Potential mitigating role of ivermectin on the spread of chlamydia trachomatis by Musca sorbens

Musca sorbens, the bazaar fly, is thought to contribute to the transmission of the blinding eye disease trachoma. It feeds on human sweat, mucous secretions and skin lesions and breeds in faeces, favouring human faecal matter (left in the environment due to open defecation).

Building from a proof of concept conducted by members of this study team and published in 2023, this study aims to assess whether ivermectin (IVM) could be a viable vector control tool against M. sorbens. IVM is on the World Health Organization (WHO) list of essential medicines and is currently used against the neglected tropical diseases, onchocerciasis and lymphatic filariasis.

Laboratory component (UK):

• To assess the concentration of IVM (in solution) that will kill 50% of adult flies (lethal concentration 50)
• To assess the concentration of IVM (over time) in human tears/nasal secretions/stool after ingestion of ivermectin

Contingent on findings from above objectives:

• To assess the lethality of IVM (over time) in human tears/nasal secretions/stool after ingestion of ivermectin

Field component (Ethiopia):

• To assess the impact of IVM mass drug administration (MDA) to people on M. sorbens population densities, in previously IVM-MDA naïve areas
• To assess the impact of IVM MDA on reducing trachoma prevalence

• Quantitative

Ivermectin has already been shown to have an inhibitive effect on insects that reproduce in dung. The analysis of Selby et al 2023 suggested an association between IVM MDA and improved control of trachoma in persistent or recrudescent areas.

If the intervention proves successful, the body of evidence will be used to support scale up in Ethiopia and policy development to support scale out to other trachoma endemic nations.

• View the journal article