCV1 & MCV2 was 68(55.3%) while immunization coverage was 50.4% among aged [&ge;]17 months. The vaccination coverage for MCV2 was 8(6.5%) while immunization coverage was 3 (2.4%). For tetani vaccine: the vaccination and immunization coverage were 185(72.5%) and 133(52.2%) for those aged <17 months who received all 3 doses while those aged [&ge;]17 months was 86 (69.9%) and 71 (57.7%, respectively. For children who received only two DTP vaccine doses, vaccination coverage was 32 (26%) and immunization coverage was 22(8.6%) among those aged <17 months while it was 6(6.5%) and 5 (8.6%) among aged [&ge;] 17 months, respectively. The main factors associated with discrepancies were birth weight [&ge;] 2.5kgs (OR=1.7), vaccination at health facility (OR=0.42), mixed breast feeding (OR=0.09), and no mother/ child history of helminthes infestation (OR=12.5).