Evaluation of a Portable light source for Photodynamic Therapy of Cutaneous Leishmaniasis

Description of impact

The purpose of this proposal is to demonstrate that light sources recently developed in St Andrews can be effective in killing leishmaniasis parasites by photodynamic therapy. It aims to demonstrate the effectiveness of the approach – initially through in-vitro studies and then evaluate its suitability for clinical use. This demonstration will substantially advance the translation of the device and provide the basis for attracting further funding for a trial after which such devices could be manufactured in the developing countries, close to where they are needed.

Who is affected

The main benefit is in health, as the project addresses a major tropical disease affecting many developing countries. There will also be economic benefits from reducing work lost due to cutaneous leishmaniasis. The possibility of using advances in optoelectronics in the treatment of disease is an exciting scientific and technological direction. Although the core idea of PDT is simple, it has the potential to transform the treatment of a serious and disfiguring tropical disease.

Narrative

Leishmaniasis is a serious and widespread tropical disease caused by parasites of the Leishmania genus and presents high morbidity and mortality levels. It occurs in 88 tropical and subtropical countries and affects many millions of people worldwide. Leishmaniasis can be divided into two main types: visceral and cutaneous. Different types of the disease occur in different regions of the world. Cutaneous disease is most common in Afghanistan, Algeria, Brazil, Colombia, and Iran. There is no broad-spectrum treatment for cutaneous leishmaniasis. Treatments that work for one species of leishmania may not work for another and available drugs such as pentavalent antimony, amphotericin B and miltefosine, have serious disadvantages such as high cost, long duration of treatment and severe toxicity.
New treatment alternatives are urgently needed. A promising candidate is photodynamic therapy (PDT) in which light in combination with a photosensitive cream causes a photochemical reaction which kills the parasite.
In terms of clinical evidence this is a promising approach but it is normally implemented using expensive light sources such as lasers or large LED arrays that are only found in a very limited number of hospitals. This severely limits its use – especially in developing countries, which is precisely where it is needed.

Impact status	Closed
Impact date	4 Dec 2017 → 30 Mar 2018