Investigating a Non-Mesh Mosquito Net Among Outdoor Sleeping Nomadic Communities in Kenya.

Abdullahi Abagira,Rebecca E Harrison,Georgia R Gore-Langton,Katie Eves,Nfornuh Alenwi,Owen M Bicknell,Stephen Munga,Farah Amin Hassan,Richard Allan,Elizabeth Juma,James Mungai

doi:10.4269/ajtmh.14-0458

Abstract

Rising reports of exophagic malaria vectors make even more pressing the need for alternatives to traditional, mesh, long-lasting insecticidal nets (LLINs) designed for indoor sleeping and often inadequate in the protection of outdoor-sleeping populations. This study tests and evaluates the retention, utilization, and durability of novel, non-mesh nets designed for outdoor use. Longitudinal, cross-sectional surveys were conducted, the physical condition of nets was assessed, and bio-efficacy and insecticide content were tested. At 22 months, retention was 98.0%; 97.1% of nets fell within the World Health Organization (WHO) category of being in “good” condition; none were in the “torn” category. At 18 months post-distribution, 100% of nets had at least WHO Pesticide Evaluation Scheme (WHOPES)-acceptable levels of insecticide, this proportion was 66.7% at 22 months. This novel mosquito net has the potential to provide a durable and context-specific tool to prevent malaria among traditionally hard-to-protect and highly vulnerable populations.

Highlights

Malaria is estimated to have caused 584,000 deaths in 2013; in the same year, there were an estimated 198 million cases of clinical malaria.[1]
Rising reports of exophagic malaria vectors make even more pressing the need for alternatives to traditional, mesh, long-lasting insecticidal nets (LLINs) designed for indoor sleeping and often inadequate in the protection of outdoor-sleeping populations
Long-lasting insecticidal nets (LLINs) have been shown to be a highly effective method of malaria prevention[3,4,5,6,7]; this effectiveness is often limited as the standard LLIN is not designed for use in all contexts

Summary

Introduction

Malaria is estimated to have caused 584,000 deaths in 2013; in the same year, there were an estimated 198 million cases of clinical malaria.[1]. Nomadic populations, defined here as groups of people with no fixed home who move according to the seasons and in search of water, food, and pasture, have been estimated at 50–100 million persons globally[12] with over 60% found in Africa, and make up approximately 19% of the population in Kenya.[12,13,14] The characteristic mobility of these populations is often associated with sleeping outdoors, an environment unprotected by indoor residual spraying (IRS) and in which LLINs designed for indoor sleeping are unsuitable or inadequate. Outdoor use and ultraviolet (UV) exposure increase the rate and degree of insecticide degradation,[15] the World Health Organization (WHO) recommendation to dry the nets in the shade. These harsh climates mean that nomads are rapidly left with inefficient nets offering little, if any, protection from the bites of malaria vectors

Methods

Results

Conclusion