Molecular Tracing of Sexual HIV Type 1 Transmission in the Southwest Border of China

Abstract

Since the first outbreak of HIV-1 was reported in heroin users in China in 1989, HIV-1 has spread steadily among injection drug users, leading to an exponential growth of nationwide outbreaks from 1998 to 2004. However, the impact of sexual transmission on outbreaks of HIV in China's general population is still unclear. Through a governmental HIV/AIDS surveillance program, an HIV serological study was conducted in volunteers between 1996 and 2005 in Xishuangbanna Dai Autonomous Prefecture of Yunnan province. We performed the transmission reconstruction by molecular epidemiological tracing in a subset of the HIV-1-seropositive individuals diagnosed during this survey. Neighbor joining and maximum likelihood trees based on the HIV-1 pol and env genes were implemented to provide information on putative epidemiological links, which were then confirmed by contact tracing. Of 25,390 volunteers, 501 (2%) accumulated cases of HIV-1 infection (21.1% in needle-sharing drug users, 77.3% in heterosexual adults, 0.4% in homosexual adults, and 1.2% in children born from infected mothers) were diagnosed. Among 44 heterosexually infected and antiretroviral-naive local-traceable individuals (27 infected with HIV-1 subtype CRF01_AE, 15 with CRF08_BC, 1 with G, and 1 with a new B/C recombinant), 18 (40.9%) were coclustered into 8 transmission chains with an average size of 2.25 infections per chain. Phylogenetic and epidemiological linkages confirmed eight heterosexual transmission events. This is the first report providing molecular epidemiological evidence of heterosexual transmission of HIV-1 in China's general population. The reconstruction of transmission of current HIV-1 outbreaks by molecular epidemiological tracing is instrumental in identifying sources of the epidemic and in defining prevention strategies.

Molecular Epidemiological Study of HIV-1 CRF01_AE Transmission in Hong Kong

“…This HIV-1 recombinant form was first identified in Thailand 2,3 in 1990 and later spread to the neighboring countries including China, Vietnam, Cambodia, Myanmar, and India, which caused different non-B HIV-1 epidemics. 1,[4][5][6][7] The CRF01_AE pandemic in China was first detected among the intravenous drug user (IDU) population in Yunnan Province in 1989. 8 Explosive numbers of infections were later reported in provinces of southern China including Fujian, Guangdong, Guangxi, Henan, and Sichuan.…”

“…9 In recent years, the number of HIV-1 CRF01_AE infections increased rapidly among individuals with sexually transmitted diseases, especially those living in southern China. 4,10,11 The low level of knowledge on HIV and reproductive health, reluctance of clients of commercial sex workers to use condoms, and the illegal status of sex work in some provinces in southern China fueled the rapid spread of HIV-1 infection. 1 The Hong Kong Special Administrative Region is located in the southern part of China.…”

Evolving Molecular Epidemiological Profile of Human Immunodeficiency Virus 1 in the Southwest Border of China

“…We have previously reported in Xishuangbanna (Banna) Dai Autonomous Prefecture, a well-developed tourist destination in the southwest border of China, that HIV-1 transmitted dominantly through heterosexual contact with less divergent genotypes and few drug resistant mutations [1]. Due to the rapid increase of newly diagnosed HIV-1 cases per year in Banna in recent years, it’s important to evaluate the evolution of HIV-1 molecular epidemiology for the better understanding of ongoing HIV-1 outbreak in this region.…”

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BackgroundWe have previously reported in Xishuangbanna (Banna) Dai Autonomous Prefecture, a well-developed tourist destination in the southwest border of China, that HIV-1 transmitted dominantly through heterosexual contact with less divergent genotypes and few drug resistant mutations [1]. Due to the rapid increase of newly diagnosed HIV-1 cases per year in Banna in recent years, it’s important to evaluate the evolution of HIV-1 molecular epidemiology for the better understanding of ongoing HIV-1 outbreak in this region.

Methodology/Principal Findings

By sequencing of HIV-1 pol genes and phylogenetic analysis, we conducted a molecular epidemiologic study in 352 HIV-1-seropositive highly active antiretroviral treatment (HAART)-naïve individuals newly diagnosed at the Banna Center for Disease Control and Prevention between 2009 and 2011.

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Short Communication: Nucleotide Variation and Positively Selected Sites in HIV Type 1 Reverse Transcriptase Among Heterosexual Transmission Pairs

“…Mutations in the env gene of HIV-1 have been the primary focus in most epidemiologically related cohort studies of virus evolution [10][11][12][13][14][15] and very few studies have focused on the reverse transcriptase (RT) region of polymerase ( pol), which is the primary target of antiretroviral therapy (ART). [16][17][18] In this study, we measured the selection pressure on HIV-1 RT and searched for the positively selected codons that may play an important role in the escape from host immunity.…”