Understanding Leishmania parasite populations in Brazil

Leishmaniasis is a globally distributed disease that affects 700,000 people annually. It is caused by Leishmania parasites spread by sand flies. The most severe form, visceral leishmaniasis (VL), can be fatal if untreated. There is no effective vaccine against the disease and chemotherapy is the main method of reducing the disease burden. Leishmania infantum was introduced to Brazil during colonialism and is becoming more common as urbanisation increases, with 6,000 cases in Brazil each year. There are indications of resistance to miltefosine in Brazil, which can be an effective treatment in other continents.

We will establish an understanding of the dispersal and evolution of Leishmania infantum in Brazil and critical aspects of disease control. We will sequence the genomes of 200 strains of the parasite collected from two locations in Brazil 1,600km apart, including strains archived 20 years ago. By examining the movement of alleles between sites and over time, we will measure migration rates and recombination rates and screen for adaptive evolution. We will also analyse clinical data to examine whether parasite genes influence disease severity.