Leishmaniasis (Kala-azar) - Types, Mode of Transmission, Lab Diagnosis, Treament

Leishmaniasis (Kala-azar or Dumdum fever)

 

Leishmaniasis is a parasitic infection caused by parasitic protozoa of the genus leishmania which are transmitted by the bite of infected female phlebotomine sandflies. People get infected by bite of Phlebotomine sand flies.

The sand flies carry Leishmania parasite,  typically found in tropical and subtropical environments. The sand flies breed in forest area, caves or burrows (hole or tunnel) and multiply their number. Leishmaniasis  is classified as a NTD (neglected tropical disease).

There are mainly three forms of leishmaniasis in people. The most common forms are - cutaneous leishmaniasis, which causes skin sores, and visceral leishmaniasis, which affects internal organs usually spleen, liver, and bone marrow.

 

Types of Leishmaniasis

 

Leishmaniasis occurs in three forms -

 

1. Visceral leishmaniasis - most serious form of the leishmaniasis disease. Also known as kala-azar, systemic leishmaniasis or black fever

2. Cutaneous leishmaniasis - most common form of leishmaniasis

3. Mucocutaneous leishmaniasis

 

1. Visceral leishmaniasis 

Visceral leishmaniasis damage the internal organs usually liver, spleen, and bone marrow, characterized by irregular fever, weight loss, enlargement of the liver and spleen, anaemia. It affects the immune system through damage to these organs.

2. Cutaneous leishmaniasis 

Cutaneous leishmaniasis is most common form of  leishmaniasis, which causes skin sores or  skin lesions, mainly causes on exposed parts of the body. These infection leaving stigma, life-long scars and serious disability.

3. Mucocutaneous leishmaniasis

Mucocutaneous leishmaniasis affect both skin and mucosal ulcers. The parasites spread to nose, throat, and mouth cause damage primarily of the nose and mouth and lead to partial or complete  destruction of mucous membranes of the, mouth nose and throat.

Epidemiological Triad

Agent- The Causative agent of leishmaniasis is obligate intracellular protozoa of the genus Leishmania which are spread by the bite of infected Phlebotomine sand flies.

 

Host- People at risk are all ages group , mainly who live or travel leishmaniasis area such a missionaries, soliders, adventure travellers.

 

Environment- Increase risk of leishmaniasis is highest from dusk to dawn because sand files are active, water storage, irrigation, deforestation.

 

 

 

Causes of Leishmaniasis

 

Leishmaniasis occurs due to protozoan parasites from the Leishmania species. Human  get leishmaniasis from being bitten by an infected Phlebotomine sand fly.

This sand fly is most active in humid environments during the warmer months and at night, from dusk to dawn.

Human to human transmission of leishmania parasite may occur through a blood transfusion or shared needles.

Transmission may occur from animal to sand fly to human and also occur from human to sand fly to human.

 

Mode of Transmission

 

Leishmaniasis infection is transmitted by  bite of infected female Phlebotomine sand flies. 

Incubation Period

 

People with cutaneous leishmaniasis develop skin sores within few weeks (2–8 weeks) after  bitten by infected sand fly.

People with visceral leishmaniasis, the incubation period is several months (2-6months) after bitten by infected sand fly.

 

Clinical Manifestation

1. Visceral leishmaniasis

Clinical manifestations of visceral leishmaniasis (kala-azar) are-

 

 

1. High fever

2. Weight loss

3. Hepatosplenomegaly -  enlarged liver and spleen

4. Anaemia

5. Progressive emaciation (abnormally thin or weak)

6. Malaise

7. Hyperpigmentation of forehead, abdomen, hands and

8. Arthralgias; pain in joint, Myalgias; muscle aches and pain

9. Decreased red blood cells, white blood cells, platelets - Pancytopenia

10. Bleeding

11. Swollen lymph nodes

 

2. Cutaneous leishmaniasis

The main symptom of Cutaneous leishmaniasis is painless skin ulcers without pruritus .

 

3. Mucocutaneous leishmaniasis

The symptom mucocutaneous leishmaniasis, primarily ulcers in  mouth and nose or on lips and also runny or stuffy nose , nosebleeds, difficulty breathing can occur.

 

 

Laboratory Diagnosis

 

1. Blood tests - To detect antibody

2. Diagnosing cutaneous leishmaniasis  -  taking a small amount of skin for a biopsy by scraping one of the ulcers. To detect DNA, or genetic material, of the parasite.

3. Diagnosing visceral leishmaniasis - perform a physical exam to look for an enlarged spleen or liver, then perform a bone marrow biopsy or take a blood sample for examination.

 

 

Complications of Leishmaniasis

 

1. Disfigurement of face

2. Haemorrhage

3. Prone to infection due to damage of the immune system

People with visceral leishmaniasis is often fatal due to affect e on internal organs and immune system.

 

Treatment of Leishmaniasis

 

1. First-choice drug for the treatment of all types of leishmaniasis - Meglumine antimoniate

2. Sodium stibogluconate drug for the treatment of cutaneous leishmaniasis and mucosal leishmaniasis.

 

3. Other drug used for treatment - Liposomal amphotericin B, pentamidine  and paromomycin

4. Incase of destructive facial lesions, disfigurement of face, plastic surgery required to correct the disfigurement.

5. Removal of spleen (splenectomy) in drug- resistant cases of leishmaniasis

 

Prevention and Control

 

1. Early diagnosis and treatment

2. Use insect repellents

3. Appropriate clothing, screening of windows, use mosquito net

4. Use of insecticides – spraying of DDT

5. Environment control – make it unsuitable for breeding

6. Avoid the outdoors between dusk and dawn

 

 

Leishmaniasis FAQs

 

1.  What is Leishmaniasis?

Leishmaniasis is a parasitic disease caused by leishmania parasite, it transmitted by the bite of infected phlebotomine sand flies.

 

2. How leishmaniasis spread from human to human?

Humans to human transmission of infection can also occur through a blood transfusion or shared needles.

 

3. What are types of Leishmaniasis?

People with leishmaniasis occurs in three form; Visceral leishmaniasis  or kala-azar or black fever, most serious form of the disease. Cutaneous leishmaniasis most common form of leishmaniasis and Mucocutaneous leishmaniasis.

The hydatid cysts or hydatidosis is also parasitic infection, Get the information about mode of transmission of hydatid disease.