HIV-1 subtypes and molecular cluster characteristics of middle-aged and elderly HIV/AIDS patients in Jiangshan, Zhejiang, 2014–2018

ObjectiveTo understand the distribution of HIV subtypes and the characteristics of molecular transmission clusters of middle-aged and elderly HIV/AIDS patients in Jiangshan of Zhejiang province, and provide technical support for the analysis of HIV epidemic trends and the prevention and control of the epidemic.

MethodsNewly HIV-1 diagnosed middle aged and elderly HIV/AIDS patients in Jiangshan from 2014 to 2018 were enrolled in this molecular epidemiological study. Total viral RNA was extracted from plasma of 94 patients, including 3 female sex workers (FSWs). The pol genes were amplified with RT-PCR and nested PCR, and then the nucleic acid was sequenced. Software MEGA 6.0 was applied to construct Neighbor-Joining phylogenetic tree for subtype analysis. Software Cytoscape 3.6.0 was applied to construct HIV molecular clusters for sequences with a genetic distance ≤0.01.

ResultsThe success rate of sequence acquisition was 86.2% (81/94). The predominant subtype was CRF01_AE (93.8%, 76/81), followed by CRF07_BC in 3 cases (3.7%) and subtype B in 2 cases (2.5%). Three molecular transmission clusters consisting of subtype CRF01_AE were found. The total clustered rate was 84.0% (68/81). The large cluster contained 64 cases (including 1 positive FSW), and two small clusters were all composed of 2 cases.

ConclusionThe HIV subtype of middle- aged and elderly people in Jiangshan was mainly CRF01_AE. Transmission clusters that closely related to positive FSWs were found. Therefore, the case epidemiological investigation in the clusters should be strengthened in order to implement targeted public health intervention.