Thermal treatment and infectivity of hepatitis A virus in human feces

The susceptibility of white-lipped marmoset monkeys (Saguinus sp) to human hepatitis A virus (HAV) provides a system for evaluation of thermal inactivation of HAV in feces and contaminated shellfish. Intramuscular or oral administration of HAV derived from feces of four patients with acute hepatitis A induced hepatitis in 28--100% of the inoculated marmosets. A 10% (w/v) fecal pool (GBG-BM) prepared from two patients (GBG and GBM) induced hepatitis in marmosets (2/4 with 1 ml; 2/2 with 3 ml) when given orally as a 1 : 3 dilution. A HAV-baby food raw oyster mixture fed to fasted marmosets induced hepatitis in 1/4 and seroconversion in 2/4 animals. Two groups of oysters were injected with HAV (concentrated 3 : 1 by centrifugation of the GBG-BM pool); one group was treated at 140 degrees F for 19 minutes and the other served as an untreated control. In animals fed the untreated inoculum, 4/6 developed hepatitis and 6/6 seroconverted, whereas of those fed the heat-treated inoculum 1/7 developed hepatitis and 2/7 seroconverted. These data suggest that pasteurization methods could be developed that would eliminate shellfish-associated hepatitis A and retain the palatability of the shellfish.