Efficacy of Two Dual Active Ingredient Long Lasting Insecticidal Nets for Control of Malaria Transmitted by Pyrethroid Resistant Vectors in Benin (NNP)

October 16, 2024 updated by: London School of Hygiene and Tropical Medicine

The massive scale-up of Long Lasting Insecticidal Nets (LLIN) has led to a major reduction in malaria burden (up to 50%) in many sub-Saharan African countries. This progress is threatened by the wide scale selection of insecticide resistant malaria vectors. New types of LLIN combining a mixture of two insecticides have been developed to control resistant mosquitoes.

The efficacy of two bi-treated LLIN are compared to a standard LLIN in a three-arm, single blinded, cluster-randomized trial in Cove, Benin. The arms are; 1/ Royal Guard, a net combining pyriproxyfen (PPF), which is known to disrupt female reproduction and fertility of eggs, and the pyrethroid alpha-cypermethrin, 2/Interceptor G2, LLIN incorporating a mixture of two adulticides with different modes of action; chlorfenapyr and a pyrethroid (alpha-cypermethrin), and 3/ The control arm: Interceptor, a standard LLIN treated with alpha-cypermethrin.

The primary outcome of the trial will be malaria case incidence in children aged 6 months to 10 years.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Background: The massive scale-up of Long-Lasting Insecticidal Nets (LLIN) has led to a major reduction in malaria burden (up to 50%) in many sub-Saharan African (SSA) countries. This progress is threatened by the wide scale selection of insecticide resistant malaria vectors.

Study site: The study will be conducted in the districts of Cove, Zagnanado and Ouinhi, a collection of three districts found in the Zou department in Benin. This area consists of 100 villages with approximately 40,000 households and a population size of 191,000.

The aim of this research is to evaluate the efficacy of 2 novel dual active Ingredient (AI) LLINs in a community randomized controlled trial on epidemiology outcomes. The trial will take place over 2 years in an area where malaria vectors are resistant to pyrethroid insecticide in Benin, West Africa. Update- the trial is now continuing for a third year.

The primary objective is to assess the efficacy of next generation LLIN on malaria case incidence in children aged 6 months to 10 years, compared to standard LLINs. The secondary objectives are to evaluate the efficacy of the 2 bi-treated LLIN as compared to standard LLIN on a) malaria infection prevalence in children aged 6 months to 10 years; b) prevalence of moderate and severe anaemia in children under 5 years old and c) entomological inoculation rate (EIR) (as a proxy for malaria transmission). In addition, we will compare potential insecticide resistance selection, between the 3 trial arms and evaluate the impact of the new types of LLIN on other entomological outcomes (species composition, blood feeding, resting/feeding behaviour and sterility (oocyte [egg] development).

Study design: Three-arm superiority, single blinded, cluster-randomized trial with village as the unit of randomisation. The arms consist of; 1/ Royal Guard, a net combining pyriproxyfen (PPF), which is known to disrupt female reproduction and egg fertility, and the pyrethroid alpha-cypermethrin, 2/Interceptor G2, a mixture LLIN incorporating two adulticides with different modes of action; chlorfenapyr and a pyrethroid (alpha-cypermethrin), and 3/ The control arm: Standard LLIN Interceptor is an alpha-cypermethrin only LLIN.

The primary outcome of the trial will be incidence of malaria cases (confirmed by rapid diagnostic test (RDT)) in children aged 6 months to 10 years followed for 24 months. Update: the study is now continuing for a further year.

Secondary outcomes are cross-sectional community prevalence of malaria infection (confirmed by RDT) in the study population at 6- and 18-months post-intervention, prevalence of moderate and severe anaemia in children under 5 years old, entomological inoculation rates (EIR), vector density and insecticide resistance intensity. Update: there will also be a 30 month cross-sectional survey.

Sample size: To compare incidence of malaria cases between study arms, we will recruit a cohort of 25 children per cluster in 60 clusters for 24 months follow up to be able to detect a 30% relative reduction in malaria cases per child per year (rate ratio 0.7) between the intervention and the reference arms. The children will be visited twice a month during the transmission season (April to November) and once a month during the dry season. We will conduct malaria infection prevalence cross-sectional surveys, at 6 and 18 months after LLIN distribution. 40 households will be randomly selected from each of the 60 clusters (20 clusters per arm x 3 arms) and information on education, socio economic status, LLIN ownership and usage recorded during each survey. From these 40 households per cluster we will randomly select 70 individuals. The study will have 80% power to detect a relative 30% lower prevalence (prevalence ratio 0.70 in each intervention arm (Royal Guard or Interceptor G2) relative to standard LLIN. Entomological inoculation rate (EIR) will be measured bi-monthly for 2 years in 8 households per cluster in all the clusters. Update: Follow up for cohort children was suspended during the pandemic meaning the primary outcome only included 21 months of follow up- to counteract this, 30 children were selected in each cluster. The follow up is now continuing up to 36 months- post-distribution. Due to logistics, the entomological data collection took place in 4 houses in each cluster every 3 months.

Frequency and intensity resistance assay with An. gambiae, An. arabiensis and An.funestus will be performed using permethrin, alpha-cypermethrin, pyriproxyfen and chlorfenapyr in 6 clusters (2 clusters per arm). An. gambiae s.l. and An. funestus will be screened for mutations in insecticide target sites (Vgsc) and metabolic resistance following CYp6 genes a small group of P450s that are over expressed in insecticide resistant populations. Changes in frequency of these genes and target site mutation will be followed every year in the three arms.

Study Type

Interventional

Enrollment (Actual)

1800

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Benin
      • Cove, Benin
        • Manfred Accrombessi

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

6 months to 9 years (Child)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria for cohort:

  • Children aged 6 months to 9 years
  • Resident in study villages
  • Written, informed consent from guardians

Exclusion Criteria:

  • Non-residents

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Interceptor G2
Chlorfenapyr/alpha-cypermethrin
Other: Bed nets
Next-generation bed nets combining insecticides with different modes of action or a standard pyrethroid bed net
Experimental: Royal Guard
Pyriproxyfen/alpha-cypermethrin
Other: Bed nets
Next-generation bed nets combining insecticides with different modes of action or a standard pyrethroid bed net
Active Comparator: Interceptor
Alpha-cypermethrin
Other: Bed nets
Next-generation bed nets combining insecticides with different modes of action or a standard pyrethroid bed net

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Malaria Case Incidence
Time Frame: 2 years
Malaria case incidence in children aged 6 months to 10 years measured through bi-monthly/monthly visits
2 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Malaria Infection prevalence
Time Frame: 18 months
Malaria infection prevalence measured in cross-sectional surveys 6 months and 18 months post- distribution
18 months
Entomological Inoculation Rate
Time Frame: 2 years
EIR measured every quarter during entomological surveys
2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

London School of Hygiene and Tropical Medicine

Collaborators

UNITAID
Global Fund
Centre de Recherche Entomologique de Cotonou
Innovative Vector Control Consortium

Investigators

  • Principal Investigator: Martin C Akogbéto, PhD, Centre de Recherche Entomologique de Cotonou
  • Principal Investigator: Natacha Protopopoff, Phd, London School of Hygiene and Tropical Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2020

Primary Completion (Actual)

May 1, 2023

Study Completion (Actual)

May 1, 2023

Study Registration Dates

First Submitted

April 25, 2019

First Submitted That Met QC Criteria

April 25, 2019

First Posted (Actual)

April 30, 2019

Study Record Updates

Last Update Posted (Actual)

October 18, 2024

Last Update Submitted That Met QC Criteria

October 16, 2024

Last Verified

October 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NewNetsProject

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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