Enzyme-linked immunosorbent assay for diagnosis of acute sporadic hepatitis E in Egyptian children.
Hepatitis E virus (HEV) is thought to be a cause of enterically transmitted non-A, non-B (ET-NANB) hepatitis. Waterborne epidemics have been recorded in many developing countries, mainly affecting young-to-middle-aged adults; sporadic infection and overt illness in children are rare. However, a convenient and sensitive diagnostic test for HEV infection is not yet available. We now report the use of a solid-phase enzyme-linked immunoassay (ELISA) that detects IgM and IgG antibody to HEV. In a prospective study of endemic acute hepatitis during 1986 in rural Benha, Egypt, 15 (42%) of 36 children with NANB hepatitis (from whom convalescent-phase sera were available every 3 months to 9 or 12 months) were positive for anti-HEV-IgG by ELISA. Of 20 sera from healthy Benha children (controls), 5 (25%) were also positive for anti-HEV-IgG. When evaluated for anti-HEV-IgM, 6 of the 15 IgG-positive children, but none of the controls, were IgM positive and were thus regarded as having confirmed acute HEV infections. These 6 cases together with 2 presumptive cases (IgM negative, IgG seroconversion from positive to negative) presented sporadically over 9 months. This ELISA is a convenient method for the diagnosis of HEV infection; we have shown that the disease is present in Egypt, that it can occur endemically as sporadic cases, and that children do have overt infection.