Association of HIV infection, other sexually transmitted infections or their coexistence with mpox among men who have sex with men: A national questionnaire-based study in China using propensity score matching.

Abstract

BACKGROUND: A marked increase in mpox cases was observed in May 2022 in previously non-endemic regions. The men who have sex with men (MSM) population exhibited a disproportionately higher rate of infection. OBJECTIVES: This study aimed to investigate the coexistence of HIV infection and other sexually transmitted infections (STIs) and their association with mpox among MSM, with validatiton conducted through a case-control study utilizing propensity score matching (PSM). METHODS: A total of 2403 eligible MSM participants were recruited for a cross-sectional study conducted across six geographically representative regions of China from October 2023 to March 2024. Data were collected via an anonymous online questionnaire. Univariable and multivariable logistic regression analyses were performed to evaluate the association between status of HIV infection and other STIs and risk of mpox. Validatiton was conducted through a case-control study employing PSM. RESULTS: Among the total 2403 participants, 56 (2.33&#x202f;%) reported diagnosis of mpox. Taking participants negative for both HIV infection and other STIs (group 1) as reference, the adjusted ORs (95&#x202f;% CIs) (p value) for mpox were 2.00 (0.60-6.65) (p&#x202f;=&#x202f;0.256), 6.26 (2.97-13.16) (p&#x202f;<&#x202f;0.001), and 8.72 (3.45-22.00) (p&#x202f;<&#x202f;0.001) for those who were only positive for HIV infection (group 2), only positive for other STIs (group 3) and positive for both (group 4), respectively. In the case-control study, 53 participants from the mpox group were matched to 149 participants from the non-infection group at a ratio of 1:3. The positive association between status of HIV infection and other STIs and mpox persisted, with adjusted ORs (95&#x202f;% CIs) (p value) of 1.53 (0.38-6.11) (p&#x202f;=&#x202f;0.547), 7.01 (3.00-16.38) (p&#x202f;<&#x202f;0.001), and 6.20 (2.21-17.43) (p&#x202f;<&#x202f;0.001) for group 2 to group 4, respectively. CONCLUSIONS: This study demonstrated a significant association between other STIs and the risk of mpox among MSM. HIV infection alone didn't significantly increase the risk of mpox, while other STIs were found to be strong and robust risk factors for mpox.