Control of a community hepatitis A outbreak using hepatitis A vaccine.

In an outbreak of hepatitis A infection among children attending a village primary school hygiene measures and prophylaxis of household contacts of initial cases with human normal immunoglobulin did not prevent spread. Over two months 16 pupils and two household contacts were infected, and seven children aged 6 to 10 years were jaundiced. Testing for salivary IgG and IgM among staff and pupils and their household contacts identified asymptomatic cases. Hepatitis A vaccine was offered to staff and pupils. Coverage was 78%. If those with previous infection are included 81% were protected. Two cases arose in the seven days after the vaccination campaign. No further cases were identified in the following 30 weeks. Our experiences illustrate a lack of public and professional awareness of the seriousness of hepatitis A in adults, and suggest that hepatitis. A vaccine alone is a useful outbreak control measure. Salivary antibody testing showed that only a quarter of those over 40 years of age (17/69) were immune to hepatitis A.