Caused by unicellular flagellate intracellular protozoa with 3 clinical syndromes:
Visceral leishmaniasis (VL, kala-azar)
Cutaneous leishmaniasis (CL)
Mucosal leishmaniasis (ML).
Most caused by zoonotic transmission from animals (chiefly canine /rodent reservoirs) to humans through phlebotomine sandfly.
Humans are the only known reservoir (anthroponotic) in major VL foci in India /Sudan.
The disease occurs in 88 countries, with annual incidence of 2 million new cases (500 000 for VL,1.5 million for CL).
3- Another sandfly bites human and ingests blood infected with Leishmania 2- Sandfly bites human and injects Leishmania into skin 1- Sandfly bites animal and ingests blood infected with Leishmania 4- Cycle continues when sandfly bites another human or animal reservoir
Antimony (Sb) compounds were the first drugs used & remain the mainstay.
The exception is the India, where almost two-thirds of cases are refractory.
Traditionally, pentavalent antimony is available as sodium stibogluconate (100 mg/ml) & meglumine antimoniate (85 mg/ml).
The daily dose is 20 mg/kg body weight, given either intravenously or intramuscularly for 28-30 days.
Side-effects are common and include arthralgias, myalgias, raised hepatic transaminases, pancreatitis, especially in patients co-infected with HIV&ECG changes (T wave inversion and reduced amplitude).
Severe cardiotoxicity, manifested by concave ST segment elevation, prolongation of QTc > 0.5 msec, ventricular ectopics, runs of ventricular tachycardia, torsades de pointes, ventricular fibrillation & sudden death, is not uncommon.
The incidence of cardiotoxicity & death can be very high with improperly manufactured Sb
An alkyl phospholipid, approved for the treatment of VL.
A daily dose of 50 mg (patient's body weight < 25 kg) to 100 mg (≥ 25 kg), or 2.5 mg/kg body weight for children, for 28 days cures over 90%.
Side-effects include mild to moderate vomiting /diarrhoea/ rarely skin allergy or nephrotoxicity.
Since it is a teratogenic drug, it cannot be used in pregnancy; female patients are advised not to become pregnant for the duration of treatment &another 2 months, because of its half-life of nearly 1 week.
(PKDL) After treatment &recovery from the visceral disease in India & Sudan some patients develop dermatological manifestations.
In India dermatological changes occur in a small minority of patients 6 months to ≥ 3 years after the initial infection seen as macules, papules, nodules (most frequently) & plaques which have a predilection for the face, especially the area around the chin.
The face often appears erythematous.
Hypopigmented macules can occur over all parts of the body &are highly variable in extent and location.
There are no systemic symptoms & no spontaneous healing.
Sandflies are extremely sensitive to insecticides & vector control through insecticide spray is very important.
Mosquito nets or curtains treated with insecticides will keep out the tiny sandflies.
In endemic areas with zoonotic transmission, infected or stray dogs should be destroyed.
In areas with anthroponotic transmission, early diagnosis & treatment of human infections, to reduce the reservoir & control epidemics of VL, is extremely important.
Serology is useful for screening of suspected cases in the field.
No vaccine is currently available .
Cutaneous & mucous leishmaniasis: Solitary facial lesions with satellites Hyraxes L. aethiopica Rapid necrosis, wet sores Gerbils, desert rodents L. major Oriental sore(Baghdad boil) Dogs L. tropica Clinical features Host Leishmania species