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Leishmaniasis

Last updated Oct. 27, 2018

Approved by: Maulik P. Purohit MD, MPH

Leishmaniasis is a widespread, global disease that is caused by protozoa (of the Leishmania genus), which is transmitted through the bite of an infected female sandfly (a type of insect) in the tropical and subtropical regions.


What are the other Names for this Condition? (Also known as/Synonyms)

  • Leichmaniosis
  • Leish
  • Sandfly Disease

What is Leishmaniasis? (Definition/Background Information)

  • Leishmaniasis is a widespread, global disease that is caused by protozoa (of the Leishmania genus), which is transmitted through the bite of an infected female sandfly (a type of insect) in the tropical and subtropical regions
  • There are 3 main types of Leishmaniasis that include:
    • Cutaneous Leishmaniasis, which affects the skin
    • Mucocutaneous Leishmaniasis, which affects the skin and mucous membrane
    • Visceral Leishmaniasis, which affects the entire body (systemic)
  • People, who generally belong to economically weaker sections (poor and illiterate) in the endemic regions, have a high risk of infection. Those who stay or travel to the rural areas are more exposed than individuals in the urban areas
  • Leishmaniasis is characterized by skin sores that ulcerated, fever, weight loss, mucosal ulcers, anemia, and swelling of the liver and spleen. Depending upon the type of infection, the complications may include irreversible skin damage, secondary infections, and severe damage to the immune system. Some forms of Leishmaniasis are more severe than others
  • The treatment of Leishmaniasis involves oral/intravenous medications and topical applications. It is based on the type and severity of the infection. Since, human infection can be caused by many different species of Leishmania; the treatment also depends upon the geographical location.
  • The prognosis depends upon the type of Leishmaniasis infection (whether cutaneous, mucocutaneous, or visceral) and promptness in providing effective treatment. The prognosis is can vary from good to guarded, but severe complications can result in permanent skin scarring or even fatal infections

Who gets Leishmaniasis? (Age and Sex Distribution)

Individuals of all ages are at risk for Leishmaniasis infection, if they are exposed to sandfly bites. There is no gender, race, or ethnicity preference noted. However, Leishmaniasis is endemic to certain regions of the world as indicated below:

  • Visceral Leishmaniasis is common in countries that include:
    • Bangladesh
    • Brazil
    • Ethiopia
    • India
    • Nepal
    • Sudan
  • Mucocutaneous Leishmaniasis is common in countries that include:
    • Latin American countries consisting of Brazil, Bolivia, and Peru account for nearly 90% of the cases
    • African countries including Ethiopia, Sudan, Kenya, and Namibia
  • Cutaneous Leishmaniasis is common in countries that include:
    • Afghanistan
    • Algeria
    • Bolivia
    • Brazil
    • Colombia
    • Iran
    • Peru
    • Saudi Arabia
    • Syria

What are the Risk Factors for Leishmaniasis? (Predisposing Factors)

The risk factors for Leishmaniasis may include:

  • People living at the following geographical locations (the infection is seen in nearly 100 countries):
    • Africa
    • Asia
    • Middle-East Asia
    • North America
    • South America
    • Southern Europe
  • Traveling or visiting places where Leishmaniasis is common
  • The following set of people may have a higher risk while visiting or staying in the endemic areas: Adventure travelers, eco-tourists, ornithologists, soldiers, peace corps volunteers, missionaries
  • Individuals, who perform various research in the region, during the night or at twilight
  • Climatic conditions and environmental changes can increase the risk of Leishmaniasis. These include deforestation, development and expansion of cities, and construction of dams
  • According to the World Health Organization (WHO), certain socio-economic indicators point to a higher risk of infection. These include:
    • Poverty
    • Malnutrition
    • Famine
    • Illiteracy
    • Lack of sanitation and proper hygiene
    • Large-scale migration and settlements
  • Leishmaniasis is more common in the villages and small towns (especially in the outskirts) than in the cities
  • Individuals with weak immune system owing to factors, such as HIV infection or other diseases, are more likely to contract Leishmaniasis

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Leishmaniasis? (Etiology)

Leishmaniasis is an infectious disease caused by the bite of sandflies; small flying insects (3-6 mm in size) that are smaller than mosquitoes and less noisy. The sandflies transmit Leishmania organisms, which are protozoan parasites, in blood causing the infection. More than 20 different species of Leishmania parasites have been identified and studied.

  • The vector-borne infection is mainly transmitted by the bite of female sandfly of the genus Phlebotomus. There are 2 other sandfly types that can cause infection in humans
  • An uninfected sandfly gets infected by feeding on the blood of infected people or animals (such as dogs, cattle, foxes, or rodents)
    • When an infected sandfly bites a human, the parasites enter the blood cells; a stage called the promastigote stage
    • The parasites then multiply in numbers and infect other cells and tissues; a stage called the amastigote stage
  • Very rarely, transmission can also take place during the following events:
    • Blood transfusion
    • Sharing of contaminated needles
    • Pregnant women can transmit the parasite to their unborn child
  • The transmission risk is high from dawn to dusk when the sandflies are active

What are the Signs and Symptoms of Leishmaniasis?

The signs and symptoms of Leishmaniasis are dependent upon the type of infection. Only a small subset of infected individuals may develop signs and symptoms of the infection.

  • Cutaneous Leishmaniasis:
    • Appearance of skin sores at bite site, which become nodules
    • The nodules form skin ulcers
    • There may be persistent rashes on the body
  • Mucocutaneous Leishmaniasis
    • Affects the skin and mucus membranes of the oral cavity (mouth and throat) and nose
    • Initial symptoms may resemble Cutaneous Leishmaniasis
    • Formation of multiple ulcers
    • Disfigured face
  • Visceral Leishmaniasis:
    • Weight loss that may be substantially high
    • Fever and malaise
    • Enlarged spleen and liver (hepatosplenomegaly)
    • Low blood cell counts (pancytopenia)

How is Leishmaniasis Diagnosed?

A physical examination, assessment of the signs and symptoms, and medical history evaluation of the infected individual may be indicative of Leishmaniasis. However, the healthcare provider may perform the following tests to definitely diagnose the condition:

  • Blood tests to detect antibodies against the parasite
  • Montenegro skin test: It is generally not a very effective method to aid in the diagnosis
  • Tests specific to Cutaneous Leishmaniasis may include:
    • The infected area (skin) is scraped and sent for a biopsy
    • Polymerase chain reaction (PCR) test are conducted during the biopsy examination
    • ELISA (enzyme linked immunosorbent assay) test to check the level of antibodies in blood
    • Tissue culture tests
  • Tests specific to Mucocutaneous Leishmaniasis may include:
    • DNA testing (hybridization) and PCR
    • Detection of pathogen using staining methods
    • Biopsy of skin lesion
  • Tests specific to Visceral Leishmaniasis may include:
    • A tissue sample is obtained from the spleen, liver, or bone marrow and observed under the microscope
    • A biopsy of the enlarged lymph node may also be performed
  • Examining tissues under a microscope to detect the parasite

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Leishmaniasis?

The severity of Leishmaniasis depends upon the type of infection and the health condition of the affected individual. Untreated or inadequately treated Leishmaniasis, may lead to complications such as:

  • Scarring of skin that may be permanent
  • Secondary infections
  • Severe bleeding
  • Deadly infections due to immune system damage
  • Multiple organ failure
  • Social ostracisation and humiliation due to severe disfigurement, especially of the face

How is Leishmaniasis Treated?

The treatment for Leishmaniasis differs from one individual to another and is also based on the severity of the disease. Proper consultation with the infectious disease consultants and public health officers are generally recommended before treatment starts.

The treatment for Leishmaniasis generally includes the administration of medications and drugs:

  • For Cutaneous Leishmaniasis:
    • The skin ulcers may heal without treatment; the administration of appropriate medications can prevent scar formation
    • If the ulcers heal and cause cosmetic disfigurement, then plastic surgery may be performed
    • Oral applications and medicines
    • Intravenous medications
  • For Mucocutaneous Leishmaniasis:
    • Intravenous medication (including intramuscular injections)
    • Topical ointments
    • The ulcers do not go away on their own without suitable treatment
    • If the ulcers heal and cause cosmetic disfigurement, then plastic surgery may be performed
  • For Visceral Leishmaniasis, the following medications are followed:
    • Intravenous medication (including intramuscular injections)
    • Topical ointments
  • For fungal (secondary) infections that develop due to Leishmaniasis, antifungal medication are prescribed
  • The medications administered vary depending upon the type of Leishmania species causing the infection

How can Leishmaniasis be Prevented?

Currently, no vaccination has been discovered to prevent Leishmaniasis. Research is being undertaken to develop a vaccine at the earliest. Nevertheless, the following preventive and precautionary measures may be taken to reduce the spread and impact of Leishmaniasis:

  • Avoid or limit exposure to sandfly bites
  • Wear protective clothing, such as long sleeves, long pants, and socks, to protect the skin from the insect bites; minimize exposed skin areas
  • Use insect repellents containing DEET, permethrin, or deltamethrine; one’s clothing and bed can be suitably sprayed with the repellents
  • Prevent entry of sandflies into homes by keeping the windows and doors suitably closed, using finely-meshed bed nets (that are tucked into the mattress) while sleeping
  • Sandflies are more active during dusk or at night; knowing their pattern, one can take steps to minimize outdoor activities or take suitable preventive measures against the bites accordingly
  • Dogs can be fitted with collars containing insect repellents
  • Local strategies (specific to each community or locality) and community development to eliminate Leishmaniasis should be encouraged
  • Individuals with weak immune systems should be aggressively treated to address any underlying health condition causing the immunocompromised state

What is the Prognosis of Leishmaniasis? (Outcomes/Resolutions)

  • The prognosis of Leishmaniasis depends upon the type of infection. In general, cutaneous form is better than mucocutaneous form, which is better than visceral form of Leishmaniasis
  • Early diagnosis and appropriate treatment of the infection generally yields a satisfactory outcome, than a lack of treatment or inadequate treatment
  • Individuals with AIDS or HIV infection should be treated for all 3 forms of the disease (skin and systemic)

Additional and Relevant Useful Information for Leishmaniasis:

Animals, such as dogs, rats, and cattle, can also be infected by Leishmaniasis. According to the World Health Organization, over 70 species of animals act as hosts for the Leishmania organism.

What are some Useful Resources for Additional Information?


References and Information Sources used for the Article:


Helpful Peer-Reviewed Medical Articles:


Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: May 9, 2016
Last updated: Oct. 27, 2018