Effect of Interventions to Reduce Malaria Incidence Among Military Personnel on Active Duty: Study Protocol for a Cluster Randomised Controlled Trial of the Impact of Etofenprox-treated Uniforms, Permethrin-treated Uniforms and DEET Insect Repellent

Abstract

\n Background: While there is strong evidence that permethrin-treated clothing and topical insect repellents are protective against insect bites, there are few studies assessing the impact on malaria infection. This study will evaluate the impact of the protective efficacy of bite prevention methods on the incidence of malaria infection among military personnel in an operational setting. Permethrin-treated uniforms will be compared to etofenprox-treated uniforms, with both clothing treatments used in conjunction with DEET insect repellent. An additional study arm will test permethrin uniforms with placebo lotion to determine if there is any additional protective effect of using DEET with insecticide-treated clothing. Method: A cluster randomised double-blind placebo-controlled trial is planned to evaluate the effectiveness of the interventions on preventing malaria infections in soldiers on active duty at Mgambo National Service Camp in Tanga, Tanzania. The arms are (1) permethrin-treated uniform with 30% DEET liposome formula; (2) permethrin-treated uniform with placebo lotion; (3) candidate insect repellent system, i.e., etofenprox-treated uniform with 30% DEET liposome formula; and (4) placebo, i.e., untreated uniforms with placebo lotion. The primary outcome is the incidence of Plasmodium falciparum malaria infection detected by polymerase chain reaction (PCR) by active case detection using surveys every 2 weeks for 12 months. Rapid diagnostic tests will be used for diagnosis of participants with symptoms. The unit of randomisation will be combania: companies formed by recruits aged 18 to 25 years; combania do activities together and sleep in the same dormitory. Unequal randomisation will be used to optimise statistical power for the primary comparison between permethrin-treated uniforms with DEET and etofenprox-treated uniforms with DEET. Discussion: This trial will estimate the effects of permethrin with DEET compared to those of the new fabric treatment etofenprox with DEET and any additional effect of using DEET. The results will inform strategies to protect military personnel and civilians who have more outdoor or occupational malaria exposure than the general public. Trial registration: clinicaltrials.gov Registration number NCT02938975.