The following are true of kala azar except.
**Core Concept**
Kala azar, also known as visceral leishmaniasis, is a severe form of leishmaniasis caused by Leishmania parasites. It primarily affects the reticuloendothelial system, including the spleen, liver, and bone marrow, leading to various systemic complications.
**Why the Correct Answer is Right**
Leishmaniasis is transmitted through the bite of infected sandflies, and the disease progresses through different stages, including the cutaneous, mucocutaneous, and visceral forms. The visceral form, also known as kala azar, is characterized by the accumulation of parasites in the reticuloendothelial system, leading to symptoms such as fever, weight loss, and splenomegaly. The diagnosis of kala azar is primarily based on clinical presentation, laboratory tests, and histopathological examination of tissue samples.
**Why Each Wrong Option is Incorrect**
**Option A:** Kala azar is caused by Leishmania parasites, which infect the reticuloendothelial system. This statement is correct, and thus cannot be the correct answer to the question "except."
**Option B:** The disease is transmitted through the bite of infected sandflies. This statement is also correct, and is a fundamental aspect of kala azar epidemiology.
**Option C:** Kala azar is characterized by the accumulation of parasites in the reticuloendothelial system. This statement is true, and is a key feature of the disease.
**Option D:** The primary treatment for kala azar involves the use of antimonial compounds, which are effective in reducing parasite load and alleviating symptoms. This statement is incorrect, as the primary treatment for kala azar has shifted towards the use of liposomal amphotericin B, miltefosine, and other alternative therapies.
**Clinical Pearl / High-Yield Fact**
It's essential to note that kala azar is a significant public health concern in many parts of the world, particularly in South Asia and Africa. Early diagnosis and treatment are critical in preventing long-term sequelae and reducing mortality rates.
**Correct Answer: D.**