Spatial repellents to reduce the outdoor transmission of malaria

ABSTRACT Despite the recognized and urgent need for public health interventions that interrupt outdoor malaria transmission, no such proven interventions are available. Transfluthrin-treated hessian fabric strips (TTHFS) offer promise, showing more than six months of mosquito bite deterrence in Tanzanian settings. This project

seeks to clarify and advance the evidence base on TTHFS through meta-analysis of Tanzanian studies, semi- field and field testing in Thailand and Cambodia, and user acceptability studies in Cambodia to inform future studies and intervention designs. Aim 1: To determine the relationship between TTHFS characteristics and their protective efficacy over

time in Tanzania. I hypothesize that an optimal transfluthrin concentration, fabric strip size, and temperature range for TTHFS can be identified from prior studies in Tanzania, and that impacts on efficacy caused by high temperature and relative humidity can be quantified. Aim 2: To investigate the protective efficacy of TTHFS over time in Thai and Cambodian outdoor

conditions. I hypothesize that TTHFS that are efficacious in Tanzania will show similar levels of efficacy in a very different setting against Thai and Cambodian malaria vectors, with similar effects of temperature and humidity on the duration of efficacy. Aim 3: To establish user acceptability and identify modifiable barriers to TTHFS uptake among

Cambodian forest rangers and forest goers. I hypothesize that Cambodian forest rangers and forest goers will find TTHFS acceptable due to their ability to reduce mosquito bites, but will be uncomfortable with the product given their limited experience with TTHFS and will have preferences on the size, shape, and design of

TTHFS. This study will inform a future interventional study of an optimized TTHFS in Southeast Asia, to be performed subsequent to this K01 study.