title: [Distribution of HIV-1 subtype and its relationship with HIV/AIDS epidemic in Guizhou province].
abstract: OBJECTIVE
  To study the HIV-1 diversity and how did it promote the rapid spread of AIDS, in Guizhou province.
  
  
  METHODS
  A total of 190 HIV-1 positive subjects were collected in different years and regions from Guizhou province. The env and gag genes were amplified with nested PCR and their sequences were determined. The subtypes were identified by the MEGA 4.0 software and the relationships between subtypes and AIDS epidemic were analyzed.
  
  
  RESULTS
  The number of HIV/AIDS reported cases was increased from 66 in 1998 up to 8435 in 2009, a 16.38 time increase in 7 years. Subtypes B (9), B' (4), C (2), CRF07_BC (75), CRF08_BC (17), CRF01_AE (64) were identified in Guizhou province among the samples collected in various periods of time. The genetic diversities in env gene of CRF07_BC and CRF08_BC increased along with the spreading of HIV (from 0.035 ± 0.006 to 0.092 ± 0.011). Subtype B' (4/11) appeared the main subtype prevailed in Guizhou in 1998 as well as CRF07_BC (26/41) in 2002 and CRF01_AE (62/119) in 2007. The HIV/AIDS epidemic in Guizhou province showed an rapidly upward trend, with the main risk factors of HIV transmission as 2610 cases through injecting drug users (IDUs). and 176 cases due to sexually transmitted infections (STIs), from year 2001 to 2006. However, STIs began to increase rapidly, after 2006, with 1713 cases of IDUs and 1833 cases of STIs. Data indicated that the change of composition of different HIV-1 subtypes was correlated with the mode of transmission in Guizhou province (χ(2) = 41.253, P = 0.000).
  
  
  CONCLUSIONS
  The types of HIV strains changed over time as well the turnover of the main risk factors. Sexual transmission, including both hetero- and homo-sexual became the main risk factors, suggesting the development of related prevention and control programs, on HIV/AIDS should be considered accordingly in the future.
authors.affiliation: Institute of AIDS/STD/Dermatology Control and Prevention, Guizhou Provincial Center for Disease Control and Prevention, Guiyang 550002, China. sxgpfs@yahoo.com.cn
authors.forename: Xian-guang
authors.initials: XG
authors.lastname: Sun
authors.forename: Hui
authors.initials: H
authors.lastname: Xing
authors.forename: Zhi-jian
authors.initials: ZJ
authors.lastname: Li
authors.forename: Chun-lin
authors.initials: CL
authors.lastname: Cheng
authors.forename: Xin-hui
authors.initials: XH
authors.lastname: Zhang
authors.forename: Li-mei
authors.initials: LM
authors.lastname: Shen
authors.forename: Xiang
authors.initials: X
authors.lastname: He
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology* / Q000821:virology*; D002681:China / Q000453:epidemiology; D015752:Genes, env; D015750:Genes, gag; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D017720:Molecular Epidemiology; D012307:Risk Factors