Epidemiology of blood-borne viruses: a study of healthy blood donors in Southern Pakistan.

There are only a few published reports regarding the prevalence of hepatitis B virus, hepatitis C virus and human immunodeficiency virus in Pakistani blood donors. The true extent of the prevalence of these viral infections in healthy adults in unclear. We examined blood donors attending the Aga Khan University Hospital and blood donation camps in the cities of Karachi and Hyderabad, Pakistan for the presence of hepatitis B surface antigen (HBsAg), antibodies to hepatitis C virus (anti-HCV) and human immunodeficiency virus (anti-HIV). Relationship of anti HCV to the surrogate marker alanine aminotransferase (ALT) was also examined. Prevalence of HBsAg was found to be 2.28% (1,173/51,257), anti HCV was 1.18%(198/16,705) and that of anti HIV to be 0.02% (10/51,257). Higher rate of prevalence of HBsAg and anti HCV was observed in the younger age group of 21 to 30 years. Male to female ratio for HBsAg was 2.5:1 and for anti HCV 1:1. Seropositivity for HBsAg was significantly greater than anti HCV (p < 0.0001). No clear relationship was found between high ALT (>55 U/l) and anti HCV positivity. Further examination of seropositive samples for HIV revealed only one donor to be positive by Western blot also. Prevalence of hepatitis B and C in the adult blood donor population in Southern Pakistan is higher than western countries but is similar to regional countries. This study also suggested that high ALT is not a useful surrogate marker for hepatitis C virus. Prevalence of HIV in this donor population is very low and is comparable to the western countries.