Survival of Flies Developing in Faecal Samples
Conditions
Keywords
Trachoma, Ivermectin, Musca flies
Brief summary
Trachoma is caused by repeated Chlamydia trachomatis infection in the eye. Routes of infection include close person-to-person contact and contaminated clothing. In addition, the bazaar fly Musca sorbens has been implicated in transmission. These flies frequently visit the faces of children and have been found positive for C. trachomatis, which may be transferred from the body of the flies or their regurgitated or defecated material. This study aims to give recruited healthy volunteers a safe dose of oral ivermectin. Their faeces will be collected over subsequent days to determine whether ivermectin excreted from the body results in faecal concentrations that are high enough to prevent emergence of M. sorbens developing in faeces. It will also quantify ivermectin concentrations in tears secretions and faecal samples for up to 30 days post-treatment.
Interventions
DRUGIvermectin
Oral dose of ivermectin (150 micrograms/kg)
Sponsors
London School of Hygiene and Tropical Medicine
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Masking description
Investigators exposing flies to the faeces of volunteers will be masked as to the treatment (whether the sample is pre- or post-treatment).
Intervention model description
All participants to be given a single doe of ivermectin.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Able and willing to give fully informed consent * Able to understand and comply with the study procedures * Able to produce a stool on most days * Consider themselves to be in good general health * Aged 18 to 65 years
Exclusion criteria
* Suspected or known to be sensitive or allergic to ivermectin * Women who are pregnant, nursing or intending to become pregnant * Aware of having any neurological disorders or recent history of seizures * History of travel to a region endemic for Loa loa. * Currently taking acenocoumarol, warfarin or levimasole
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Musca sorbens larvae surviving to adulthood | Days 1, 2, 3, 4, 5, 10 and 30 post treatment | The difference in the mean number of Musca sorbens larvae surviving to adulthood in faecal samples collected at each post-treatment time point compared to pre-treatment samples. The treatment effect will be estimated separately at each time point. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Concentration of ivermectin in faeces | Days 1, 2, 3, 4, 5, 10 and 30 post treatment | The mean concentration of ivermectin in faecal samples (ng/g) and tear samples (ng/mL) at baseline and at each post-treatment time point. |
| First oviposition event | Days 1, 2, 3, 4, 5, 10 and 30 post treatment | The time from presentation of each faecal sample to the first oviposition event by Musca sorbens at baseline and each post-treatment time point. |
| Behvioural response | Days 1, 2, 3, 4, 5, 10 and 30 post treatment | Observed behavioural response(s) of adult female Musca sorbens when presented with faecal samples at baseline and each post-treatment time point. |
| Adult fly survival | Each time pointDays 1, 2, 3, 4, 5, 10 and 30 post treatment | The survival of adult female Musca sorbens when presented with faecal samples collected at baseline and each post-treatment time point, measured as time to death. |
Countries
United Kingdom
Outcome results
None listed