[Analysis on the relationship of molecular transmission between HIV infected men who have sex with men and their sexual partners].

Objective: To investigate the relationship between HIV-infected men who have sex with men and their sexual partners in Zhejiang province. Methods: A cross-sectional survey was conducted to recruit newly confirmed HIV/AIDS among MSM from 2015 to 2017, including sexual partner identification and molecular epidemiological study. Plasma was collected to extract RNA, and the pol gene of HIV-1 was amplified by RT-PCR/nested PCR. Phylogenetic tree and molecular transmission cluster were analyzed to identify the transmission relationship between sexual partners. Results: A total of 937 HIV/AIDS among MSM were recruited to promote HIV testing for their sexual partners, and 173 positive sexual partners were identified. 50.8% (61/120) of the gene sequences were clustered among the positive sex partners. Seven pairs of clustered sex partners combined with the results of recent infection preliminarily determined the transmission direction. In the clusters, there were statistical differences between the partners who were diagnosed in the same year (OR=12.190, 95%CI: 1.563-95.054) or with current residence in the different districts (OR=17.054, 95%CI: 1.742-166.982). Conclusions: Combined with a molecular transmission network, HIV test for the sexual partners of HIV/AIDS among MSM can improve the accurate tracking of cases and preliminarily determine the direction of transmission, according to the results of recent infection. It is suggested that after HIV is confirmed for HIV/AIDS among MSM, HIV tests should be carried out as soon as possible for their sexual partners, including a cross-regional sexual partner tracking test, which is helpful to improve the tracing procedure.