Disparate distribution of hepatitis B virus genotypes in four sub-Saharan African countries.

Forbi JC, Ben-Ayed Y, Xia GL, Vaughan G, Drobeniuc J, Switzer WM, Khudyakov YE.

Source

Molecular Epidemiology and Bioinformatics Laboratory, Division of Viral Hepatitis, National Center for HIV, Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333, USA. Electronic address: JForbi@cdc.gov.

Abstract

BACKGROUND:

Hepatitis B virus (HBV) places a substantial health burden on Africa. Here, we investigated genetic diversity of HBV variants circulating in 4 countries of sub-Saharan Africa using archived samples. In total, 1492 plasma samples were tested from HIV-infected individuals and pregnant women, among which 143 (9.6%) were PCR-positive for HBV DNA (Côte d'Ivoire, 70/608 [11.5%]; Ghana, 13/444 [2.9%]; Cameroon, 33/303 [10.9%]; and Uganda, 27/137 [19.7%]).

STUDY DESIGN/RESULTS:

Phylogenetic analysis of the S-gene sequences identified HBV genotypes E (HBV/E, n=96) and A (HBV/A, n=47) distributed as follows: 87% of HBV/E and 13% of HBV/A in Côte d'Ivoire; 100% of HBV/E in Ghana; 67% of HBV/E and 33% of HBV/A in Cameroon; and 100% of HBV/A in Uganda. The average and maximal nucleotide distances among HBV/E sequences were 1.9% and 6.4%, respectively, suggesting a greater genetic diversity for this genotype than previously reported (p<0 .001="" 68="" 7.7="" 93="" acid="" adw2="" africa="" also="" amino="" analysis="" and="" antigen="" as="" associated="" available="" ayw4="" b="" belonged="" c="" cameroon.="" carried="" classified="" d="" earlier="" east="" entral="" escape.="" found="" from="" hbsag="" hbv="" hepatitis="" immune="" in="" into="" of="" on="" only="" origin="" p="" phylogeographic="" predicted="" respectively.="" sag="" sequences="" serotype="" south="" strains.="" strains="" subgenotype="" subgenotypes="" substitutions="" suggestions="" supported="" surface="" te="" the="" to="" uganda="" using="" voire="" was="" were="" west="" whereas="" with="">

CONCLUSIONS:

The observations of pan-African and global dissemination of HBV/A1 and HBV/A2, and the circulation of HBV/E and HBV/A3 almost exclusively in West and Central Africa suggest a more recent increase in prevalence in Africa of HBV/E and HBV/A3 compared to HBV/A1 and HBV/A2. The broad genetic heterogeneity of HBsAg detected here may impact the efficacy of prevention and control efforts in sub-Saharan Africa.
Published by Elsevier B.V.