Behavioral and molecular tracing of risky sexual contacts in a sample of Chinese HIV-infected men who have sex with men.

Contact tracing, coupled with molecular epidemiologic investigation, is especially useful for identifying an infection with few cases in the population, such as human immunodeficiency virus (HIV) infection in China. No such research is available on Chinese men who have sex with men (MSM). From 2008 to 2010 in Taizhou Prefecture in China, every newly diagnosed HIV-infected MSM was invited to participate as an "index case" in a contact tracing survey by providing contact information for up to 8 sexual contacts, who themselves were approached to receive voluntary HIV counseling and testing. Those who tested HIV-positive were then subjected to another contact tracing survey. This process was repeated until no more sexual contacts were reported or tested positive. A total of 100 HIV-infected MSM served as "index cases," including the initial 49 cases identified through routine surveillance programs and 51 cases from the present survey. Traced MSM exhibited little willingness to receive voluntary counseling and testing. CRF01_AE (HIV type 1) was the dominant subtype. Seven of 49 independent sexual networks were deemed HIV transmission clusters. Fear of stigma or discrimination may deter Chinese MSM from receiving voluntary counseling and testing. Nonetheless, the integration of behavioral network analysis and HIV phylogenetic analysis provides enhanced evidence for developing tailored prevention strategies for HIV-infected MSM.