Background: We aimed to find out whether symptomless infection with Trichuris trichiura is associated with impairment of growth and to assess the effect of a multiple-doses regimen of anthelmintic drugs on the growth of children.
Methods: In a community based trial, 622 Mexican children were randomly allocated one of three treatment regimens: 3 days of albendazole 400 mg daily (high efficacy); one dose of albendazole 400 mg (moderate efficacy); one dose of pyrantel (pyrantel embonate) 11 mg/kg (low efficacy). Growth was monitored for 12 months. Analyses were by intention to treat.
Findings: 113 (18%) children were lost to follow-up--34 from the pyrantel group, 45 from the albendazole 400 mg group, and 34 from the albendazole 1200 mg group. Among the 127 children with heavy pretreatment infections, albendazole 1200 mg was better than pyrantel in terms of an increase in arm circumference (mean 0.26 cm, p=0.044). Among the 381 children with low pretreatment levels of infection, changes in weight (mean difference between groups -0.33 kg, p=0.036), arm circumference (-0.18 cm, p=0.0095), and thickness of triceps skinfold (-0.41 mm, p=0.0031) were less in children on albendazole 1200 mg than in those on pyrantel.
Interpretation: Symptomless trichuriasis impairs growth and albendazole or pyrantel may affect growth, independently of a therapeutic action on parasites. Possible toxic effects of high-dose albendazole require further investigation.