ABSTRACT
Hepatitis E virus [HEV] is largely responsible for water borne epidemics in many developing countries. The principle mode of HEV transmission is the fecal oral route in epidemic and sporadic forms with a high case fatality ratio in pregnant women. Serum samples from 50 healthy subjects and from 435 acute viral hepatitis patients, 4-75 years old, were screened for markers of acute viral hepatitis. These included [HBsAg, anti-HBc [IgM], anti- HDV [IgM], HAV [IgM], anti-HCV [IgG], and anti-HEV [IgG], and [IgM] tests by enzyme- linked immunoassays [EIA]. Furthermore isolation of HEV from peripheral blood lymphocytes and from stools belonging to anti-HEV IgG-positive patients was attempted by inoculation of HepG2 and Vero cell line cultures. The inoculated cell cultures were examined after immunoperoxidase staining for the detection of HEV antigen. Plasma, lymphocytes and stool samples from anti-HEV IgM positive patients were examined for HEV RNA by PCR.Anti-HEV IgG was found in 144/435 [33%] of these acute hepatitis patients. Anti-HEV [IgM] was detected in 8/52 [15.4%] out of 52 chosen from the 144 sera that were anti-HEV IgG positive cases. HEV was isolated in HepG2 from 32.6% of lymphocyte and from 34.9% of stools from patients positive for anti-HEV [IgG]. While it was isolated from 71.4% of lymphocytes and from 100% of stools from patients positive for anti-HEV [IgM]. In Vero cell cultures there was no HEV isolation from stools but HEV was isolated from 50% of lymphocytes. HEV RNA was detected by PCR in 85.7% of stools, 62.5% of plasma, and in 37.5% of lymphocyte samples belonging to anti-HEV IgM positive cases. Analysis of these diagnostic tests indicated that virus isolation from peripheral blood lymphocytes and stools by inoculation of HepG2 cell cultures is more sensitive than virus-RNA detection by PCR