Prevalence of Hepatitis B Virus, Social Demographic Factors and Circulating Genotypes among Antenatal Clinic Attendees at Mbagathi Country Referral Hospital

Abstract

The World Health Organization approximates that 257 million people are living with hepatitis B virus (HBV) infection with 887,000 deaths related to its complication. This is fuelled by the occurrence of varied risk factors in populations across continents. Majority of HBV chronic carriers reside in Asia and Africa. There are nine genotypes of HBV (A-I) and their variants exist worldwide. Genotypes A, D and E are found in Sub-Saharan Africa. In Kenya genotypes A is dominant. This cross-sectional study was aimed at identifying the prevalence of HBV , associated social demographic risk factors and circulating genotypes, among 287 antenatal attendees at Mbagathi county referral hospital Nairobi.A structured questionnaire capturing social, demographic, explanatory variables was administered. Blood samples were also drawn from the participants and tested for HBV using the ELISA system. The viral DNA was extracted, purified and sequenced. Phylogenetic and mutation analysis was conducted on the generated sequences. The study established the prevalence of HBV infections in the study subjects to be 3.8% with highest infection rate being among the 35-39 years age group(9.5%).The risk factors associated with HBV positivity were; type of family (χ² =19.753 df2 p=0.01), parity (χ²=7.128 df2 p=0.01), History of abortions (χ²=9.094 df1 p=0.01), early age (11 – 15 years) at first sexual encounter (χ² =8.185 df1 p=0.01). The prevalent HBV genotype was genotype A. Hence HBV was transmitted horizontally in this study population. In order to control the spread of the virus there is need to identify cases both during antenatal as well as postnatal care, offer treatment for positive cases and HBV immunization for negative s as well as all women of childbearing age.