title: A primary care level algorithm for identifying HIV-infected adolescents in populations at high risk through mother-to-child transmission.
abstract: OBJECTIVE
  To present an algorithm for primary-care health workers for identifying HIV-infected adolescents in populations at high risk through mother-to-child transmission.
  
  
  METHODS
  Five hundred and six adolescent (10-18 years) attendees to two primary care clinics in Harare, Zimbabwe, were recruited. A randomly extracted 'training' data set (n = 251) was used to generate an algorithm using variables identified as associated with HIV through multivariable logistic regression. Performance characteristics of the algorithm were evaluated in the remaining ('test') records (n = 255) at different HIV prevalence rates.
  
  
  RESULTS
  HIV prevalence was 17%, and infection was independently associated with client-reported orphanhood, past hospitalization, skin problems, presenting with sexually transmitted infection and poor functional ability. Classifying adolescents as requiring HIV testing if they reported >1 of these five criteria had 74% sensitivity and 80% specificity for HIV, with the algorithm correctly predicting the HIV status of 79% of participants. In low-HIV-prevalence settings (<2%), the algorithm would have a high negative predictive value (≥ 99.5%) and result in an estimated 60% decrease in the number of people needing to test to identify one HIV-infected individual, compared with universal testing.
  
  
  CONCLUSIONS
  Our simple algorithm can identify which individuals are likely to be HIV infected with sufficient accuracy to provide a screening tool for use in settings not already implementing universal testing policies among this age-group, for example immigrants to low-HIV-prevalence countries.
authors.affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. rabferr@gmail.com
authors.forename: Rashida A
authors.initials: RA
authors.lastname: Ferrand
authors.forename: Helen A
authors.initials: HA
authors.lastname: Weiss
authors.forename: Kusum
authors.initials: K
authors.lastname: Nathoo
authors.forename: Chiratidzo E
authors.initials: CE
authors.lastname: Ndhlovu
authors.forename: Stanley
authors.initials: S
authors.lastname: Mungofa
authors.forename: Shungu
authors.initials: S
authors.lastname: Munyati
authors.forename: Tsitsi
authors.initials: T
authors.lastname: Bandason
authors.forename: Diana M
authors.initials: DM
authors.lastname: Gibb
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Corbett
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D004812:Epidemiologic Methods; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000635:transmission; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D011320:Primary Health Care / Q000379:methods*; D015030:Zimbabwe / Q000453:epidemiology