On 8 June 2022, the World Health Organization (WHO) published a new treatment guideline for visceral leishmaniasis in patients who are coinfected with the human immunodeficiency virus (HIV), with the guideline targeting visceral leishmaniasis in East Africa and South-East Asia.
Visceral leishmaniasis, or kala azar, is caused by different Leishmania species in distinct geographical areas. In East Africa (Ethiopia, South Sudan and Sudan) and South-East Asia (Bangladesh, India and Nepal), it is caused by L. donovani and has an anthroponotic cycle with a human reservoir.
The new recommendations are based on the results of studies conducted in India by Médecins Sans Frontières (MSF) and partners, and in Ethiopia by the Drugs for Neglected Diseases initiative and partners. The expectation is that there will be increased access to treatment and improved treatment outcomes, which will benefit national control programmes for neglected tropical diseases, HIV, tuberculosis and vector-borne diseases. Up to 5-7% of visceral leishmaniasis patients in India are detected with HIV infection, the highest level in South Asia, while a significant proportion also suffer from tuberculosis (TB).
The new guideline updates the 2010 recommendations, which were based on limited evidence extrapolated mainly from experience in countries around the Mediterranean Basin, where zoonotic L. infantum is the main causative species. The recommended treatment consisted of daily injections of liposomal amphotericin B (AmBisome) over a period of up to 38 days. However, evidence from the studies in Ethiopia and India shows that the new regimen combining liposomal amphotericin B with oral miltefosine performs better, as results in India found that relapse-free survival was recorded at 96%, against 88% for the standard treatment.
In Ethiopia, visceral leishmaniasis-HIV coinfection has increased by 20 to 30% since the early 1980s, with the highest coinfection rate in the world, and although the rate has declined, coinfection nevertheless remains a major public health challenge. The new combined regimen showed an increased efficacy of 88%, compared with the current standard treatment of 55%.
Leishmania and HIV coinfections have challenged the control and elimination of visceral leishmaniasis, as HIV-infected people are particularly vulnerable to the disease. Leishmania and HIV reinforce each other, posing significant clinical and public health problems, with both conditions suppressing the immune system, resulting in more severe morbidity, with limited therapeutic options and higher rates of relapse, exposure to medicines with increased toxicity and higher mortality rates.
First reported in the mid-1980s in southern Europe, the coinfection is now documented in around 45 countries, with high rates being reported in Brazil, Ethiopia and the Bihar state in India. Coinfected patients are vulnerable not only to other comorbid conditions, such as tuberculosis and cryptococcal meningitis, but also to stigmatization and human rights issues.
Leishmaniasis is caused by a protozoa parasite from over 20 Leishmania species, with over 90 sandfly species known to transmit Leishmania parasites. There are three main forms of the disease:
- Visceral leishmaniasis, which can be fatal if untreated, and is characterized by irregular bouts of fever, weight loss, enlargement of the spleen and liver, and anaemia.
- Cutaneous leishmaniasis which is the most common form of leishmaniases, causing skin lesions, mainly ulcers, on exposed parts of the body, leaving life-long scars and serious disability or stigma.
- Mucocutaneous leishmaniasis, which leads to partial or total destruction of mucous membranes of the nose, mouth and throat.
Source: WHO, 8 June 2022