Shoes for Kids on the Island of Pemba (SKIP): A Pragmatic, Cluster Randomised Controlled Trial to Test if Shoes Reduce Hookworm Infection and Transmission in School-aged Children on Pemba Island, Zanzibar

Aim: To carry out a cluster randomised controlled trial (non-blinded) to test under field conditions whether the provision of shoes to school-aged children on Pemba Island, Zanzibar, an area of high hookworm prevalence and anaemia, could reduce the transmission, incidence and disease burden of hookworm infection among this susceptible population.

Methods:

Setting: Pemba Island is the northern of the two main islands that make up the Zanzibar archipelago, situated in the Indian Ocean and close to the coast of East Africa, just below the equator. The climate is tropical and humid and the island has two rainy seasons, from March-June (Masika) and October-December (Vuli). Humidity is high, up to 1000mm during the Masika rains. Economic activities are mainly agriculture and fishing and considerable improvements to infrastructure - roads and electricity - have been made in recent years. The island's population totalled 460,196 in 2008, of whom 50 percent were children aged <15 years. Zanzibar is an autonomous part of the United Republic of Tanzania and on the mainland, the under 5 mortality rate (U5MR) is 81 per 1,000 live births but is substantially higher on Zanzibar at 116 per 1,000 live births. The area is highly endemic for soil transmitted helminths - a recent study on neighbouring Unguja Island found three-quarters of rural inhabitants and half of urban inhabitants to be infected with parasitic worms, despite 15 years of mass drug treatment. Other risk factors for concomitant anaemia are poor nutrition, focal areas of Schistosoma haematobium transmission and malaria, although recent control efforts have made impressive reductions in malaria transmission (reduced to 0.8% prevalence in 2007).

Study schools (clusters): 12 government primary schools from across the entire island were identified for the trial, where hookworm prevalence in a previous survey totalled >50%: Mizingani, Ng'ombeni, Chambani, Uwandani, Bagamoyo, Shumba Viamboni, Mkanyageni, Ziwani, Wesha, Tumbe, Wingwi, and Ngwachani.

Study design: Pragmatic, cluster (non-blinded) randomised controlled trial with school-aged children randomized to either the intervention (a pair of shoes alongside standard care) or standard care (periodic de-worming with antihelminthics and health education). Children already wearing shoes were advised to continue to do so in the control arm.