Details of Leishmaniasis
Causative Agent:
- Caused by more than 20 species of obligate intracellular protozoa from the genus Leishmania.
- Transmitted by sandflies (Lutzomyia in the Americas and Phlebotomus elsewhere).
Transmission:
- Sandflies transmit the parasite when they bite an infected host. The parasites multiply in the fly’s midgut and migrate to the anterior midgut, ready to infect a new host.
Clinical Forms and Symptoms:
- Cutaneous Leishmaniasis:
- Skin lesions (ulcers or nodules) that may leave scarring.
- Mucocutaneous Leishmaniasis:
- Destructive lesions of the nose, mouth, and throat.
- Visceral Leishmaniasis (Kala-Azar):
- Fever, weight loss, enlarged spleen and liver, and anemia. Can be fatal if untreated.
Diagnosis:
- Microscopic examination of tissue samples (e.g., skin smears, biopsies) for amastigotes.
- Serological tests, PCR, or skin tests for confirmation.
- Blood smears or cultures in acute phases.
Treatment:
- Cutaneous: Topical antiseptics, cryotherapy, or systemic drugs like miltefosine or amphotericin B.
- Visceral: Antimony compounds (e.g., sodium stibogluconate), amphotericin B, miltefosine, or paromomycin.
- HIV-coinfected cases require special considerations (refer to WHO guidelines).
Epidemiology:
- Present in over 90 countries, primarily in tropical and temperate regions, affecting 1 billion people.
- Risk factors include poverty, poor housing, and weak healthcare systems.
Prevention:
- Vector control (insecticide-treated nets, residual spraying).
- Protective clothing to prevent sandfly bites in endemic areas.
Prognosis:
- Cutaneous forms often heal spontaneously but may leave scars.
- Visceral leishmaniasis is fatal if untreated; early diagnosis and treatment are critical.
Additional Notes:
- Co-infection with HIV is a growing concern, complicating diagnosis and treatment.
- Misdiagnosis is common due to nonspecific symptoms; consider leishmaniasis in patients with fever, adenopathy, or organ enlargement from endemic areas.
Key Warning:
- Severe cases (e.g., visceral leishmaniasis) require urgent medical attention to prevent death.