Nigerian medical students are at risk for hepatitis B infection.

Medical students are exposed to blood and body fluids. This study was conducted to estimate the prevalence of hepatitis B virus (HBV) infection amongst medical students of the Lagos State University College of Medicine, Ikeja, Nigeria. Data were collected through a self-administered questionnaire and through blood analysis for hepatitis B surface antigen (HBsAg), hepatitis B 'e' antigen (HBeAg) as well as antibodies to the core (anti-HBc), surface (anti-HBs) and 'e' (anti-HBe) antigens. Three hundred and thirteen of 325 students (96%) participated. The mean age was 24.3+/-3.98 years; 231 (74%) were pre-clinical students and 82 (26%) were in the clinical years of study. Only 8 (2.6%) had received three doses of vaccination against HBV. Eighty-one (26%) tested positive for anti-HBc, 10 (3.2%) were positive for HBsAg and 56 (17.9%) had anti-HBs antibodies. A significant relationship was found between students who had a positive history of hepatitis B in the family and anti-HBc (P=0.03). Age was also significantly associated with HBsAg (P=0.012). Two hundred and twenty-five (72%) students were susceptible to the infection and required vaccination. Most students at this medical school are susceptible to HBV infection and should be vaccinated.

Prevalence of hepatitis B surface antigen in vaccinated children and controls in rural Nigeria.

OBJECTIVE: To determine the prevalence of hepatitis B surface antigen (HBsAg) amongst vaccinated children and controls aged 1-4 years in a rural community in mid-western Nigeria. METHODS: The vaccinated children had received at least three doses of hepatitis B vaccine. The vaccines included recombinant hepatitis B vaccine at birth and a combined diphtheria, tetanus, pertussis (whole cell) plus hepatitis B (DTPw-HBV) vaccine. HBsAg was determined by a rapid immunoassay method based on the immunochromatographic sandwich principle. Two hundred and twenty-three children and 219 controls were recruited into the study. RESULTS: The prevalence of HBsAg was significantly lower in the vaccinated group (1.3%) than in the control group (4.6%, p=0.04). The prevalence rates were significantly higher in males (p=0.02) and two-year birth cohort (p=0.01). The controls were estimated to be at a six-fold higher risk of being positive for the surface antigen than the vaccinated children. The vaccine effectiveness was estimated to be approximately 80%. CONCLUSION: These results confirm that hepatitis B vaccine protects against hepatitis B surface antigen carriage and confirm immunogenicity of the combined DTPw-HBV vaccine.

Short term evaluation of a rural immunization program in Nigeria.

BACKGROUND: Immunization remains the primary strategy in both the control and prevention of common childhood diseases, particularly in the developing world. Immunization and preprimary health care services were commenced in a rural community in Nigeria in 1998, when vaccine coverage for all Expanded Program on Immunization (EPI) diseases (tuberculosis, polio, diphtheria, pertussis, tetanus, measles, and hepatitis B) was considerably low with only 43% of children fully immunized. METHODS: Children aged 0-2 years and living in a rural community were recruited into the study. Data on vaccination history was collected by both vaccination card and maternal history. Three hundred and twenty-seven children were recruited into the study. Study participants were vaccinated for EPI diseases. Hepatitis-B vaccine was administered at birth, and a combined diphtheria and tetanus toxoids, and pertussis whole cell vaccine (DTP) plus hepatitis-B vaccine was administered in a single injection after six weeks. RESULTS AND CONCLUSIONS: Two years after the program was started, immunization coverage rates were 94% for BCG, 88% for DTP (third dose), and 82% for measles. All antigens showed significant improvements from baseline values (p < 0.0001). Eighty four percent of children were fully immunized against all six diseases, compared with 43% at the commencement (p < 0.0001). Hepatitis-B coverage (three doses) was 58%. The vaccination program has significantly improved vaccination coverage and could be a model for under served, non-industrialized communities.