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Testing Insect Repellents Against Musca Sorbens, the Vector of Trachoma

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT03813069
Recruitment Status : Suspended (The laboratory stage of the trial is complete, we are preparing for the field stage)
First Posted : January 23, 2019
Last Update Posted : March 15, 2019
Sponsor:
Collaborators:
Federal Minstry of Health of Ethiopia
Oromia Regional Health Bureau, Ethiopia
The Fred Hollows Foundation, Ethiopia
The Fred Hollows Foundation, UK
The Fred Hollows Foundation, Australia
Information provided by (Responsible Party):
London School of Hygiene and Tropical Medicine

Brief Summary:
Musca sorbens, a fly that feeds from ocular and nasal discharge on humans, is thought to be the vector of trachoma. We are developing methods of fly control that specifically target this species, in the hope of interrupting Ct transmission. To our knowledge, the use of commercially available insect repellents has never been tested for prevention of Musca sorbens fly-eye contact (i.e. nuisance and landing in the peri-ocular area). Given the likely necessity for prolonged and/or high frequency fly-eye contact for Ct transmission, the reduction of these contacts through the use of fly repellents presents an exciting opportunity for disease control. Here we propose a within-subject, non-masked, trial of the use of commercially available insect repellents against Musca sorbens, with two consecutive participant groups in the laboratory and in the field, and a primary endpoint of measuring the protective efficacy of each repellent product. Repellent products will be chosen from: DEET (N,N-diethyl-3-methylbenzamide), IR3535 (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester), Picaridin (2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester); PMD (para-Menthane-3,8-diol) or permethrin (m-Phenoxybenzyl)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate). Products tested will be either (1) topical repellents, or (2) in long-lasting, plastic formulations of repellents that can be worn on the body (wearable repellent technologies). The insect repellent synergist Vanillin (4-Hydroxy-3-methoxybenzaldehyde) may be added to the long-lasting plastic formulations, to improve the duration of protection.

Condition or disease Intervention/treatment Phase
Trachoma Other: IR3535 Other: Permethrin lower dose Other: Permethrin higher dose Phase 2

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 103 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Intervention Model Description:

This is a within-subject, non-masked, trial of the use of commercially available insect repellents against Musca sorbens, with two consecutive participant groups in the laboratory and in the field, and a primary endpoint of measuring the protective efficacy of each repellent product.

The first (laboratory-based) study has one arm, in which all participants test all repellent products. Those that are found to generate at least 30 % protective efficacy will be tested in the second (field-based) study, which will have four arms. Up to three arms will test a repellent product and there will be a control arm.

Masking: Single (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: A Within-subject Laboratory and Field Trial to Test the Use of Commercially Available Insect Repellents Against Contact From Musca Sorbens, the Putative Vector of Trachoma
Actual Study Start Date : January 10, 2019
Estimated Primary Completion Date : June 2019
Estimated Study Completion Date : July 2019

Resource links provided by the National Library of Medicine

Drug Information available for: Permethrin

Arm Intervention/treatment
Laboratory study Other: IR3535
The topical repellent IR3535 (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester) only

Other: Permethrin lower dose
A fabric scarf, impregnated with the insecticide permethrin (m-Phenoxybenzyl)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate) that has contact irritancy/spatial repellency. Dose appropriate to children of 10-20 kg.

Other: Permethrin higher dose
A fabric scarf, impregnated with the insecticide permethrin (m-Phenoxybenzyl)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate) that has contact irritancy/spatial repellency. Dose appropriate to children more than 20 kg.

Field study: IR3535 Other: IR3535
The topical repellent IR3535 (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester) only

Field study: Permethrin lower dose Other: Permethrin lower dose
A fabric scarf, impregnated with the insecticide permethrin (m-Phenoxybenzyl)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate) that has contact irritancy/spatial repellency. Dose appropriate to children of 10-20 kg.

Field study: Permethrin higher dose Other: Permethrin higher dose
A fabric scarf, impregnated with the insecticide permethrin (m-Phenoxybenzyl)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate) that has contact irritancy/spatial repellency. Dose appropriate to children more than 20 kg.

No Intervention: Field study: control arm



Primary Outcome Measures :
  1. Protective Efficacy (PE) [ Time Frame: 2 months ]
    The protection (protective efficacy, p) afforded by a repellent product will be presented as a percentage. p will be estimated by comparing fly-arm contact duration and fly-eye contact frequency, in laboratory and field trials respectively, after application (or wearing) of the repellent product to that during the control period.

  2. Complete Protection Time (CPT) [ Time Frame: 3 months ]
    Median CPT will be estimated in stage two ('persistence') laboratory trials only, for those repellents that demonstrated more than 30 % PE. The complete protection time for a specific dose will be estimated as the time elapsed until the first fly landing on the arm in each replicate, and based on repeat estimates of CPT, the mCPT will be estimated using a Kaplan-Meier function.



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Ages Eligible for Study:   3 Years to 65 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Laboratory trial eligibility criteria

  1. Participant is aged > 18 years and < 65 years and in good health
  2. Participant has a good understanding of the procedures of the study and agrees to abide to these procedures
  3. Participant is able to communicate well with the investigator, and attend the laboratory for all aspects of the laboratory studies
  4. Participant has no known adverse reactions, or evidence at screening of adverse reactions, to the commercially available repellents DEET, PMD, IR3535, Picaridin or Permethrin, or to Vanilla
  5. Participant has no known history of skin allergies or hypersensitivity to topical creams
  6. Participant agrees to a pre-trial skin reactivity test for all the repellents that will be used in the trial
  7. If in the event of the participant experiencing an adverse reaction to a repellent during the trial, the participant agrees to inform his/her general practitioner and seek appropriate treatment if necessary
  8. Participant is willing to allow laboratory-reared Musca sorbens flies to land and crawl on their arm, during the modified arm-in-cage assay, for periods of up to ten minutes at a time
  9. Participant agrees not to use any perfumed or scented product, including bathing products, for a 24-hour period before each laboratory session
  10. Participant has signed informed consent
  11. Participant is not a smoker, and will agree to refraining from smoking for the 12 hours before each laboratory trial

Field trial eligibility criteria

  1. Participant lives in the designated study site
  2. Participating households must be within a one-hour drive of Feya General Hospital
  3. Participant considers themselves to be in good health, as does the parent or guardian
  4. Participant is aged > 3 years and < 12 years
  5. Participant has a good understanding of the procedures of the study and agrees to abide to these procedures
  6. The parent or guardian of the participant has a good understanding of the procedures of the study and agrees to abide to these procedures
  7. Participant is able to communicate well with the investigator or fieldworker who is conducting the study
  8. Participant has no known adverse reactions to the commercially available repellents DEET, PMD, IR3535, Picaridin or Permethrin, or to Vanilla
  9. Participant has no known history of skin allergies or hypersensitivity to topical creams
  10. Participant agrees to a pre-trial skin reactivity test for all the repellents that will be used in the trial
  11. If in the event of the participant experiencing an adverse reaction to a repellent during the trial, the participant can request medical advice from the Stronger-SAFE field team nurses if they wish
  12. Participant is willing to sit still on a chair outside their house, for sequential periods of up to ten minutes, allowing wild fly contact and landing on the body and face, as much as possible without disturbing fly behaviour
  13. Participant agrees not to use any perfumed or scented product, including bathing products, for a 24-hour period before each laboratory session
  14. Able and willing to give fully informed assent
  15. The parent or guardian has signed informed consent

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03813069


Locations
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Ethiopia
Fred Hollows Foundation
Addis Ababa, Ethiopia
United Kingdom
London School of Hygiene and Tropical Medicine
London, United Kingdom, WC1E 7HT
Sponsors and Collaborators
London School of Hygiene and Tropical Medicine
Federal Minstry of Health of Ethiopia
Oromia Regional Health Bureau, Ethiopia
The Fred Hollows Foundation, Ethiopia
The Fred Hollows Foundation, UK
The Fred Hollows Foundation, Australia
  Study Documents (Full-Text)

Documents provided by London School of Hygiene and Tropical Medicine:

Publications:
Bell, M.J. (2018) The impact of latrine construction on densities and pathogen infection rates of synanthropic flies and Culex quinquefasciatus mosquitoes in Odisha, India. PhD thesis.
Burgess, I. (1993) The function of a repellent in head louse control. The Pharmaceutical Journal. 15, 674-675.
European Commission (2014) Assessment Report: Permethrin. Available at: http://dissemination.echa.europa.eu/Biocides/ActiveSubstances/1342-18/1342-18_Assessment_Report.pdf
World Health Organization (2017) How to design vector control efficacy trials: Guidance on phase III vector control field trial design provided by the Vector Control Advisory Group.

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Responsible Party: London School of Hygiene and Tropical Medicine
ClinicalTrials.gov Identifier: NCT03813069    
Other Study ID Numbers: 2018-kep-132
First Posted: January 23, 2019    Key Record Dates
Last Update Posted: March 15, 2019
Last Verified: January 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description:

Formal reports will be written for the Ethiopian Federal and Regional health authority and the Federal Ministry of Science and Technology (FMOST). Reports will also be prepared for the Wellcome Trust and The Fred Hollows Foundation (Ethiopia and UK).

To ensure operational uptake of the findings of the studies, we intend to present these data at the annual National Trachoma Task Force and NTD Research Symposium (Ethiopia). Additionally, we will present this research at the annual Trachoma Scientific Informal Workshop prior to the WHO GET2020 Alliance meeting. Scientific results will be published in Open Access in peer-reviewed journals and presented at relevant international conferences.

The Sensitisation/Community Liaison Team will disseminate the results of the study to the study community in community dialogues and radio broadcasts in conjunction with The Fred Hollows Foundation Ethiopia Communications Team.


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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Trachoma
Conjunctivitis, Bacterial
Eye Infections, Bacterial
Bacterial Infections
Chlamydia Infections
Chlamydiaceae Infections
Gram-Negative Bacterial Infections
Eye Infections
Infection
Conjunctivitis
Conjunctival Diseases
Eye Diseases
Corneal Diseases
Permethrin
Insect Repellents
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs