Acute viral hepatitis in Lebanon: evidence for a HAV-like non-A non-B hepatitis.

Ninety-three cases of acute viral hepatitis in adult Lebanese patients were followed-up prospectively for a period ranging from 6 to 18 months. These included 33 hepatitis A (HAV), 32 hepatitis B (HBV) and 21 non-A, non-B hepatitis (NANB) cases. The clinical and seroepidemiologic characteristics of the three types were evaluated. HAV was characterized by a short prodroma (less than 1 week) and a high IgM level. HBV did not differ from similar cases reported in the Western world except for a complete absence of male homosexuals and drug addicts as a possible route of transmission. NANB hepatitis in Lebanon is mainly a sporadic infection similar to HAV except that the prodromal phase is prolonged (greater than 14 days) and IgM levels are within normal limits. The failure to develop chronicity in NANB suggests that the virus of sporadic NANB may be different from that which causes post-transfusional (PTH) NANB.