Visceral Leishmaniasis

Leishmaniasis is caused by Leishmania species; divided into visceral (VL), cutaneous (CL), mucocutaneous (ML). VL = kala-azar by L. donovani; chronic fever, hepatosplenomegaly, leukopenia, hypergammaglobulinemia.

Common Symptoms

Papulomacular rash; weakness; lymphadenopathy; fatigue; gingival bleeding; diarrhea; anorexia; abdominal pain; epistaxis

Causes and Pathogenesis

(1) Etiology: L. donovani donovani/infantum/chagasi (some consider separate species); L. tropica rarely. Life cycle: promastigote (sandfly/culture) and amastigote (mammalian host). Promastigote 15-25 × 1.5-3.5 µm; amastigote 2.9-5.7 × 1.8-4.0 µm with nucleus/kinetoplast. Sandfly bite → amastigotes in gut → promastigotes → proboscis → bite → phagocytosed → amastigotes in RES. (2) Pathogenesis: Gp63 binds macrophage C3 receptor; LPG activates complement; CR3-mediated phagocytosis; replication until macrophage rupture; RES hyperplasia → lymphadenopathy/hepatosplenomegaly. Pathology: Kupffer cell hyperplasia stuffed with amastigotes, plasma cells; spleen enlargement with hematopoietic hyperplasia; lymphocyte depletion.

Treatment

Drug therapy, supportive therapy

Preventive Measures

(1) Find/kill infected dogs; screen/treat patients. (2) Spray insecticides (dichlorvos/trichlorfon); 2.5% deltamethrin dip for dogs. (3) Bed nets; indoor hygiene; repellents on exposed skin.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.