Since the implementation of the 1978 “open door policy” that promoted foreign trade and investment, China has experienced rapid economic growth in many coastal urban areas and major cities. Large economic disparities led to the emergence of large population movement patterns, particularly rural-to-urban migration to seek after better employment opportunities, higher income, and a more attractive lifestyle in urban China.1,2 According to the latest official statistics, there are 225.5 million rural-to-urban migrants (also named “floating population”) in China, accounting for 17% of its population.3,4 Owing to the strict household registration (Hukou) system in China, very few migrants are able to obtain urban permanent residency, and a large proportion of them work in an urban city for a certain period and eventually return to their rural hometown or move to another city.5 These migrants travel between urban and rural areas seasonally during Chinese holidays.3,6
Rural-to-urban migrants are often considered a potential high-risk population for HIV infection and transmission in China. Being away from one’s spouse and family leads to increased risks of extramarital sexual behaviors, especially male migrants. In addition, female migrants who are unable to find other employment in urban areas may engage in commercial sex.7–11 Approximately 6% of female migrants have participated in sex work during their stay in urban areas.12 Multiple sources have indicated that migrant workers account for most HIV-infected patients in China cities.13–21 In addition, population mobility of the migrants has been identified as a major risk factor for facilitating transmission of HIV infection in China,22,23 and frequent shifts between work locations and seasonal visits back home may further spread HIV infection to their partners and other uninfected populations9
Scattered sources have reported HIV prevalence among rural-to-urban migrants in China with large variations (0–2.59%).2,24–27 However, little is known about the changes in the prevalence during various stages of the migration. Although these migrants are often thought to be a potential bridge of HIV infection between the urban and the rural areas, there is little quantified evidence that the infection was transmitted by the returning migrants to the uninfected population. Based on a systematic literature review and meta-analysis, this study aimed to determine the HIV prevalence among rural-to-urban migrants at different stages of migration and the likely causes of variations of HIV prevalence. It also compared the risk of HIV infection among different subgroups of migrants using the general Chinese population as the referencing population.
Three independent investigators (E.P.F.C., H.J.J., L.Z.) conducted a systematic review of published peer-reviewed research articles by searching both English and Chinese electronic databases: PubMed (H.J.J., L.Z.), VIP Chinese Journal Database (VIP), China National Knowledge Infrastructure, and Wanfang Data (E.P.F.C., L.Z.) until June 15, 2011. Keywords used in the database search included (“HIV” OR “AIDS”) AND (“floating migrants” OR “rural-to-urban migrants” OR “floating-in” OR “floating-out” OR “migrant workers (Nong Min Gong)”) AND “China.” We also performed a manual search on the reference lists of the retrieved articles. This review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement issued in 2009.28
Studies were eligible for inclusion in this systematic review if they met the following criteria: (1) study published in Chinese or English language, (2) study reported HIV prevalence estimates among rural-to-urban migrants in China, and (3) HIV infection must be diagnosed from laboratory serologic testing.
We excluded review articles, non-peer-reviewed local/government reports, conference abstracts, and presentations. Self-reported HIV infections and nonserologic HIV diagnoses (i.e., urine and oral fluid) were excluded. Studies with non-Chinese migrants or ones focusing exclusively on risk groups such as migrant commercial sex workers were also excluded. If the same data were published in both English and Chinese sources, the articles published in Chinese language were excluded.
In this review, we investigated the prevalence of HIV infection among different types of migrants in China, namely, (1) people who were about to migrate from their mostly rural home to urban areas (floating-out population), (2) migrants who already migrated from rural areas and residing in urban areas when the study took place, and (3) migrants who have returned from urban areas back to their home in rural areas.
The quality of studies was assessed using a validated quality assessment tool for cross-sectional studies.29 The following 8 items were assessed to calculate a total quality score: (1) clear definition of the target population, (2) representativeness of probability sampling, (3) sample characteristics matching the overall population, (4) adequate response rate, (5) standardized data collection methods, (6) reliability of survey measures/instruments, (7) validity of survey measures/instruments, and (8) appropriate statistical methods. Answers were scored 0 and 1 for “No” and “Yes,” respectively. The total quality score varied between 0 and 8 (see Table 1).
We extracted the following information from all eligible studies: first author and published year, study period, study location, type of study, percentage of male and female participants, sample size, testing method for HIV, and HIV prevalence. The studies were categorized in floating-in, floating-out, and return migrants population (Table 1).
Meta-analyses were carried out using the Comprehensive Meta-Analysis software (V2.0; Biostat, Englewood, NJ).30 Pooled HIV prevalence estimates and 95% confidence intervals (CIs) for each study and odds ratios (ORs) for group comparisons (migrant subgroups among each other and migrant subgroups vs. general Chinese population) were calculated. Heterogeneity tests were performed using the Cochran Q test (P < 0.10 represents statistically significant heterogeneity) and I 2 statistic.31–33 The value of the I 2 statistic indicates low (25), moderate (50), and high (75) heterogeneity between studies. Random-effect model was used when there was a high and significant heterogeneity across studies, whereas fixed-effect model was used otherwise. Results were graphically presented in forest plots. We investigated the factors (i.e., language of article, type of study, study location, and study period) that were associated with heterogeneities in the stratified meta-analyses using meta-regression analysis.34 Potential presence of publication bias was measured by the Begg and Mazumdar rank correlation (P < 0.05 represents statistically significant publication bias).35,36
Study Identification and Selection
Our initial search criteria identified 1753 articles from 4 electronic databases, and 5 additional articles were identified through reference lists from identified articles. We excluded 976 articles because they were unrelated to the topics or duplicated titles from different databases. Abstracts were screened among the remaining 782 articles, and 164 were excluded because they were not related to floating migrants. After screening the full text of the 618 eligible articles, 564 were further excluded because they did not cover the population of floating migrants (N = 110) or did not report the HIV prevalence among the rural-to-urban migrants population (N = 454). The remaining 54 studies (4 in English and 50 in Chinese) were eligible for quantitative synthesis. Of 54 eligible studies, 3 reported HIV prevalence in multiple years,27,37,38 which resulted in 59 HIV prevalence estimates. We performed stratified meta-analyses for the different types of migrants: floating-out population (N = 7), floating-in population (N = 48), and return population (n = 4). The selection process is illustrated in Figure 1.
In the total of 54 studies, the sample size of the selected studies ranged from 182 to 37,829 (median, 818; interquartile range, 505–1854), and the reported HIV prevalence among Chinese migrants ranged from 0% to 2.59%. Seven studies provided data from floating-out migrants, 43 studies reported floating-in population data, and 4 studies referred to returning migrants. Four studies were national sentinel analyses, and the remaining 50 articles were independent studies. A total of 121,027 migrants were surveyed. The mean age of the migrant participants was 33.71 years. Approximately one third of the migrants (36.39%) were primary school graduates or illiterate. Furthermore, 69.22% of migrants were Han ethnic, 61.04% were currently married, and 57.41% of study participants were female.
Quantitative Data Synthesis
It is well accepted that the HIV epidemic in China remains concentrated among the key behavioral populations (of intravenous drug users, female sex workers, and men who have sex with men), and HIV prevalence among the Chinese population is low (0.057%23,39). This official national HIV prevalence level was calculated based on the current estimate of 78,000 people living with HIV/AIDS nationwide in China. Our results show that rural-to-urban migrants, recruited before they leave their home towns, had a higher HIV prevalence (0.15%; 95% CI, 0.060–0.34%; Fig. 2C), representing higher odds of HIV infection as compared with the Chinese population (OR, 2.63; 95% CI, 1.34–5.14).
In comparison, migrants who were recruited in their residing urban areas had a much higher HIV prevalence (0.38%; 95% CI, 0.29%–0.50%; Fig. 2A), corresponding to 6.70 (95% CI, 6.05–7.41) times higher odds of HIV infection than the overall Chinese population. Strikingly, among these urban recruited migrants, HIV prevalence among women was even higher (0.69%; 95% CI, 0.51%–0.93%; Fig. 2B), reflected in a much higher OR of 12.18 (95% CI, 11.11–13.35). The pooled estimated HIV prevalence among migrants returning from urban areas, regardless of temporary stay or permanent residence, was 0.18% (0.12%–0.29%; Fig. 2D), and their OR for HIV infection was 3.16 (95% CI, 2.06–4.84) in comparison with the overall Chinese population (Table 2). However, our findings did not show a significant higher odds of HIV infection among returning migrants than among the floating-out migrants (OR, 1.20; 95% CI, 0.54–2.65; Table 2).
Of 18 studies that reported percentages of female migrants and HIV prevalence, HIV prevalence was found to be positively correlated with the proportion of female migrants (Spearman ρ: r = 0.506; 95% CI, 0.23–0.71; P < 0.001). We identified 4 studies that exclusively reported on male migrants, 3 of which reported zero HIV prevalence40–42 and 1 reported 9 infections of 1624 male migrants (0.55%).43
Twelve studies reported a more detailed migratory history of HIV-infected individuals,13–21,44–46 and the pooled estimate from our meta-analysis showed that a proportion of 53.4% (95% CI, 33.5%–72.4%) of HIV-infected individuals in urban China was among migrants (Fig. 2E).
No publication biases were observed among the 4 types of migrants in the meta-analyses (P = 0.881, 0.455, 0.307, and 0.497 for floating-out and floating-in, floating-in female, and returning populations, respectively; Fig. 2A–D). Significantly high heterogeneities were observed in the floating-in population (I 2 = 74.87, P < 0.001) and floating-in female population (I 2 = 82.33, P < 0.001). Meta-regression analyses showed that the language of the articles (β = −4.133, P = 0.008), study location (β = −0.260, P = 0.007), and study period (β = −0.568, P = 0.036) significantly contributed to this relatively high heterogeneity among the floating-in population, whereas only study period (β = −0.913, P = 0.007) significantly contributed to high heterogeneity among the floating-in female population.
To our knowledge, this is the first study that systematically reviewed HIV prevalence among rural-to-urban migrants in China according to their status of migration based on an exhaustive search in both Chinese and English literature. Our results indicated that most people living HIV in urban China have a migratory background. In addition, we identified a higher HIV prevalence among migrants who were migrating from their registered rural areas of residency to urban cities in comparison with the overall Chinese population.
In comparison, migrants recruited from urban areas had 6.70 times higher odds of being infected with HIV than did the overall Chinese population. Furthermore, the odds of female migrants in this group were 12.18-fold higher than the overall Chinese population. It was previously documented that both male and female migrants are more likely to participate in high-risk behaviors when they are away from their home town. Male migrants are more likely to have multiple sexual partners and/or seek for commercial sex, whereas female migrants are more likely to offer commercial sex in case they face financial difficulties in the urban cities.7–11 Past findings indicated that 70% to 95% of the female sex workers in China were from a rural-to-urban migrant background.47–53 This is in line with our result that HIV prevalence was positively correlated with the percentage of females in the collected studies.
One of our key results is that migrants returning to their registered rural home residence, regardless of their length of stay, had a much lower HIV prevalence than those recruited in urban areas. This clearly suggests that HIV-infected migrants tend to stay in urban areas, rather than returning to their rural home residence.54–57 This may partly be caused by to social stigmatization and less sufficient HIV/AIDS-related medical support within the public health care service sector. The nature of participation in commercial sex work of female migrants, in the context of strong cultural and moral values among their rural families and communities, could be a reason for their extended stay in urban areas. In addition, infected migrants may be reluctant to return to their hometown because of strong stigmatization toward HIV-infected individuals.58 Since 2003, the Chinese government launched extensive programs to provide affordable and reachable health care services for HIV-infected people in China.59 However, implementation of the intervention programs fell substantially behind in rural China because of its geographical isolation, underdeveloped medical facilities, and undersupported staffs to provide comprehensive HIV/AIDS treatment including second-line antiretroviral therapy and treatment of multiple opportunistic diseases.60 Because returning migrants had a 3.16 times higher odds of being HIV infected than did the overall Chinese population, their return may pose a threat for bridging HIV infection to the rural general population.
Several limitations of this study should be noted. First, the result that 53.4% of HIV-infected urban cases have a migratory background needs to be interpreted with caution. In China’s sentinel surveillance system, the migrant population is as one of key populations subjected to HIV screening. Therefore, HIV cases among migrants are more likely to be detected than the general population, indicating an overestimate of the actual contribution of migrants to HIV cases. HIV prevalence among rural-to-urban migrants remains low in comparison with highly at-risk groups in China, implying that a large sampling size is required to detect any HIV infections. As a result, our analysis may underestimate the actual HIV prevalence among the migrants because of the small sampling sizes of individual studies. Besides, strong social stigma against HIV-infected individuals in their rural hometown may substantially reduce their participation in the collected studies, leading to an underestimate of HIV prevalence among return migrants. Furthermore, the rural-to-urban migrant population includes a diverse array of subpopulations with different occupations that can be quite different in their risk of HIV infection. For instance, migrants who are long-distance truck drivers or miners are more prone to purchasing sex, whereas female migrants employed in entertainment industries are more likely to be involved in commercial sex trade than those with other occupations. It is important to note that, of course, there are many migrants who are at very low or no risk for HIV acquisition when away from home. In the current study, we were unable to investigate these effects because of the limitations and unavailability of the relevant demographic data in the collected studies. Owing to limited available studies that stratified according to sex, subgroup analysis with the sex factor was not performed for floating-out and return populations.
The trend of rural-to-urban migration will increase if the economic disparity between the 2 areas of China remains large. Hence, our findings have important implications for HIV prevention and interventions in China. A number of previous reviews have identified rural-to-urban migrants as a high-risk population for HIV infection and transmission.42,61–63 Consistently, our results demonstrate that most HIV-infected individuals in urban China (53.4%; 95% CI, 33.5%–72.4%) had a migratory background. Thus, intervention strategies preventing HIV transmission among rural-to-urban migrants would expectedly have large impacts on confining the overall HIV epidemic in China.
HIV prevention strategies targeting migrants in urban China need to be implemented with the involvement of key institutions at various administrative levels, including both provincial- and inner-city district–level governmental institutions. Grassroots partners such as employers of migrants and workers’ unions in urban cities should also be engaged in strategies to protect the health of migrants. An integrated and concerted intervention approach can reach and be implemented to prevent the further spread of HIV among the migrants. Intervention strategies for migrants should also address the issue of mobility. Considering the regular movement and the higher odds of HIV infection among returning migrants, voluntary HIV counseling and testing (VCT) should be substantially scaled up among migrants traveling back and forth between rural and urban areas. Mobile VCT services can be set up at major train and long-distance bus stations to offer free VCT. In this case, rapid HIV testing may be provided as screening tests; also, posttest counseling and referral of confirmation test can be offered to those tested positive. The increase in HIV diagnosis may, in turn, encourage timely initiation of antiretroviral treatment that reduces the risk of further transmission. Furthermore, commercial sex provision among female migrants and utilization among male migrants should be targeted. Health education, in combination with condom distribution, should be tailored for the migrant population. For instance, employment agencies that are frequently used by working migrants could be a channel to offer health materials in prevention and treatment of sexually transmitted diseases and HIV. Health education should start early in rural schools to reduce stigmatization of people living with HIV/AIDS (PLHIV) and risk of HIV transmission in rural communities.
1. Gorbach PM, Ryan C, Saphonn V, et al.. The impact of social, economic and political forces on emerging HIV epidemics. AIDS 2002; 16 (suppl 4): S35–S43.
2. Fu JH, Liu XZ, Kang DM, et al.. A survey on HIV infections among immigrant women in rural areas of Shandong province. Chin J AIDS STD 2005; 11: 403–405.
3. Wang B, Li X, Stanton B, et al.. The influence of social stigma and discriminatory experience on psychological distress and quality of life among rural-to-urban migrants in China. Soc Sci Med 2010; 71: 84–92.
4. Grusky O, Liu H, Johnston M. HIV/AIDS in China 1990–2001. AIDS Behav 2002; 6: 381–393.
5. Wang WW, Fan CC. Success or failure: Selectivity and reasons of return migration in Sichuan and Anhui, China. Environ Plann A 2006; 38: 939–958.
6. Zhang L. Migration and privatization of space and power in late socialist China. Am Ethnol 2001; 28: 179–205.
7. Rogers SJ, Ying L, Xin YT, et al.. Reaching and identifying the STD/HIV risk of sex workers in Beijing. AIDS Educ Prev 2002; 14: 217–227.
8. van den Hoek A, Yuliang F, Dukers NH, et al.. High prevalence of syphilis and other sexually transmitted diseases among sex workers in China: potential for fast spread of HIV. AIDS 2001; 15: 753–759.
9. Qian HZ, Vermund SH, Wang N. Risk of HIV/AIDS in China: Subpopulations of special importance. Sex Transm Infect 2005; 81: 442–447.
10. Zhu TF, Wang CH, Lin P, et al.. High risk populations and HIV-1 infection in China. Cell Res 2005; 15: 852–857.
11. Zheng L, Zhu J, Tian P, et al.. Sexual behaviors and associated factors among unmarried female migratory workers in Guangzhou. Chin J Fam Plann 2000; 60: 162–164.
12. Yang H, Li X, Stanton B, et al.. Workplace and HIV-related sexual behaviours and perceptions among female migrant workers. AIDS Care 2005; 17: 819–833.
13. Qiao XC, Guo XL, Zhang LF, et al.. Study of prevalence of HIV infection in floating population among HIV infected people in Shandong province. Chin J STD AIDS Prev Control 2000; 6: 265–267.
14. Yang HT, Liu GZ, Ni DX, et al.. Analysis of HIV Surveillance from 1986 to 1999 in Jiangsu Province. Chin J STD AIDS Prev Control 2000; 6: 283–285.
15. Liu CX, Su SL, Pu JH, et al.. Study of prevalence of HIV infection in floating population among HIV infected people in Shandong province. Chin J STD AIDS Prev Control 2002; 8: 28–30.
16. Editorial. HIV prevalence among floating population in Beijing. Sci Travel Med 2006; 12: 8.
17. Chen JQ, Chen WY. Analysis of HIV/AIDS prevention and control in Hangzhou, Zhejiang Province. Zhejiang J Prev Med 2006; 18: 59–60.
18. Wang WJ. Analysis on the status, issues and trend on AIDS prevention and control among the mobile population. Chin J Epidemiol 2009; 30: 407–409.
19. Zhang QL, Wang XX, Xia XZ, et al.. Epidemiological study on HIV/AIDS in Dongguan City. Dis Surveill 2007; 22: 6–9.
20. Zhou ZM, Yu XH, Wang JH, et al.. Epidemic characteristics of HIV infection of floating population in Wenzhou. Dis Surveill 2003; 18: 123–125.
21. Zhang YJ, Wang JH, Ni HN. Prevalence of HIV infection among floating population in Xianju County, Zhejiang Province. Zhejiang J Prev Med 2008; 20: 25.
22. Zhang Kl KL, Ma SJ. Epidemiology of HIV in China. BMJ 2002; 324: 803–804.
23. Ministry of Health People’s Republic of China, Joint United Nations Programme on HIV/AIDS, World Health Organization. 2009 Estimates for the HIV/AIDS Epidemic in China. Beijing, China: National Center for AIDS/STD Control and Prevention, China CDC, 2010.
24. Dai DM, Liu X, Xun ZM. lnvesligalion and analysis on AIDS epdiemiology of immigratory women in certain county of Yimeng mountains area. Med Lab Sci Clin 2007; 18: 36–38.
25. Hu SY, Yuan F, Lei SG, et al.. An intervention study of the status of HIV infection and preventing AIDS dangerous behavior in the floating population of Guiyang. Guizhou Med J 2003; 27: 120–122.
26. Ge FQ, Cao NX, Zhang HL, et al.. Investigation on the characteristics of STD/AIDS infections among floating construction workers. Chin J Health Educ 2007; 23: 741–743.
27. Lu F, Zhang JH, Zhang RF, et al.. Analysis of HIV epidemic situation and immigrant population. Infect Dis Inform 2006; 19: 259–261.
28. Moher D, Liberati A, Tetzlaff J, et al.. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 2009; 6: e1000097.
29. Boyle MH. Guidelines for evaluating prevalence studies. Evid Based Ment Health 1998; 1: 37–39.
30. Borenstein M, Hedges LV, Higgins JPT, et al.. Introduction to Meta-Analysis. New York: John Wiley & Sons Ltd; 2009.
31. Huedo-Medina TB, Sanchez-Meca J, Marin-Martinez F, et al.. Assessing heterogeneity in meta-analysis: Q
statistic or I 2
index? Psychol Methods 2006; 11: 193–206.
32. Higgins JP, Thompson SG. Quantifying heterogeneity in a meta-analysis. Stat Med 2002; 21: 1539–1558.
33. Higgins JP, Thompson SG, Deeks JJ, et al.. Measuring inconsistency in meta-analyses. BMJ 2003; 327: 557–560.
34. Thompson SG, Higgins JP. How should meta-regression analyses be undertaken and interpreted? Stat Med 2002; 21: 1559–1573.
35. Thornton A, Lee P. Publication bias in meta-analysis: Its causes and consequences. J Clin Epidemiol 2000; 53: 207–216.
36. Song F, Khan KS, Dinnes J, et al.. Asymmetric funnel plots and publication bias in meta-analyses of diagnostic accuracy. Int J Epidemiol 2002; 31: 88–95.
37. Yu XF, He JC, Yi HR, et al.. Analysis on HIV surveillance of floating population in Jiulongpo district of Chongqing. Chongqing Med J 2011; 40: 893–895.
38. Li R, Tong W, Zhao ZJ, et al.. Analysis on the surveillance results and epidemiological characteristics of HIV/AIDS in Dalian. Dis Surveill 2009; 24: 852–855.
39. Ministry of Health of the People’s Republic of China. China 2010 UNGASS Country Progress Report. Beijing, China: Ministry of Health; 2010.
40. Ye W, Fang Y, Tian ZG, et al.. Study on prevalence of sexually transmitted infections among migrant workers in Shanghai. Shanghai J Med Lab Sci 2003; 18: 372–373.
41. Zhang P, Zhang J. Investigation of HIV knowledge and high-risk behavior among floating population. Shanxi Med J 2011; 40: 42–43.
42. He N, Detels R, Zhu J, et al.. Characteristics and sexually transmitted diseases of male rural migrants in a metropolitan area of Eastern China. Sex Transm Dis 2005; 32: 286–292.
43. Lu L, Jia MH, Ma YL, et al.. An analysis of epidemic of HIV/AIDS in Yunnan Province in 1989–2005. Chin J AIDS STD 2006; 12: 517–519, 540.
44. Xu ZX, Liu FB, Wang ZS, et al.. Analysis of HIV prevalence among floating population in Xingtai city, Hebei Province. Chin J Pest Control 2011; 27: 301–303.
45. Fu JH, Lu CX, Liu XZ, et al.. Analysis on HIV/AIDS cases among immigrant women in Shandong province. Chin J Public Health 2009; 25: 1004–1005.
46. Liu XC, Gao LM, Lu JB, et al.. Analysis of the human immunodeficiency virus prevalence among immigrant population in Yuxi City, 1994–2009. Prev Med Tribune 2011; 17: 263–264, 267.
47. Yang H, Li X, Stanton B, et al.. Heterosexual transmission of HIV in China: A systematic review of behavioral studies in the past two decades. Sex Transm Dis 2005; 32: 270–280.
48. Zhou XL, Ling L, Xu HF, et al.. Knowledge and behavior about AIDS/STD among female sex workers. Chin J Public Health 2010; 26: 954–956.
49. Lau JT, Tsui HY, Siah PC, et al.. A study on female sex workers in southern China (Shenzhen): HIV-related knowledge, condom use and STD history. AIDS Care 2002; 14: 219–233.
50. Liao SS, Schensul J, Wolffers I. Sex-related health risks and implications for interventions with hospitality women in Hainan, China. AIDS Educ Prev 2003; 15: 109–121.
51. Liao SS, He QY, Choi KH, et al.. Working to prevent HIV/STIs among women in the sex industry in a rural town of Hainan, China. AIDS Behav 2006; 10: S35–S45.
52. Yang H, Li X, Stanton B, et al.. Condom use among female sex workers in China: Role of gatekeepers. Sex Transm Dis 2005; 32: 572–580.
53. Hong Y, Li X. Behavioral studies of female sex workers in China: A literature review and recommendation for future research. AIDS Behav 2008; 12: 623–636.
54. Peng Y, Chang W, Zhou H, et al.. Factors associated with health-seeking behavior among migrant workers in Beijing, China. BMC Health Serv Res 2010; 10: 69.
55. Chan C, Lucas H, Bloom G, et al. Internal Migration and ‘Rural/Urban’ Households in China: Implications for Health Care. In: CPRC International Conference 2010 - Ten Years of War Against Poverty. Manchester, UK; 2010.
56. Fan Y. Achievements and Challenges of the Rural Migrant Workers in Access to Healthcare Service in Urban China - A Case of Nanjing [Master]. Sweden: Lund University; 2006:40.
57. He N. Sociodemographic characteristics, sexual behavior, and HIV risks of rural-to-urban migrants in China. Biosci Trends 2007; 1: 72–80.
58. Liu H, Li X, Stanton B, et al.. Relation of sexual risks and prevention practices with individuals’ stigmatising beliefs towards HIV infected individuals: An exploratory study. Sex Transm Infect 2005; 81: 511–516.
59. Shao Y. AIDS epidemic at age 25 and control efforts in China. Retrovirology 2006; 3: 87.
60. Zhang X, Miege P, Zhang Y. Decentralization of the provision of health services to people living with HIV/AIDS in rural China: The case of three counties. Health Res Policy Syst 2011; 9: 9.
61. Detels R, Wu Z, Rotheram MJ, et al.. Sexually transmitted disease prevalence and characteristics of market vendors in eastern China. Sex Transm Dis 2003; 30: 803–808.
62. Wu J. Current status of sexual and reprodutive health among migrants in China. J Intl Reprod Health Fam Plann 2010; 29: 414–417.
63. Hong Y, Stanton B, Li X, et al.. Rural-to-urban migrants and the HIV epidemic in China. AIDS Behav 2006; 10: 421–430.
64. Cai W, Lu JY, Wang N. Prevalence of sexually transmitted infections among migrant workers in Heze City, Shangdong Province. J Huaihai Med 2005; 23: 303.
65. Ding XB, Zhang W, Lu RR, et al.. Investigation on knowledge, behavior related HIV/AIDS and infection rate of HIV among migrant workers. Chin J Dis Control Prev 2007; 11: 203–205.
66. Fang DW. Prevalence on HIV infection among floating population in Dongxing City in Guangxi Province, 1995 to 1998. Lit Inf Prev Med 2000; 6: 270.
67. Geng GH, Fu JH, Xu LZ. A survey on HIV infection and knowledge of AIDS among immigrant women in Huantai County. Prev Med Tribune 2007; 13: 296–297.
68. Gu MD, Li SL, Zhao G, et al.. Survey of status of HIV infections in 576 peasant workers in Pingjiang City returned from outside. China Trop Med 2009; 9: 904.
69. Guo HJ, Gao FH, Liu C, et al.. Evaluation on anti-AIDS health education and behavior intervention among migrant workers in Ningyang County. Prev Med Tribune 2010; 16: 881–882, 885.
70. Hesketh T, Li L, Ye X, et al.. HIV and syphilis in migrant workers in eastern China. Sex Transm Infect 2006; 82: 11–14.
71. Hong PK, Zeng XL, Lai QB, et al.. Jinjiang 2010 of the floating population AIDS monitoring results analysis. Jilin Yi Xue 2010; 31: 6735–6737.
72. Huang WJ, Xiao Y, Li YL, et al.. Survey for KAP related with HIV and HIV infection state among the outgoing farm workers. Chin J Dis Control Prev 2011; 15: 72–74.
73. Huang XT, Lin ZW, Ma XZ, et al.. A study on willingness to participate in HIV voluntary counseling and testing among migrants in Shantou City of Guangdong Province. South J Prev Med 2010; 36: 28–30.
74. Jiang YF, Ren J, Cai YQ, et al.. Survey on AIDS knowledge and HIV/syphilis infection situation in female floating population. Zhejiang Med J 2010; 32: 646–648.
75. Li JH, Yan XD, Yuan XH, et al.. Investigation on the awareness of AIDS and HIV infection among mirgant women in Tonghua County of JiLin Province. Med Soc 2010; 23: 9–11.
76. Liao MZ, Liu XZ, Fu JH, et al.. Analysis of HIV/AIDS surveillance data in Shandong Province in 2007. Prev Med Tribune 2008; 14: 1143–1145.
77. Liao MZ, Liu XZ, Kang DM, et al.. Analysis on the HIV/AIDS data in Shandong Province in 2009. Prev Med Tribune 2010; 16: 398–400, 403.
78. Liu XZ, Liao MZ, Fu JH, et al.. Analysis on HIV/AIDS surveillance data of Shandong Province in 2004. Prev Med Tribune 2006; 12: 80–82.
79. Meng XJ, Wang L, Meng XD, et al.. Investigation on AIDS prevention, infection situation and behavior among peasant workers. Mod Prev Med 2010; 37: 2696–2699.
80. Meng XJ, Zheng J, Ding GW, et al.. Investigation on HIV and syphilis infection among migrant workers. Int J Epidemiol Infect Dis 2010; 37: 84–87.
81. Mu FS, Xu LS. Investigation on HIV infection among immigrated women in rural areas of Taian in 2005. Prev Med Tribune 2006; 12: 685–686.
82. Ni HN, Ying YP, Wang YL, et al.. Prevalence of HIV infection and HIV/AIDS related knowledge among immigrant marriage women in Xianju County, Zhejiang Province. Chin Rural Health Serv Admin 2010; 30: 302–304.
83. Pan XH, Du JW, He QY, et al.. Survey on AIDS and STD knowledge in floating population of Li minorities in Hainan Province. Chin J Public Health 2002; 18: 719–720.
84. Qiu JQ, Xu ZL, Fang XW. Survey of HIV/AIDS prevention and control knowledge among migrant workers in Kaihua County of Zhejiang Province. Zhejiang J Prev Med 2011; 23: 85–86.
85. Tang HL, Wu ZH, Xu YJ, et al.. Investigation on current status of AIDS infection and AIDS related knowledge among out-migranbt workers in Dongyang. Modern Prev Med 2009; 36: 1117–1118, 1129.
86. Wang LJ, ZHou Y, Liu SW. Prevalence of HIV and HBsAg infection among floating employees in Chongwen District of Beijing City. China Prev Med 2006; 7: 541–542.
87. Wang MH, Ruan SM, Zhu YW, et al.. Investigation on HIV infection among immigrant women in rural area of Ji’nan City from 2005 to 2006. Prev Med Tribune 2008; 14: 405–406.
88. Wang X. A survey of HIV infections among non-native women in rural areas in certain city, Shandong Province. Chin J Dis Control Prev 2006; 10: 620–621.
89. Wang YL, Ding XB, Yi HR, et al.. Investigation on knowledge and prevalence of AIDS floating population. Chin J Public Health 2006; 22: 1285–1287.
90. Wu YJ, Bi YG, Dai JS. HIV infection and KAP status among female immigrant women in Jinxiang County, Shangdong Province. Chin J Pest Control 2006; 22: 673–674.
91. Xiao Y, Wu JC, Huang JS, et al.. Survey for HIV prevalence and AIDS related KAP among outgoing country workers in Jiujiang. Pract Prev Med 2007; 14: 92–93.
92. Xing AH, Wang LY, Wang JJ, et al.. Study on the prevalence of HIV/syphilis infection and related behavior among migrant workers who return to their hometown Shaanxi Province. Chin J AIDS STD 2007; 13: 260–261.
93. Xiu CZ, Jiang ZX, Fa P, et al.. Prevalence of HIV infection among rural married female migrants of childbearing age in Qingdao City, Shangdong Province. Strait J Prev Med 2007; 13: 31–32.
94. Xu Y. Monitoring analysis on AIDS of 400 migrant workers on Changxing Istand of Chongming County in Shanghai. Chin J Social Med 2010; 27: 322–323.
95. Yang X, Derlega VJ, Luo H. Migration, behaviour change and HIV/STD risks in China. AIDS Care 2007; 19: 282–288.
96. Yao AJ, Wu ZP, Yu LZ, et al.. Analysis on health examination among migrant workers in Xizhou District of Hubei Province. China Mod Doct 2010; 48: 96, 143.
97. Yi ZM, Li XP, Xiong YH, et al.. Study on HIV infection and prevention knowledge among migrant workers who return their hometown. Pract Prev Med 2008; 15: 1610–1611.
98. Yin L, Zheng YL, Zhao ZQ. Study on HIV infection among rural immigrant women in Zhangqiu City of Shangdong Province, 2005 to 2008. Chin J Rural Med Pharm 2010; 17: 63.
99. Zhang X, Shi YH, Cai YL. Prevalence of HIV infection among rural female migrants in Huai’an City, Jiangsu Province. Jiangsu J Prev Med 2010; 21: 28–29.
100. Zhang YQ, Zhu HY, Liu DY, et al.. Investigation on AIDS prevention, infection situation and behavior in peasant workers. Chin J Public Health 2008; 24: 8–9.
101. Zhang YQ, Li ZC, Kong Y, et al.. Analysis on HIV and syphilis infection situation among married immigrant women in rural areas. Chin J Public Health 2008; 24: 17–18.
102. Zhao R, Gao H, Shi X, et al.. Sexually transmitted disease/HIV and heterosexual risk among miners in townships of Yunnan Province, China. AIDS Patient Care STDS 2005; 19: 848–852.