Last Updated: 12/02/2020

Estimating the Malaria Prevention Impact of New Nets: Observational Analyses to Evaluate the Evidence Generated During Piloted New Net Distributions in Rwanda

Objectives

The aim of this research is to better understand the effectiveness and cost-effectiveness of IG2 ITNs in Rwanda and to collect data on community uptake of the ITNs. During the upcoming pilot implementation, entomological, epidemiological, and anthropological data will be collected in three study districts, one that will receive IG2 ITNs, one comparator district that will receive standard LLINs, and one additional comparator district that will receive standard LLINs with IRS. Data will be analyzed and results disseminated to support the NMCP, donors, policymakers, and other national and regional stakeholders in their ITN decision-making and planning processes. Each component specifically aims to:

Epidemiological component – measure the epidemiological impact of the new IG2 ITNs and standard LLINs in real deployment scenarios through observational studies. These studies will compare trends in (1) malaria case incidence rates passively reported to the national health system (passive case detection, PCD) and (2) malaria infection prevalence, measured through Rapid Diagnostic Tests (RDTs), in participants 6 months of age and older from annual cross-sectional surveys during peak transmission periods.
Entomological component – evaluate the impact of IG2 ITNs on vector populations and biting rates, compared to standard LLINs, through national mosquito surveillance data that will measure trends in species-specific (1) adult vector densities (2) indoor and outdoor human landing rates (3) estimated entomological inoculation rates and (4) insecticide resistance patterns.
Anthropological component – map the social determinants of impact for IG2 LLINs and determine transmission risk defined as the intersection between time at risk of mosquito blood feeding and human activities not under protection of an ITNN, through gathering evidence on LLIN uptake and usage. The collection of reliable data using observation, focus group discussions, and key informant interviews is an essential component of the evaluation for both modeling and contextual analysis of impact.
Costing and cost-effectiveness component – estimate the cost and cost-effectiveness of IG2 ITNs in Rwanda through data on the price of the product, delivery and deployment costs, and product effectiveness based on case incidence rates measured during the epidemiological component of this study. Additionally, mean costs per case averted that might occur in other contexts will be modeled and incorporated into the cost-effectiveness evaluations.

Principal Institution

PATH, United States

Principal Investigators / Focal Persons

Molly Robertson

Partner Institutions

Liverpool School of Tropical Medicine (LSTM), United Kingdom
Rwanda Biomedical Centre (RBC)

Rationale and Abstract

The use of insecticide-treated bed nets (ITNs) has contributed to the substantial reduction in malaria cases and deaths. This progress is threatened by increasing resistance in mosquito populations to commonly used insecticides. Newly developed, next-generation ITNs using two insecticides or an insecticide synergist and an insecticide are effective against resistant mosquitoes, but large-scale uptake of these nets has been slow due to higher costs and lack of enough evidence to support broad policy recommendations.

This observational study will occur alongside a pilot distribution of next-generation ITNs and collect data over three years on their entomological and epidemiological impact as well as anthropological factors that influence their uptake and use. Enhanced data collection will occur in three districts: one district that will receive Interceptor G2 ® ITN (BASF) and two comparator districts, one that will receive standard pyrethroid-only ITNs and one that will receive standard pyrethroid-only ITNs and indoor residual spraying (IRS). Data will be collected on malaria vector bionomics, disease epidemiology, and human behaviours in order to help better demonstrate the public health value of next-generation ITNs and to support donors, policymakers, and National Malaria Control Programs in their ITN decision-making and planning processes.

ClinicalTrials.gov Identifier: NCT04230161

Study Design