Deadly sleeping sickness can also be spread via skin

Skin plays a significant role in harbouring and transmitting trypanosomes -- the parasite that causes the Human African Trypanosomiasis, more commonly known as African sleeping sickness, which is often fatal if left untreated, a new research has found.

The findings could have a major impact on the way the disease is diagnosed, treated and potentially eradicated.

The disease, which kills thousands in Sub-Saharan Africa every year, is primarily transmitted to humans via the bite of an infected tsetse fly as it takes a blood meal, with diagnosis then confirmed through the presence of parasites in the blood.

The current study, published recently in the journal elife, showed that substantial quantities of trypanosomes that cause the disease can exist within the skin and can be transmitted back to the tsetse fly vector.

"Our results have important implications with regard to the eradication of sleeping sickness. Firstly, our findings indicate that current diagnostic methods, which rely on observing parasites in the blood, should be re-evaluated and should include examining the skin for parasites," said lead researcher Annette Macleod from University of Glasgow in Britain.

"In terms of treatment, it may also be necessary to develop novel therapeutics capable of targeting sources of infection outside the blood circulation and in the reservoirs underneath the skin," Macleod noted.

The team of researchers from University of Glasgow's Wellcome Trust Centre for Molecular Parasitology and the Institut Pasteur in Paris were also able to observe the presence of parasites in human skin biopsies from individuals who displayed no symptoms. 

The study's findings suggest skin-dwelling parasites could be sufficiently abundant in the skin to be ingested, transmitted and so able to spread the disease further.