Efficacy of mebendazole and levamisole alone or in combination against intestinal nematode infections after repeated targeted mebendazole treatment in Zanzibar.
OBJECTIVE
To evaluate the efficacy of and resistance to mebendazole (500 mg) and levamisole (40 or 80 mg), alone or in combination, for the treatment of Ascaris lumbricoides, Trichuris trichiura and hookworm infections on Pemba Island - an area exposed to periodic school-based mebendazole treatment since 1994.


METHODS
A randomized, placebo-controlled trial was carried out in 914 children enrolled from the first and fifth grades of primary schools. Stool samples collected at baseline and 21 days after treatment were examined by the Kato-Katz technique to assess the prevalence and intensity of helminth infection.


RESULTS
Efficacies of mebendazole and levamisole as single treatments against intestinal nematode infections were comparable with those in previous trials, but mebendazole treatment of hookworm infections gave significantly lower cure (7.6%) and egg reduction (52.1%) rates than reported in a study undertaken before the beginning of periodic chemotherapy (cure rate, 22.4%; egg reduction rate, 82.4%). Combined treatment with mebendazole and levamisole had a significantly higher efficacy against hookworm infections (cure rate, 26.1%; egg reduction rate, 88.7%) than either drug given alone. No difference in mebendazole efficacy was found in children who had been treated repeatedly compared with those who had not been treated previously.


CONCLUSIONS
The overall efficacy of mebendazole against hookworm infections after periodic chemotherapy is reduced. The efficacy of benzimidazoles in chemotherapy-based control programmes should be monitored closely. Combined treatment with mebendazole and levamisole may be useful as a tool to delay the development of benzimidazole resistance.
Albonico
M
M
Ivo de Carneri Foundation, Milan, Italy.
Bickle
Q
Q
Ramsan
M
M
Montresor
A
A
Savioli
L
L
Taylor
M
M
D000969:Antinematodal Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D002648:Child; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000188:drug therapy* / Q000469:parasitology; D007978:Levamisole / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D008463:Mebendazole / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D009349:Nematode Infections / Q000188:drug therapy* / Q000469:parasitology; D010270:Parasite Egg Count; D010919:Placebos; D013636:Tanzania / Q000453:epidemiology; D016896:Treatment Outcome
D000969:Antinematodal Agents; D010919:Placebos; D007978:Levamisole; D008463:Mebendazole