Visceral Leishmaniasis (Kala-azar)
What is Visceral Leishmaniasis (Kala-azar)?
Visceral leishmaniasis is a serious parasitic disease that affects internal organs. It is also called kala-azar, which means black fever in Hindi. The condition is caused by a tiny parasite called Leishmania that spreads through the bite of infected sandflies.
The parasite attacks organs like the spleen, liver, and bone marrow. Without treatment, visceral leishmaniasis can be fatal. It is most common in parts of India, East Africa, South America, and the Mediterranean region. In the United States, cases are rare and usually occur in travelers or military personnel returning from affected areas.
This is the most severe form of leishmaniasis. Other forms affect only the skin or mucous membranes. Visceral leishmaniasis requires prompt medical attention and specialized treatment to prevent serious complications.
Symptoms
- Prolonged fever that comes and goes over weeks or months
- Weight loss and loss of appetite
- Enlarged spleen and liver that can be felt in the abdomen
- Fatigue and weakness
- Anemia that causes pale skin
- Reduced white blood cells and platelets
- Darkening of the skin, especially on hands, feet, abdomen, and face
- Dry, thin, and scaly skin
- Easy bruising or bleeding
- Swollen lymph nodes
Symptoms typically appear 2 to 6 months after infection. Some people may not show symptoms for years after being bitten by an infected sandfly. Early symptoms are often vague and can be mistaken for other conditions.
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Causes and risk factors
Visceral leishmaniasis is caused by Leishmania parasites transmitted through the bite of female sandflies. These tiny insects are smaller than mosquitoes and are most active at dusk and night. When an infected sandfly bites, it injects the parasite into the bloodstream. The parasite then travels to internal organs where it multiplies.
Risk factors include living in or traveling to areas where the disease is common. People with weakened immune systems have higher risk of developing severe disease. This includes those with HIV, people taking immunosuppressive drugs, and individuals with malnutrition. Poor housing conditions, overcrowding, and lack of sanitation increase exposure to sandflies. Climate change may expand the range of sandflies to new areas. The disease cannot spread directly from person to person.
How it's diagnosed
Diagnosis requires specialized medical evaluation and laboratory testing. A doctor will review your symptoms and travel history. Physical examination may reveal an enlarged spleen and liver. Blood tests can detect antibodies against the Leishmania parasite, indicating current or past infection.
Definitive diagnosis often requires examining tissue samples from bone marrow, spleen, or liver under a microscope. These samples can show the parasite directly. Molecular tests like PCR can detect parasite DNA with high accuracy. Rite Aid does not currently offer specialized testing for visceral leishmaniasis. If you have symptoms or exposure history, talk to a doctor who can refer you for appropriate testing and treatment.
Treatment options
- Antiparasitic medications like liposomal amphotericin B, miltefosine, or paromomycin
- Hospitalization for severe cases to monitor organ function
- Nutritional support to address malnutrition and weight loss
- Treatment of secondary infections that occur due to weakened immunity
- Blood transfusions if severe anemia develops
- Follow-up testing to confirm the parasite is eliminated
- Long-term monitoring for relapse, especially in immunocompromised patients
- Preventive measures like insect repellent and bed nets when traveling to affected areas
Frequently asked questions
Visceral leishmaniasis affects internal organs like the spleen, liver, and bone marrow. Cutaneous leishmaniasis only causes skin sores that heal on their own in many cases. Mucocutaneous leishmaniasis affects mucous membranes of the nose, mouth, and throat. Visceral leishmaniasis is the most serious form and is fatal without treatment.
You get visceral leishmaniasis from the bite of an infected sandfly. These tiny insects live in tropical and subtropical regions around the world. The disease cannot spread from person to person through casual contact. You must be bitten by a sandfly carrying the Leishmania parasite to become infected.
Yes, visceral leishmaniasis can be cured with proper antiparasitic treatment. Medications like liposomal amphotericin B are highly effective when given promptly. Treatment success rates are high in people with healthy immune systems. People with HIV or other immune problems may need longer treatment and have higher risk of relapse.
Symptoms typically appear 2 to 6 months after being bitten by an infected sandfly. In some cases, the incubation period can be as short as a few weeks or as long as several years. Many people do not remember being bitten because sandfly bites are small and often painless. Early symptoms like fever and fatigue are often mistaken for other illnesses.
No, visceral leishmaniasis is very rare in the United States. Most cases occur in travelers or military personnel returning from affected regions. The sandflies that spread the disease are not common in most parts of the US. Areas with higher risk include parts of India, East Africa, Brazil, and the Mediterranean region.
Blood tests can detect antibodies against the Leishmania parasite, specifically IgG antibodies. These antibodies indicate your immune system has responded to the infection. However, antibody tests may be negative early in infection or in immunocompromised patients. Additional tests like bone marrow examination or PCR may be needed for definitive diagnosis.
Yes, you can reduce your risk by avoiding sandfly bites in affected areas. Use insect repellent containing DEET on exposed skin. Sleep under fine-mesh bed nets treated with insecticide. Wear long sleeves and pants, especially at dusk and night when sandflies are most active. There is currently no vaccine available for leishmaniasis.
Untreated visceral leishmaniasis is almost always fatal within 2 years. The parasite continues to damage vital organs including the spleen, liver, and bone marrow. Severe anemia, bleeding problems, and overwhelming infections can occur. Death often results from severe bleeding, secondary infections, or organ failure.
Kala-azar means black fever in Hindi. The name refers to the darkening of the skin that often occurs in people with the disease. This hyperpigmentation is especially noticeable on the hands, feet, abdomen, and face. The term has been used for over a century in India, where the disease is common.
People with weakened immune systems face the highest risk of severe disease. This includes individuals with HIV, those taking immunosuppressive medications, and people with malnutrition. Young children and older adults may also have more severe symptoms. In areas where the disease is common, poverty and poor living conditions increase exposure to infected sandflies.