CompletedPhase 2

Testing Insect Repellents Against Musca Sorbens, the Vector of Trachoma

Ethiopia, United Kingdom64 participantsStarted 2019-01-10

Plain-language 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.

Who can participate

Age range3 Years – 65 Years

SexALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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. Par…

What they're measuring

Protective Efficacy (PE)

Timeframe: 2 months

Complete Protection Time (CPT)

Timeframe: 3 months

Trial details

NCT IDNCT03813069

SponsorLondon School of Hygiene and Tropical Medicine

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2019-12-23