Hepatitis B virus subgenotype A1, occurrence of subgenotype D4, and S gene mutations among voluntary blood donors in Kenya

Kwange, S. O.; Budambula, Nancy L. M.; Kiptoo, Michael; Okoth, Fredrick; Ochwoto, Missiani; Oduor, Margaret; Kimotho, James

doi:10.1007/s11262-013-0976-1

Cited by 25 publications

(37 citation statements)

References 23 publications

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“…In our study, almost all strains belonged to genotype A. This genotype predominates in many eastern and southern African countries including South Africa, Malawi, Botswana, Mozambique, Tanzania, and Kenya . The majority of genotype A found in our study (38/40) belonged to A1, the main “African” A sub‐genotype as found along the eastern coast of Africa from the Republic of South Africa to the Horn of Africa (Fig.…”

Section: Discussionsupporting

confidence: 55%

Genetic and phylogenic characterization of hepatitis B virus in the eastern part of the Democratic Republic of Congo

Shindano

Horsmans

Kabamba

2017

Journal of Medical Virology

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Hepatitis B virus (HBV) genotypes show a distinctive geographical distribution worldwide and genotypes A, D, and E are the most frequently found in Africa. There are only limited studies on HBV genotype distribution in Democratic Republic of Congo (DRC), all done in the western part showing a vast majority of genotype E. In our study, HBV strains from South Kivu, an eastern province of the DRC, were analyzed. Sequencing of 41 serum samples from HBV infected patients revealed strains of genotype A in 40/41 (97.6%) and genotype E in 1/41 (2.4%). The phylogenetic analysis showed that nearly all genotypes A (38/40) were closely related to A1 subgenotype strains found in Rwanda, Haiti, and Martinique while only two strains attached to the A2 subgenotype cluster were isolated. The remaining genotype E case was linked to the western African E crescent. Only the I169T nucleotide substitution was observed in two genotype A samples. In conclusion, the genotype A seems to be the most predominant genotype in eastern DRC with the majority belonging to the Afro-Asian subgenotype (A1). This contrasts with the western part of DRC where genotype E is predominant. These results support the hypothesis of an East-West genotypic demarcation.

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Section: Discussionsupporting

confidence: 55%

Genetic and phylogenic characterization of hepatitis B virus in the eastern part of the Democratic Republic of Congo

Shindano

Horsmans

Kabamba

2017

Journal of Medical Virology

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“…The HBV genotype D is second to genotype A in terms of predominance in Southern Africa, with the dominant D subgenotype reported to be the D3 [20,29]. However, a recent South African study isolated the subgenotype D4 [26] as was the case in the current study, showing potential importation from other countries like Kenya [24] and Somalia [29] where the D4 subgenotype has been reported.…”

Section: Discussionmentioning

confidence: 51%

Hepatitis B virus infection in post-vaccination South Africa: Occult HBV infection and circulating surface gene variants

Amponsah-Dacosta

Lebelo

Rakgole

et al. 2015

Journal of Clinical Virology

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Background and objective The aim of this study was to investigate the prevalence of occult hepatitis B virus (HBV) infection and the HBV surface (S) gene variants circulating in the South African population after nearly two decades of universal hepatitis B vaccination. Study design From a previous serosurvey, 201 serum samples with serological evidence of exposure to HBV were identified and these were stratified into post- and pre-vaccine introduction populations. For all samples, HBV DNA was screened and quantified using a real-time PCR assay and results analysed together with HBV serological markers. Where HIV results were available, subset analysis was performed. The HBV S gene was PCR-amplified and sequences analysed for a total of 37 isolates. Results The prevalence of occult HBV infection reduced from 70.4% in the pre-vaccine introduction era to 66.0% post-vaccine introduction. There was an association between HIV infection and an increase in prevalence of occult HBV infection within the post-vaccine introduction population, although this was not statistically significant. Furthermore, sequence analysis revealed the following HBV subgenotypes; A1 (n = 34), A2 (n = 2) and a rare D4 isolate. HBV S gene variants, including diagnostic escape mutants were isolated. Conclusion There was a decline in the prevalence of occult HBV infection in post-vaccination South Africa, although the disease burden remains significant in the HIV co-infected population. After nearly two decades of a universal hepatitis B vaccination programme, no positive selection of vaccine escape mutants were observed.

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“…One clade is mainly ‘African’ and includes isolates from southern, eastern and central Africa, while the other, comprising isolates from Asia and Somalia, has been called ‘Asian’ [45]–[47] or ‘Afro-Asian’ [48]. Recently, the term ‘Asian-American’ has also been used to design this latter clade, based on phylogenetic analyses that included HBV/A1 isolates from Caribbean islands and a restricted number of South American strains [19], [31].…”

Section: Resultsmentioning

confidence: 99%

Hepatitis B Virus Subgenotype A1: Evolutionary Relationships between Brazilian, African and Asian Isolates

et al. 2014

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Brazil is a country of low hepatitis B virus (HBV) endemicity in which the genotype A of HBV (HBV/A) is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase), and one (Phe17) in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an ‘Asian-American’ clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300–400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

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Hepatitis B virus subgenotype A1, occurrence of subgenotype D4, and S gene mutations among voluntary blood donors in Kenya

Cited by 25 publications

References 23 publications

Genetic and phylogenic characterization of hepatitis B virus in the eastern part of the Democratic Republic of Congo

Genetic and phylogenic characterization of hepatitis B virus in the eastern part of the Democratic Republic of Congo

Hepatitis B virus infection in post-vaccination South Africa: Occult HBV infection and circulating surface gene variants

Hepatitis B Virus Subgenotype A1: Evolutionary Relationships between Brazilian, African and Asian Isolates

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