K. Yassin et al., The epidemiology of hepatitis A infection in Palestine: a universal vaccination programme is not yet needed, EPIDEM INFE, 127(2), 2001, pp. 335-339
In Palestine, there has been an increase in the reported incidence of acute
hepatitis A virus (HAV) infection since 1995. Since overt clinical disease
occurs only among adults, questions were raised whether or not a shift in
the epidemiology of HAV has occurred. This is generally characterized by a
decrease in the overall incidence rate and a shifting in the mean age of in
fection towards adolescence and early adulthood. The need for a vaccination
programme is being discussed. To resolve this issue, we examined the preva
lence of anti-HAV in a representative sample of 396 school children in the
Gaza Strip. The prevalence of anti-HAV was 93.7% (95% CI: 91.3, 96.1%). Str
atifying the prevalence by age showed that 87.8% (95% CI: 78.6, 97%) were H
AV antibody positive by the age of 6. By the age of 14, almost 98% (95% CI:
92.7, 100%) were HAV antibody positive. This means that the majority of HA
V infection is still taking place in early childhood, when it is usually as
ymptomatic and of little clinical significance. The results refuted the shi
fting epidemiology theory and we recommend that a vaccination programme aga
inst HAV infection is not yet needed. Alternative explanations for the incr
ease in reported cases are discussed.