Use of hygiene advice and active immunisation to control an outbreak of hepatitis A

A community outbreak of at least 16 cases of hepatitis A is described. Salivary antibody testing of 126 children within a school in that community showed only one case of undiagnosed previous infection. Three other children had received hepatitis A vaccine previously, and this was reflected in their antibody titres. For the schools serving the community control measures included advice on good hygiene (supervised handwashing and additional cleaning in the schools). All close contacts of cases (household and childminding contacts and all staff in one school) were given active immunisation, though two subsequently developed hepatitis A, 17 and 27 days after vaccination. The use of human normal immunoglobulin (HNIG) was fully discussed with contacts, but was declined in all cases. The low prevalence of previous infection found in the schoolchildren implies that, in future, few adults will be immune. Public concern about blood products after the recent Department of Health decision to stop using British-sourced plasma may be a factor in limiting the uptake of HNIG, especially as there is now a perceived safer alternative, namely hepatitis A vaccine. Lack of evidence of spread of disease within the schools involved demonstrates that good hygiene, especially handwashing, remains the most important element in the control of hepatitis A.