Leishmaniasis is a potentially fatal parasitic disease. It’s caused by leishmania parasites. You can get it if you are bitten by phlebotomine sand flies that carry this parasite.
Experts classify leishmaniasis as a neglected tropical disease (NTD). These are diseases that mostly affect poor populations in developing parts of the world. They are called “neglected” because they receive little attention compared with other diseases despite the vast amounts of harm they do to people around the world.
The disease occurs in about 90 different countries. It’s mostly found in parts of the subtropics and tropics, as well as southern Europe. But it has been documented in other regions of the world, too.
In the Western Hemisphere, the disease is usually found in Central America, Mexico, and South America but not Uruguay or Chile. In the Eastern Hemisphere, it’s found in the Middle East, Africa, and parts of Asia but not in the Pacific Islands or Australia.
Though uncommon, it has been found in parts of the U.S., including Texas and Oklahoma.
“In Texas and Oklahoma, a type of cutaneous leishmaniasis can be locally transmitted by sand flies, the insect vector for this infection,” says Dawn Wetzel, MD, an infectious diseases specialist at Children’s Health and Assistant Professor at UT Southwestern Medical Center in Dallas. “Although it’s not particularly common, the frequency of this disease has been increasing over the years.”
Types of Leishmaniasis
Experts divide the disease into three main types of leishmaniasis:
Cutaneous leishmaniasis. This causes an infection on your skin. This is the most common form of leishmaniasis.
Mucosal or mucocutaneous leishmaniasis. This develops when cutaneous leishmaniasis spreads to the mucous lining inside your mouth, throat, or nose. It often develops as a result of cutaneous leishmaniasis that was not adequately treated or treated at all.
Visceral leishmaniasis. This affects internal organs such as your bone marrow, liver, and spleen. It can be fatal if untreated. It’s less common than the other types of leishmaniasis, particularly in the U.S.
How Does Infection Happen?
Female phlebotomine sand flies can spread leishmania parasites when they drink the blood of an infected animal, such as dogs and rodents. Once you’re bitten by an infected sand fly, you will notice a red ring on your skin. These bites are not always painful, so it’s not always obvious that you’ve been infected.
There are also less common ways to become infected, such as during a blood transfusion or organ transplantation or if you are injected or you inject yourself with a contaminated needle.
The disease also can be transmitted congenitally, meaning it can be passed from an infected mother to a baby during pregnancy or at birth.
Additionally, you can get visceral leishmaniasis through blood transfusion or needle sharing.
How many people develop this condition every year?
It’s estimated that around 600,000 to 1 million people develop cutaneous leishmaniasis every year, and about 50,000 to 90,000 people develop visceral leishmaniasis.
Who’s at most risk?
People of all genders and ages are at risk if they go to areas where leishmaniasis occurs. This infection is typically more common in rural areas, so be sure to take precautions as needed if you spend a lot of time outdoors in areas where leishmaniasis occurs.
People at a higher risk for infection include:
- Ornithologists (people who study birds)
- Travelers
- Peace Corps volunteers
- Missionaries
- People who are outside at sunrise, sunset, or night
- Ecotourists
- Soldiers
- Those who live in poverty (in crowded conditions with poor housing and sanitation)
Reinfection. You can catch cutaneous leishmaniasis even if you’ve had it before. You always need to be careful when you’re going to an area with leishmaniasis.
What Are the Symptoms of Leishmaniasis?
Symptoms depend on whether you have cutaneous, mucocutaneous, or visceral leishmaniasis. In some cases, you won’t have symptoms. This is called a “silent infection.” Wetzel says you may not have symptoms if your immune system can effectively control the infection. She adds that certain species or strains of disease are less likely than others to cause symptoms.
Cutaneous leishmaniasis symptoms.Symptoms of this type of leishmaniasis typically begin within weeks or months of being bitten by an infected sand fly. In some cases, years may pass before signs of the disease appear.
Often, you’ll first notice bumps (papules) or lumps (nodules) on your skin. Over time, these may become open sores, or ulcers, with hard raised sides with a depression in the center, giving them the appearance of a volcano. Raised, hardened areas of skin called plaques also can develop. These skin symptoms usually do not cause pain, unless they become infected or develop near a joint. They may be accompanied by swollen lymph glands. They can be dry and crusty or moist and weepy, leaking a pus-like liquid.
Common places where these occur are exposed areas of your body, such as your:
- Face
- Ears
- Legs
- Arms
It may also take months or years to heal from the sores, which can leave scars.
Mucosal or mucocutaneous leishmaniasis symptoms. This type of leishmaniasis typically develops years, or even decades, after your cutaneous leishmaniasis sores have healed.
It can cause the following symptoms:
- Stuffy nose
- Mouth or nose sores
- Frequent nose bleeds
If you don’t get treated for this condition, your face may become severely disfigured. That can cause emotional harm in addition to the physical harm.
“The disfigurements associated with untreated mucosal leishmaniasis may lead to stigma and social isolation,” says Sarah Mann, MD, an assistant professor of infectious disease at the University of Colorado School of Medicine in Aurora, CO.
Visceral leishmaniasis symptoms. As with cutaneous leishmaniasis, some people with visceral leishmaniasis won’t have symptoms. However, says Wetzel, “lacking symptoms early on doesn’t guarantee that the disease won’t progress later.”
If you do have symptoms, they typically will include:
- Weight loss
- Fever
- Chills and cold sweats
- Fatigue
- Patches of darkened or discolored skin
- Swelling of the belly, liver, and spleen
- Abnormal blood tests
- Low blood counts, such as a low white blood cell count (leukopenia), low red blood cell count (anemia), and low platelet count (thrombocytopenia)
How Is Leishmaniasis Diagnosed?
To find out if you have leishmaniasis, you should ask yourself if you’ve been in a part of the world where leishmaniasis occurs, and check if you have any of the symptoms covered above.
If you suspect you have leishmaniasis, contact your doctor immediately.
“Early diagnosis and treatment are critical, especially for mucosal and visceral leishmaniasis,” says Wetzel. “These forms of the disease can become more severe over time and may cause lasting damage or even be life-threatening if untreated. The earlier the infection can be identified, the more effective the treatment will be.”
She adds that it’s also essential to diagnose cutaneous leishmaniasis right away in order to prevent the spread of skin lesions and reduce your risk of permanent scarring. Catching this form of the disease early also can help prevent it from progressing to mucosal leishmaniasis. This is particularly true if you have a compromised immune system due to HIV/AIDS or other causes.
“Immunocompromised [people] are at a higher risk for rapid progression of disease and higher mortality if diagnosis is delayed,” says Mann.
When talking with your doctor, be sure to mention any recent travel. This may help get leishmaniasis on your doctor’s radar.
“Because leishmaniasis has historically been rare in most of the U.S., many health care providers may not immediately consider it, especially if a patient doesn’t mention recent travel, which can delay diagnosis and treatment,” says Wetzel, who advocates for raising awareness of leishmaniasis among both patients and providers in order to recognize the disease more readily and improve treatment outcomes.
If you are in the U.S., your provider can consult with experts at the CDC, which can help test you for leishmaniasis.
When testing for leishmaniasis, specimens may be taken via biopsy from your skin sores, spleen, lymph nodes, or bone marrow to be examined for leishmania parasites. Blood and DNA tests may also be used.
What Are the Treatment Options for Leishmaniasis?
Treatment depends on the type of leishmaniasis you have. According to Wetzel, treatments for the disease have improved.
“Many people do respond well and recover fully, especially if the disease is diagnosed early,” she says.
However, says Mann, treatment options remain limited, and there is expanding resistance to treatment. Also, while many people do make a full recovery, people with compromised immune systems, such as those with HIV/AIDS or who are on immunotherapy, often have poorer outcomes, she says. Wetzel agrees.
“They are at greater risk of severe disease and may have more difficulty clearing the infection,” she says. “They often need longer or repeated treatment, and careful follow-up.”
Some drugs used to treat leishmaniasis are not available in the U.S. These include sodium stibogluconate and paromomycin.
Cutaneous leishmaniasis treatment. Cutaneous leishmaniasis will sometimes go away on its own, but you should get it treated, as it can turn into mucosal leishmaniasis.
The injectable drug liposomal amphotericin B and the oral drug miltefosine can treat this form of the disease. You can also get topical treatment such as cauterization, cryotherapy, and the local application of heat. Leishmania is sensitive to heat, so applying heat to your sores can be an effective way of treating this infection.
“Some of these choices work better than others, all carry their own risks and toxicities, and none can completely prevent scarring,” says Wetzel.
Mucosal or mucocutaneous leishmaniasis treatment. Two drugs are commonly used: either miltefosine, which you take by mouth, or liposomal amphotericin B, which is given by shot. Because this disease can cause disfigurement, you may require reconstructive surgery of your nose or face. But you’ll wait a year before undergoing any procedure to be sure that the disease does not relapse.
Visceral leishmaniasis treatment.Liposomal amphotericin B is the go-to treatment for visceral leishmaniasis, approved by the FDA. The FDA has also approved miltefosine to treat visceral leishmaniasis for adults and teens who are not breastfeeding or pregnant.
Leishmaniasis Complications
Without proper care, leishmaniasis can have serious consequences.
“Untreated leishmaniasis may be fatal,” says Mann.
In addition to being life-threatening, the disease can lead to other complications, including:
- Bacterial infections that can make skin ulcers worse while also burrowing deep into your body and making you severely ill
- Scarring, which can be severe and permanent
- Septal perforation or collapse, in which a hole develops between your nasal passages, possibly causing your nose to become disfigured and making breathing more difficult
- Pneumonia and infections in your gastrointestinal tract, caused by mucosal and visceral leishmaniasis
- Airway obstruction if mucosal leishmaniasis affects your larynx, which can lead to life-threatening breathing difficulties
Mucosal leishmaniasis can be a complication of untreated or undertreated cutaneous leishmaniasis, says Wetzel.
Visceral leishmaniasis also may lead to the following severe complications:
- Chronic anemia, in which your body does not produce a normal amount of red blood cells
- Post kala-azar dermal leishmaniasis (PKDL), which is a large, bumpy rash that can cause severe scarring on your face or other places on your skin
- Significant bleeding, which can be fatal
- Hemophagocytic lymph histiocytosis, in which your immune system attacks healthy parts of your body
- Sepsis, which is triggered by infection and causes systemic inflammation that can result in tissue damage, organ failure, and death
Leishmaniasis Prevention
Unfortunately, there currently aren’t any drugs or vaccines to prevent this infection. This means that you must take special precautions when traveling to a part of the world where leishmaniasis is found.
“Basic precautions to prevent diseases spread by biting insects, like wearing long sleeves, using insect repellent, and sleeping under bed nets that have been treated with insecticide, can help reduce the risk of acquiring leishmaniasis,” says Wetzel.
To avoid sand fly bites, you also should consider the following precautions:
- Avoid outdoor activity during sunrise or sunset.
- Sleep in an air-conditioned room with window screens.
- Avoid camping near animal habitats, as some carry leishmaniasis.
- Avoid traveling to areas where leishmaniasis can occur.
You should also spray the sleeping and living areas with insecticides to kill any sand flies present.
Takeaways
Leishmaniasis is a disease caused by parasites spread through sand fly bites. It mostly affects people in tropical and subtropical areas, but cases have been popping up in places such as Texas and Oklahoma, too.
There are three types of leishmaniasis: cutaneous (which affects the skin), mucosal or mucocutaneous(which spreads to the nose and mouth), and visceral (which impacts internal organs and can be deadly if not treated).
There are treatments available for leishmaniasis, especially if it’s caught early. But there’s no vaccine yet. Treatment can be tough, especially if you have a weakened immune system.
You can protect yourself from sand fly bites when traveling by using insect repellent, wearing long sleeves, and sleeping under treated bed nets.
Leishmaniasis FAQs
Is leishmaniasis contagious?
No. It’s spread by the bite of an infected sand fly. In rare cases, it can be spread via contaminated blood transfusions or needles.
What are the first signs of leishmaniasis in dogs?
The symptoms in dogs can vary widely, but those that commonly occur and will be apparent to pet owners may include skin lesions, weight loss, loss of interest in exercise, less energy, and loss of appetite.
Can cats get leishmaniasis?
Yes, but it is rare for cats to get this disease.
Do all sand flies carry leishmaniasis?
No. Out of the approximately 900 species of sand fly that experts have identified, only 98 are known to transmit leishmaniasis.
