Hepatitis B virus carrier rate, prevalence and susceptibility and impact of immunization program among households in the city of Taiz, Yemen

Abstract

ObjectiveTo examine the carrier rate, prevalence and susceptibility to hepatitis B virus infection in the city of Taiz, Yemen. MethodsIn a community-based household survey 521 subjects from 98 randomly selected households were enrolled. Carrier rate, prevalence and susceptibility of hepatitis B virus infection in the city of Taiz, Yemen were examined. ResultsThe median age of the subjects was 19 years (range <1–85 years), 219 (42.0%) of whom were males and 305 (58.0%) were females. The HBsAg carrier rate was 4.2% (22/521), the prevalence was 16.9% (88/521) and the susceptibility rate was 57.5% (287/499). Male vs female carrier rate, prevalence and susceptibility rate were comparable. Children (age ≤18 years) vs adults had carrier rates of 2.7% vs 5.7% (odds ratio=2.2) and a prevalence of 5.1% vs 28.4% (OR: 5.6). The carrier rate, prevalence and immunity to HBV among subjects who reported vaccination vs those unvaccinated was; 2.1% vs 5.5%, 11.3 vs 20.8% and 53.1% vs 18.8%. A proportion of 47.2% of subjects who aged ≤10 years had isolated anti-HBs. Of 142 of the cohort born after full implementation of vaccination program (age:≤9 years) 72 (50.7%) were immune and 70 (49.3%) were susceptible whereas of 357 subjects borne before program implementation (Age:≥10 years) 140 (39.2%) were immune and 217 (60.8%) were susceptible (p<0.02 (Pearson) OR: 1.6 CI=0.42–0.93). ConclusionsAn intermediate endimicity was identified in Taiz city. Vaccination reduced carrier rate prevalence and susceptibility among vaccinated subjects. The high rate of subjects with isolated anti- HBs together with the reduced susceptibility rate among the cohort born after inclusion of HBV vaccine to EPI reflects impact of the program. Improving vaccination coverage will further reduce susceptibility rate.