Diversity of Hepatitis B virus infecting Malaysian candidate blood donors is driven by viral and host factors

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http://www.ingentaconnect.com/content/bsc/jvh/2011/00000018/00000002/art00003

Diversity of Hepatitis B virus infecting Malaysian candidate blood donors is

driven by viral and host factors

Authors: Meldal, B. H. M.1; Bon, A. H.2; Prati, D.; Ayob, Y.2; Allain, J-P.1

Source: Journal of Viral Hepatitis, Volume 18, Number 2, February 2011 , pp.

91-101(11)

Publisher: Wiley-Blackwell

Abstract:Summary. 

Malaysia is a medium endemic country for hepatitis B virus (HBV) infection but

little is known about HBV strains circulating in Malaysian blood donors. Viral

load, HBsAg concentrations and nested PCR products from 84 HBV surface antigen

(HBsAg) positive samples were analysed in detail. Median viral load was

3050 IU/mL and median HBsAg 1150 IU/mL. Fifty-six full genome, 20 pre-S/S, 1

S gene and six basic core promoter/precore-only sequences were obtained.

Genotypes B and C were present at a ratio of 2:1, and two genotype D samples

were obtained, both from donors of Indian background. Phylogenetically, genotype

B was more diverse with subgenotypes B2-5, B7 and B8 present, while most

genotype C strains were from subgenotype C1. Genotypes B and C were equally

frequent in ethnic Malays, but 80% of strains from Chinese were genotype B.

HBsAg concentrations were higher in genotype C than in genotype B, in Chinese

than Malays and in donors under the age of 30. HBV vaccine escape substitutions

(P120S/T, I126N and G145G) were present in six strains. In the large surface

protein, immuno-inactive regions were more mutated than CD8 epitopes and the

major hydrophilic region. Strains of genotype B or from ethnic Malays had higher

genetic diversity than strains of genotype C or from Chinese donors. Hence HBV

strains circulating in Malaysia are phylogenetically diverse reflecting the

ethnic mix of its population. Ethnic Malays carry lower HBsAg levels and higher

genetic diversity of the surface antigen, possibly resulting in more effective

immune control of the infection.

Document Type: Research article

DOI: 10.1111/j.1365-2893.2010.01282.x