title: Estimating community prevalence of ocular Chlamydia trachomatis infection using pooled polymerase chain reaction testing.
abstract: OBJECTIVE
  Trachoma is the leading cause of blindness from infection worldwide. Treatment programs require accurate Chlamydia trachomatis infection prevalence rates to guide decision making. The use of clinical examination is by far the most common way to monitor activity, but may yield overestimates of infection prevalence. Laboratory testing on individual specimens such as polymerase chain reaction (PCR) is highly sensitive and specific, but prohibitively expensive. Here we demonstrate simulations of pooled PCR results may estimate infection prevalence of an entire community yielding substantial cost savings if pool size is chosen correctly.
  
  
  METHODS
  Community infection prevalence was estimated using maximum likelihood estimation with data collected from a previously described study. Simulations for communities were performed to determine the accuracy of prevalence estimation using pooled results. The root mean squared error was then used to determine an acceptable inaccuracy in estimates allowing for a pooling strategy to be formed.
  
  
  RESULTS
  Results from simulations and empirical data suggest optimum pooling strategies to estimate community infection prevalence while keeping the root mean squared error of the estimate below 2%. Reduction of PCR testing which permits cost savings is shown to be between 5 and 80% given a community infection prevalence below 60%.
  
  
  CONCLUSIONS
  Pooling specimens for PCR testing often provides enough data to accurately estimate infection prevalence at the community level.
authors.affiliation: F.I. Proctor Foundation, University of California , San Francisco, CA , USA .
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Ray
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Zhou
authors.forename: Vicky
authors.initials: V
authors.lastname: Cevallos
authors.forename: Stephanie
authors.initials: S
authors.lastname: Chin
authors.forename: Wayne
authors.initials: W
authors.lastname: Enanoria
authors.forename: Fengchen
authors.initials: F
authors.lastname: Lui
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lietman
authors.forename: Travis C
authors.initials: TC
authors.lastname: Porco
mesh_terms: D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000235:genetics*; D002986:Clinical Trials as Topic; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology*; D003198:Computer Simulation; D004269:DNA, Bacterial / Q000032:analysis*; D006801:Humans; D007223:Infant; D016013:Likelihood Functions; D016133:Polymerase Chain Reaction / Q000379:methods*; D015995:Prevalence; D012680:Sensitivity and Specificity; D014141:Trachoma / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D004269:DNA, Bacterial