HIV-1 molecular transmission network among men who have sex with men in Shaoxing City / 预防医学

ABSTRACT

Objective@#To investigate the molecular transmission network characteristics of HIV-1 among men who have sex with men (MSM) in Shaoxing City, Zhejiang Province, so as to provide insights into AIDS prevention and control among MSM.@*Methods@#Newly reported HIV/AIDS cases among MSM in Shaoxing City were selected from January 2021 to September 2023. Plasma samples before the antiviral treatment were collected. The HIV-1 pol gene was amplified using reverse transcription PCR and nested PCR to construct phylogenetic trees for gene subtype analysis. The HIV-TRACE method was used to construct a molecular transmission network with a genetic distance of 1.5% to analyze clustering and the characteristics of cases within molecular clusters.@*Results@#A total of 216 HIV/AIDS cases among MSM were included, and 179 qualified sequences were obtained. The predominant HIV-1 subtypes were CRF07_BC and CRF01_AE, with 95 and 66 cases, respectively. At 1.5% genetic distance, 20 molecular clusters were formed, with 61 nodes and 58 edges. A total of 61 sequences were connected to the transmission network (34.08%). HIV/AIDS cases among MSM from all the counties (cities, districts) in Shaoxing City were included in the network. There was the largest molecular cluster with ≥10 nodes, involving 12 cases from five counties (cities, districts), 3 medium-sized molecular clusters with 4 to 5 nodes, and the 16 small-sized molecular clusters with 2 or 3 nodes. Seven cases with high risk of transmission, each with ≥4 edges, were all CRF07_BC subtypes. Among them, two cases were from the large molecular cluster, and five cases were from the same molecular cluster composed of cases from Shengzhou City and Xinchang County.@*Conclusions@#The predominant HIV-1 subtypes among MSM in Shaoxing City were CRF07_BC and CRF01_AE. There was cross-regional HIV transmission, and potential transmission risk might exist in Shengzhou City and Xinchang County.