HIV subtypes and molecular transmission characteristics among elderly HIV-infected individuals aged 50 and above: a cross-sectional study in Huzhou City, Eastern China.

ABSTRACT

OBJECTIVE: To analyse the HIV-1 subtypes and molecular transmission characteristics of HIV-infected older individuals aged 50 and above in Huzhou City, and provide a scientific basis for prevention and treatment strategies for them. DESIGN: A cross-sectional study with clustered molecular transmission network cases was performed, and basic epidemiological information was retrieved from the Chinese Centres for Disease Prevention and Control (CDC) Information System. SETTING AND PARTICIPANTS: A molecular epidemiological study was conducted in 899 newly diagnosed HIV-infected individuals from January 2019 and March 2023 in Huzhou city, Zhejiang province, Eastern China. Out of these, HIV sequences were successfully obtained from 673 individuals, including 274 who were older individuals aged 50 and above. PRIMARY AND SECONDARY OUTCOMES: Reverse transcription-polymerase chain reaction (PCR) and nested PCR were used to amplify the polymerase gene of HIV-1, and gene sequencing was performed. We used univariate and multivariate logistic regression to describe the association of clustered molecular transmission network cases. RESULTS: In total, 274 valid HIV sequences of older individuals were obtained, which revealed 14 subtypes. Circulating recombinant forms (CRF) 07_BC accounted for 55.8% and CRF01_AE accounted for 20.1% of the subtypes. Data of 150 older individuals were included in the molecular transmission network, and the proportion of elderly individuals in clustered cases is 52.26% (150/287). The results of multivariable logistic regression analysis showed that the older age group (60-82 years) and CRF07_BC subtype were associated with case clustering (transmission risk). CONCLUSIONS: The key high-risk transmission network was mainly composed of the older age group (60-82 years) and CRF07_BC subtype. It is necessary to further strengthen AIDS health promotion and education for individuals aged 60 years and above, as well as for patients with the CRF07_BC subtype, to reduce HIV transmission and clustering risk.