4th Conference on Retroviruses and Opportunistic Infections Washington, DC - January 22-26, 1997

Conf Retroviruses Opportunistic Infect 1997 Jan 22-26; 4th:70 (abstract no. 32)

Takebe Y, Kusagawa S, Sato H, Katoh K, Nohtomi K, Thwe M, Kywe B, Hien N, Long HT, Samrith C, Leng HB, Yamazaki S; National Institute of Health, Japan.

Objectives: To determine the molecular epidemiology of HIV spread and to understand the epidemiologic patterns of HIV transmission in southeast Asia.

Methods: Sera and whole blood specimens were collected in 1994-5 from seropositive persons in Yangon, Myanmar, and Phnom Penh, Cambodia, Ho chi Minh city and Angiang province, Vietnam, from various risk populations, including IDUs, STD patients, CSWs, and antenatal clinic attendants. The env C2/V3 regions of HIV proviral DNAs were amplified by and sequenced. The phylogenetic relationship and the sequence divergences were analyzed. Results and

Conclusion: Two distinct HIV-1 subtypes E (Thai-A) and B (Thai-B), originally identified in Thailand, were broadly detected in surrounding southeast Asian countries. The intra-subtype inter-person sequence divergence were 5.5% for subtype B and 5.3% for subtype E in Myanmar, close to the values observed in Thailand in 1994 (4.35 and 5.3%, respectively), suggesting that HIV spread in Myanmar might have taken place almost at the same time as in Thailand. The HIV-1 subtype E was exclusively detected in Cambodia and Vietnam. The interperson sequence divergences were 3.6% (n=9) in Cambodia and 4.0% for CSW (n=9) and 1.8% for IDU (n=5) in Vietnam. These results were consistent with the fact that the epidemic in these countries started very recently and the extremely low sequence divergence among IDU in Vietnam might suggest that HIV-1 epidemic started among heterosexual population and later spread to IDU in Vietnam. Findings in the present study will help to understand the epidemiologic patterns of HIV transmission in southeast Asia, where one of fastest growing HIV epidemic is now under way, and will provide important insights for future vaccine strategies.

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Copyright © 1980, 1997 - Foundation for Retrovirology and Human Health. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Foundation for Retrovirology and Human Health. Licensed through AIDSLINE, National Library of Medicine.