What Is Leishmaniasis?
Leishmaniasis is a parasitic disease caused by the Leishmania parasite. This parasite
typically lives in infected sand flies. You can contract leishmaniasis from a
bite from an infected sand fly.
There are three forms of the disease. Different species of the
parasite cause each form. Cutaneous leishmaniasis affects your skin and is
usually not serious. Visceral leishmaniasis damages your internal organs and
can be life-threatening. Visceral leishmaniasis is also known as kala azar. Mucocutaneous
leishmaniasis can lead to partial or complete destruction of the mucous
membranes found in your nose, throat, and mouth.
The sand flies that carry the parasite typically reside in
tropical and subtropical environments. Fatal epidemics have occurred in areas
of Africa, such as Sudan, Kenya, and Ethiopia.
Unfortunately, affected regions are often remote and unstable,
with limited resources for treating this disease. Doctors
Without Borders calls leishmaniasis one of the most dangerous neglected
What Are the Types of Leishmaniasis?
Three forms of leishmaniasis are cutaneous, visceral, and
mucocutaneous, which is rare. Different species of the Leishmania parasite
are associated with each form. Experts believe that there are about 20 Leishmania species
that can transmit the disease to humans.
Visceral leishmaniasis is sometimes known as systemic
leishmaniasis. It usually occurs two to eight months after being bitten by a
sand fly. It damages internal organs, such as your spleen and liver. It also
affects your immune system through damage to those organs. The condition is
almost always fatal if it’s not treated.
Cutaneous leishmaniasis only causes ulcers on your skin. It’s the
most common form of leishmaniasis. Treatment may not always be necessary, but it
can speed healing and prevent complications.
A rare form of the disease is called mucocutaneous leishmaniasis.
It can occur several months after skin ulcers heal. This type of leishmaniasis
affects the mucous membranes of the nose and palate. It’s usually considered a
subset of cutaneous leishmaniasis. However, it’s more serious. It doesn’t heal
on its own and always requires treatment.
What Causes Leishmaniasis?
Leishmaniasis is due to protozoan parasites from the Leishmania
species. You get
leishmaniasis from being bitten by an infected sand fly.
The parasite lives and multiplies inside the female sand fly. The
insect is most active in humid environments during the warmer months and at
night, from dusk to dawn. Domestic animals, such as dogs, can serve as
reservoirs for the parasite. Transmission can occur from dog to sand fly to
Humans can also transmit the parasite between each other through a
blood transfusion or shared needles.
Who Is at Risk for Leishmaniasis?
The disease is found everywhere in the world except Australia and
Antarctica. However, about 95 percent
of cutaneous cases occur in the Americas, the Mediterranean basin, central
Asia, and the Middle East.
90 percent of visceral cases occur in:
- South Sudan
If you live in or travel to the tropical or subtropical areas of
these countries and regions, you’re at a much higher risk of contracting the
disease. Environmental and climate factors heavily influence the spread of the
According to the World Health Organization
(WHO), poverty is a determining factor for the disease. Leishmaniasis often
occurs in areas where the following conditions are common:
- large migrations caused by urbanization,
emergency situations, or environmental changes
People who have weakened immune systems are also at increased
risk of this condition. Leishmaniasis can also speed the advancement of HIV
into AIDS. You’re at increased risk of developing a more serious case of
leishmaniasis if you’re infected with HIV.
What Are the Symptoms of Leishmaniasis?
People can carry some species of Leishmania for
long periods without becoming ill. Symptoms depend on the form of the disease.
The main symptom of this condition is painless skin ulcers.
Cutaneous symptoms may appear only one to two weeks after being bitten by the
sand fly. However, sometimes symptoms will not appear for months or years.
In people with the mucocutaneous form of the disease, symptoms
usually appear one to five years after skin lesions heal. These are primarily
ulcers in the mouth and nose or on the lips. Other symptoms may include:
- stuffy or runny nose
- nose bleeds
- difficulty breathing
Symptoms often don’t appear for months after the bite. Most cases
are apparent two to six months after infection. Symptoms include:
- weight loss
- fever that lasts for weeks or months
- enlarged spleen
- enlarged liver
- decreased production of red blood cells (RBCs)
- other infections
- night sweats
- thinning hair
- scaly skin
- dark, ashen skin
How Is Leishmaniasis Diagnosed?
It’s important to tell your doctor if you lived in or visited a
place where leishmaniasis is common. That way your doctor will know to test you
for the parasite. If you have leishmaniasis, your doctor will use other tests to
determine which species of Leishmania is the cause.
Diagnosing Cutaneous Leishmaniasis
Your doctor may take a small amount of skin for a biopsy by
scraping one of the ulcers. They’ll examine the samples under a microscope or
in a culture to identify the parasite. A culture is a way to see if there are
parasites in a sample. It gives a small amount of parasites the opportunity to
grow to detectable levels.
Diagnosing Visceral Leishmaniasis
Many times, people don’t remember a bite from a sand fly or a skin
sore. This condition may be hard to diagnose.
A doctor may first perform a physical exam to look for an
enlarged spleen or liver. They may then perform a bone marrow biopsy or take a
blood sample for examination. They’ll check these samples for the parasite.
Diagnosis may take two to four weeks if a culture is necessary.
What Are the Treatments for Leishmaniasis?
Antiparasitic drugs, such as amphotericin B, treat this
Cutaneous ulcers will often heal without treatment. However,
treatment can speed healing and reduce scarring. It can also prevent the
development of further disease. Ulcers on the face that cause disfigurement may
require plastic surgery.
Visceral disease always requires treatment. Several medications
are available. The main types of medicine used are compounds that contain
antimony. These include meglumine antimoniate and sodium stibogluconate.
These lesions don’t heal naturally. They always require treatment.
Liposomal amphotericin B and paromomycin can treat mucocutaneous
leishmaniasis. WHO launched an advocacy campaign to help reduce the price of
these drugs. The program reduced the price of liposomal amphotericin B by 90 percent and
meglumine antimoniate by 60
percent. The hope is that lowering the cost will make it easier for people
to get these treatments.
What Are the Potential Complications of
Cutaneous complications may include:
- other infections due to a weakened immune system,
which can be life-threatening
Visceral leishmaniasis is often fatal. However, death often
occurs due to complications of the disease and not the disease itself. If you
have HIV or AIDS, you’re at high risk of getting this disease. The
complications are also often resistant to treatment.
How Can I Prevent Leishmaniasis?
There’s no vaccine or prophylactic medication available. The only
way to prevent leishmaniasis is to avoid getting bitten by a sand fly.
Follow these steps to help prevent being bitten by a sand fly:
- Wear clothing that covers as much skin as
possible. Long pants, long-sleeved shirts tucked into pants, and high socks are
- Use insect repellent on any exposed skin and on
the ends of your pants and sleeves. The most effective insect repellants
- Spray indoor sleeping areas with insecticide.
- Sleep on the higher floors of a building. The
insects are poor fliers.
- Avoid the outdoors between dusk and dawn. This
is when sand flies are most active.
- When indoors, use screens and air conditioning.
- Use a bed net tucked into your mattress. Sand flies
are much smaller than mosquitos. Spray the net with insecticide containing
pyrethroid if possible.
Buy bed nets, insecticides, and repellents before traveling to
What Is the Long-Term Outlook?
Sores can result in permanent scars and disfigurement. Treatment
may reduce their severity.
Medication can cure the disease. However, treatment is most
effective when started before damage to your immune system occurs.
Visceral leishmaniasis is often fatal within two years if it’s
not treated properly.