FOODBORNE OUTBREAKS OF HEPATITIS-A IN A LOW ENDEMIC COUNTRY - AN EMERGING PROBLEM

This paper describes 2 outbreaks of hepatitis A infection in Finland, a very low endemic area of hepatitis A infection, where a large propor tion of the population is now susceptible to infection by hepatitis A virus (HAV). The first outbreak involved people attending several scho ols and day-care centres; the second employees of several bank branche s in a different city. The initial investigation revealed that both we re related to food distributed widely from separate central kitchens. Two separate case-control studies implicated imported salad food items as the most likely vehicle of infection. HAV was detected in the stoo l of cases from both outbreaks using reverse-transcriptase polymerase chain reaction; however, comparison of viral genome sequences proved t hat the viruses were of different origin and hence the outbreaks, alth ough occurring simultaneously, were not linked. Foodborne outbreaks of HAV may represent an increasing problem in populations not immune to HAV.