Volume 11 Supplement 1

16th Interntional Conference on Human Retroviruses: HTLV and Related Viruses

Open Access

HTLV-1 molecular epidemiology in central Australia: Two distinctive HTLV-1 Subtype C lineages in Indigenous Australians

  • Olivier Cassar1, 2Email author,
  • Lloyd Einsiedel3,
  • Philippe V Afonso1, 2 and
  • Antoine Gessain1, 2
Retrovirology201411(Suppl 1):P56

DOI: 10.1186/1742-4690-11-S1-P56

Published: 7 January 2014

HTLV-1 infects approximately 5-10 million people worldwide. It is widely distributed, with clusters of high endemicity in certain geographic areas or ethnic groups. Seven main HTLV-1 subtypes have been described and the Melanesian/Australian subtype C is only found in Oceania. In Australia, HTLV-1 is endemic with ATLL, TSP/HAM, bronchiectasis, ID and severe scabies cases reported. However, HTLV-1 clinical significance is debated and only one partial HTLV-1 sequence from an Aboriginal Australian (MSHR-1) is available. Therefore, establishing a large HTLV-1 sequence database is essential for the understanding of the epidemiology and pathogenesis of this virus in Indigenous people. Samples were obtained from 23 HTLV-1 patients originated from four broad geographical and language-based areas. Sequence comparison indicated that the 23 new HTLV-1 LTR and Tax-Gag sequences belong to the subtype C as MSHR-1 strain. Phylogenetic analyses evidenced two main clades (Solomon Islands/Vanuatu versus Australia) within subtype C. Interestingly, the Australian clade can be itself divided into two clusters: the first comprising strains characterized among most of the Indigenous Australians from the North and the second including a majority of individuals originating from the South and Central Australia. Thus, there is a clear evidence of a specific HTLV-1 clustering according to the childhood residence of the HTLV-1 infected individuals, and subsequently their language group affinity. Taking into account that non-human primates have never been found in Australia, we believe that these HTLV-1 subtype C variants have been present among the first ancestors of modern Indigenous Australians for several tens of millennia.

Authors’ Affiliations

(1)
Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Département de Virologie, Institut Pasteur
(2)
UMR 3569, CNRS
(3)
Flinders University/Northern Territory Rural Clinical School, Alice Springs Hospital

Copyright

© Cassar et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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