title: Performance of local light microscopy and the ParaScreen Pan/Pf rapid diagnostic test to detect malaria in health centers in Northwest Ethiopia.
abstract: BACKGROUND
  Diagnostic tests are recommended for suspected malaria cases before treatment, but comparative performance of microscopy and rapid diagnostic tests (RDTs) at rural health centers has rarely been studied compared to independent expert microscopy.
  
  
  METHODS
  Participants (N = 1997) with presumptive malaria were recruited from ten health centers with a range of transmission intensities in Amhara Regional State, Northwest Ethiopia during October to December 2007. Microscopy and ParaScreen Pan/Pf® RDT were done immediately by health center technicians. Blood slides were re-examined later at a central laboratory by independent expert microscopists.
  
  
  RESULTS
  Of 1,997 febrile patients, 475 (23.8%) were positive by expert microscopists, with 57.7% P. falciparum, 24.6% P. vivax and 17.7% mixed infections. Sensitivity of health center microscopists for any malaria species was >90% in five health centers (four of which had the highest prevalence), >70% in nine centers and 44% in one site with lowest prevalence. Specificity for health center microscopy was very good (>95%) in all centers. For ParaScreen RDT, sensitivity was ≥90% in three centers, ≥70% in six and <60% in four centers. Specificity was ≥90% in all centers except one where it was 85%.
  
  
  CONCLUSIONS
  Health center microscopists performed well in nine of the ten health centers; while for ParaScreen RDT they performed well in only six centers. Overall the accuracy of local microscopy exceeded that of RDT for all outcomes. This study supports the introduction of RDTs only if accompanied by appropriate training, frequent supervision and quality control at all levels. Deficiencies in RDT use at some health centers must be rectified before universal replacement of good routine microscopy with RDTs. Maintenance and strengthening of good quality microscopy remains a priority at health center level.
authors.affiliation: The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Tekola
authors.initials: T
authors.lastname: Endeshaw
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Graves
authors.forename: Berhan
authors.initials: B
authors.lastname: Ayele
authors.forename: Aryc W
authors.initials: AW
authors.lastname: Mosher
authors.forename: Teshome
authors.initials: T
authors.lastname: Gebre
authors.forename: Firew
authors.initials: F
authors.lastname: Ayalew
authors.forename: Asrat
authors.initials: A
authors.lastname: Genet
authors.forename: Alemayehu
authors.initials: A
authors.lastname: Mesfin
authors.forename: Estifanos Biru
authors.initials: EB
authors.lastname: Shargie
authors.forename: Zerihun
authors.initials: Z
authors.lastname: Tadesse
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Teferi
authors.forename: Berhanu
authors.initials: B
authors.lastname: Melak
authors.forename: Frank O
authors.initials: FO
authors.lastname: Richards
authors.forename: Paul M
authors.initials: PM
authors.lastname: Emerson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D008288:Malaria / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D010963:Plasmodium falciparum; D010966:Plasmodium vivax; D015995:Prevalence; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D055815:Young Adult
chemical_list: D011933:Reagent Kits, Diagnostic