Molecular transmission networks of human immunodeficiency virus-1 CRF01 AE strains in China / 中华微生物学和免疫学杂志

ABSTRACT

Objective To construct the molecular transmission networks of HIV-1 CRF01 AE strains circulating in China and to analyze their characteristics. Methods Sequences of the pol genes of Chinese CRF01 AE strains were downloaded from Los Alamos database and the related demographic informa-tion was checked. Transmission networks were created by four steps,including phylogenetic tree construc-tion,transmission cluster extraction,minimum genetic distance identification and network visualization. Chi-square test was performed to analyze the differences in the distribution of different populations in the networks and the differences in the distribution of subjects with different degrees among different sub-populations. De-scriptive analysis was used to investigate the transmission links between sub-populations and various regions. Results The 2 419 sequences constituted 250 separate networks including 847 nodes and 610 edges. The number of subjects covered by different networks ranged from 2 to 25. Subjects with degree ≥2 represented only 26. 4%(224 / 847)of network-individuals,but were connected with 66. 5%(563 / 847)of all network-individuals. There were 37. 6%(669 / 1 781)of men who have sex with men(MSM),28. 4%(102 / 359) of heterosexual men,16. 1%(10 / 62)of intravenous drug users(IDUs)and 30. 4%(66 / 217)of hetero-sexual women involved in the networks(χ2 =23. 774,P﹤0. 001). The percentage of subjects with degree ≥2 was high in MSM(10. 8% ,193 / 1 781)compared to that in heterosexual men(5. 6% ,20 / 359)(P =0. 002)and heterosexual women(4. 6% ,10 / 217)(P=0. 004). Of the 669 MSM in the networks,95. 5%(639 / 669)linked to other MSM and only 2. 4% (16 / 669)linked to heterosexual women. However, 15. 1%(10 / 66)of the heterosexual women in the networks linked to MSM. Of the heterosexual men in the networks,35. 3%(36 / 102)linked to heterosexual women,9. 8%(10 / 102)linked to MSM. Of the sub-jects in the networks,20. 9%(177 / 847)linked to other regions' individuals. Conclusion The super-spreaders played an important role in the molecular transmission networks of HIV-1 CRF01 AE strains even though they were in a minority. The transmission of HIV-1 CRF01 AE strains between sub-populations and various regions was complicated and active.