The prevalence of viral hepatitis markers in apparently healthy individuals of both sexes, born and living in both urban and rural areas of all the Portuguese provinces, was studied by radioimmunoassay.The anti-HAV prevalence was determined in 1770 individuals, 1-84 years old, divided into 8 age groups. The HBsAg prevalence was determined in 1440 individuals, 15-84 years old, divided into 5 age groups, while the anti-HBs prevalence was determined in 1980 individuals, 1-84 years old, divided into 8 age groups. The data were standardized for the Portuguese population.The anti-HAV results were similar for both sexes and showed a general prevalence of 84.9%. No significant difference in the prevalences between urban and rural areas was found. Age-group prevalences of anti-HAV were: 1-4 years, 23.9%; 5-9 years, 61.3%; 10-14 years, 76.4%; 15-19 years, 93.4%; and over 30 years, 99%.The HBsAg results showed a general prevalence of 1.25% for persons over 15 years old (2.04% for males and 0.78% for females). The anti-HBs results were similar for both sexes and showed a general prevalence of 24.3%. The northern provinces tended to have a higher anti-HBs prevalence than the southern ones, except for Lisbon province which had the highest figure. Age-group prevalences of anti-HBs were: 1-4 years, 7.6%; 5-9 years, 12.6%; 10-14 years, 8.7%; 15-19 years, 23.5%; 20-29 years, 28.4%; and over 30 years, between 30.0% and 34.3%.Only 5.3% of the anti-HAV-positive individuals, 11.2% of the HBsAg carriers, and 9.2% of the anti-HBs-positive individuals had a history of acute hepatitis.These results show that Portugal may be considered an endemic area for viral hepatitis infections.
Adolescent Adult