title: [Occurrence of human immunodeficiency virus-1 resistance through a six-year surveillance in rural areas of Henan].
abstract: OBJECTIVE
  To analyze the occurring rules of human immunodeficiency virus (HIV) drug resistance under an unique therapy model among HIV-1 infected individuals on antiretroviral therapy (ART) in rural areas of Henan, China.
  
  
  METHODS
  A cohort of 75 individuals on an ART regimen of zidovudine (ZDV), dideoxyinosine (ddI) and nevirapine (NVP) was established in March 2003. A total of 12 surveillance were conducted and 788 person-times were studied until 2010. The parameters of CD4 cell count and viral load (VL) were tested in each survey. And genotypic resistance testing was performed in patients with a failure of viral suppression. Survival analysis was used to estimate the occurrence time of resistance.
  
  
  RESULTS
  The cumulative mortality rate was 16% (12/75) in the cohort. And the cumulative resistance rate was 88% (66/75) from 2004 to 2010. The rate of resistance reached 54.7% and the probability from susceptibility to drugs developing resistance decreased drastically from 100% to 45.3% within the first 1 year of initiation. The occurrence time of resistance for half of individuals in the cohort was at 12.0 months (95%CI 8.6 - 17.0) after initiation, 25.1 months (95%CI 19.0 - 33.3) in those whose VL was less than 4.0 lgU/ml and 4.8 months (95%CI 4.1 - 5.6) at VL > 4.0 lgU/ml during the first investigation. The individuals with an early occurrence of resistance within 12 months carried high risks for a failure of viral suppression and a decrease of CD4 counts.
  
  
  CONCLUSIONS
  The occurrence of resistance rises with the course of therapy. And the greatest probability for resistance is within the first 1 year of initial therapy. A high level of VL has a significant impact on the development of resistance. Preventing the occurrence of resistance during the initial therapy remains a key goal.
authors.affiliation: Academy of Military Medical Science, Beijing 100071, China.
authors.forename: Han-ping
authors.initials: HP
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Yong-jian
authors.initials: YJ
authors.lastname: Liu
authors.forename: Zuo-yi
authors.initials: ZY
authors.lastname: Bao
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Dao-min
authors.initials: DM
authors.lastname: Zhuang
authors.forename: Si-yang
authors.initials: SY
authors.lastname: Liu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiao-lin
authors.initials: XL
authors.lastname: Wang
authors.forename: Jing-yun
authors.initials: JY
authors.lastname: Li
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000453:epidemiology / Q000821:virology*; D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D024882:Drug Resistance, Viral; D005260:Female; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012424:Rural Population
chemical_list: D019380:Anti-HIV Agents