Leishmaniasis is a parasitic disease transmitted by the bites of infected sand flies. It is found in nearly 88 countries, from rain forests in Central and South America to deserts in the Middle East and west Asia. Some cases of the disease have also appeared in Mexico and Texas. The disease takes several different forms, including the most common cutaneous leishmaniasis, which causes skin sores, and the more severe visceral leishmaniasis (also known as kala azar), which affects internal organs such as the spleen, liver, and bone marrow.
Why Is the Study of Leishmaniasis a Priority for NIAID?
The World Health Organization estimates there are 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis in the world each year. Leishmaniasis not only affects people who live in countries where the disease is endemic but also poses a risk to people who travel in those areas. For example, the cutaneous form of the disease is a growing health problem for U.S. soldiers in sand fly-rich Afghanistan and Iraq—where it has been nicknamed the "Baghdad boil." According to the World Health Organization (WHO), 90 percent of all cutaneous leishmaniasis cases occur in Afghanistan, Brazil, Iran, Peru, Saudi Arabia, and Syria.
How Is NIAID Addressing This Critical Topic?
NIAID conducts and supports leishmaniasis research to advance the understanding of all aspects of the disease, including the different species of disease-causing Leishmania parasites, the varieties of sand flies that transmit the parasites to animals and humans, and how the host immune system responds to the infection.
NIAID scientists are researching different species of disease-causing Leishmania parasites and the varieties of sand flies that transmit the parasites to animals and humans.
NIAID has a research program focused on designing vaccines that confer long-term protection from diseases that require cell-mediated immunity in humans, such as tuberculosis and leishmaniasis.
Sand-Fly Vaccine Provides Protection in Monkeys Against Leishmaniasis
Researchers at NIAID and collaborators exposed rhesus macaques to sand flies that were not infected with Leishmania parasites and found that monkeys bitten by the flies developed some immunity to the disease.