Kala-azar

Parasites are responsible for spreading Kala-azar, an infectious disease common in parts of the tropics, subtropics, and even southern Europe.

Experts call this condition Leishmaniasis because it is brought on by parasites named Leishmania that are transmitted by infected sandflies.

Last Updated: February 25, 2024

Leishmaniasis is a disease that is native to certain parts of the world, including Asia, the Middle East, Northern Africa, the Mediterranean, as well as South and Central America. It has been documented in 89 countries, with 1.5-2 million new cases reported annually. An estimated 70,000 people die yearly due to the mucocutaneous or visceral disease it induces.

Cutaneous Leishmaniasis

This subtype presents with an infection that shows no outward evidence of illness. Skin sores are a common infection symptom in those who develop clinical symptoms. The size and appearance of the wounds can change over time. Ulcers are open sores on the skin that develop from papules or nodules and eventually create a raised edge and a central crater, much like a volcano. A scab or crust may cover skin ulcers. These lesions rarely cause pain, but they occasionally do. Lymph nodes near the lesions may enlarge in some circumstances (for example, under the arm if the sores are on the arm or hand).

 

Visceral Leishmaniasis

Infected people often experience symptoms like fever, loss of appetite, enlargement of the spleen and liver, and signs of infections in the blood.

The best way to diagnose the disease is a microscopic view of tissue samples where the parasite is seen.

Doctors also diagnose by taking a tissue sample and then checking if there is parasitic growth, in the lab.  Other tests such as enzyme-linked immunosorbent assays (ELISA), western blotting, and direct agglutination are sometimes done.

 

Checking for specific antibody levels is another way to find out if someone has an infection. For delayed-type hypersensitivity skin reactions, doctors or experts also use intradermal skin tests.

 

Treatment

Cutaneous Leishmaniasis typically resolves spontaneously. However, dermatologic lesions can be damaging, cause secondary infections, or leave severe scars. 

First-line treatments for restricted cutaneous illness include: 

  • Sodium Stibolgluconate
  • Meglumine Antimoniate 
  • Miltefosine
  • Amphotericin B 
  • Pentamidine isethionate 
  • Paromomycine
  • Granulocyte-Macrophage Colony-Stimulating Factor. 

 

In cutaneous Leishmaniasis if lesions are less than five, the usual treatment is with heat or cryotherapy while antimony sodium stibogluconate, amphotericin, paromomycin, and miltefosine are used to treat visceral Leishmaniasis. 

No vaccines exist, so travelers should avoid sand fly bites to avoid infection.

Follow these precautions to avoid being bitten:

  • When sand flies are most active, it's best to stay indoors between twilight and dawn;
  • When outside (or unprotected):
    • Reduce bare skin;
    • Wear long-sleeved shirts, long pants, and socks, and tuck your shirt into your pants.
    • Apply insect repellant to exposed skin, sleeves, and pants. DEET-based repellents work best.
  • When indoors:
    • Stay in well-screened or air-conditioned rooms indoors;
    • Bear in mind that, unlike mosquitoes, sand flies can fit through tiny holes;
    • The insecticide should be sprayed in living/sleeping areas;
    • Use a bed net if you're not in a well-screened or air-conditioned region;
    • Use a pyrethroid-treated bed net if possible;
    • Screens, curtains, sheets, and clothing can be treated similarly (clothing should be retreated after five washings).

References

Maxfield L, Crane JS. Leishmaniasis. [Updated 2022 Oct 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK531456/

Centers for Disease and Control Prevention (2022). Parasites- Leishmaniasis. Retrieved December 16, 2022, from https://www.cdc.gov/parasites/leishmaniasis/

Last Updated: February 25, 2024