Abstract
Description of the spatial characteristics of viral dispersal is important in understanding the history of infections. Nine hepatitis B virus (HBV) genotypes (A-I), and a putative 10th genotype (J), with distinct geographical distribution, are recognized. In sub-Saharan Africa (sub)-genotypes A1, D3 and E circulate, with E predominating in western Africa (WA), where HBV is hyperendemic. The low genetic diversity of genotype E (HBV/E) suggests its recent emergence. Our aim was to study the dispersal of HBV/E using full-length, non-redundant and non-recombinant sequences available in public databases. HBV/E was confirmed, and the phylogeny reconstruction performed using maximum likelihood (ML) with bootstrapping. Phylogeographic analysis was conducted by reconstruction of ancestral states using the criterion of parsimony on the estimated ML phylogeny. 46.5% of HBV/E sequences were found within monophyletic clusters. Country-wise analysis revealed the existence of 50 regional clusters. Sequences from WA were located close to the root of the tree, indicating this region as the most probable origin of the HBV/E epidemic and expanded to other geographical regions, within and outside of Africa. A localized dispersal was observed with sequences from Nigeria and Guinea as compared to other WA countries. Based on the sequences available in the databases, the phylogenetic results suggest that European strains originated primarily from WA whereas a majority of American strains originated in Western Central Africa. The differences in regional dispersal patterns of HBV/E suggest limited cross-border transmissions because of restricted population movements.
Highlights
Hepatitis B virus (HBV) is a common cause of liver disease and the prototype member of the family Hepadnaviridae [1]
It should be noted that all genotype E sequences sampled from Europe and Americas may have been derived from HBV carriers of African origin regardless of their country of residence since genotype E is rarely found outside Africa
We studied 318 complete genome sequences sampled from 29 countries around the world, which showed a mean nucleotide diversity of 1.95% ranging between 0% and 3% (S1A Table)
Summary
Hepatitis B virus (HBV) is a common cause of liver disease and the prototype member of the family Hepadnaviridae [1]. Despite the availability of an effective vaccine, HBV infections continue to be a public health problem [2, 3]. In 2015, the World Health Organization (WHO). Phylogeography of HBV genotype E awarded to A.K. L.A.O.I. received a Doctoral Research fellowship grant from the Organization of Women in Science for the Developing World (OWSD) [https://owsd.net/] funded by the Swedish International Development Cooperation (SIDA) [https://www.sida.se/English/], and bursaries from the L’Oreal-UNESCO For Women In Science (FWIS)[https://www.forwomeninscience.com/en/ home] and the Poliomyelitis Research Fund (PRF) [https://www.prf.ac.za/]. K. received a travel grant provided by the Hellenic Association for the Study of Liver (HASL) to present part of this work at the International Liver Congress-EASL meeting held in Vienna, Austria in April 2019. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
