China is host to several simultaneous HIV epidemics. HIV first appeared in the early 1990s among IDUs the country’s far western and southern provinces. HIV is now found among IDUs in every province, with prevalence ranging from 5-8% on average among this group. A second epidemic was recognized in 1998 among blood plasma donors who acquired HIV through unsafe blood collection practices and contaminated medical equipment in the 1990’s. Though there are wide variations in prevalence between geographic areas for this group, a 2003 epidemiological survey showed an overall prevalence of 2.7%.

While injecting drug use continues to drive the spread of HIV in China, sex (heterosexual and homosexual) is an increasingly important mode of transmission. The proportion of female HIV cases has increased from 19.4% in 2000 to 39% in 2004. Many of China’s estimated 6 million sex workers are women from poor rural areas who move to large cities seeking economic opportunities but who can only find work in the sex trade. They often lack the skills to negotiate safe sex and the power to refuse unprotected sex. Disease patterns are beginning to indicate the dangers of this combination. Among sex workers, the HIV prevalence rate is about 1% (though epidemiological surveys indicated prevalence rates as high as 6.7% in some areas), unprotected sex is common (with regular condom use ranging from 14% to 60% in a recent survey). In addition, a significant percentage of sex workers also inject drugs. (At sentinel surveillance sites, the proportion of HIV positive sex workers who injected drugs was between 25 and 100 percent in Guangxi, Hunan, and Chongqing.)

Sexually transmitted infections are increasing rapidly in China, raising concerns about how quickly HIV/AIDS may spread from high-risk groups into the general population. In 2002, for example, the incidence of reported STIs was nine times greater than in 1986 and almost two times greater than in 1996. The incidence of syphilis and gonorrhea increased approximately twenty times and 2.6 times respectively from 1990 to 1998. There were 860,000 new STI cases reported in 2000, but the actual number of new STI cases is thought to be five to ten times higher with many STI patients seeking treatment in private clinics, where cases are often not reported.

HIV among MSM is also on the rise. There is limited surveillance data on the HIV infection rate among MSM, but a number of surveys suggest that HIV prevalence among this group is between 1% and 3% percent in a number of Chinese cities. Behavioral surveys indicate that regular condom use is low, that there is limited understanding of the risk of HIV infection, and that a significant percentage (more than 25%) of MSM also have sex with women. Chinese experts estimate that there are at least 10-20 million MSM in China. Given the high HIV prevalence rates, and the high levels of risk behaviors among this population, MSM represent a significant bridge population in China.

A rural-to-urban migrant population of approximately 120 million is also at high risk of contracting and spreading HIV. Most migrants are young and either unmarried or living apart from their spouses and children. Surveys indicate that most have a very low awareness and understanding of HIV and STIs. Increasing sexual transmission of HIV is of particular concern in China’s current social environment. Rapid economic change has created millions of migrant laborers seeking an escape from widespread rural poverty, and there is a large surplus of males due to sex selection before birth (the ratio of newborn boys to girls in China is approximately 116:100).