Leishmaniasis

Leishmaniasis is a group of parasitic diseases spread by the bite of infected female sandflies. Three main forms occur worldwide:

• Visceral leishmaniasis (kala-azar) — affects internal organs, most serious form. Historically endemic in eastern India (Bihar, Jharkhand, West Bengal, UP). India has run a major elimination programme, dramatically reducing case numbers.
• Cutaneous leishmaniasis — skin ulcers; less severe, more widespread
• Post-kala-azar dermal leishmaniasis (PKDL) — a skin rash that can develop after treatment of kala-azar; important in maintaining transmission

Visceral leishmaniasis (kala-azar) — India context

Most relevant form in India. Untreated, kala-azar is fatal in over 95% of cases; with treatment, most people recover. India's elimination programme has brought case numbers down sharply and the goal is to eliminate it as a public-health problem.

Symptoms

Kala-azar develops gradually over weeks to months:

• Long-standing, irregular fever
• Weight loss, weakness
• Enlarged spleen and liver (can become prominent)
• Pallor, anaemia
• Darkening of the skin ("kala-azar" means "black fever" in Hindi)
• Bleeding tendencies

Cutaneous leishmaniasis causes painless skin nodules or ulcers, usually on exposed areas bitten by sandflies. Heals slowly, often with scarring.

Diagnosis

• rK39 rapid test — widely used, point-of-care
• Bone marrow or splenic aspirate for confirmation in complicated cases
• Skin biopsy or scraping for cutaneous form

Treatment

Antileishmanial medicines are effective. Different regimens are used depending on location, form, and host factors. Free treatment and follow-up are available in India for kala-azar.

Prevention

• Sleep under insecticide-treated bed nets
• Indoor residual spraying of insecticides — a key component of India's elimination programme
• Use repellents on exposed skin
• Long sleeves and trousers at dawn/dusk
• Control stray dogs and reservoir animals (more relevant for other regions)
• Prompt diagnosis and treatment of cases; active case finding in endemic areas
• People treated for kala-azar should be followed up for PKDL — and PKDL should be treated promptly because it maintains transmission

If you live in or have visited an endemic area and have unexplained prolonged fever with weight loss and an enlarged spleen, tell your doctor — early diagnosis is curative.