Nitrite inhalants use, sexual behaviors and HIV/syphilis infection among men who have sex with men in Chongqing, China

Background: Emerging evidence indicates nitrite inhalants have become increasingly prevalent among men who have sex with men (MSM). The present study aimed to describe the prevalence and correlates of nitrite inhalants use and its association with risky sexual behaviors and human immunodeficiency virus (HIV)/syphilis infection among MSM in Chongqing, a city in China where MSM were burdened with the highest pooled HIV prevalence in the country.Methods: This cross-sectional study was conducted in Chongqing between March 2019 and February 2020. Information of demographics, drug use, sexual behaviors and HIV testing was collected through an anonymous survey. Blood samples were drawn from each participant for the diagnoses of HIV and syphilis. Logistic regression analysis was performed to evaluate factors correlated with nitrite inhalants use and its relationship with risky sexual behaviors and HIV/syphilis infection.Results: Of the 1151 eligible participants, 18.9% (218) reported use of at least one type of recreational drugs in the past 6 months, and nitrite inhalants were the most commonly used substance (17.7, 95% confidence interval [CI]: 15.6-20.2%). The proportions of participants reported engaging in group sex and practicing condomless internal ejaculation during anal sex in the past six months were 5.8% (95%CI: 4.4-7.2%) and 41.7% (95%CI: 38.7-44.7%), respectively. The general prevalence of HIV and syphilis infection among the enrolled MSM were 16.8% (95%CI: 14.7-19.0%) and 12.6% (95%CI: 10.7-14.4%), respectively. Factors positively associated with nitrite inhalants use included: age ≤ 25 (adjusted odds ratio [aOR] = 2.08, 95%CI: 1.10-3.94), monthly individual income ≥ CNY 3000 (Chinese Yuan) (aOR = 1.95, 95%CI: 1.18-3.22), preferring receptive anal intercourse (aOR = 2.27, 95%CI: 1.34-3.84) and versatile anal intercourse (aOR = 2.60, 95%CI: 1.64-4.13), age at first anal intercourse < 18 (aOR = 1.79, 95%CI: 1.21-2.67), engaging in group sex in the past six months (aOR = 9.34, 95%CI: 4.95-17.63), having multiple male sex partners in the past 6 months (aOR = 2.32, 95%CI: 1.50-3.58), practicing CIE during anal sex in the past six months (aOR = 1.71, 95%CI: 1.19-2.46), HIV infection (aOR = 1.72, 95%CI: 1.11-2.66) and syphilis infection (aOR = 1.98, 95%CI: 1.23-3.17).Conclusions: This study found that nitrite inhalants were the most commonly used recreational substance among MSM and nitrite inhalants use were associated with higher probability of HIV and syphilis infection. Therefore, increased attention and counselling should be given to nitrite inhalants-using MSM.