Comparison of syphilis among MSM and low-tier FSW in China
| Variable | MSM | Low-tier FSW* |
| Syphilis prevalence estimates | 9.1% (95% CI 7.6% to 10.8%)8 | 12.5% (IQR 4.1–20.1)19 |
| Syphilis incidence estimates | 8–17 cases per 100 person years9–13 | Unknown† |
| Population size | 3.6–7.1 million30† | Unknown‡ |
| Partner notification | Not routine | Not routine |
| Civil society organisations31 | 121 | 30 |
↵* Defined as women who usually solicit clients on the street or public outdoor places and sell sex for less than €2–10 per client.
↵† Number of men who have sex with men (MSM) at high risk, which was estimated in 2005.30
↵‡ Low-tier female sex workers (FSW) are difficult to reach by conventional public health outreach and estimating the population size and retaining them in cohorts is challenging.