Genetic diversity of hepatitis B virus (HBV) in Madagascar

Abstract

Hepatitis B virus (HBV) is a DNA virus belonging to Hepadnaviridae family. Chronic infection with HBV is one major risk factor of hepatic disease. In Madagascar, former studies classified the country as part of high endemic area, as HBV prevalence can reach 23% in general population. However, this prevalence differs largely between urban and rural areas and is estimated to be, respectively, 5% and 26%. The aims of the present study were to describe the genetic diversity of HBV strains from different regions of Madagascar, and to describe the viral gene flow throughout the country by using phylogenetic analysis. This is the first large‐scale molecular and phylogenetic study analyzing HBV sequences from 28 different Malagasy areas, never sampled in the past. In this study, the most prevalent genotype/sub‐genotypes was E. Migration analysis showed a gene flow from zone 3 (rural) to zone 2 (suburban), and a greater gene flow from the middle part of Madagascar to the north than to the south. It is important to study the HBV infections in Madagascar and to monitor the potential spread of this viral strain inside this country. J. Med. Virol. 88:2138–2144, 2016. © 2016 Wiley Periodicals, Inc.

Origin and evolutionary dynamics of Hepatitis B virus (HBV) genotype E in Madagascar

“…Madagascar is considered a country with a high level endemicity for HBV [25][26][27]35]; inside this country the genotype E is the most prevalent, followed by genotype A1 and D [28].…”

“…Madagascar is classified as a high endemic area for HBV, and around 5% of the urban population and 30% of the rural population are chronic HBsAg carriers [25][26][27]. A recent study indicated that genotype E is the most prevalent in Madagascar followed by genotype A1 and D [28].…”

“…For the purpose of phylogenetic analysis three data-sets were built. The first data-set included 445 HBV-E genotype P-PreS/S (Pre/S/S region with partial overlapping of P gene) sequences, 366 of which downloaded from NCBI (http://www.ncbi.nlm.nih.gov/) with associated information regarding the geographic location (CM, Cameroon, n = 33; GH, Ghana, n = 22; CD, Democratic Republic of the Congo, n = 4; NG, Nigeria, n = 85; HT, Haiti, n = 10; GN, Guinea, n = 66; AO, Angola, n = 9; SD, Sudan, n = 23; BN, Benin, n = 12; TG, Togo, n = 22; BF, Burkina Faso, n = 10; ML, Mali, n = 18; CF, Central African Republic, n =27; ZA, South Africa, n = 2; CI, Cote d'Ivoire, n = 7; CO, Colombia, n = 9; SN, Senegal, n = 3; LR, Liberia, n = 1; GM, Gambia, n = 3), and 79 were isolates from Madagascar obtained in a previous work [28]. These 79 isolates were collected from different areas in Madagascar (urban, suburban, rural; north, center, and south) as previously described [28].…”

First epidemiological and phylogenetic analysis of Hepatitis B virus infection in migrants from Mali

“…After a first serological screening searching HBs antigen, total DNA was extracted from positive sera using the NucleoSpin1 Dx Virus (MACHEREY‐NAGEL SARL, a67722 Hoerdt, France), according to the manufacturer's instructions, as previously described [Andriamandimby et al, ]. Sequences of about 1,348 nucleotides were amplified using a previously described multiple nested PCR protocol in order to obtain the HBV polymerase (P) and surface antigen (PreS/S) sequences [Zehender et al, ].…”