STD history predicts persistent condom non-use and partner HIV seroconversion in older Chinese adults with HIV: A retrospective cohort mediation analysis.

OBJECTIVES

This study assessed the impact of STD history on condom use and partner HIV seroconversion among older adults with HIV in Southwest China.

STUDY

DESIGN

We conducted a retrospective cohort study using data from the Chinese HIV/AIDS Comprehensive Response Information Management System (CRIMS) across five cities in Southwest China (2003-2023).

METHODS

Participants included older adults (aged ≥50 years) newly diagnosed with HIV and with documented baseline STD history. Outcomes were inconsistent condom use and partner HIV seroconversion, assessed using longitudinal follow-up records. Logistic regression examined associations, and mediation analysis estimated the indirect effect of condom use on the STD history-seroconversion relationship. Sensitivity analyses stratified participants by sex, marital status, education, and occupation.

RESULTS

Among 30,492 included older adults with HIV (median age: 62.28 years; IQR: 56.26-68.74), 7.3 % had a documented STD history at diagnosis. Most participants were male (72.1 %), farmers (79.8 %), and married/cohabitating (67.8 %). Of the 27,313 participants included in the analysis of condom use, 18.2 % reported inconsistent use, while among the 5025 participants in the partner seroconversion analysis, 6.5 % reported partner HIV seroconversion. STD history was significantly associated with inconsistent condom use post-diagnosis (aOR: 2.18; 95 %CI: 1.96-2.41) and increased partner HIV seroconversion risk (aOR: 1.90; 95 %CI: 1.27-2.84). The mediation analysis indicated that inconsistent condom use explained 11.9 % of the total effect of STD history on partner seroconversion, while the residual effect was unexplained and not captured by the measured mediator.

CONCLUSIONS

Prior STD exposure was associated with persistent sexual risk and elevated partner HIV transmission among older adults, underscoring the need to integrate STD history into risk assessments and long-term monitoring strategies for serodiscordant partnerships in high-burden settings with aging HIV populations.