Global transmission of HIV-1 subtype C and its impact on the circulation of B/C recombination strains in China

Abstract

This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus (HIV) 1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the form of B/C recombinant strains. Envelope sequences of HIV-1 subtype C and some other subtypes deposited before December 31, 2020 were downloaded from the Los Alamos HIV Database and the Chinese National Center for AIDS/STD Control and Prevention Database. The available sequences were screened for quality, and Bayesian analysis was used to build the maximum clade credibility evolutionary tree to analyze and judge the origin and spread of HIV-1 subtype C. HIV-1 subtype C originated in central Africa around 1952, then spread to southern Africa around 1969 and to eastern Africa around 1973. HIV-1 subtype C from southern Africa was introduced into India in 1977. HIV-1 subtype C of eastern Africa was introduced into Brazil in 1987. Indian HIV-1 subtype C was exported to China in three migration events during the period from 1986 to 1989. The two predominant recombinants in China (CRF07_BC and CRF08_BC) emerged in 1988 and 1990, respectively. Other B/C recombinants, namely, CRF64_BC, CRF61_BC and CRF62_BC, originated in 1993, 2002 and 2000, respectively. Our study has reconstructed the global origin and evolutionary history of HIV-1 subtype C. In addition, our study demonstrated that the Chinese HIV-1 subtype C originated from three related Indian lineages around the mid to late 1980s and, since then, has formed some B/C recombinants with subtype B that caused a widespread epidemic in China.

The emergence and circulation of human immunodeficiency virus (HIV)-1 subtype C

“…Regarding the observed transmission dynamics between Africa and Asia, a recent study from China suggested that the seeding of subtype C from southern Africa into India occurred in 1977, which subsequently exported the virus to China via multiple introductions [42].…”

From a Deadly Disease to a Manageable Chronic Disease, HIV/AIDS Remains a Challenge for Mankind

“…According to a nationwide molecular epidemiological research study in 2012, there were over 11 HIV-1 subtypes and circulating recombinant forms (CRFs) in China, among which CRF07_BC (35.5%), CRF01_AE (27.6%), CRF08_BC (20.1%) and subtype B′ (9.6%) were the four dominant strains 13 . Liu et al 14 revealed that CRF07_BC and CRF08_BC emerged in 1988 and 1990, following the previous introduction of the HIV-1 B strain from Southeast Asia and the C strain from north India. The CRF01_AE was first introduced into China in seven clusters in cross heterosexual groups visiting southeast Asian countries 15 and later became the most prevalent strains for sexual transmission (44.54%) in China, 16 especially among men-who-have-sex-with-men (57.36%) 17 …”