Testing Insect Repellents Against Musca Sorbens, the Vector of Trachoma

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.

Conditions

• Trachoma

Interventions

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.

Sponsors & Collaborators

• Federal Minstry of Health of Ethiopia

  collaborator OTHER_GOV

• Oromia Regional Health Bureau, Ethiopia

  collaborator UNKNOWN

• The Fred Hollows Foundation, Ethiopia

  collaborator UNKNOWN

• The Fred Hollows Foundation, UK

  collaborator UNKNOWN

• The Fred Hollows Foundation, Australia

  collaborator UNKNOWN

• London School of Hygiene and Tropical Medicine

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

SINGLE_GROUP

Eligibility

Min Age

3 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2019-01-10

Primary Completion

2019-12-23

Completion

2019-12-23

Countries

• Ethiopia
• United Kingdom

Study Locations