Leishmaniases


The leishmaniases are a group of parasitic diseases caused by protozoa of the genus Leishmania, transmitted by the bite of a sandfly. Over 20 species cause disease in man.
– Cutaneous leishmaniasis is endemic in more than 70 countries in South and Central America, Middle East, Central Asia, and Africa.
– Mucocutaneous leishmaniasis occurs in Latin America and, more rarely, in Africa (Ethiopia, Sudan).
– Visceral leishmaniasis occurs in more than 60 countries in East and North Africa, South and Central Asia, Southern Europe, and South and Central America.

Clinical features

Cutaneous and mucocutaneous leishmaniasis

– Single or multiple lesions on the uncovered parts of the body: an erythematous papule begins at the sandfly bite, enlarges to a nodule and extends in surface and depth to form a scabbed ulcer. Ulcers are painless, unless there is secondary bacterial or fungal infection.
Usually, lesions heal spontaneously, leaving a scar, and result in lifelong protection from disease.
– Lesions may also spread to the mucosa (mouth, nose, conjunctiva) giving rise to the mucocutaneous form, which may cause severe disfigurement.

Visceral leishmaniasis

Visceral leishmaniasis (kala azar) is a systemic disease, resulting in pancytopenia, immunosuppression, and death if left untreated.

– Prolonged (> 2 weeks) irregular fever, splenomegaly, and weight loss are the main signs.
– Other signs include: anaemia, diarrhoea, epistaxis, lymphadenopathy, moderate hepatomegaly.
– Bacterial diarrhoea, pneumonia, and tuberculosis may develop due to immunosuppression.

Post-kala azar dermal leishmaniasis

Macular, nodular or papular skin rash of unknown aetiology, particularly on the face, and typically occurring after apparent cure of visceral leishmaniasis.

Laboratory

Cutaneous and mucocutaneous leishmaniasis

– Parasitological diagnosis: identification of Giemsa-stained parasites in smears of tissue biopsy from the edge of the ulcer.
– No useful serological tests.

Visceral leishmaniasis

– Parasitological diagnosis: identification of Giemsa-stained parasites in smears of splenic, bone marrow, or lymph node aspiration-biopsy. Splenic aspiration is the most sensitive technique but carries a theoretical risk of potentially fatal haemorrhage.
– Serological diagnosis: rK39 dipstick test and direct agglutination test (DAT) can be used for diagnosis of primary visceral leishmaniasis in clinically suspect cases. Diagnosis of relapse is only by parasitological confirmation.

Treatment

The various species of Leishmania respond differently to drugs. Follow national recommendations.
For information:

Cutaneous and mucocutaneous leishmaniasis

– Cutaneous lesions generally heal spontaneously in 3 to 6 months. Treatment is only indicated if lesions are persistent (> 6 months), disfiguring, ulcerating, or disseminated.

– Forms with a single lesion or few lesions: start with local treatment with a pentavalent antimonial: sodium stibogluconate or meglumine antimoniate, 1 to 2 m 6 infiltrated into the lesion if it is a nodule and into the edges and base around the crust if it is an ulcer.
It should be repeated every 3 to 7 days for 2 to 4 weeks. Once healing begins, the treatment can be stopped and healing will continue.

– IM treatment with a pentavalant antimonial (20 mg/kg daily for 10 to 20 days) is restricted to severe cases and must be administered under close medical supervision.

– Miltefosine PO (as for visceral leishmaniasis) for 28 days is effective in many forms of cutaneous leishmaniasis.

– Ulcers are often secondarily infected with streptococci and staphylococci: administer suitable antibiotics.

– Mucocutaneous forms: as for visceral leishmaniasis.

Visceral leishmaniasis

Visceral leishmaniasis in East Africa

– First-line treatment:
pentavalent antimonial IM or slow IV: 20 mg/kg daily for 17 days
paromomycin IM: 15 mg (11 mg base)/kg daily for 17 days

– Second-line treatment for relapse and for specific vulnerable groups: severe disease, pregnant women, patients over 45 years:
liposomal amphotericin B IV infusion: 3 to 5 mg/kg once daily for 6 to 10 days up to a total dose of 30 mg/kg

– Treatment in HIV co-infected patients:
liposomal amphotericin B IV infusion: 3 to 5 mg/kg once daily for 6 to 10 days up to a total dose of 30 mg/kg
miltefosine PO for 28 days:
Children 2 to 11 years: 2.5 mg/kg once daily
Children ≥ 12 years and < 25 kg: 50 mg once daily
Children ≥ 12 years and adults 25 to 50 kg: 50 mg 2 times daily
Adults > 50 kg: 50 mg 3 times daily

Visceral leishmaniasis in South Asia

– First-line treatment:
liposomal amphotericin B IV infusion: 3 to 5 mg/kg once daily for 3 to 5 days up to a total dose of 15 mg/kg
or
liposomal amphotericin B IV infusion: 10 mg/kg single dose

– Second-line treatment for relapse:
liposomal amphotericin B IV infusion: 3 to 5 mg/kg once daily for 5 to 8 days up to a total dose of 25 mg/kg

For all patients with visceral leishmaniasis, hydration, nutritional support and treatment of intercurrent infections (malaria, dysentery, pneumonia, etc.) are essential.
Tuberculosis and/or HIV infection may also be present and should be suspected if relapse occurs more than once or in the event of treatment failure.

Post-kala azar dermal leishmaniasis (PKDL)

Only patients with severe or disfiguring disease or with lesions remaining for > 6 months, and young children with oral lesions that interfere with feeding, are treated.

PKDL in East Africa

pentavalent antimonial IM or slow IV: 20 mg/kg daily for 17 to 60 days
paromomycin IM: 15 mg (11 mg base)/kg daily for 17 days
or
liposomal amphotericin B IV infusion: 2.5 mg/kg once daily for 20 days
or
miltefosine PO for 28 days (as for visceral leishmaniasis) may be beneficial in HIV co-infected patients

PKDL in South Asia

liposomal amphotericin B IV infusion: 5 mg/kg 2 times weekly up to a total dose of 30 mg/kg

Prevention

– Insecticide-treated mosquito nets.
– Vector control and elimination of animal reservoir hosts.