title: Diagnostic accuracy of Kato-Katz and FLOTAC for assessing anthelmintic drug efficacy.
abstract: BACKGROUND
  Sensitive diagnostic tools are required for an accurate assessment of prevalence and intensity of helminth infections in areas undergoing regular deworming, and for monitoring anthelmintic drug efficacy. We compared the diagnostic accuracy of the Kato-Katz and FLOTAC techniques in the frame of a drug efficacy trial.
  
  
  RESULTS
  Stool samples from 343 Zanzibari children were subjected to duplicate Kato-Katz thick smears and the FLOTAC basic technique in a baseline screening in early 2009. The FLOTAC showed a higher sensitivity than the Kato-Katz method for the diagnosis of Trichuris trichiura (95% vs. 88%, p = 0.012) and Ascaris lumbricoides (88% vs. 68%, p = 0.098), but a lower sensitivity for hookworm diagnosis (54% vs. 81%, p = 0.006). Considering the combined results from both methods as 'gold' standard, the prevalences of T. trichiura, hookworm and A. lumbricoides were 71% (95% confidence interval (CI): 66-75%), 22% (95% CI: 17-26%) and 12% (95% CI: 8-15%), respectively. At follow-up, 3-5 weeks after 174 among the 269 re-examined children were administered anthelmintic drugs, we observed cure rates (CRs) against A. lumbricoides, hookworm and T. trichiura of 91% (95% CI: 80-100%), 61% (95% CI: 48-75%) and 41% (95% CI: 34-49%), respectively, when using the Kato-Katz method. FLOTAC revealed lower CRs against A. lumbricoides (83%, 95% CI: 67-98%) and T. trichiura (36%, 95% CI: 29-43%), but a higher CR against hookworm (69%, 95% CI: 57-82%). These differences, however, lacked statistical significance. Considerable differences were observed in the geometric mean fecal egg counts between the two methods with lower egg reduction rates (ERRs) determined by FLOTAC.
  
  
  CONCLUSIONS
  Our results suggest that the FLOTAC technique, following further optimization, might become a viable alternative to the Kato-Katz method for anthelmintic drug efficacy studies and for monitoring and evaluation of deworming programs. The lower CRs and ERRs determined by FLOTAC warrant consideration and could strategically impact future helminth control programs.
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Knopp
authors.forename: Benjamin
authors.initials: B
authors.lastname: Speich
authors.forename: Jan
authors.initials: J
authors.lastname: Hattendorf
authors.forename: Laura
authors.initials: L
authors.lastname: Rinaldi
authors.forename: Khalfan A
authors.initials: KA
authors.lastname: Mohammed
authors.forename: I Simba
authors.initials: IS
authors.lastname: Khamis
authors.forename: Alisa S
authors.initials: AS
authors.lastname: Mohammed
authors.forename: Marco
authors.initials: M
authors.lastname: Albonico
authors.forename: David
authors.initials: D
authors.lastname: Rollinson
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Marti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cringoli
authors.forename: Jürg
authors.initials: J
authors.lastname: Utzinger
mesh_terms: D000293:Adolescent; D000723:Ancylostomatoidea / Q000302:isolation & purification; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use*; D001196:Ascariasis / Q000188:drug therapy* / Q000469:parasitology; D017164:Ascaris lumbricoides / Q000302:isolation & purification; D002648:Child; D005260:Female; D006725:Hookworm Infections / Q000188:drug therapy* / Q000469:parasitology; D006801:Humans; D008297:Male; D010274:Parasitology / Q000379:methods*; D013636:Tanzania; D016896:Treatment Outcome; D014257:Trichuriasis / Q000188:drug therapy* / Q000469:parasitology; D014258:Trichuris / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D000871:Anthelmintics