Worldwide human distribution of Leishmaniasis
A Brazilian boy with a cutaneous lesion
Hepatosplenomegaly in a 4-year old Brazilian boy with visceral leishmaniasis
Human Disease
| Leishmaniasis is a complex and widespread human disease that has been recognized throughout history. The disease is of high prevalence with 12 million cases worldwide and 1.5 to 2 million new cases occurring each year. Although humans often exist as asymptomatic carriers of leishmania, the clinical syndrome takes on two forms: cutaneous, which can occur in a mucocutaneous form, and visceral. |
Worldwide human distribution of Leishmaniasis |
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A Brazilian boy with a cutaneous lesion |
Cutaneous leishmaniasis is the most common form of leishmaniasis encompassing 50-75% of new cases annually. The disease is typically caused by L. major and L. tropica in the old world and L. mexicana and L. braziliensis in the new world. The cutaneous infection presents as single or multiple, nodular or ulcerative lesions found on the face, arms, and legs. The lesions can result in serious disability and permanent scarring. 90% of these cases are seen in Africa, the Middle East, and South America. Only the more severe cases of the cutaneous disease require treatment. The mucocutaneous subset of cutaneous leishmaniasis often occurs as a metastatic disease months to years after cutaneous sores have healed. This results in facial disfigurement affecting the mucous membranes of the nose, mouth, and throat. The mucocutaneous form occurs predominately in South America and requires treatment. |
| Visceral leishmaniasis, also known as "Black Fever" or Kala-Azar, is the most severe form of leishmaniasis and is fatal if untreated. The most common causative species are L. donovani, primarily found in India, Bangladesh, and Sudan; and L. chagasi/L. infantum, primarily found in Brazil and Mediterranean countries. Visceral leishmaniasis has been shown to be predominant in children and to occur as an opportunistic infection in immunosuppressed people including those infected with the HIV virus. Clinical signs are nonspecific including anorexia, pyrexia, wasting, hepatosplenomegaly, epistaxis, diarrhea, and cough. Laboratory findings include anemia, hyperglobulinemia, hypoalbuminemia, leukopenia, and thrombocytopenia. |
Hepatosplenomegaly in a 4-year old Brazilian boy with visceral leishmaniasis |
| An accurate diagnosis of leishmaniasis is essential for the determination of treatment. This is typically confirmed with both a parasitological and immunological diagnosis. Pentavalent Antimonials have historically been the first line of treatment. Amphotericin B and pentamidine are also recognized as effective therapies. Due to the complex nature of leishmaniasis each case should be evaluated and managed on an individual basis. | |