Long-acting Spatial Emanators / Repellents (LASER) (LASER)

January 27, 2026 updated by: Liverpool School of Tropical Medicine

Long-acting Spatial Emanators / Repellents (LASER) vs Indoor Residual Spraying (IRS) in Western Kenya: a Cluster-randomised Trial

Malaria is a major problem in western Kenya, particularly around Lake Victoria. Whilst current prevention methods like bed nets and vaccines help to reduce malaria burden, additional tools are needed to better protect communities from malaria. The investigators will test a new technology called LASER Guardian™, which are devices that release chemicals to keep mosquitoes away from homes. The investigators will conduct a large study involving 69 villages in western Kenya over two years. Each village will be randomly chosen to receive one of three approaches: the new LASER devices, indoor residual spraying with insecticide (a method already known to work), or the standard prevention methods currently used. All villages will continue to receive the usual malaria prevention tools provided by the Kenyan government, including bed nets and vaccines. In villages receiving LASER, the investigators will install 2-3 small device inside structures once a year for two years. In villages receiving IRS, the investigators will spray the inside walls of homes with insecticide once a year for two years. The investigators want to find out if the LASER devices can reduce malaria better than current methods alone, and whether they work as well as indoor spraying. To do this, the investigators will carry out surveys of the community every six months over two years (four rounds in total), testing about 4,485 children between ages 1 and 15 from approximately 3,450 households in each survey to see how many have malaria. The investigators will also work with local health clinics to track malaria cases, study mosquitoes to understand how the interventions affect them, talk with community members about their experiences, and calculate the costs of these different approaches. This study will help us understand whether LASER tool can effectively protecting against malaria in Kenya and other African countries where malaria is common.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
22815

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

Yes

Description

The inclusion criteria are:

  1. Child aged 1-15 years
  2. Usual resident (a person who has been residing in the survey area for at least the past 4 months) who was present in the sampled household on the night before the survey
  3. Agreement of adult or parent/guardian (of children) to provide informed consent
  4. Agreement of child aged 12 years or older to provide assent

The exclusion criterion is:

1. Child not at home after 3 attempts

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: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: LASER
Device: Guardian
The SC Johnson long-acting product (Guardian™) is a vapor releasing product (VP) formed from a polyester (PET) mesh substrate carrier dosed with 2,500 mg of transfluthrin per unit (CAS No. 118721-89-3). Transfluthrin is a type I synthetic pyrethroid that acts through modulation of nerve axon sodium channels, causing neurotoxicity in insects. The product is intended to be used as spatial emanator for the control of mosquitoes. The insecticide emanates from the product and subsequently kills or disrupts the biting behaviour of the surrounding vector population. The LASER product will be procured locally from the SC Johnson factory in Nairobi, Kenya (SC Johnson).
Experimental: IRS
Device: IRS with Pirimiphos - methyl
In clusters that are randomised to the IRS arm, IRS will be carried out using pirimiphos-methyl (Actellic®300CS) manufactured by Syngenta, an organophosphate insecticide that is registered for use in Kenya and has demonstrated effectiveness in malaria vector control. The product will be obtained directly from Syngenta to ensure quality and authenticity, with proper documentation and chain of custody maintained throughout the procurement and storage process.
No Intervention: Standard control

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Malaria prevalence
Time Frame: Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
The primary outcome of the study will be malaria parasite prevalence (any plasmodium species) in participants aged 1-15 years old
Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Prevalence of parasitaemia in children aged 1-5 years
Time Frame: Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
Proportion of children aged 1-5 years with blood smears positive for parasites by microscopy at the time of community cross-sectional surveys.
Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
Prevalence of parasitaemia in children aged 6-10 years
Time Frame: Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
Proportion of children aged 6-10 years with blood smears positive for parasites by microscopy at the time of community cross-sectional surveys.
Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
Prevalence of parasitaemia in children aged 11-15 years
Time Frame: Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
Proportion of children aged 11-15 years with blood smears positive for parasites by microscopy at the time of community cross-sectional surveys.
Measured one time in randomly selected participants at baseline and 6, 12, 18 and 24 months post intervention deployment.
Prevalence of anaemia in children under 5 years
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of children under 5 years of age with haemoglobin < 11 g/dL at the time of community cross-sectional surveys.
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of households that owned at least one LLIN
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of households with at least one long-lasting insecticidal net (LLIN) at the time of community cross-sectional surveys.
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of households with at least one LLIN for every two occupants
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of households with at least one long-lasting insecticidal net (LLIN) per every two household occupants at the time of community cross-sectional surveys.
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of household residents who slept under an LLIN the previous night
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of household residents who report sleeping under a long-lasting insecticidal net (LLIN) the previous night at the time of community cross-sectional surveys.
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
LASER intervention coverage
Time Frame: Measured at 6, 12, 18 and 24 months post initial intervention deployment
Proportion of sampled households in the LASER intervention arm that have the required number of SCJ Guardian spatial emanators present at the time of community cross-sectional surveys.
Measured at 6, 12, 18 and 24 months post initial intervention deployment
Indoor residual spraying (IRS) coverage
Time Frame: Measured at 6, 12, 18 and 24 months post inital intervention deployment
Proportion of surveyed households that report received indoor residual spraying (IRS) as part of the study in the IRS arm.
Measured at 6, 12, 18 and 24 months post inital intervention deployment
Malaria incidence in patients of all ages from health facility surveillance
Time Frame: Data captured monthly for 24 months post intervention deployment
Number of cases of malaria diagnosed at participating health facilities among patients of all ages residing in study clusters per unit time, divided by the estimated population of the cluster villages.
Data captured monthly for 24 months post intervention deployment
Anopheles spp. vector density
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post initial intervention deployment
Number of female Anopheles mosquitoes collected by ultra violet light traps per household at the time of entomology surveys in randomly selected households
Measured at baseline and 6, 12, 18 and 24 months post initial intervention deployment
Anopheles mosquitoes species composition
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of each Anopheles mosquito species identified among collected specimens at the time of entomology surveys by molecular identification.
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Sporozoite rate in Anopheles spp. mosquitoes
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post initial intervention deployment
Proportion of screened Anopheles mosquitoes that test positive for Plasmodium sporozoites.
Measured at baseline and 6, 12, 18 and 24 months post initial intervention deployment
Insecticide resistance in Anopheles spp.
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post initial intervention deployment
Proportion of Anopheles mosquitoes surviving standard WHO insecticide susceptibility tests at the time of entomology surveys.
Measured at baseline and 6, 12, 18 and 24 months post initial intervention deployment
Frequency of insecticide resistance genetic variants in Anopheles mosquitos
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of screened Anopheles mosquitoes carrying molecular markers associated with insecticide resistance at the time of entomology surveys.
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Acceptability of LASER and preventive measures by participant demographics
Time Frame: Baseline, 12 months post intervention deployment and within 3 months post intervention withdrawal
Proportion of participants reporting acceptability of spatial repellents (SR) and other preventive measures, assessed using structured questionnaires. Data stratified by gender, age group, and socio-economic activity categories.
Baseline, 12 months post intervention deployment and within 3 months post intervention withdrawal
Appropriateness of LASER and other preventive measures in local context
Time Frame: Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Proportion of participants rating long-acting spatial emanators (LASER) and other preventive measures as appropriate for their local context, assessed using structured questionnaires. Stratified by gender, age group, and socio-economic activity.
Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Proportion of participants reporting barriers to LASER use
Time Frame: Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Proportion of participants in LASER arm identifying specific barriers to LASER intervention use, assessed using semi-structured interviews and focus group discussions. Barriers categorized and quantified by thematic analysis.
Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Reasons for non-adherence to LASER intervention
Time Frame: Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Proportion of non-adherent participants citing specific reasons for non-adherence, assessed using semi-structured interviews. Reasons categorized by thematic analysis and reported as percentage of non-adherent participants per category.
Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Contextual factors affecting LASER delivery and transferability
Time Frame: Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Number and type of contextual factors (social, environmental, health system) affecting LASER delivery identified through key informant interviews and focus group discussions. Factors categorized by thematic analysis to inform transferability to other malaria endemic areas.
Baseline, 12 months post intervention deployment, and within 3 months post intervention withdrawal.
Cost per household protected per year
Time Frame: Cost data collected monthly throughout 24-month trial period; final calculation at 24 months post intervention deployment
Annual cost in US dollars (USD) per household protected by the interventions, calculated as total intervention costs divided by the number of households receiving protection. Costs include implementation, distribution, and maintenance costs.
Cost data collected monthly throughout 24-month trial period; final calculation at 24 months post intervention deployment
Incremental cost-effectiveness ratio: Cost per malaria case averted
Time Frame: 24 months post intervention deployment
Incremental cost in US dollars (USD) per malaria case averted compared to standard of care.
24 months post intervention deployment
Incremental cost-effectiveness ratio: Cost per DALY averted
Time Frame: 24 months post intervention deployment
Incremental cost in US dollars (USD) per disability-adjusted life year (DALY) averted compared to standard of care
24 months post intervention deployment
Mean Household Willingness to Pay
Time Frame: 24 months post intervention deployment
Mean willingness to pay in US dollars (USD) and local currency units (LCU) per household for the intervention, assessed using contingent valuation methodology with bidding game administered via structured questionnaire.
24 months post intervention deployment
Budget impact at scale
Time Frame: 24 months post intervention deployment
Estimated total cost in US dollars (USD) for scaling up the intervention to a defined target population, calculated using budget impact analysis modeling based on observed unit costs and projected coverage scenarios.
24 months post intervention deployment
Equity of intervention coverage
Time Frame: Measured at baseline and 6, 12, 18 and 24 months post intervention deployment
Proportion of sampled households that have the intervention present at the time of community cross-sectional surveys assessed as coverage by socio-economic status group (quantile).
Measured at baseline and 6, 12, 18 and 24 months post intervention deployment

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Liverpool School of Tropical Medicine

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Radboud University Medical Center
Centers for Disease Control and Prevention
Institute of Tropical Medicine, Belgium
Kenya Medical Research Institute

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 17, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 19, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 27, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 4, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 101190818

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

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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