Prevalence of hepatitis B and C markers in volunteer blood donors in Crete. A 5-year study.

Greece is a country with an intermediate prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Crete, the third-largest island of the Mediterranean sea, has a different prevalence of viral hepatitis. One-eighth of the total island population, of 550,000, was included in a 5-year study of blood donors from three out of four blood banks, serving three out of four prefectures of the island. Markers for HBV and HCV were studied and evaluated according to geographical area, gender and age of donor. A total of 65219 blood donors were studied. A greater number of males than females were hepatitis B surface antigen (HBsAg) positive (0. 41% vs 0.28%, respectively) with a peak at a younger age for males and older age for females. Males are more frequently exposed to HBV and become carriers more often than females. For HCV, an opposite gender trend was found, females being infected more frequently (0. 49%) than males (0.37%). Statistical differences were found among geographical areas of the island. Hence, Crete is an area of low endemicity for HBsAg in blood donors. The HCV infectivity is more similar to Northern Europe than to other neighbouring countries. Differences in geographical distribution within the island and during different years indicate the need for extended epidemiological surveys for valid results.