The decline of hepatitis B viral infection in South-Western Saudi Arabia.

OBJECTIVE

Hepatitis B virus (HBV) infection is endemic in the Kingdom of Saudi Arabia (KSA). The Jizan region in the South-Western area of the country was noted for a high prevalence of hepatitis B surface antigen (HbsAg) carrier rate. The study was carried out to determine the prevalence of HBsAg and other markers of HBV among residents of Jizan and evaluate the impact of the measures adopted in the last decade, to control HBV.

METHODS

The study was carried out between 1995 and 1998. The subject were studied in 4 groups: Group A consisted of voluntary blood donors (n=14883) tested within the blood banking system during the time period June 1995 to June 1997, Group B were patients treated in the hospitals (n=4692) during the period June 1995 to June 1996, Group C consisted of volunteers recruited from the community (n=1172) and Group D children aged <10 years (n=229). Serum samples were obtained from the subjects tested for HBsAg, total antibody to hepatitis B core antigen, antibody to HBsAg and antibody to hepatitis C virus.

RESULTS

Hepatitis B surface antigen was positive in 5.4% of 14883 voluntary blood donors (Group A) and in 5.1% of 1172 persons recruited from the community (Group C) 40.2% were positive for at least one marker of HBV. The prevalence of HBsAg in-patients in Group B was 9.7% (456 of 4692). These prevalence rates are significantly lower than the prevalence of 12% and 32% reported in 1985 and 1986. Only 2 (0.9% of 229) children in Group D were positive for HBsAg, indicating a major decline from the rate of 8.8% observed in an earlier survey.

CONCLUSION

The low prevalence of HBsAg in children, provides evidence for the effectiveness and efficacy of the integration of hepatitis B vaccination into the extended program of immunization in KSA. The significant decline of HBV markers among unvaccinated Saudi adults indicated an indirect effect of other factors (for example health education and socio-economic progress) on the prevalence and transmission of HBV in Jizan. In areas of high endemicity, the epidemiological characteristics HBV are modified significantly by the combination of HBV vaccination and other complimentary control strategies.