12
Aug

Delayed finger pointing - a report from the International AIDS Conference

There were fewer than ten published references to Burma Myanmar at the recently concluded International AIDS Conference in Mexico.

Regular readers know how flippant [him] is about HIV genetic studies. He thinks most HIV phylogeneticists are wankers. And the findings are used to try to point to the place where HIV "came from". HIV almost invariably came from somewhere else that it is convenient to blame.

Now they report that HIV *possibly* entered the Middle Kingdom from Burma in the year of the US Bicentennial.

[him] moderator

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Phylodynamics of HIV-1 CRF08_BC and CRF07_BC in Asia: a Bayesian coalescent strategy
Presented by Angela Donini, Brazil.

K.K. Tee1, O.G. Pybus2, X.J. Li3, X. Han4, H. Shang4, A. Kamarulzaman5, Y. Takebe1

1National Institute of Infectious Diseases, Laboratory of Molecular Virology and Epidemiology, AIDS Research Center, Tokyo, Japan, 2University of Oxford, Department of Zoology, Oxford, United Kingdom, 3Shanghai Jiao Tong University, Department of Dermatology, The First People's Hospital, Shanghai, China, 4China Medical University, Key Laboratory of AIDS Immunology, The First Affiliated Hospital, Liaoning, China, 5University of Malaya, Department of Medicine, Faculty of Medicine, Kuala Lumpur, Malaysia

Background: HIV-1 CRF08_BC and CRF07_BC are two closely-related recombinants descended from subtype B´ and C that predominate among injecting drug users (IDU) in China. Despite their massive epidemic impact, the divergence times and migration patterns of these recombinants remain unknown.

Methods: Phylogenetic and population genetic analyses were performed on 228 HIV-1 nucleotide sequences, representing CRF08_BC, CRF07_BC and subtype C strains isolated from different locations across China, India and Myanmar. The genome-specific rates of evolution were independently estimated using a Bayesian MCMC framework under various evolutionary models. Using these rates, the times of the most recent common ancestors of CRF08_BC, CRF07_BC and subtype C were estimated.

Results: Genealogy-based analyses show that CRF08_BC originated in 1990.3 (95% credible region, CR: 1988.6-1991.9) in Yunnan province, before spreading to Guangxi (south) and Liaoning (northeast) around 1995. Inside Guangxi region, the eastward expansion of CRF08_BC continued from Baise city (west) to Binyang (central) between 1997 and 1998, and later spread into Pingxiang around 1999 in the south (near the Vietnamese border), mainly through injecting drug use. Additionally, CRF07_BC diverged from its common ancestor in 1993.3 (95% CR: 1991.2-1995.2) before crossing the border into southern Taiwan in the late 1990s. Phylogenetic analysis indicates that both CRF08_BC and CRF07_BC can trace their origin to Yunnan. The parental Indian subtype C lineage likely entered China around 1981.2 (95% CR: 1976.7-1985.9), possibly through Myanmar.

Conclusions: This is the first phylodynamic survey of the eastward dissemination of HIV-1 CRF08_BC, CRF07_BC and subtype C in China. We highlight the significance of their evolutionary histories to viral epidemiology, migration and molecular taxonomy.

http://www.aids2008.org/Pag/Abstracts.aspx?SID=221&AID=4912

Comments

  1. Anonymous says:

    Good point, Anon. Thanks for commenting.

  2. Anonymous says:

    I am affraid you are conflating the work of the philogeneticists and the use other make of it. The formers are scientists whose work is under scrutiny of their peers. The later may well be the wankers you think they are.
    This work has some importance beyond finding where the virus came from first; it provides insight in the virus mutation rate, an essential information when it comes to design vaccines.

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