TY - JOUR T1 - Modelling the impact of a sex work crackdown on syphilis transmission among female sex workers and their clients in South China JF - Sexually Transmitted Infections JO - Sex Transm Infect SP - 45 LP - 50 DO - 10.1136/sextrans-2020-054497 VL - 97 IS - 1 AU - Ngai Sze Wong AU - Kimberly A Powers AU - Joseph D Tucker AU - Shui Shan Lee AU - Beng Tin Goh AU - Peizhen Zhao AU - Lei Chen AU - Cheng Wang AU - Li Gang Yang AU - Bin Yang AU - Heping Zheng AU - Shujie Huang AU - Kate M Mitchell Y1 - 2021/02/01 UR - http://sti.bmj.com/content/97/1/45.abstract N2 - Objective To estimate the potential effects of an intense sex work crackdown on syphilis transmission in Guangdong Province, China.Methods We developed a deterministic compartmental model of syphilis transmission among female sex workers (FSW) and their male clients in Guangdong Province, China. We based model assumptions on census data and scientific literature, and we fitted the model to sentinel surveillance estimates of syphilis prevalence (positive results in both treponemal and non-treponemal tests) among FSW between 2009 and 2013. We estimated the impact of an intense sex work crackdown in 2014 by comparing the number of new syphilis infections between 2014 and 2020 in crackdown versus basecase (no crackdown) scenarios. In modelling scenarios, we examined main crackdown mechanisms of impact, including changed number of FSW engaging in sex work, reduction of weekly transactions, condom usage rate and syphilis diagnosis rate.Results In the basecase, predicted syphilis prevalence in FSW decreased from 2% in 2014 to 0.4% in 2020. In crackdown scenarios, syphilis incidence was predicted to transiently decrease and then to rebound relative to basecase levels a few years later. Shorter crackdowns led to higher, faster rebounds.Conclusions Short-term intense crackdowns may exacerbate syphilis transmission among FSW and further marginalise an already vulnerable group. This study provides a quantitative, infection-related basis for changing sex work policies to reduce harms. ER -