title: The changing trends of HIV-1 prevalence and incidence from sentinel surveillance of five sub-populations in Yunnan, China, 2001-2010.
abstract: BACKGROUND
  Yunnan is one of the provinces hardest-hit by HIV in China. To understand HIV epidemic dynamics and evaluate prevention effectiveness, we studied the changing trends in HIV-1 prevalence and incidence among five sub-populations in Yunnan.
  
  
  METHODS
  Consecutive sentinel surveillances were conducted among people who inject drugs (PWID), male sexually transmitted diseases (STD) clinic attendees, and pregnant women for 2001-2010,female sex workers (FSWs) for 2007-2010, men who have sex with men (MSM) for 2008-2010. For the newly diagnosed HIV-seropositive samples, the recent infections were determined with BED-capture enzyme immunoassay (BED-CEIA), based on which HIV incidence was calculated for each sub-population using McDougal algorithm.
  
  
  RESULTS
  From 231,117 individuals, 6,107 HIV-positive samples were tested with BED-CEIA, among which 964 samples were identified as recent infections. In PWID, HIV prevalence for 2001-2010 was between 27.16% and 18.35%, while the estimated incidence rate significantly decreased from 11.68% in 2001 to 1.70% in 2010. Among male STD clinic attendees, both the HIV prevalence (from 3.62% in 2001 to 1.73% in 2010) and incidence (from 1.10% in 2001 to 0.40% in 2010) showed a significant decreasing trend. In FSWs, the HIV prevalence for 2007-2010 kept stable (between 2.46% and 1.95%), while the HIV incidence significantly decreased (from 0.71% in 2007 to 0.31% in 2010). In MSM, the HIV prevalence (between 11.78% and 9.42%) and incidence (between 6.01% and 8.38%) remained stable at a relatively high level for 2008-2010. In pregnant women, the HIV prevalence (between 0.44% and 0.30%) and incidence (between 0.15% and 0.08%) remained stable for 2001-2010.
  
  
  CONCLUSIONS
  The HIV incidences in PWID, male STD clinic attendees and FSWs showed the decreasing trend, supporting a positive effect of prevention strategies for these sub-populations. MSM with the highest HIV incidence have become the sub-population most at risk. In most sub-populations, the HIV prevalence did not decline, suggesting the disease burden is still heavy. These findings are valuable for developing HIV prevention strategies in Yunnan.
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. yanglilady@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. chenminyx@hotmail.com.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. mayanling68@aliyun.com.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. luo716@163.com.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Luo
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. Yangcj6910@163.com.
authors.forename: Chaojun
authors.initials: C
authors.lastname: Yang
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. suyingzhen@163.com.
authors.forename: Yingzhen
authors.initials: Y
authors.lastname: Su
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. huichao_chen@126.com.
authors.forename: Huichao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. Yuhua.shi@msn.com.
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. jingyuan_mei@126.com.
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Mei
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. jiamanhong@hotmail.com.
authors.forename: Manhong
authors.initials: M
authors.lastname: Jia
authors.affiliation: Institute for STD/AIDS Control and Prevention, Yunnan Center for Disease Control and Prevention, No 158, Dongsi Street, Xishan District, Kunming, 650022, , Yunnan Province, China. lulin@yncdc.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology; D000328:Adult; D002681:China / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D015497:HIV-1; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology; D015995:Prevalence; D018571:Sentinel Surveillance; D060386:Sex Workers / Q000706:statistics & numerical data; D015819:Substance Abuse, Intravenous / Q000453:epidemiology; D055815:Young Adult