Modeling the Course of the HIV/AIDS Epidemic in China: An Application of a Bio-Behavioral Macrosimulation Model of the Spread of

Type Working Paper - Department of Sociology and Center for Demography and Ecology University of Wisconsin, Madison
Title Modeling the Course of the HIV/AIDS Epidemic in China: An Application of a Bio-Behavioral Macrosimulation Model of the Spread of
Publication (Day/Month/Year) 2004
The magnitude of the HIV/AIDS epidemic has exceeded all expectations since the virus
was first identified 20 years ago. Today, an estimated 42 million people are infected with
HIV, and more than 20 million have already died. The epidemic has hit hardest in SubSaharan
Africa. AIDS deaths in this region account for over three quarters of the global
death toll. Because of its large population, Asia is the home to the largest number of
people living with HIV/AIDS of any region beside Sub-Saharan Africa. In Thailand,
Cambodia and Myanmar adult prevalence rates range from 1.8% to 3%. It is expected
that HIV may soon spread in the world’s most populous countries, India and China.
In China, after a decade of generally low levels of infection, the Ministry of
Health reported that HIV infections have risen by 30% a year since 1994 (Plafker 2001).
The overall number of infections was estimated at more than 1 million at the end of 2001,
based on HIV surveillance (UNAIDS 2002c). According to the national surveillance
system, the epidemic has, until recently, been contained within high-risk populations,
such as injection drug users (IDUs) and villages with faulty plasma collection practices in
rural Henan province. Today there are an estimated 3 to 3.5 million IDUs in China (Reid
and Costigan 2002). HIV prevalence in this population has risen from 0.5% in 1995 to
recently reported rates of 5%, 10% and 80% in some areas of Xinjiang and Yunnan
province (China Ministry of Health and UN Theme Group on HIV/AIDS in China 2003;
Zheng et al. 1997), and is associated with Burmese and Laotian heroine trafficking routes
(Beyrer et al. 1999). Very high prevalence rates have also been reported for some Henan
villages, with up to 62% of their population infected (Hua 2001). Sharing of infected
needles among drug users and faulty plasma collection practices are thought to account
for almost 90% of the cumulative number of HIV infections in China (Yuan et al. 2002).
More recently, infection rates have risen among female sex workers (FSW), with
an estimated 1.32% infected in 2000 (United States Embassy in China 2001), and with
recorded high prevalence pockets among the FSW population of Yunnan province (2%),
Guangzhou (2%) and Guanxi province, bordering Vietnam (10%). Behavioral-risk
assessment data collected among FSW reveal that a large proportion never use condoms,
ranging from 31% in Beijing to 70% in economically backward Anhui province (WHO
2001). Between 1995 and 2000, the percentage of FSW always using condoms with
clients in sentinel sites in Yunnan, Guangzhou and Guangxi has remained stable at
around 10% (MAP 2001:7).
The early phases of the Chinese epidemic resemble those already seen in other
Asian countries, where infection has spread from high-risk to low-risk populations. In
Thailand, the first cases of HIV were detected in 1984, but the rapid growth of the
epidemic did not occur until 1987 when seroprevalence among IDUs reached 44%, soon
followed by increases in seroprevalence among female sex workers (FSWs) and, in 1988,
in the heterosexual population (Brown, Mulhall and Sittitrai 1994; Brown, Sittitrai,
Vanichseni and Thisyakorn 1994). Seroprevalence among Thai FSWs peaked at 33% in
1994 but has since declined to around 22%, following an aggressive 100% condom
program among commercial sex workers in the 1990s (Rojanapithayakorn and
Hanenberg. 1996). In the early 1990’s, more than 80% of all new adult infections were
among sex workers and their clients. Currently, around 50% of new adult infections are
women who have been infected by their husbands or sex partners, 25% are due to
injection drug use, and only about 20% occur among sex workers and their clients (World
Bank 2000; UNAIDS 2000).
In China too, there is great concern that HIV/AIDS may soon spread to the
general population and that it will become an endemic disease sustained by heterosexual
transmission (United Nations Team Group on HIV/AIDS in China. 2002; Brady et al.
2001). Projections of the future impact of HIV/AIDS (if no interventions are
implemented) range from 10 million people infected by 2010 (UN Theme Group
HIV/AIDS in China 2002; Kaufman and Jing 2002) to 20 million infected (Brady et al.
2001; Morrison and Gill 2003).

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