Using molecular transmission networks to understand the epidemic characteristics of HIV-1 CRF08_BC across China

Abstract

HIV-1 CRF08_BC has become a major epidemic in heterosexuals and intravenous drug users (IDUs) in southern China. In order to evaluate the trends of its epidemic and facilitate targeted HIV prevention, we calculated pairwise genetic distance and constructed the genetic transmission networks based on its pol sequences, derived from the National HIV Molecular Epidemiology Survey. We conducted retrospective network analyses to evaluate changes in inferred clusters over time and studied the epidemic and demographic correlates with transmission networks. Of the 1,829 study subjects, 639 (34.9%) were clustered in 151 transmission networks. A trend of decrease in HIV-1 CRF08_BC infected people clustering in the transmission network was noticed with time. Factors associated with increased clustering include IDUs, heterosexual men, young adults and people with lower education (P<0.05 for all). The IDUs, MSM, young adult and person with low education had more potential transmission links as well (P<0.05 for all). The most crossover links were found between heterosexual women and IDUs, with 30.9% heterosexual women linked to IDUs and 45.4% IDUs to heterosexual women. The crossover links heterosexual women were mainly those with middle age and single (P<0.001). This study indicated that the HIV-1 CRF08_BC epidemic was still on going in China with more than one third of the infected people clustered in the transmission networks. Meanwhile, the study could help identify the active CRF08_BC spreader in the local community and greatly facilitate précising AIDS prevention with targeted intervention.

Research Progress in the Epidemiology of HIV/AIDS in China

“…They found that the molecular transmission networks formed by CRF01_AE, CRF07_BC, and B did not have interconnections. A molecular epidemiological study of HIV-1 among newly diagnosed MSM in 2017 in Jiangsu Province found that 182 (23.7%) of 767 sequences were included in the HIV-1 transmission networks, forming 79 clusters with 4 clusters identified as fast-growing (43). Transmission among young MSM within networks was greater than the other age groups; thus, they could be essential in the control of the HIV epidemic in Jiangsu Province.…”

“…Transmission among young MSM within networks was greater than the other age groups; thus, they could be essential in the control of the HIV epidemic in Jiangsu Province. Li et al constructed genetic transmission networks of CRF08_BC based on its pol sequences, derived from the National HIV Molecular Epidemiology Survey ( 44 ). Of the 1,829 subjects, 639 (34.9%) were clustered in 151 transmission networks.…”

Impacts of HIV-1 Subtype Diversity on Long-Term Clinical Outcomes in Antiretroviral Therapy in Guangxi, China

“…Patients with CRF08_BC are mainly distributed in Guangxi, Yunnan, and Sichuan in southwest China. 21 The application value of our findings should be further validated.…”

“… 20 Of all CRF08_BC, 67% were found in patients infected HIV through heterosexual contact and 23% through injecting drug use. 21 In Guangxi, the proportion of CRF01_AE and CRF08_BC was higher than the overall proportion in China, whereas the proportion of CRF07_BC was lower than the overall proportion in China. 22 The number of men who have sex with men in reported HIV cases increased ranging from 1% to 6% annually between 2010 and 2017.…”

Practice and Prospect: HIV-1 Molecular Network-Based Studies in China

“…28 This finding suggested that prioritizing middle-aged IDUs and HIV-infected heterosexual women might be the most effective strategy to prevent further transmission of the CRF08_BC strain. 28 After CRF55_01B was identified for the first time in China, 29 it has become one of the most recent prevalent strains in China. Through combined molecular networks of CRF55_01B with phylogeographical analysis it was found that it originated in the MSM population in Shenzhen City, and then rapidly spread to all areas in Guangdong and other provinces in China.…”