Kala Azar (leishmaniasis)

Some three decades ago, a mystery disease spread throughout Sudan and what is now South Sudan, decimating communities, sewing fear, and killing scores. It turned out to be kala azar, also known as visceral leishmanaisis, a disease that is spread by the bite of a sandfly and that is, as this episode showed, fatal if not treated.MSF began caring for kala azar patients during that epidemic and has continued to do so through the present day, in both Sudan and South Sudan, and in other East African nations where the disease appears, as well as in South Asia. The needs are different in the different locations, because the strains of the disease found have their own particular characteristics. What unites them, however, is that the people trying to combat the disease are hamstrung by shortcomings in targeted research and development that has resulted in a lack of suitable diagnostics and treatment regimens.There are 400,000 new cases of kala azar diagnosed worldwide each year with approximately 40,000 deaths due to the parasitic disease. The eight most affected countries – Bangladesh, Brazil, India, Ethiopia, Kenya, Nepal, Sudan, and South Sudan – represent over 90 percent of new cases.MSF has successfully adapted its treatment protocols over the years in order to bring shorter, less toxic, and less painful options to patients, but as VII Photo’s John Stanmeyer saw on a recent trip to MSF projects in South Sudan, a great deal remains to be done in order to provide better, more specialized, more accessible treatment and testing, and to prevent further devastation.

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

A neglected tropical disease, kala azar is caused by a parasite spread to humans through the bite of infected female sand flies. It attacks the immune system and is almost always fatal if not treated.

Also known as visceral leishmaniasis, kala azar is the most serious form of leishmaniasis and is endemic in 76 countries, with hundreds of millions at risk of infection. There are between 50,000 and 90,000 new cases a year, about 90 per cent of which occur in Brazil, Ethiopia, India, Kenya, Somalia, South Sudan and Sudan. Between 1989 and 2020, MSF teams treated nearly 150,000 people for kala-azar, over a third in South Sudan.

Diagnosis and treatment of the disease, especially of the variety found in eastern Africa, can be complex and painful.

About Kala Azar

What causes kala azar?

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

The sandflies 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.

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

Co-infection of kala azar and HIV is a major challenge, as the diseases influence each other in a vicious spiral as they attack and weaken the immune system.

Diagnosing kala azar

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.

Treating kala azar

Today, liposomal amphotericin B is becoming the primary treatment drug in Asia, either alone or as part of a combination therapy.

While safer and shorter than previously used medication, it requires intravenous administration, which remains an obstacle to its use in local clinics. An oral drug, miltefosine, is often added to optimise treatment regimens in patients.

In Africa, the best available treatment is still a combination of pentavalent antimonials and paromomycin, which is toxic and requires a number of painful injections. Research into other treatment combinations is underway.

MSF treated 9,900 patients for kala azar in 2018.