Bangladesh 2010 © Gazi Nafis Ahmed/MSF

Kala azar

Kala azar, or visceral leishmaniasis, is the second deadliest parasitic disease in the world—only malaria kills more people.

Putting kala azar in context

Along with chagas disease and sleeping sickness, kala azar is one of the most dangerous neglected tropical diseases (NTDs). Kala azar is endemic in 76 countries with approximately 200 million people at risk of infection.

The parasite is spread to humans through the bite of infected female sand flies. It attacks the immune system, and is almost always fatal if not treated.

There are between 200,000 and 400,000 new cases a year, about 90 percent of which are in India, Bangladesh, Nepal, Sudan, and Brazil.

Facts about kala azar

Kala azar is caused by bites from female phlebotomine sandflies—the vector (or transmitter) of the leishmania parasite.

The sand flies feed on animals and humans for blood, which they need for developing their eggs.

If blood containing leishmania parasites is drawn from an animal or human, the next person to receive a bite will then become infected and develop leishmaniasis.

Months after this initial infection the disease can progress into a more severe form, called visceral leishmaniasis or kala azar.

Initially, leishmania parasites cause skin sores or ulcers at the site of the bite. If the disease progresses, it attacks the immune system.

Kala azar presents after two to eight months with more generalized symptoms including prolonged fever and weakness.

The most effective diagnostic tests for leishmaniasis are invasive and potentially dangerous, where tissue samples are required from the spleen, lymph nodes, or bone marrow. These tests require lab facilities and specialists not readily available in resource-poor, endemic areas.

The most common method of diagnosing kala azar is by dipstick testing. However, this method is highly problematic. In endemic areas, people can become infected with kala azar but it may not develop into the disease. Therefore, no treatment will be required.

Unfortunately, dipstick testing only establishes whether a patient is immune to kala azar—so if the parasite is present it would appear that the patient has the disease. Because of this, dipstick testing can’t be used to see if the patient is cured, is re-infected, or has relapsed.

There are different treatment options available for kala azar, with varying effectiveness and side effects. Pentavalent antimonials are usually the first line group of drugs, given as a 30 day course of intramuscular injections.

While antimonials are quite toxic and present a risk to patients receiving treatment, those who are cured for kala azar almost always develop immunity for life. Researchers hope to identify ways to simplify treatment regimes, improve their safety, and reduce the risk of drug resistance.

Since 1989 Doctors Without Borders/Médecins Sans Frontières (MSF) has treated around 100,000 patients with kala azar. MSF is also campaigning for more research into suitable diagnostic techniques and affordable drugs to treat this neglected disease.

Treating kala azar-HIV co-infection in India

How you can help

Not everyone can treat patients in the field. But everyone can do something.

Some humanitarian crises make the headlines—others don’t. Unrestricted support from our donors allows us to mobilize quickly and efficiently to provide lifesaving medical care to the people who need it most, whether those needs are in the spotlight or not. And your donation is 100 percent tax-deductible.