Hepatitis A virus infections in urban children--are preventive opportunities being missed?

To determine the prevalence of hepatitis A virus (HAV) infections in children in a large urban center, a point prevalence survey was conducted using a novel, ultrasensitive assay for HAV-specific IgG in saliva. A structured sample of 224 grade-six students (5.8% of grade registrants) was obtained from 23 schools throughout Vancouver. All students provided saliva samples adequate for testing. The anti-HAV prevalence rate was 7.1% (95% confidence interval, 4.1%-11.3%). Among 167 Canadian-born students, only 5 (3%) were positive, whereas among 57 students born elsewhere, 11 (19.3%) were positive (P < .001), with circumstances in the latter group supporting infection prior to emigration. No clustering of positive persons was evident. The cumulative risk of HAV infection in Canadian-born children was low through age 11-12 years even in less affluent parts of the city, speaking against a need for routine use of HAV vaccine in this setting.