Spatial Repellents for Vector Control

Study Overview
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Brief Summary
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The primary objective of the study is to demonstrate and quantify the protective efficacy of a single Spatial Repellent (SR) product, in reducing malaria infection in a human cohort. The study design will be a prospective cluster Randomized Control Trial (cRCT).

Detailed Description
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Children ≥ 6 months to < 10 years of age will be enrolled in a single cohort across 60 clusters (30 clusters per treatment arm). The cohort will be followed for 6 months for baseline covariate measurements and 24 months with intervention. Blood samples will be taken once every 4 weeks from all cohort subjects to test for malaria infection and whenever a subject reports a recent history of fever (within previous 48 hours). During follow up of enrolled subjects, study clinicians will have the option to conduct a Hb test for enrolled subjects when they may present signs of anemia to see if they might need additional treatment beyond malaria ACTs (if malaria infection is indicated). Rapid Diagnostic Tests (RDTs) will be used for point-of-care diagnosis of malaria infection with microscopy used to confirm infection status. All positive malaria infections as indicated by either RDT or microscopy, clinical and asymptomatic, will be treated. If a subject has a RDT negative outcome but a positive microscopy diagnosis, follow up treatment for the malaria infection will be provided to the subject within 72hrs of the microscopy read. Cohort subjects who test positive for malaria by either RDT or microscopy, symptomatic or asymptomatic, during both scheduled and unscheduled visits will be treated with ACTs. The incidence of malaria infection will be measured by microscopy and estimated and compared between treatment arms to determine the benefit of using an SR in an area with high, seasonal transmission of malaria. Entomological endpoints of exposure risk to mosquitoes will also be measured to identify entomological correlates of SR efficacy that may be useful for the evaluation of new SR products. Twenty clusters (10 SR, 10 placebo) will be randomly selected to estimate the impact of the SR on entomological measures of malaria transmission. Within each cluster, light trap collections will be conducted monthly in 10 randomly selected households to assess the impact of SRs on the density of Anopheles mosquitoes indoors. Human landing catches will be done indoors and outdoors in 6 intervention and 6 control clusters (the 12 clusters will remain fixed throughout the study) in four houses (randomly selected) in each cluster for the period of 2 nights (total of 48 houses across both arms) once every quarter (3 months) to determine the effect of SR on the host seeking behavior of mosquitoes. The SR will be a new formulation of transfluthrin. This active ingredient (AI) is widely used in mosquito coils and other household pest control products. The new formulation is a passive emanator that will release the AI over a period of up to four weeks. The emanator will consist of a pre-treated piece of cellulose acetate, which will be positioned within consenting households according to manufacturer specifications. The SRs and placebos for this study will be designed and manufactured by S.C. Johnson, Inc. USA.

Official Title
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Spatial Repellent Products for Control of Vector Borne Diseases

Conditions
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Malaria

Intervention / Treatment
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* Device: Transfluthrin
* Device: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Children ≥ 6 months to < 10 years of age Children with Hb > 7 g/dL and no signs of known chronic disease or other other serious illness Sleeps in cluster ≥ 90% of nights during any given month Not participating in another clinical trial investigating a vaccine, drug, medical device, or a medical procedure during the trial Provision of informed consent (and/or assent) form (ICF) signed by the parent(s) or guardian Exclusion Criteria: Children < 6 months or ≥ 10 years Childrend with Hb <= 7 g/dL with signs of known chronic disease or other serious illness, or Hb <6 g/dL with signs of clinical decompensation Sleeps in cluster <90% of nights during any given month Participating or planned participation in another clinical trial investigating a vaccine, drug, medical device, or a medical procedure during the trial No provision of ICF (and/or assent) signed by the parent(s) or guardian

Ages Eligible for Study
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Minimum Age: 6 Months
Maximum Age: 10 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study design will be a prospective cluster Randomized Control Trial (cRCT)
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Spatial Repellent<br>Transfluthrin | Device: Transfluthrin<br>* Passive emanator with formulated transfluthrin<br>|
| Placebo Comparator: Placebo<br>Inert ingredients | Device: Placebo<br>* Passive emanator with formulated inert ingredients<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of first-time malaria infections during intervention period. | Measured by microscopy in children aged between 6 months to 10 years. | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of overall new malaria infections during intervention period. | Measured by microscopy in children aged between 6 months to 10 years. | 24 months | 
| Parasite-species-specific first-time malaria infections. | Measured by microscopy in children aged between 6 months to 10 years. | 24 months | 
| Parasite-species-specific overall malaria infections. | Measured by microscopy in children aged between 6 months to 10 years. | 24 months | 
| Number of first-time malaria infections by two age groups (≤ 59 months old; 5 years old to 10 years old). | Measured by microscopy in children aged between 6 months to 10 years. | 24 months | 
| Number of overall malaria infections by two age groups (≤ 59 months old; 5 years to 10 years old). | Measured by microscopy in children aged between 6 months to 10 years. | 24 months | 
| Anopheline-human contact (indoor and outdoor) using human biting rate (HBR) as an indicator for all anophelines and by anopheline species. | Measured by human-landing catch (HLC) during 12-h intervals on a quarterly basis during intervention period. | 24 months | 
| Anopheline parity rate as an indicator of population age structure for all anophelines and by anopheline species. | Measured by mosquito ovarian dissections from a sub-sample of anophelines collected during HLC procedures during intervention period. | 24 months | 
| Anopheline infectivity using sporozoite rate as an indicator for all anophelines and by anopheline species. | Measured by laboratory detection of sporozoites in mosquito head-preps from a sub-sample of anophelines collected during HLC and/or CDC-light trap procedures during intervention period. | 24 months | 
| Anopheline infectivity using entomological inoculation rate (EIR) as an indicator for all anophelines and by anopheline species. | Measured by calculating the number of sporozoite-infected anopheline mosquitoes captured per person during intervention period from HLC and/or CDC-light trap procedures. | 24 months | 
| CDC-light trap indoor density for all anophelines and by anopheline species. | Measured by CDC-light trap collections during 12-h intervals on a monthly basis during intervention period. | 24 months | 
| Insecticide resistance. | Measured by WHO filter paper test and CDC bottle assays during baseline and intervention period. | 30 months | 
| Adverse Events and Serious Adverse Events. | Measured by solicited and unsolicited reports during baseline and intervention period. Mean, minimum and maximum frequency and percentage of Adverse Events(AEs) and Severe Adverse Events (SAEs) across clusters among enrolled subjects will be summarized by treatment arm. | 30 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Malaria, Spatial Repellent, Transfluthrin, Vector-borne diseases, Mosquito vectors, Incidence