Visceral Leishmaniasis Overview
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What is one of the primary classifications of leishmaniasis that affects visceral tissues?

  • Leishmania tropica complex
  • Leishmania braziliensis complex
  • Leishmania donovani complex (correct)
  • Leishmania mexicana complex

    • What symptom was notably observed in the case scenario of the 20-year-old Indian male?

  • Frequent urination
  • Loss of appetite (correct)
  • Dizziness
  • Recurrent headaches

    • Which haematological finding was presented in the case scenario that indicates a problem with blood components?

  • Anemia of chronic disease
  • Leukocytosis
  • Polycythemia
  • Thrombocytopaenia (correct)

    • What is the geographical distribution characteristic of Old World visceral leishmaniasis?

    <p>Africa, Asia, and Europe</p> Signup and view all the answers

    Which of the following is least likely to be a characteristic of Leishmania spp. causing visceral leishmaniasis?

    <p>Association with thrombocytosis</p> Signup and view all the answers

    Which organism is primarily responsible for causing visceral leishmaniasis in the New World?

    <p>Leishmania chagasi</p> Signup and view all the answers

    What is the most significant pathological examination finding in the patient's bone marrow?

    <p>Abundance of mononucleated rounded bodies</p> Signup and view all the answers

    Which of the following is not a typical manifestation of visceral leishmaniasis?

    <p>Coughing</p> Signup and view all the answers

    How do amastigotes transform into promastigotes in sand flies?

    <p>They are ingested with the blood meal and multiply in the gut.</p> Signup and view all the answers

    Which condition increases the risk of severe visceral leishmaniasis?

    <p>Immunocompromised status</p> Signup and view all the answers

    What effect do amastigotes have on fixed macrophages?

    <p>They lead to marked hyperplasia and destruction of RECs.</p> Signup and view all the answers

    What condition is characterized by the infiltration of the bone marrow with parasitized macrophages?

    <p>Pancytopenia</p> Signup and view all the answers

    What leads to ulceration in the intestinal mucosa during leishmaniasis?

    <p>Presence of parasitized macrophages</p> Signup and view all the answers

    What type of anemia occurs due to a lack of iron absorption in kala-azar?

    <p>Microcytic anemia</p> Signup and view all the answers

    What is a notable symptom of visceral leishmaniasis during its clinical presentation?

    <p>Remittent fever with varied patterns</p> Signup and view all the answers

    In which organ system do amastigotes lead to significant symptoms such as hepatosplenomegaly?

    <p>Lymphatic system</p> Signup and view all the answers

    What is the purpose of the Leishmanin skin test (Montenegro test)?

    <p>To assess past exposure and immunity to Leishmania</p> Signup and view all the answers

    Which method is NOT used for the indirect immunological diagnosis of Leishmania?

    <p>Complete blood count (CBC)</p> Signup and view all the answers

    What is a characteristic finding in smears from positive cases following animal inoculation?

    <p>Amastigotes in ulcers or nodules</p> Signup and view all the answers

    What condition is indicated by hypergammaglobulinemia and low albumin levels in the blood picture for Leishmania?

    <p>Pancytopenia</p> Signup and view all the answers

    After how long is the Leishmanin skin test considered positive after an individual has been cured from Leishmania?

    <p>6-8 weeks</p> Signup and view all the answers

    Which stain is NOT typically used for smears of body fluids in Leishmania diagnosis?

    <p>Oil immersion stain</p> Signup and view all the answers

    What is a key feature seen in promastigotes when cultured on Novy-MacNeal-Nicolle (NNN) medium?

    <p>Rosette grouping</p> Signup and view all the answers

    What is the primary treatment of choice for systemic therapy of Leishmania infection?

    <p>Pentavalent antimony compounds</p> Signup and view all the answers

    What is the preferred habitat for Leishmania species in the human body?

    <p>Reticuloendothelial cells of various organs</p> Signup and view all the answers

    Which of the following accurately describes the Promastigote form of Leishmania?

    <p>Infective stage found in the female sand fly</p> Signup and view all the answers

    What mechanism allows Leishmania to infect the human body?

    <p>Bite of an infected sand fly</p> Signup and view all the answers

    Which of the following is NOT a reservoir host for Leishmania?

    <p>Felines</p> Signup and view all the answers

    What happens after Promastigotes are inoculated into the skin during a sand fly's blood meal?

    <p>They are phagocytosed by macrophages</p> Signup and view all the answers

    Which life cycle stage is responsible for the transmission of Leishmania from the insect vector to the human host?

    <p>Promastigote stage in the insect vector</p> Signup and view all the answers

    What type of infection mode can occur through nasal secretions during epidemics?

    <p>Direct transmission</p> Signup and view all the answers

    Which of the following is a common feature of the life cycle of Leishmania in sand fly insects?

    <p>Biological transmission of cyclo-propagative type</p> Signup and view all the answers

    What is the most fatal complication associated with visceral leishmaniasis (VL)?

    <p>Disseminated intravascular coagulation</p> Signup and view all the answers

    What type of lesions are characteristic of Post-Kala Azar Dermal Leishmaniasis (PKDL)?

    <p>Granulomatous, non-ulcerating, hypopigmented nodular lesions</p> Signup and view all the answers

    What is the main clinical feature to suspect kala azar in endemic areas?

    <p>Persistent, irregular or remittent fever</p> Signup and view all the answers

    In Para-Kala Azar Dermal Leishmaniasis (Para-KDL), which symptoms are typically present?

    <p>Fever, splenomegaly, and poor nutritional status</p> Signup and view all the answers

    Which lab method is used to directly detect amastigotes in suspected visceral leishmaniasis cases?

    <p>Microscopy of peripheral blood smears</p> Signup and view all the answers

    Which of the following symptoms is NOT typically associated with visceral leishmaniasis?

    <p>Constant high fever</p> Signup and view all the answers

    How long after treatment can Post-Kala Azar Dermal Leishmaniasis (PKDL) occur?

    <p>6 months to 5 years</p> Signup and view all the answers

    What causes fever in visceral leishmaniasis patients?

    <p>Release of pyrogens by infected macrophages</p> Signup and view all the answers

    Study Notes

    Visceral Leishmaniasis

    • Visceral leishmaniasis (VL), also known as kala azar or black fever, is a deadly parasitic disease caused by Leishmania donovani complex.
    • The parasite is transmitted through the bite of infected female sandflies.
    • Leishmania is an insect-transmitted protozoa that infects the blood and tissues of humans and reservoir hosts.
    • VL is the second most deadliest parasitic disease following malaria.
    • There are three principle species of Leishmania:
      • **L. donovani **, responsible for Old World VL, found in India, Pakistan, Indonesia, Thailand, Ethiopia, East and Central Africa, Mediterranean areas, the Middle East and China.
      • **L. infantum **, also responsible for Old World VL, found in Mediterranean areas, the Middle East and China
      • **L. chagasi **, responsible for New World VL, found in Central and South America.

    Morphology

    • Leishmania exists in two forms:
      • Amastigote: The round, non-motile form, found inside macrophages.
      • Promastigote: The elongated, motile form, found inside the sandfly vector and in culture.

    Life cycle

    • Human and Reservoir hosts:
      • The parasite enters the body through a sandfly bite.
      • The promastigotes transform into amastigotes within macrophages.
      • Amastigotes multiply by binary fission, causing destruction of the host's cells.
      • Parasitized macrophages travel throughout the body leading to generalized infection.
    • Sandfly Insect:
      • Amastigotes are ingested by the sandfly during a blood meal.
      • Amastigotes transform into promastigotes inside the insect's gut.
      • Promastigotes multiply by binary fission.
      • Promastigotes migrate to the sandfly's mouth ready to be transmitted.

    Pathogenicity

    • VL is an opportunistic infection, where the risk of severe disease is heightened in patients who are immunocompromised, have a low protein diet, and have deficiencies in iron, vitamin A, and zinc.
    • Amastigotes multiply within macrophages, leading to enlargement and destruction of these cells.
    • Infected macrophages spread to various organs, including the liver, spleen, and lymph nodes, leading to hepato-splenomegaly and lymphadenopathy.
    • The bone marrow is heavily infiltrated with parasitized macrophages, resulting in pancytopenia (decreased red blood cells, white blood cells, and platelets).

    Clinical Picture

    • Incubation Period: 2-6 months.
    • Fever is a common symptom, often remittent.
    • Hepatosplenomegaly is a hallmark of the disease.
    • Other symptoms include: fatigue, weight loss, anemia, emaciation, lymphadenopathy, diarrhea, dysentery, and epistaxis (nosebleeds).

    Complications

    • Disseminated Intravascular Coagulation (DIC) is the most fatal complication.
    • Thrombocytopenia can lead to spontaneous bleeding from the nose and mouth.
    • Pancytopenia occurs due to the suppressive effects of the infection on bone marrow, splenic sequestration, and hemolysis.
    • Lymphoid macrophages are heavily infiltrated with parasites, leading to ulceration of the intestinal mucosa and the presence of Leishman-Donovan bodies in feces.
    • The urinary tract can be infiltrated with parasitized macrophages, leading to mucosal breakdown and the presence of Leishman-Donovan bodies in urine.

    Post-Kala Azar Dermal Leishmaniasis (PKDL)

    • A chronic, progressive, granulomatous, non-ulcerating, hypopigmented nodular cutaneous lesion that can develop 6 months to 5 years after treatment for kala-azar.
    • Characterized by persistent skin papules, especially on the face, resembling lepromatous leprosy or disseminated cutaneous leishmaniasis.

    Para-Kala Azar Dermal Leishmaniasis (Para-KDL)

    • A condition where PKDL occurs while a patient is still undergoing treatment for VL.
    • Characterized by fever, splenomegaly, hepatomegaly, lymphadenopathy, and poor nutritional status.
    • Occurs mainly in East Africa and South Asia.

    Diagnosis

    • A) Clinical:*
    • Suspect VL in individuals residing in endemic areas with persistent, irregular, or remittent fever.
    • Other clinical features include hepatosplenomegaly, anemia, leucopenia, and emaciation.
    • B) Laboratory:*
    • I. Direct:*
    • Microscopy: Detect amastigotes in smears from peripheral blood, bone marrow, spleen, liver, lymph nodes, nasalopharyngeal secretions, stool, urine, or PKDL lesions.
    • Culture: Grow Leishmania promastigotes on Novy-MacNeal Nicolle (NNN) medium.
    • Animal inoculation: Inoculate hamsters intraperitoneally and observe for amastigotes in smears from lesions or organs.
    • II. Indirect:*
    • Immunological diagnosis:
      • Serological Tests: Detect antibodies against Leishmania antigens using IFA, IHA, ELISA, CFT, DAT, and Rapid Immunochromatographic Dipstick (ICT).
      • Leishmanin Skin Test (Montenegro Test): A delayed hypersensitivity skin test that detects exposure to Leishmania.
    • Molecular diagnosis: Assists in species identification.
    • Blood picture: Complete blood count may show anemia, leucopenia, and thrombocytopenia (Pancytopenia or Aplastic anemia).

    Treatment

    • Supportive Treatment: Nutritional support with vitamins and iron, antibiotic therapy, and blood transfusions.
    • Specific Treatment:
      • Systemic Therapy (parenteral, IV):
        • Pentavalent Antimony Compounds: Pentostam (Sodium stibogluconate).
        • Amphotericin B.
        • Interferon gamma + Pentostam (in case of relapse).

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    Description

    This quiz covers the essential aspects of visceral leishmaniasis (VL), including its causative agents and transmission. Learn about the different species of Leishmania and their geographical distribution. Test your knowledge on this serious parasitic disease known as kala azar.

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