A controlled evaluation of two school-based anthelminthic chemotherapy regimens on intensity of intestinal helminth infections

Background School-based deworming programmes have been promoted as a cost-e ffective strategy for control of nematode infection in developing countries . While numerous efficacy studies have been conducted, there is little info rmation on actual programme effectiveness in areas of intense transmission. Methods A randomized trial of a school-based deworming programme was conduc ted in 12 primary schools on Pemba Island, Zanzibar. Four schools each were randomized to control, twice a year deworming with single dose mebendazole or three times a year deworming. Baseline and 12-month follow-up data on h elminth infection using the Kato-Katz technique, demographic information an d nutritional status were collected on 3028 children from March 1994 to May 1995. Results Intensity of infection measured as eggs per gram of faeces (epg) de clined significantly for Ascaris lumbricoides, Trichuris trichiura and hook worm infections in both treatment groups. A. lumbricoides infection intensi ty declined 63.1% and 96.7% in the twice and three times per year treatment groups compared to the controls. T. trichiura infection intensity declined 40.4% and 75.9% respectively and hookworm intensity declined 35.3% and 57. 2% respectively compared to control schools. Conclusions These results suggest that school-based programmes can be a cos t-effective approach for controlling the intensity of intestinal helminth i nfection even in environments where transmission is high.