Age-specific prevalence of antibodies to hepatitis A in Santiago, Chile: risk factors and shift in age of infection among children and young adults.
Transition from high to lower endemicity of hepatitis A virus (HAV) infection may portend increased public health burden with the shift of infection to older ages and increasing morbidity and mortality. This report describes age-specific prevalence of antibodies to HAV (anti-HAV) among children and young adults in Santiago, Chile, compared with previous prevalence data and assesses factors predictive for anti-HAV. In 1998, a serosurvey was performed in Metropolitan Santiago, designed to enroll a representative, age-stratified population on the basis of area of residence. A total of 784 individuals (age range, 1-24 years) were enrolled. Anti-HAV prevalence by year of life was as follows: ages 1 to 4, 12.5%; 5 to 9, 26.2%; 10 to 14, 43.4%; 15 to 19, 57.4%; 20 to 24, 73.9%. Adjusting for age, factors associated (inversely) with anti-HAV included residential areas of higher socioeconomic status (SES), parental education, and household characteristics of potable water, municipal sewage system, and the presence of a toilet or refrigerator in the house. In logistic regression analysis, only maternal years of education and residence in areas of higher SES remained independently associated with anti-HAV. Excluding those from higher SES areas, comparison of the age-specific anti-HAV prevalence data from previous studies of similar methodology in areas of lower SES revealed consistent decreases across all age groups; the age-standardized prevalence for this age range (1-24 years) dropped from 53.7% in 1990 to 40.6% in 1998. In light of the growing pool of susceptible individuals at older ages, with HAV continuing to circulate in the communities, evaluation of the feasibility of vaccination programs would be judicious.
International Health Division, Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore 21201, USA. afix@epi.umaryland.edu
Alan D
AD
Fix
Oriana San
OS
Martin
Lisa
L
Gallicchio
Pablo A
PA
Vial
Rosanna
R
Lagos
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002677:Chile / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology / Q000635:transmission; D035922:Hepatitis A Antibodies; D006508:Hepatitis Antibodies / Q000097:blood*; D006798:Housing / Q000592:standards; D006801:Humans; D006920:Hygiene / Q000592:standards*; D007223:Infant; D008297:Male; D009679:Nuclear Family; D015995:Prevalence; D012307:Risk Factors; D014881:Water Supply / Q000592:standards
D035922:Hepatitis A Antibodies; D006508:Hepatitis Antibodies