Detection of hepatitis E virus RNA and genotype in Bangladesh

Hepatitis E virus (HEV) in Bangladesh has not been adequately documented. We report HEV RNA and genotype detection in Bangladesh. In total, 82 samples were used; 36 sporadic acute hepatitis (AH), 12 fulminant hepatitis (FH), 14 chronic liver disease (CLD) and 20 from an apparently healthy population (HP) positive for both immunoglobulin (Ig) M and IgG specific anti-HEV antibodies (anti-HEV). The male/female ratio was 61/21, ages 12-67 (mean 30.4) years. RNA was extracted, transcribed to cDNA and amplified in nt 6345-6490 (ORF2) of HEV. Nucleic and amino acid sequences were determined. Homology comparison between Bangladesh clones and other representative HEV clones and phylogenetic tree analyses were done. Relations between HEV RNA-positivity and clinical factors were analyzed. HEV RNA was positive in 9/36 (25.0%) of AH cases, 4/12 (33.3%) FH, 3/14 (21.4%) CLD and 0/20 (0%) HP samples; total 16/82 (19.5%). Four factors correlated significantly with HEV RNA-positivity (Mann-Whitney U test); alanine aminotransferase (ALT) (P = 0.0229), aspartate aminotransferase (AST) (P = 0.0448), and titers of IgG (P = 0.0208) and IgM (P = 0.0095) specific anti-HEV. The 16 HEV clones were divided mainly into two groups, A and B, including six different cDNA sub-groups. HEV RNA was found in sporadic AH and FH and sub-clinical CLD cases, but not in HP. HEV RNA-positivity was significantly related to values of ALT and AST and titers of IgG and IgM specific anti-HEV, with IgM specific anti-HEV showing the most significant relationship. All clones were genotype I, which is prevalent in South Asia.