Characterization Of HIV-1 Transmission Among HIV-infected Foreigners And Chinese Natives In Guangzhou,China Based On Molecular Transmission Network Analysis

BackgroundBased on the genetic diversity,HIV-1 molecular transmission network is a recently developed tool to characterize the transmissions between individuals and the epidemic among risk group for HIV-1 infection,and to evaluate the transmission fitness of viruses.Post-migration infection and domestic transmission of HIV-1 between immigrants and local population are critical for the HIV epidemic,but have not been addressed thus far in China.Men who have sex with men（MSM）are vulnerable risk group for HIV-1 infection.However,some MSM do not disclose their same-sex behavior and could impact the HIV-1 transmission.The distributions of HIV-1 genotypes are complex and sharply shifting in China,while the transmission fitness of HIV-1 genotypes has yet to be systematically evaluated.ObjectiveWe aimed to characterize HIV-1 infection of foreigners and potential non-disclosed MSM in HIV-1 networks in Guangzhou,China and to investigate transmission fitness of HIV-1 genotypes.The results could provide fundamental evidence for precise intervention and prevention of HIV-1 infection among the risk populations.Methods1.HIV-1 transmission networks were constructed with two methods,HIV-TRACE and ClusterPicker,using 1695 HIV-1 pol sequences of 139 HIV-infected foreigners and 1556 Chinese natives in Guangzhou,China from 2008 to 2012.The geographic origin of the HIV-1 sequences was further determined by PastML while the factors associated with HIV-1 transmission were determined by logistic regression analysis.2.HIV-1 pol sequences were obtained from HIV-infected Chinese in Guangzhou,from 2008 to 2015.Transmission network was constructed using HIV-TRACE at a pairwise genetic distance of 0.5%.The position of non-disclosed MSM in the network was further determined by centrality analysis.The factors associated with pnMSM were determined by logistic regression analysis.3.Based on HIV-1 pol sequences from HIV-infected Chinese above,transmission network was constructed at a pairwise genetic distance of 1.5%.Cluster growth indicator and degree were further calculated and logistic regression was used to compare transmission fitness among HIV-1 genotypes.Results1.HIV-1 genotypes that are prevalent in Afirican and East Asian countries were identified in HIV-infected Chinese subjects and vice versa.In addition,more NNRTIrelated drug resistance mutations were detected in HIV-infected foreigriers than in native Chinese（P<0.001）.HIV-1 transmission between HIV-infected foreigners and native Chinese individuals was documented in 12.95%of the foreigners.Furthermore,Asian（odds ratio[OR]=3.45）,male（OR=16.88）and those with known HIV-1 infection routes（OR=3.23）were associated with the HIV-1 transmissions.2.Non-disclosed MSM were inferred in 9.92%（61/615）of slightly older,selfreported non-MSM（P=0.006）.They were more likely to be married（P=0.002）and less educated（P<0.001）than MSM they clustered with.Network centrality was better for pnMSM than for MSM（P<0.001）,indicating the central position and relatively great contribution of non-disclosed MSM in transmitting HIV-1.3.Both cluster growth indicator and degree were significantly different among HIV-1 genotypes,suggesting transmission fitness is dififerent between genotypes.Referred to CRF01_AE,CRF07_BC and CRF55₀1B has higher transmission fitness while subtype B has lower transmission fitness.ConclusionOur study demonstrates the impact of HIV-1 transmission between HIV-infected foreigners and Chinese natives on the HIV-1 epidemic in China and highlights the need for specific prevention strategies that target the immigrant population.Non-disclosed MSM are a specific group,and play important role in HIV-1 transmission.Therefore,specific prevention and intervention targeting nondisclosed MSM are urgently needed.Also,HIV-1 genotype is a main factor associated with transmission fitness of virus.