Abstract
BACKGROUND: Mpox (formerly known as monkeypox) has disproportionately affected men who have sex with men (MSM), yet evidence from East Asia on psychosocial and behavioral correlates is limited. We examined factors associated with Mpox infection among MSM in China, with attention to health equity considerations. METHODS: A multi-center cross-sectional survey was conducted in six Chinese cities (November 2023-March 2024). Eligible MSM (≥ 18 years; male-to-male sexual contact in the past six months) completed an anonymous questionnaire capturing sociodemographics, Human Immunodeficiency Virus (HIV) infection status (along with other health statuses like hypertension, diabetes, and hyperlipidemia), unprotected anal intercourse (UAI), multiple sex partnerships (MSP), pre-sex substance use (alcohol and drugs), recent voluntary counseling and testing for HIV (VCT), and psychosocial measures (perceived discrimination and self-esteem). Mpox infection was ascertained by self-reported clinical diagnosis or syndromic criteria aligned with national guidance. Multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI). False discovery rate was controlled using the Benjamini-Hochberg procedure within prespecified hypothesis families. RESULTS: Among 2403 participants (mean age 30.6 years), 5.9% met the Mpox case definition. In multivariable logistic regression analyses, younger men had the highest odds of Mpox infection. Using ages 18-24 years as the reference, older groups showed significantly lower odds: 25-34 years (OR = 0.508, 95% CI 0.317-0.814, P = 0.005), 35-44 years (OR = 0.142, 95% CI 0.064-0.316, P < 0.001), and ≥ 45 years (OR = 0.170, 95% CI 0.045-0.641, P = 0.009). Behavioral and health correlates that significantly increased the odds of Mpox included UAI (OR = 2.841, 95% CI 1.858-4.345, P < 0.001), MSP (OR = 1.586, 95% CI 1.063-2.368, P = 0.024), pre-sex drug use (OR = 2.359, 95% CI 1.199-4.639, P = 0.013), and pre-sex alcohol use (OR = 3.955, 95% CI 2.530-6.181, P < 0.001). Furthermore, recent VCT participation was positively associated with Mpox (OR = 2.079, 95% CI 1.19-3.632, P = 0.010). Psychosocial measures were significantly associated with Mpox infection, including higher perceived discrimination (OR = 1.136, 95% CI 1.026-1.258, P = 0.014) and lower self-esteem (OR = 0.962, 95% CI 0.929-0.997, P = 0.034). CONCLUSIONS: Mpox infection among MSM in China was associated with psychosocial (perceived discrimination, self-esteem) and behavioral (condomless anal sex, partner number, pre-sex substance use) characteristics, with higher odds observed among younger men. Integrating Mpox screening and risk-reduction support into existing HIV/sexually transmitted infection services, alongside anti-stigma and youth-focused outreach, may help address observed disparities.