Leishmaniasis is a life-threatening illness caused by protozoa parasites (the Leishmania species). There are three main forms of leishmaniasis: cutaneous, visceral or kala-azar (meaning “black fever”), and mucocutaneous.
Visceral leishmaniasis affects the spleen, liver, and bone marrow and has a high mortality rate. The disease most commonly occurs in Latin America, East Africa, the Middle East, China, and India and is also endemic in the Mediterranean region (Italy, Spain, Portugal, Northern Africa, and Southern France). Developing nations in these regions tend to be the hardest hit - according to the Center for Disease Control (CDC), most of the world’s cases of visceral leishmaniasis occur in India, Bangladesh, Nepal, Sudan, South Sudan, Ethiopia, and Brazil.
Here are some of the most commonly asked questions about the diagnosis, treatment, and prevention of visceral leishmaniasis:
1. How can I get leishmaniasis?
People contract visceral leishmaniasis through the bite of an infected female sand fly. These flies are often carried by dogs. In much rarer cases, the disease can be passed through blood transfusions or shared needles. However, in general, the disease cannot be passed from person to person.
2. What are the symptoms of leishmaniasis?
Many people carry the Leishmania parasite without ever showing any symptoms. The term “leishmaniasis” refers to the actual infection caused by the parasite. Visceral leishmaniasis infection presents with fever, weight loss, enlarged spleen, blood disorders (anemia, leukopenia, and thrombocytopenia, or deficiencies in red cells, white cells, and platelets, respectively), and enlarged lymph nodes. The onset of the illness can occur suddenly or gradually over weeks or months. In HIV and AIDS patients, leishmaniasis infection can occur years after initial exposure and can present with gastrointestinal issues.
3. How is leishmaniasis diagnosed?
If you have traveled to or live in a country where leishmaniasis is common and have experienced any of the symptoms listed above, see your doctor immediately. Several methods can be used to officially diagnose visceral leishmaniasis. Bone marrow aspiration detects leishmaniasis DNA in potentially infected bone marrow; however, the procedure is painful, potentially dangerous, and is not always successful in detecting the parasites. Alternatively, serologic testing can be used; this method is much less invasive, uses a simple blood test, and provides rapid results.
4. How is leishmaniasis treated?
People infected with visceral leishmaniasis will often be referred to an infectious disease specialist or tropical medicine specialist. Depending on which form of leishmaniasis is present, your doctor will prescribe a specific medication regimen. Treatment may also include cardiac monitoring, blood transfusions, and nutrition management. While most cases of cutaneous leishmaniasis will clear up on their own, visceral and mucocutaneous leishmaniasis infections must be treated; without treatment, visceral leishmaniasis can lead to death within two years of infection.
5. How can I prevent leishmaniasis infection?
Vaccines or drugs to prevent leishmaniasis currently do not exist. Prevention typically centers on reducing exposure to sand flies through limiting time spent outdoors in areas where sand flies are prevalent and using insect repellent, protective clothing, and insecticide-treated bed nets.
6. What are the different types of leishmaniasis tests?
Aside from blood marrow aspiration, the main tests used to diagnose leishmaniasis are serologic tests. Among serologic tests, ELISA tests, like the New Life Leishmania Microwell Serum ELISA, are most commonly used. Indirect immunoflourescent antibody tests (IFAT) and direct agglutination tests (DAT) can also be used either in combination with ELISA tests or by themselves.
Visceral leishmaniasis is a very serious disease, and a swift diagnosis and treatment are crucial for a full recovery. If you are traveling to a place where leishmaniasis is commonly found or where sand flies are prevalent, make sure to take the proper precautions to prevent exposure. If you develop any symptoms of leishmaniasis, see a doctor immediately and tell them about your previous travel.
Center for Disease Control (CDC). “Parasites – Leishmaniasis.” Available at http://www.cdc.gov/parasites/leishmaniasis/.
CDC. “Travelers’ Health. Chapter 3: Infectious Diseases Related to Travel.” Available at http://wwwnc.cdc.gov/travel/yellowbook/2016/infectious-diseases-related-to-travel/leishmaniasis-visceral.
World Health Organization (WHO). “Leishmaniasis” Available at http://www.who.int/leishmaniasis/en/.