Identifying the prevalence and risk factors of secondary human immunodeficiency virus (HIV) transmission from people living with HIV (PLWH) to other people is crucial for ending the HIV epidemic. However, the data among antiretroviral therapy (ART) patients is limited. This study aims to assess the prevalence and risk factors of secondary HIV transmission among PLWH receiving ART by longitudinal molecular networks in China. In this study, the prevalence of secondary HIV transmission was 10.8%. The R0 was greater than 1 from 2017 to 2021 and peaked in 2019. PLWHs who were male sex, older age, engaged in condomless sex, experienced higher ART follow-up viral load, experienced ART medical omissions, infected with non-CRF01_AE subtype, and self-reported sexually transmitted infections (STIs) at HIV diagnosis increased the risk of secondary HIV transmission. However, those participants with higher education were less likely to be involved in secondary HIV transmission. The diagnostic age of the participants was nonlinearly associated with the risk of secondary HIV transmission, with a cutoff value of 43.13 years indicating a higher risk of secondary HIV transmission for patients diagnosed at or above this age. This study revealed substantial secondary HIV transmission and persistent HIV expansion among local PLWH, highlighting the necessity of enhancing viral load monitor, promoting adherence to ART, and promoting safe sex practices, particularly among older adults with HIV, to mitigate secondary HIV transmission.
Keywords: HIV; HIV molecular network; PLWH; condomless sex; secondary HIV transmission.