Identification of a novel variant of hepatitis E virus in Italy

Hepatitis E infection is typically associated with areas in which hepatitis E virus (HEV) is endemic. Except for a few cases in Europe and in the United States, acute hepatitis E is usually associated with travel to endemic areas. We set out to determine the etiologic role of HEV in acute non‐A‐C hepatitis in Italy. The presence of HEV‐RNA and antibody was determined in 218 patients diagnosed with acute viral non‐A‐C hepatitis. Acute hepatitis E infection was defined by the presence of HEV‐RNA in sera and positivity for IgM anti‐HEV and seroconversion to IgG anti‐HEV. Acute hepatitis E was found in 10.1% of the patients with acute non‐A‐C, with 95.5% exhibiting a benign course. A more severe course was observed in a patient co‐infected with HAV and HEV. Most cases were travelers to endemic areas, although 18.2% reported no travel. One patient was from a household with an infected patient. Sequence analyses of the polymerase chain reaction (PCR) product derived from a patient who never visited endemic areas, identified an isolate that is divergent significantly from all reported isolates of HEV (79.5–85.8% nucleotide identity). Evidence from this study suggests that HEV accounts for approximately 10% of acute non‐A‐C viral hepatitis in Italy, diagnosed generally in travelers returning from endemic areas. However, the identification of a new HEV variant in an individual who never indicated travel or contact with individuals associated with endemic areas, suggests that this virus may be native to Italy. J. Med. Virol. 57:356–360, 1999. © 1999 Wiley‐Liss, Inc.