New research describes leishmaniasis, a neglected tropical disease spread through sandflies, as a “Russian Doll’ disease. There is the Leishmania virus inside the Leishmania brazileinsis and L. guyanensis parasites which are, in turn, inside the sandfly. And the virus lurking inside the parasite is silently helping the latter thwart drugs and survive, at least in patients in Latin America, study in Bolivia and Peru shows.
A different strain, L. donovani, circulates in South Asia and scientists have not yet detected the virus in it. So whether it accounts for the worryingly rising rates of relapse after treatment in patients, as seen in a study in Nepal and reported in Nature, is not yet known. But it worth looking at, say scientists. Parts of the Indian sub-continent are endemic to the infection, known here as ‘kala azar’. And worldwide, 1.2 new infections are added each year, and there are already 12 million cases globally.
And one scientist who is dedicated in tracking the Leishmania parasite is Jean-Claude Dujardin, professor at the Institute of Tropical Medicine, Antwerp, Belgium who led in both theLatin American and Nepal studies. Here he is explaining the dynamics of drug resistance in leishmaniasis in a video: