OBJECTIVETo understand the characteristics of recreational drug users' behaviors and social network, as well as their potential impact to the transmission of sexual transmitted infections (STI).

METHODSQualitative interview was used to collect information on rough estimation of population size and behavior change before and after recreational drug use. A total of 120 participants were recruited by convenient sampling from April to October, 2013 in a community of Qingdao city. Blood specimens were taken for HIV/syphilis serological testing and social network analysis was performed to understand the characteristics of their behavior and social network.

RESULTSAll participants used methamphetamine and 103 of them showed social connection. The prevalence of syphilis and HIV were 24.2% (29/120) and 2.5% (3/120) respectively. The estimated size of recreational drug users was big with a wide diversity of occupations and age range, and males were more frequent than females. Drug use may affect condom use and frequent drug users showed symptom of psychosis and neuro-toxicities. The size of social network was 2.45 ± 1.63 in the past 6 months, which indicated an increasing trend of the sexual partner number and risky behaviors.

CONCLUSIONRecreational drug use could increase the size of social network among sex partners, the frequency of risky sexual behaviors and syphilis prevalence, which indicate a high risk of HIV/STI among this population as well as a huge burden of disease prevention and control in the future.