We assessed the prevalence and predictors of HIV sero-positive among 689 IDUs with serious illicit drug problems in China using community-based cross sectional surveys with consistent sampling procedures in all three provinces (or autonomous regions). HIV prevalence was very high (51.8%), but was lower in persons living in Guangxi (16.4%) compared to Xinjiang and Yunnan (67.8%). The HIV prevalence rates were remarkably similar to those from the same sites among IDUs from detoxification or detention centers , and were significantly higher than estimates from community-based surveys in other regions in China .
Lower rates are reported in other provinces. For example, in January 2005, HIV prevalence rates of 0% to 5.9% were reported in six community-based surveys of 1,260 IDUs in Guangxi and Yunnan's adjacent provinces of Sichuan (3.7%), Guangdong (5.9%), and Guizhou (0%), with even lower prevalence noted in sites in Fujian (0.4%), Henan (0%), and Hubei (0%), provinces located farther from Guangxi and Yunnan . Higher HIV prevalence rates among IDUs in 2004–2006 surveys are seen in those regions of Guangxi, Xinjiang, and Yunnan where rapid spread of the virus among drug users occurred earliest; HIV was first reported in Yunnan in 1989 [7, 22]. Overall prevalence was noted to be 71.9% among IDUs from detoxification centers in Honghe and Wenshan Prefectures of Yunnan Province in 2000, having declined subsequently. One may speculate that rates have dropped due to deaths and/or prevention successes . Five out of 15 prefectures in Yunnan have reported high HIV prevalence rates among IDUs, ranging from 48.9% to 75.0% [7, 22, 29]. Biological sentinel surveillance data show that HIV prevalence rates have reached 75.0% in certain sites of Xinjiang and 51.0% in certain sites of Guangxi in 2005 . The majority of the participants in sentinel surveillance were recruited from detoxification or detention centers and they are likely to be higher risk injectors than IDUs in community settings. These differences could also reflect the availability of proactive testing in the detoxification or detention centers rather than a proven difference between the sub-group and a wider population of IDUs.
High HIV prevalence among IDUs, prevalent needle sharing and high frequency of injecting practices suggest an urgent need to improve drug addiction treatment and risk reduction measures in China. We found that 51.0% of the participants had shared needles and/or syringes and 27.2% had injected drugs more than twice in the last week. An HIV epidemic becomes self-perpetuating (endemic) and even a modest level of risk behavior can lead to a substantial rate of infection in the face of efficient needle/blood transmission [30, 31]. Because they live along major drug trafficking routes, many of the HIV-infected IDUs in our survey will continue to serve as a major source for continued transmission and further spread unless drug abuse treatment, antiretroviral therapy, and risk reduction are implemented, as indicated.
While longer duration of IDU, shared injection needle and/or syringe, and higher frequency of injection were the independent risk factors for HIV infection [14, 15, 33, 34], greater awareness of HIV was associated (unexpectedly) with higher HIV prevalence. This may suggest some successes in educating IDUs. Higher income was also a risk factor. We speculate that drug users with higher incomes may use drugs more often; they may also have a greater awareness of HIV issues. There was some diversity in associated risk factors among the IDU subgroups in the three regions where HIV prevalence was especially high. Although a high portion of participants know HIV transmission routes in all three sites, the needle sharing rates and unprotected sexual behaviors were still high among IDUs. Most astonishingly, a very small portion (overall 5.1%) of participants reported ever receiving VCT, a gateway for the prevention programs. This indicated that a large proportion of IDUs who have been infected with HIV don't know their status and could continue to spread the virus [26, 35]. China has scaled up HIV control efforts since 2004 ; however, low HIV testing rates (≈20% nationwide) remain an impediment to prevention and care. Lack of affordable accessibility to sterile needles and syringes was the major reason for high risk sharing of "works" in this study. Other data suggested social norms that foster stigma, discrimination associated with drug use and HIV/AIDS, fear of arrest due to illegal practice, knowing a positive result, a lack of coping skills, and knowledge of HIV risks are the other reasons for the low rate of HIV testing among IDUs [4, 26]. This suggested that risk reduction education alone cannot help drug users and their sex partners make lasting behavioral changes. The community-based needle exchange programs and elimination of any barriers to accessing clean needles and syringes could reduce the prevalence of needle sharing among IDUs[36, 37]. In addition to providing accurate and up-to-date information on risky behaviors, effective community-based prevention programs not only make clean needles and condoms available and accessible, but also focus on enhancing individuals' motivation to change their behavioral patterns, teaching concrete strategies, and behavioral skills to reduce risk, providing tools for risk reduction, and reinforcing positive behavior change.
We found that there were significant differences between sex, age, marital status, residency, ethnicity, education level, and monthly income among the participants in the three study sites. A larger portion of participants who were single and belong to the Han ethnic group, with >6 years of education and higher income, were recruited in Honghe, Yunnan than in the other two sites. Yili, Xijiang's participants were more likely to be younger, belong to non-Han ethnic groups (86.9% Wei ethnic group in Yili, Xijiang; 11.2% Hani and Yi ethnic groups in Honghe, Yunnan and 32.2% Zhuang ethnic group in Nanning, Guangxi), and receive lower levels of education. Nanning, Guangxi's participants were more likely to have less monthly income (74.2% with ≤ 300 Yuan RMB monthly income). We found that higher income in Honghe, being male in Nanning, and old age in Yili were independently associated with HIV infection. There could be other factors beyond this study, besides gender, age and the sharing of needles, such as the actual availability of syringe distribution and exchange programs, condom distribution and promotion, and other social determinants of health that account for the differences for the HIV prevalence rates in the three study sites. China's central government has scaled up HIV/AIDS control efforts since 2004 , including setting up national policy framework for responding to HIV/AIDS, increasing funding inputs, and expanding collaborations with international organizations. However, responses to drug use and the HIV/AIDS epidemic vary significantly at provincial and lower administrative levels. A literature review indicated that Yunnan and Guangxi provinces have done far more than other provinces in supporting, implementing, and advocating for harm reduction interventions for IDUs . Some local governments are not fully motivated to confront drug abuse and HIV/AIDS problems .
Among IDUs in other studies from China, risky sexual behaviors have been reported as a risk factor for HIV infection [14, 15, 34], although we did not find this association in our three populations. Most of our participants that lived in remote rural areas of Honghe, Yunnan and Yili, Xinjiang were less likely to receive health education and services. Furthermore, due to relatively poor economic status and lower levels of education, they may be more likely to be involved in drug smuggling and abuse, and unprotected sexual behavior. Risk reduction programs should give high priority to these poorer, more isolated IDUs who are also more likely to be of minority ethnic origin. Because of the high prevalence of HIV and often risky sexual behavior among IDUs, there is a great potential for IDUs serving as a bridge population to transmit HIV to the general population. The overlapping of risk behaviors among at-risk persons facilitates the rapid HIV spread from IDUs to other risk groups, e.g., from female sex workers and their clients to their clients' regular partners. We found that low condom use rates and the high proportion of female drug users who had reported engaging in commercial sex underscore the importance of behavioral surveillance in IDUs to provide early warnings and more effective interventions. This highlighted the need for condom distribution and promotion. As noted in this study, most of the target IDUs interviewed already knew the causes of HIV; the problem is not knowledge translation, it is more basic social determinants of health. They don't have access to free condoms. Free condoms should be provided widely to sex trade workers and IDUs.
The prevalence of syphilis by RPR in our high risk IDUs was 5.4% (33/647), similar to estimates in 10 sentinel surveillance sites using RPR screening in 1,414 IDUs in the same three provinces (average: 6.6%, range from 1.2 to 14.1%) . Syphilis seropositivity did not predict HIV, suggesting that most infections were due to injection-related behaviors. Other studies have reported an association between HIV infection and other STDs among IDUs [38–41]. Syphilis should be considered one indicator of high sexual risk behavior among IDUs . Previous studies of syphilis among IDUs have suggested that while a high prevalence of syphilis and low HIV prevalence may be found in clinical or community settings, the reverse pattern of high HIV prevalence and low prevalence of syphilis may be more common in detoxification centers where IDUs, who are heavier drug users, are overrepresented [22, 43]. The patterns of STD co-morbidity among IDUs vary significantly by venue and high risk group [22, 44].
Strengths of this study include its substantial sample size, the geographic diversity of our venues, and community-based outreach and peer referral using "snowball" and mapping strategies. There are also limitations. First, IDUs recruited into the study may have been higher risk such that their HIV prevalence may not exactly reflect the true background rate among IDUs in the study community. Second, recall bias and social desirability bias are possible, since the drug use and sexual behavioral information was collected based on self-reporting. Most information about drug use and sexual behaviors in the last year were used in the data collection, instead of collecting the behaviors in more recent period, in the last three or six months. Third, our cross-sectional study cannot ascertain a causal association between predictors and HIV infections. Fourth, we do not include a complete list of factors in this study. Other factors beyond this study may also account for the differences.
China has initiated harm reduction projects, including needle exchange programs, methadone treatment, condom promotion, and VCT programs among drug users [4, 25, 36, 37, 45, 46]. China Center for Disease Control and Prevention provincial authorities have been organizing the needle exchange and methadone treatments since early 2004 [20, 46, 47]. China plans to scale up harm reduction projects, including needle exchange programs and methadone treatments, since only a small portion of IDUs have been covered by these programs so far. Our data suggest the urgent need for expanded community-level needle exchange programs, opiate agonist-based drug treatment, and advocacy for community-based VCT with bridges to HIV preventive services and care. Condom distribution along with condom promotion should also be highlighted. In vulnerable target populations where condom use is directly related to availability, condom distribution and promotion is crucial to helping curb the spread of HIV and other STDs. These prevention and treatment efforts are likely to require an infrastructure that not only provides operational and financial support, but also creates an environment in which IDUs feel comfortable and safe in seeking help without any barriers. Implementation research programs can critically assess these programs and provide insight as to where they might be improved.