Analysis on HIV-1 subtypes and transmission clusters in newly reported HIV/AIDS cases in Yiwu, Zhejiang Province, 2016 / 中华流行病学杂志

ABSTRACT

Objective To understand the characteristics of distribution on HIV-1 subtypes and the transmission clusters in Yiwu in Zhejiang province.Methods A cross-sectional study of molecular epidemiology was carried out on newly reported H1V/AIDS cases in Yiwu.RNA was extracted from 168 plasma samples,followed by RT-PCR and nest-PCR for pol gene amplification,sequencing,phylogenetic tree construction used for analyzing the subtypes and transmission clusters.Mutations on drug resistance was analyzed by CPR 6.0 online tool.Results Subjects were mainly males (86.3％,145/168),with average age as (39.1 ± 13.4) years old and most of them were migrants (66.7％,112/168).The major routes of transmission included homosexual (51.2％,86/168) and heterosexual (48.8％,82/168) contacts.The rate of success for sequence acquisition was 89.9％ (151/168).The dominant subtypes showed as CRF01_AE (74,49.0％) and CRF07_BC (64,42.4％),followed by CRF08_BC (5,3.3％),CRF55_01B (3,2.0％),each case of subtype B,CRF45_cpx,CRF59_01B,CRF85_BC and URF (B/C).CRF45_cpx and CRF85_BC were discovered the first time in Zhejiang province.Twenty-six transmission clusters involving 65 cases were found,with the total clustered rate as 43.0％ (65/151),in which the CRF01_AE clustered rate appeared as 54.1％ (40/74),higher than that of CRF07_BC (21/64,32.8％).The average size of cluster was 2.5 cases/cluster,with average size of cluster in CRF01_AE patients infected through heterosexual transmission as the largest (3.5 cases/cluster).The prevalence of transmitted drug resistance was 4.6％ (7/151).Seven cases with surveillance drug resistant mutations (SDRM) were found,including 5 cases of M46L (3.3％),and one case of F77L or Y181C.Conclusion HIV genetic diversity and a variety of transmission clusters had been noticed in this study area (Yiwu).Programs on monitoring the subtypes and transmission clusters should be continued and strengthened.