Kala azar, also known as visceral leishmaniasis, is a severe infectious disease caused by the protozoan parasite of the Leishmania genus, primarily Leishmania donovani and Leishmania infantum. It is transmitted to humans through the bites of infected female sandflies.
The condition is characterized by its propensity to attack the body's internal organs, most notably the spleen, liver, and bone marrow, hence its name which translates to "black fever" in Hindi. Its symptoms typically include prolonged and irregular fever, weight loss, enlargement of the liver and spleen (hepatosplenomegaly), and anemia due to bone marrow suppression. In advanced stages, individuals may exhibit a distinctive grayish discoloration of the skin, giving it a "black fever" appearance.
Kala azar can have severe consequences if left untreated, often resulting in death. It is endemic in certain regions of Africa, South Asia, and South America, where poverty, malnutrition, and overcrowding create conditions conducive to the spread of the disease. Diagnosis of kala azar may involve laboratory tests, such as blood smears or polymerase chain reaction (PCR) tests, for the detection of the parasite.
Treatment options for kala azar include a variety of antiparasitic drugs, such as sodium stibogluconate, paromomycin, miltefosine, or liposomal amphotericin B. Preventive measures primarily focus on controlling the sandfly population and avoiding sandfly bites, usually through the use of insecticide-treated bed nets, protective clothing, and indoor residual spraying.
