New research, led by Imperial College London, suggests the parasites that cause the tropical disease Leishmaniasis convince the immune system to help them rather than kill them.
Leishmania parasites are transmitted by sand flies and affect around 12 million people per year, generally in tropical and sub-tropical climes. Currently no vaccine exists but the new findings may be an important step towards understand the disease.
In a sand fly that carries the disease, the parasite resides in their midgut and produces a gel that blocks the fly’s digestive system. The fly is forced to regurgitate the gel before it can feed on human blood and this is how the parasite gel enters the human body. The new findings reveal that gel goes on to persuade cells to feed the parasite rather than kill it. The study also suggests that the sand fly’s saliva has a big effect on establishing infection.
Dr Matthew Rogers, lead author of the study at Imperial College London said: “Leishmaniasis is a very debilitating disease, yet we know comparatively little about the way the parasites are transmitted by sand flies. This is because when scientists study the disease they usually inject the parasite into the tissues without including the gel or the sand fly’s saliva.”
Their new findings show that how the parasite enters the body (including the gel and saliva) is fundamental to understand how the disease is transmitted.
By Leila Sattary