Sporadic acute or fulminant hepatitis E in Hokkaido, Japan, may be food-borne, as suggested by the presence of hepatitis E virus in pig liver as food

Abstract

Among ten patients who contracted sporadic acute or fulminant hepatitis E between 2001 and 2002 in Hokkaido, Japan, nine (90 %) had a history of consuming grilled or undercooked pig liver 2–8 weeks before the disease onset. We tested packages of raw pig liver sold in grocery stores as food in Hokkaido for the presence of hepatitis E virus (HEV) RNA by RT-PCR. Pig liver specimens from seven (1·9 %) of 363 packages had detectable HEV RNA. Partial sequence analyses revealed that the seven swine HEV isolates belonged to genotype III or IV. One swine HEV isolate (swJL145) from a packaged pig liver had 100 % identity with the HE-JA18 isolate recovered from an 86-year-old patient in Hokkaido. Two swine HEV isolates (swJL234 and swJL325) had 98·5–100 % identity with the HE-JA4 isolate obtained from a 44-year-old patient in Hokkaido. These results indicate that inadequately cooked pig liver may transmit HEV to humans.