Incidence of hepatitis A virus (HAV) infection in rural Liberia.
To provide background for future hepatitis A vaccine trials, sera were collected from 0- to 4-year-old Liberian infants and their mothers on two occasions an average of 14.75 months apart and tested for antibody to hepatitis A virus (anti-HAV). The prevalence of anti-HAV rose from 2.5% in infants 0-6 months of age to 70% in children 3-4 years of age and did not differ between male and female infants. The annual incidence of new infections was slightly lower in the first year of life (35%) than in the subsequent 3 years, when it averaged 45%. The presence of HBV infection did not affect the incidence of HAV seroconversion. No clinical hepatitis was recognized in the subjects who seroconverted. Dual hepatitis A and B virus infection were observed; these were all clinically inapparent. The extraordinary incidence of HAV infection documented in the present study offers an opportunity for vaccine efficacy trials requiring minimal numbers of subjects.
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology* / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007988:Liberia; D008297:Male; D008875:Middle Aged; D012424:Rural Population; D014761:Viral Hepatitis Vaccines
D000914:Antibodies, Viral; D006514:Hepatitis B Surface Antigens; D014761:Viral Hepatitis Vaccines