title: Epidemiology / vaccine efficacy trials. "HIV Incidence in Adults in Northern Thailand".
abstract: According to an abstract submitted by the authors to the X International Conference on AIDS, held August 7-12, 1994, in Yokohama, Japan, "
  
  
  OBJECTIVE
  To measure the HIV-1 incidence, follow-up rates and high risk behaviors in cohorts of seronegative adults in northern Thailand.
  
  
  METHODS
  We screened cohorts of female commercial sex workers (CSWs), male STD clinic patients, Royal Thai Army (RTA) conscripts, and discharged RTA conscripts at baseline and q3 to 6 months for HIV infection by ELISA and WB and did interviews for high risk behavior, medical history, and STD cultures.
  
  
  RESULTS
  Of 1068 CSWs, 409 (38.3%) were HIV positive, and 396 HIV negative were enrolled in the study; follow-up at 6 months was 70.7% and 19 seroconverted, for an incidence of 12.8/100 person years.  Of 1031 male STD patients, 164 (15.9%) were HIV positive, and 264 HIV negative (30.4%) were enrolled; follow-up at 6 months was 91.9% and 6 seroconverted, for an incidence of 4.92/100 person years.  Of 969 RTA conscripts, 12.4% were HIV positive at baseline and 90% were followed at 6 months; 3 of 778 seroconverted, for an incidence of 0.87/100 person years.  (Previous RTA cohorts have had an incidence of 3.4%/year).  Among 380 men discharged from RTA, follow-up at 9 months was 81.8% and the incidence was 5.2/100 person years.  Sample sizes required to show an HIV vaccine efficacy of 60%, with a power-.90, alpha-.05 varies from CSUs 644, STD patients 1456 to ex-RTA-1306.
  
  
  CONCLUSIONS
  Several populations in northern Thailand appear to have sufficiently high HIV-1 incidence and adequate follow-up for HIV vaccine efficacy trials and other preventive intervention trials.
mesh_terms: D001208:Asia; D001210:Asia, Southeastern; D015331:Cohort Studies; D003906:Developing Countries; D004194:Disease; D015658:HIV Infections; D015994:Incidence; D012107:Research Design; D013785:Thailand; D014777:Virus Diseases
keywords: Asia; Cohort Analysis; Developing Countries; Diseases; Hiv Infections; Incidence; Measurement; Southeastern Asia; Thailand; Viral Diseases