PLoS Neglected Tropical Diseases (Mar 2011)

Assessment of the anthelmintic efficacy of albendazole in school children in seven countries where soil-transmitted helminths are endemic.

  • Jozef Vercruysse,
  • Jerzy M Behnke,
  • Marco Albonico,
  • Shaali Makame Ame,
  • Cécile Angebault,
  • Jeffrey M Bethony,
  • Dirk Engels,
  • Bertrand Guillard,
  • Thi Viet Hoa Nguyen,
  • Gagandeep Kang,
  • Deepthi Kattula,
  • Andrew C Kotze,
  • James S McCarthy,
  • Zeleke Mekonnen,
  • Antonio Montresor,
  • Maria Victoria Periago,
  • Laurentine Sumo,
  • Louis-Albert Tchuem Tchuenté,
  • Thi Cam Thach Dang,
  • Ahmed Zeynudin,
  • Bruno Levecke

DOI
https://doi.org/10.1371/journal.pntd.0000948
Journal volume & issue
Vol. 5, no. 3
p. e948

Abstract

Read online

The three major soil-transmitted helminths (STH) Ascaris lumbricoides, Trichuris trichiura and Necator americanus/Ancylostoma duodenale are among the most widespread parasites worldwide. Despite the global expansion of preventive anthelmintic treatment, standard operating procedures to monitor anthelmintic drug efficacy are lacking. The objective of this study, therefore, was to define the efficacy of a single 400 milligram dose of albendazole (ALB) against these three STH using a standardized protocol.Seven trials were undertaken among school children in Brazil, Cameroon, Cambodia, Ethiopia, India, Tanzania and Vietnam. Efficacy was assessed by the Cure Rate (CR) and the Fecal Egg Count Reduction (FECR) using the McMaster egg counting technique to determine fecal egg counts (FEC). Overall, the highest CRs were observed for A. lumbricoides (98.2%) followed by hookworms (87.8%) and T. trichiura (46.6%). There was considerable variation in the CR for the three parasites across trials (country), by age or the pre-intervention FEC (pre-treatment). The latter is probably the most important as it had a considerable effect on the CR of all three STH. Therapeutic efficacies, as reflected by the FECRs, were very high for A. lumbricoides (99.5%) and hookworms (94.8%) but significantly lower for T. trichiura (50.8%), and were affected to different extents among the 3 species by the pre-intervention FEC counts and trial (country), but not by sex or age.Our findings suggest that a FECR (based on arithmetic means) of >95% for A. lumbricoides and >90% for hookworms should be the expected minimum in all future surveys, and that therapeutic efficacy below this level following a single dose of ALB should be viewed with concern in light of potential drug resistance. A standard threshold for efficacy against T. trichiura has yet to be established, as a single-dose of ALB is unlikely to be satisfactory for this parasite.ClinicalTrials.gov NCT01087099.