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13th International AIDS ConferenceDurban, South Africa - July 9-July 14, 2000 |
Int Conf AIDS 2000 Jul 9-14; 13:(abstract no. MoOrA167)
Shao Y, Xing H, Pan P, Feng Y, Shen T, Zhang Y, Yang W, Zhang J, Lu B
Y. Shao, National Center for AIDS Prevention and Control, 27, Nanwei road, Xuanwu district,Beijing, China, Tel.: +86 10 631 546 38, Fax: +86 10 631 546 38, E-mail: yshao@public3.bta.net.cn
BACKGROUND: The HIV epidemic in China was initiated in Yunnan by subtype B/B' HIV-1, followed by subtype C and other strain. The recombinant viruses were found among IDUs in the same region. More careful study will provide better understanding at the genetic variation, phenotype change and epidemic evolution of the various virus clades and recombinant
METHODS: The HIV env, gag, vif/tat and nef regions were amplified from the uncultured PBMC and sequenced. Virus isolation and viral load (NASBA and Amplicor) tests were done to some samples for monitoring virus phenotype and natural history.
RESULTS: Among 920 persons sampled, 40.6% are IDUs, from which more than 1000 HIV sequences were obtained. The subtype C HIV-1 strains in IDUs were increased from 30.8% in 1996 (in 5 provinces) to 63.2% in 1999 (in 16 provinces). Two types of C and Bi recombinants were discovered in Yunnan, the initial epidemic region of the two parental strains. Only one of the recombinant was spread along a major drug traffic road of 4000 km long across western China. It started from 5% in infected IDUs in Yunnan and steadily increased to 100% of that in Xinjiang at the other end. Both the C and recombinant viruses have NSI and CCR5 phenotype. The people carrying the recombinant viruses have a very low viral load (average 9567 copy/ml, n = 45) compared with its parental strains (average 85376 copy/ml, n = 22).
CONCLUSION: The major HIV-1 subtypes in IDUs have shifted from subtype Bi to C in China. One of the two recombinants has taking over the parental strains among IDUs in the western part of the country. People carrying this recombinant virus have a very low viral load. Special mutations were found in their tat protein, which may link to the above observation. Considering presence of 7 HIV-1 subtypes in China, more attention should be put on the circulating recombinant strains in future studies.
Copyright © 2000 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.
