Leishmaniasis is a parasitic infection caused by protozoan parasites belonging to genus Leishmania. This parasite is transmitted by a vector of selected specie of sand flies (specifically the female phlebotomine sand fly). Usually, transmission occurs among animals but in rare cases, certain sand fly can transmit the parasitic infection to humans. Incidences are recorded along tropical and temperate regions of the world where most of these fly specie exist.
Types / Classification
- Post-kala-azar dermal leishmaniasis (follows an attack of Visceral leishmaniasis)
- Viscerotropic leishmaniasis
- Cutaneous leishmaniasis (the most common form of leishmaniasis, involves the skin)
- Mucocutaneous leishmaniasis (involves the mucotaneous membranes)
- Visceral leishmaniasis (involves the organs of the body, can be the most fatal)
For Cutaneous leishmaniasis:
- Raised lesion/ presents as papule
- Painful sores (leaves a scar)
- Symptoms may progress to other types of leishmaniasis
For Mucocutaneous leishmaniasis:
- Nodules (at the bite site) that may spread to mucocutaneous regions (e.g. nose, mouth)
- Tissue damage to mucocutaneous regions
- Voice changes
For Visceral leishmaniasis:
- May be asymptomatic
- Skin darkening
- Skin pigmentation
- Organ dysfunction (may involve the lungs, the kidneys and the bowel)
Infected sand flies attack animals and humans through a bite. When a sand fly bites a human being, it injects the parasites into the system. The parasites are taken over by mononuclear blood cells (often called, promastigote stage). After which, the parasites undergo the amastigote stage, in this phase, they are able to reproduce and starts to invade and infect other cells. Uninfected sand flies get infection when they get to bite and feed on infected animals and humans.
- Blood tests (confirms presence of antibodies against the disease; visualize the presence of parasites undergoing the amastigote stage)
- Microscopic examinations of samples from infected individuals
- Polymerase Chain Reaction tests
- ELISA (detection and confirmation of presence of antibodies)
Until now, no vaccine has yet been developed. A cautious avoidance and exposure reduction to sand flies are recommended. Individuals should use clothing that could protect exposed skin, the use of long pants and long sleeved shirts can be very helpful. Applying insect repellent lotion or sprays and putting up screened rooms (including doors and windows) and bed nets can prevent possible attacks. Sand flies are known to be active at night; therefore, activities during such hours should be minimal (risk of exposure).
Leishmaniasis involves medications that are intended to treat specific types of the parasitic disease. Visceral leishmaniasis is managed by an intravenous medication known as liposomal amphotericin along with miltefosine and paromomycin. On the other hand, Cutaneous leishmaniasis miltefosine, ketoconazole, intravenous pentamidine, or liposomal amphotericin B, in some cases, no treatment may be necessary.