Serological and molecular analyses of icteric hepatitis E in Bangladeshi women

Abstract

Bangladesh is an endemic zone for Hepatitis E Virus (HEV) which is associated with both epidemic and sporadic infections. Since there have been few population-based studies of this country’s HEV burden, its epidemiological characteristics and virological features remain ambiguous. The study included a total of 30 female patients (13 pregnant and 17 nonpregnant women) between the ages of 18 and 70 years, who were all representative of the urban community in Dhaka city. All the subjects had visible jaundice and visited the physicians within the study period (i.e. from August 2016 to May 2017). Clinical and epidemiological data were collected from these patients using questionnaires and the serology-based diagnoses of the Hepatitis viruses, as manifested by the levels of IgM and IgG in case of Hepatitis A, C and E viruses and the presence of HBsAg in case of Hepatitis B virus (HBV), were determined. Nucleic acids were isolated from the serologically positive HEV samples and amplified with primers specific for the Open Reading Frame 2 (ORF2) of the HEV genome in order to ascertain their HEV genotypes. Out of 30 patients, 29 were serologically positive for HEV and 1 was positive for Hepatitis C Virus (HCV). Co-infections of Hepatitis A Virus (HAV) and HEV and that of HBV and HEV were detected. Both pregnant and non pregnant subjects had very high levels of serum bilirubin, Aspartate transaminase (AST), Alanine transaminase (ALT) and Alkaline phosphatase (ALP), with no significant difference in these levels between the HEV mono-infection and co-infection states. Both anti-HEV IgM and IgG antibodies were detected in 51.7% of the HEV positive patients while 41.4% and 6.9% of the patients were positive for only anti-HEV IgG and anti- HEV IgM respectively. 15 out of 29 HEV samples were found positive for HEV RNA. Sanger sequencing-based phylogenetic tree analysis of the HEV RNA positive samples resulted in the formation of a single cluster within genotype 1. This is one of the very first studies to report the clinical, epidemiological, and molecular characterization of an outbreak of Hepatitis E in Bangladesh.