Heat therapy could burn out leishmaniasis

Leishmaniasis is spread by phlebotomine sand flies

CDC/Frank Collins

Patients suffering from cutaneous leishmaniasis normally undergo a series of painful injections but a single session of heat therapy may be sufficient to treat the disease, according to a study.

The study comes as the WHO Expert Committee on the Control of Leishmaniasis revises its guidelines on treatment options for the disease, which is transmitted by sandflies and causes disfiguring skin ulcers. At a meeting held last month (22–26 March) the committee found there is now sufficient evidence to recommend heat therapy.

Researchers compared the standard treatment for the disease — a course of intravenous injections of the drug sodium stibogluconate over 20 days — with a single session of heat therapy applied directly to the ulcers.

They found that the heat therapy was just as effective as the injections — and caused fewer side effects such as pain, headaches and fatigue.

Cutaneous leishmaniasis is caused by Leishmania parasites, which are transmitted through bites from infected phlebotomine sand flies. This leads to ulcers that often become infected with other parasites, causing further problems. The disease affects more than ten million people with an estimated two million new cases each year — mainly in developing countries.

The standard treatment requires substantial follow-up and patient commitment to ensure the course is completed, Richard Reithinger, honorary lecturer at the Disease Control and Vector Biology Unit, London School of Hygiene and Tropical Medicine, told SciDev.Net.

"The [heat therapy] device is easy to use, battery operated and a fairly lightweight piece of equipment," said Naomi Aronson, lead author of the study and an infectious disease physician at the Uniformed Services University of the Health Sciences, Bethesda, United States.

Additionally, because only a single treatment is required, health care workers do not need to spend a long time in one location in order to treat people, she said.

Reithinger pointed out that this ability to treat more patients in a shorter time period is important when many cases occur, as in epidemic outbreaks.

But he also said the high initial cost of the ThermoMed device used in the study — priced at US$24,500 — means that it is best used in settings where there is a continual need for managing cases.  And a drug therapy might still be more practical for patients with many lesions or those with lesions on joints.

Link to full paper in PLoS Neglected Tropical Diseases