Leishmaniasis
Leishmaniasis is a sand fly-transmitted protozoan infection causing either destructive cutaneous ulcers or visceral disease (kala-azar) with hepatosplenomegaly and pancytopenia, diagnosed by direct visualization of amastigotes and treated with liposomal amphotericin B or miltefosine.
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What this article covers
- Overview
A sand fly-transmitted protozoan infection with two clinically distinct patterns: Leishmania species cause either a destructive cutaneous ulcer (cutaneous leishmaniasis) or a systemic illness with…
- Epidemiology
Transmitted by the bite of an infected sand fly: Leishmania is a vector-borne protozoan disease acquired through sand fly bites in endemic regions.
- Risk factors
Residence in or travel to an endemic region with sand fly exposure: unprotected outdoor exposure in endemic areas is the principal risk factor for acquiring either clinical form.
- Pathophysiology
Sand fly inoculation delivers promastigotes into the skin: the sand fly vector transmits the flagellated promastigote form of Leishmania during a blood meal.
- Clinical features
Cutaneous leishmaniasis begins as a painless papule that progresses to an ulcer: the lesion typically develops at the sand fly bite site, evolves over weeks, and can be self-limited or, particularly…
- Differential diagnosis
Brucellosis (visceral-pattern mimic): intermittent, waxing-and-waning (undulant) fever with hepatosplenomegaly, arthralgia, and depression; distinguished by a positive blood culture or serology for…
- Diagnosis
The diagnosis is confirmed by direct visualization of Leishmania amastigotes on tissue aspirate or biopsy: bone marrow, splenic, or lymph node aspirate for visceral disease, or a skin lesion…
- Management
First, confirm the species and clinical form (cutaneous, mucosal, or visceral), since this determines drug choice and urgency: visceral disease requires prompt systemic treatment given its potential…
- Complications
Progressive marrow failure and death in untreated visceral disease: untreated kala-azar is progressive, with worsening pancytopenia, cachexia, and eventual death.
- Prognosis
Visceral leishmaniasis is fatal if untreated but highly treatable with appropriate therapy: prompt initiation of the antileishmanial regimens above produces a favorable outcome in most patients.
- Prevention
Sand fly bite avoidance is the primary preventive measure: insect repellent, protective clothing, and fine-mesh bed netting (sand flies are smaller than mosquitoes and can pass through standard…
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