AEGiS-13IAC: The first HIV-1 inter-subtype recombinant between subtype C and AE is discovered in Thailand.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

The first HIV-1 inter-subtype recombinant between subtype C and AE is discovered in Thailand.

Int Conf AIDS 2000 Jul 9-14; 13:32 (abstract no.. LbPeA7005)

Watanaveeradej V, Benenson MW, Chanbancherd P, Polonis VR, Nitayaphan S, Trichavaroj R, de Souza MS, Birx DL, Brown AE, Carr JK
Henry M. Jackson Foundation, Rockville, MD 20850. Fax: 301-294-1898, E-Mail: vwatana@hotmail.com.

Two prospective, non-IDU cohorts in Thailand recently showed a high relative prevalence of HIV-1 V3 EIA which were not subtype AE (10%). Genetic investigation of these samples was performed in order to determine their genetic subtype.

OBJECTIVE: To genetically characterize HIV-1 non-subtype AE in Thailand.

METHODS: Fifteen sera with V3 EIA of either subtype B or both B and AE were collected from two provinces known for beach tourism. RNA was extracted and a 640 bp fragment of env (C2-V5) was reverse transcribed and PCR amplified. This product was then directly sequenced and phylogenetically analyzed. From one sample, full length genome was amplified from PBMC DNA and the product directly sequenced.

RESULTS: Using phylogenetic analysis of the C2-V5 region of the envelope gene, 12 out of 13 samples with subtype B V3 EIA were confirmed to be subtype B. All but one of them showed a close genetic relationship to the Thai strain of subtype B. Of the 2 samples with V3 EIA of both B and AE, 1 was shown to be subtype AE and the other was subtype C. The subtype C sample, C2266, was sequenced in full and determined to be an inter-subtype recombinant between subtype C and subtype AE. Gag and gpl20 were subtype C, while pol, the alpha-helical domain of gp4l and nef were subtype AE. The subtype C portions of the genome resembled the subtype C sequences found in India. The sample was found in a Thai fisherman with no history of injecting drug use.

CONCLUSION: The predominance of subtype AE in heterosexually exposed populations in Thailand may be changing. From two populations in coastal Thailand, there is an unusually high prevalence of subtypes other than AE and the first reported occurrence of an inter-subtype recombinant between subtypes C and AE.

Keywords: AEGIS, HIV-1, Thailand, Polymerase Chain Reaction, Prevalence, India, AIDS
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