Spatial Repellents for Aedes-borne Virus Control in Sri Lanka (AEGIS ABV)

September 12, 2025 updated by: University of Notre Dame

A Cluster Randomized, Placebo Control Trial to Evaluate the Efficacy of a Spatial Repellent (Mosquito ShieldTM) Against Aedes-borne Virus Infection Among Children ≥ 4-16 Years of Age in the Gampaha District, Sri Lanka

The primary objective of the study is to demonstrate and quantify the protective efficacy (PE) of a single SR product, in reducing DENV infection and active Aedes-borne virus (ABV) disease in human cohorts. The study design will be a prospective, cluster randomized controlled trial (cRCT). Although not a specific objective of this project, an overall goal is to allow for official recommendations (or not) from the World Health Organization (WHO) for the use of SRs in public health. A WHO global policy recommendation will establish evaluation systems of SR products to regulate efficacy evaluations, thereby increasing quality, overall use and a consequent reduction in disease.

Study Overview

Status

Completed

Detailed Description

The study will be a prospective, cRCT, participant and observer-blinded, placebo-controlled trial in a site endemic for ABV to measure the impact of a SR product on new ABV virus infections. Clusters of households, each cluster containing 110-120 residents testing negative for antibodies against DENV (seronegative) or positive to a single DENV infection (monotypic), will be selected from three MOH areas in the district of Gampaha: Negambo, Wattala, Kelaniya. All participating houses in each cluster will be monitored entomologically for adult Aedes aegypti surveys for 3 months before deployment of the SR intervention and monthly after the intervention is in place. Entomological surveys will include monitoring of indoor Ae. aegypti adult population densities and blood-fed status. DENV infection in study participants will be assessed by serologic testing of scheduled longitudinal blood samples (primary outcome) and passively by monitoring febrile persons for acute Dengue illness (secondary outcome). Seroconversion to DENV from baseline (pre-intervention) and follow-up (post-intervention) samples as well as ABV active disease rates will be compared between active intervention and placebo (control) clusters. Testing and confirmation of Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection at baseline and during the intervention phase of the trial will be dependent on circulation history/detection in study area during study period.

The spatial repellent (SR) will be a new formulation of transfluthrin. This active ingredient (AI) is widely used in mosquito coils and other household pest control products worldwide. The new formulation is a passive emanator that will release the AI over a period of up to four weeks, Mosquito ShieldTM. The emanator will consist of a pre-treated piece of cellulose acetate or other medium, which will be positioned within consenting households according to manufacturer specifications of 2 units/9m2. A placebo product of matched design with inert ingredients will be applied similarly. The Mosquito ShieldTM and placebo products for this study will be designed and provided by S.C. Johnson, INC. A Family Company.

Study Type

Interventional

Enrollment (Actual)

6949

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

    • West
      • Colombo, West, Sri Lanka, 00100
        • Epidemiology Unit, Ministry of Health
      • Ragama, West, Sri Lanka, 01010
        • Clinical Trials Unit

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 and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

LONGITUDINAL SEROCONVERSION Individual Level

Inclusion Criteria:

  • ≥ 4 - 16 years of age
  • Plans to stay in residence and/or study area for a minimum of 24 months
  • Resident of household or frequent visitor (~20% of day hours in house / month)

Exclusion Criteria:

  • < 4 and > 16 years of age
  • Plans to leave residence and/or study area within next 24 months
  • Temporary visitor to household (<20% of day hours in house/ month)

FEBRILE SURVEILLANCE Household Level

Inclusion Criteria:

  • Adult head of households agrees to census, health visits and logging resident symptoms when febrile (or in the case of suspected Zika in the absence of fever, presenting with rash, arthralgia, arthritis or non-purulent conjunctivitis).
  • Individuals spend a minimum of 4hrs per week during the daytime hours or sleep in the house.

Exclusion Criteria:

  • Adult head of households does not agree to census, health visits or logging symptoms of residents.
  • Households where study personnel identify a security risk (i.e., site where drugs are sold, residents are always drunk or hostile).
  • Sites where no residents spend time during the day (i.e. work 7d a week outside the home).

FEBRILE SURVEILLANCE Individual Level

Inclusion Criteria:

  • ≥ 6mo of age.
  • Fever at the time of presentation or report of feverishness within the previous 24 hours or presenting with a rash, arthralgia, arthritis or non-purulent conjunctivitis (suspicion of ZIKA determined by project physician)
  • Individual who spends a minimum of 4 hours per week within the household or sleeps in the house.

Exclusion Criteria:

  • < 6mo of age.
  • No fever at time of presentation or report of feverishness within the previous 24 hours or not reporting with a rash, arthralgia, arthritis or non-purulent conjunctivitis
  • Individuals who have spent less than 4 hours in the household during the week prior to illness.

ENTOMOLOGICAL MONITORING Household Level

Inclusion Criteria:

  • Adult head of household agrees to surveys.
  • Properties where study personnel do not identify a security risk (i.e., site where drugs are sold, residents are always drunk or hostile).

Exclusion Criteria:

  • Adult head of household does not agree to surveys.
  • Properties where study personnel identify a security risk (i.e., site where drugs are sold, residents are always drunk or hostile).

SPATIAL REPELLENT INTERVENTION Household Level

Inclusion Criteria:

  • Adult head of households agrees to have intervention applied inside the home and to provide access to team member at 4-week intervals to change products.
  • Properties where study personnel do not identify a security risk (i.e., site where drugs are sold, residents are always drunk or hostile).

Exclusion Criteria:

  • Adult head of household does not agree to Mosquito ShieldTM deployment or study team access.
  • Properties where study personnel identify a security risk (i.e., site where drugs are sold, residents are always drunk or hostile).

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Spatial Repellent
Transfluthrin
Passive emanator with formulated transfluthrin
Placebo Comparator: Placebo
Inert ingredients
Passive emanator with formulated inert ingredients

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Aedes-borne virus (ABV) infection in the 'longitudinal cohort'.
Time Frame: 24 months
The primary endpoint is the fraction of monotypic or seronegative individuals in the 'longitudinal cohort' who seroconvert to an arbovirus during the follow-up period post randomization with intervention. Here, the intervention follow-up period is 2 years after initial deployment of SR or placebo. There will be 3 blood samplings from longitudinal cohort participants for measure of seroconversion: one for baseline serostatus characterization (T0), a second at 12 months (T1) and a third at 24 months (T2) from time of initial placement of intervention.
24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinically apparent cases of Aedes-borne virus (ABV) disease.
Time Frame: 24 months
Clinically apparent is defined as an acute infection that causes overt symptoms (fever, rash, etc.) indicating virus circulation in the blood. For the longitudinal cohort participants, acute and convalescent blood sampling based on time of health facility visit when febrile throughout the intervention period. For other household members participating in febrile surveillance, case definition measured and reported whenever they visit designated health facilities throughout the intervention period.
24 months
Adult female Aedes aegypti indoor abundance.
Time Frame: 24 months
Measured by comparing adult female Aedes aegypti indoor abundance in households using Procopak mosquito aspiration with active and placebo product receiving standard entomological surveillance and control procedures by the local Ministry of Health, as an indicator for reduced mosquito house entry due to effect of product. Indoor mosquito collections in enrolled households once every 28 days during intervention.
24 months
Adult female Aedes aegypti blood fed rate.
Time Frame: 24 months
Measured by comparing adult female Aedes aegypti blood fed rate in households with active and placebo product receiving standard entomological surveillance and control procedures by the local Ministry of Health, as an indicator for reduced mosquito human contact due to effect of product. Direct mosquito abdominal observation by microscopy from samples taken by Procopak aspiration during indoor mosquito collections in enrolled households once every 28 days during intervention.
24 months
Diversion of Aedes aegypti mosquitoes into untreated houses.
Time Frame: 24 months
Measured by comparing adult female Aedes aegypti abundance using Procopak mosquito aspiration in untreated households adjacent to treatment clusters (with active product) to untreated households adjacent to placebo clusters as an indicator for mosquito diversion due to effect of product. Indoor mosquito collections in enrolled households once every 28 days during intervention.
24 months
Overall incidence of Aedes-borne virus (ABV) infection.
Time Frame: 24 months
Measured by the seroconversion rates of all children enrolled in the trial, independent of order of infection (i.e., including tertiary and quaternary infections). Based on blood samples taken for longitudinal seroconversion and febrile surveillance from time of initial placement of intervention.
24 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Adverse Events (AEs) and Serious Adverse Events (SAEs).
Time Frame: 24 months
Measured by solicited and unsolicited reports from both the longitudinal cohort and febrile surveillance cohort during the trial period. Mean, minimum and maximum frequency and percentage of AEs and SAEs across clusters among enrolled subjects will be summarized by treatment arm.
24 months
Incidence of Aedes-borne virus (ABV) infection in subjects residing in households within treatment clusters but without SR product.
Time Frame: 24 months
Measured by comparing Aedes-borne virus infection rates between subjects residing in households with SR product in treatment clusters and subjects from the same clusters who did not agree to the SR application in their households but are receiving standard entomological surveillance and control procedures by the local ministry of health, as an indicator of community effect due to effect of product.
24 months
Clinically apparent cases of Aedes-borne virus (ABV) disease in subjects residing in households within treatment clusters but without SR product.
Time Frame: 24 months
Measured by comparing Aedes-borne virus disease case rates between subjects residing in households with SR product in households in treatment clusters and individuals from the same clusters who did not agree to the SR application in their households but are receiving standard entomological surveillance and control procedures by the local ministry of health, as an indicator of community effect due to effect of product.
24 months
Adult female Aedes aegypti indoor abundance using Procopak mosquito aspiration in households within treatment clusters but without SR product.
Time Frame: 24 months
Measured by comparing adult female Aedes aegypti indoor abundance in households with SR product in treatment clusters and households from the same clusters who did not agree to the SR application but are receiving standard entomological surveillance and control procedures by the local ministry of health, as an indicator of community effect to effect of product. Indoor mosquito collections in enrolled households once every 28 days during intervention
24 months
Adult female Aedes aegypti blood fed rate using Procopak mosquito aspiration in households within treatment clusters but without SR product.
Time Frame: 24 months
Measured by comparing adult female Aedes aegypti blood fed rate in households with SR product in treatment clusters and households from the same clusters who did not agree to the SR application but are receiving standard entomological surveillance and control procedures by the local ministry of health, as an indicator of community effect to effect of product. Samples from indoor mosquito collections in enrolled households once every 28 days during intervention.
24 months

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Korelege Hasitha Aravinda Tissera, M.D., Epidemiology Unit, Ministry of Health, Sri Lanka
  • Study Director: John P Grieco, Ph.D., University of Notre Dame

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)

March 2, 2023

Primary Completion (Actual)

June 30, 2025

Study Completion (Actual)

June 30, 2025

Study Registration Dates

First Submitted

July 6, 2022

First Submitted That Met QC Criteria

July 6, 2022

First Posted (Actual)

July 11, 2022

Study Record Updates

Last Update Posted (Estimated)

September 15, 2025

Last Update Submitted That Met QC Criteria

September 12, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Analytical datasets will be anonymized and GPS tag-blurred to remove sensitive information prior to sharing.

IPD Sharing Time Frame

The data and supporting information will be made available 12 months following completion of data analysis and will remain open access in the public domain.

IPD Sharing Access Criteria

Open-access repository distributed under the terms of the Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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