- Clinical science
Leishmaniasis is a parasitic disease caused by protozoans of the Leishmania genus, which are transmitted by infected phlebotomine sand flies. Depending on the parasite subtype and the strength of the host's immune system, the disease manifests in a cutaneous or visceral form. Cutaneous leishmaniasis is characterized by skin ulcers. The most important clinical manifestation of visceral leishmaniasis is kala-azar (Hindi for “black fever”), which presents with fever, weight loss, hepatosplenomegaly, and immunosuppression. Leishmaniasis is diagnosed by microscopic visualization of macrophages containing amastigotes in blood smears or tissue. Local treatment (cryotherapy, topical paromycin) suffices for most cases of cutaneous leishmaniasis. Visceral leishmaniasis requires systemic treatment with amphotericin B.
- Distribution: endemic in the Mediterranean region, Africa, India, southwest and central Asia, South and Central America
- Visceral: 200,000–400,000 infections/year
- Cutaneous: 700,000–1,200,000 infections/year
Epidemiological data refers to the US, unless otherwise specified.
- Pathogen: Leishmania donovani (protozoan)
- Vector: phlebotomine sandflies
- Reservoir: mammals (especially dogs, humans, and rodents)
- Localized cutaneous leishmaniasis
- Mucosal leishmaniasis
- Detection of pathogen in skin biopsy
- The objective of treatment is to manage clinical symptoms
Uncomplicated disease (no immunosuppression, small lesions, no mucosal involvement)
- No systemic treatment
- Local treatment (cryotherapy, thermotherapy, or topical paromycin) for skin lesions that do not heal spontaneously.
Complicated disease (mucosal involvement, numerous lesions, immunosuppression)
- See treatment of visceral leishmaniasis
- Treatment reduces the recurrence rate of cutaneous leishmaniasis, accelerates healing of lesions, and reduces the risk of dissemination and incidence of mucosal leishmaniasis.
- Incubation period: 2–6 months
- Many patients are asymptomatic.
- Kala-azar (hindi for “black fever,” in reference to the darkening of the skin it can cause)
- Laboratory tests
- Detection of pathogen
- Amphotericin B is the preferred monotherapy in Europe, North America, and South America.
- Other drugs that may be used include:
- Sodium stibogluconate
Kala-azar is highly fatal without treatment!