Leishmaniasis, Cutaneous and visceral leishmaniasis (Oriental Sore and Kala-azar)

Leishmaniasis

Sample for Leishmaniasis

1. Prepare a smear from the lesion of the patient.
2. Spleen, tissue or aspirate, and  (FNA) of lymph nodes.
   1. Splenic puncture.
   2. Nasal smears.
3. Bone marrow aspirate.
4. Culture from the above samples.
5. Buffy coat of peripheral blood.

Indications for Leishmaniasis

1. This helps in the diagnosis of Cutaneous Leishmaniasis or oriental sore.
2. For diagnosis of visceral leishmaniasis.

Pathophysiology of Leishmaniasis

1. Leishmaniasis is caused by a protozoan of the genus Leishmania, which causes many syndromes.
2. The sandfly transmits cutaneous Leishmania (CL).
3. Genus of protozoa comprising parasites of worldwide distribution.
   1. It is best known in the Middle East, and also occurs in the Far East. It is not seen in Japan.
   2. It is seen in various areas of Africa, Central, and South America, the Island of the Caribbean, and occasionally the European side of the Mediterranian area.
4. Several species of which are pathogenic to humans. All species are morphologically indistinguishable.
5. These are divided into the Clinical syndrome they produce:
   1. Visceral (Kala-Azar).
   2. Cutaneous (Localized or widespread).
   3. Mucocutaneous.
6. Leishmania is classified into :
   1. L. donovani.
   2. L. tropica.
   3. L. Mexicana.

Summary of the Leishmania life cycle:

1. Leishmania is zoonotic and carried by rodents, dogs, and foxes transmitted to humans by the bite of sandflies (Phlebotomus).
2. From the sandfly bite, promastigote invades phagocytic cells (macrophages) and transforms into nonmotile amastigotes.
3. Amastigotes multiply in the macrophagic cells of lympho nodes, spleen, liver, and bone marrow.

Leishmaniasis: Leishman life cycle

Cutaneous leishmaniasis

1. Leishmania tropica:
   1. L. Tropica complex consists of:
      1. L. tropica.
      2. L. major.
      3. L. aethiopica.
   2. This complex causes Oriental sore, also called Baghdadi boil, old world cutaneous leishmaniasis, or Delhi ulcer.
   3. This is transmitted by sandflies belonging to the genus Phlebotomus.
   4. Epidemiology: 
      1. These lesions are seen in the Mediterranean littoral, Armenia, Azerbaijan, Uzbekistan, Turkmenistan, Afghanistan, India, Pakistan, and Iran.
      2. The dog may be the natural host but does not look like an effective reservoir for a human.
   5. Incubation time is 2 months to 3 years.
   6. In general, cutaneous leishmaniasis causes skin lesions, persisting for months, sometimes years.
   7. The skin lesions usually develop within several weeks or months after exposure.
      1. These lesions are usually on the face.
      2. The lesions typically evolve from dry papules to nodular plaques to ulcerative lesions.
      3. These ulcers are usually 2 cm in Diameter or more with typical itching.
      4. These lesion has raised border and central depression, which can be covered by scab or crust.
   8. Rarely do some lesions persist as nodules.
   9. These lesions are painless but sometimes may give rise to pain when infected.
   10. The healing process typically results in atrophic scarring.
2. Leishmania Major:
   1. It produces an acute infection with a duration of 3 to 6 months.
   2. The lesion primarily occurs on the lower limbs.
   3. These lesions are moist and tend to ulcerate very early.
   4. There may be secondary lesions on other sites.
   5. This disease is seen in Turkmenistan, Uzbekistan, Iran, Kazakhstan, Syria, Israel, Jordan, Africa, Algeria, Sahara, Tunisia, Sudden, Nigeria, Niger, Mali, Senegal, and Kenya.
3. Leishmania Mexicana:
   1. This causes new world cutaneous leishmaniasis
   2. It causes a Chiclero ulcer or Bay sore.
   3. It is found in Belize, the Yucatan peninsula, and Guatemala.
   4. It is endemic in these areas.
   5. The amastigotes are found in the skin lesion of humans, woodrats, and cats.
   6. Lesions are usually single, and 40% involve ears.
   7. This may give rise to the diffuse cutaneous lesion.
4. Signs and symptoms:
   1. The first sign of the infection is a red papule.
   2. There is itching, which may grow to 2 cms or more in diameter.
   3. In L. major infection, the papule is covered with serous exudate and ulcerates early.
   4. In L. tropical, papules are dry and ulcerate only after several months.
   5. This cutaneous form may be seen as:
      1. Diffuse cutaneous leishmaniasis may be due to lake cell-mediated immunity.
      2. Leishmaniasis recideva is due to good antibody and cellular response. In this case, the central lesion heals, and the peripheral area is active.

Mucocutaneous Leishmaniasis:

1. It is the least common syndrome, and it occurs in Central and South America.
   1. It follows after the cutaneous leishmania.
2. L. braziliensis causes mucocutaneous leishmaniasis, also called espundia and uta.
   1. There is the formation of the ulcer on the oral-nasal mucosa.
   2. This is common in Brazil.
   3. The cutaneous lesions are multiple and large in size.
   4. Secondary infection plays a role in the persistence of the large size lesion.
   5. Signs and symptoms:
   6. Sometimes it spreads to the mucous membranes.
      1. The entire nasal mucosa and the hard and soft mucosa are involved.
      2. The nasal septum will be destroyed.
      3. But unlike syphilis, the bone is not involved.
      4. The ulceration leads to the loss of all soft parts of the nose, lips, and palate.
      5. Death may occur in these patients due to secondary infection.
   7. A similar disease is also seen in Sudan and Ethiopia.
   8. Diagnosis of mucocutaneous leishmania:
      1. Organisms are identified by histologic examination in scrapings or biopsy from the lesion.
      2. Culture can be done and are positive in  50% of the cases.
      3. Positive immunofluorescent antibody test.
      4. PCR gene amplification for Leishmania DNA or culture.

Visceral leishmaniasis (Kala-Azar)

Leishmania donovani:

1. It is caused by three types of Leishmania Donovani complex:
   1. L. Donovani donovani.
   2.  L. Donovoni chagasi.
   3. L. Donovani infantum.
2. It causes visceral leishmaniasis, called Kala-azar or black disease, Dumdum fever.
3. This occurs in India, Burma, Bangladesh, Thailand, and Sumatra.
   1. Also seen in the Central African Republic, Sudan, Kenya, Gambia, Gabon, Northern Uganda, and Niger.
   2. This was seen in China, but now it is controlled.
4. Vector is Phlebotomus sandflies.
5. In some cases, L.tropica has been found, in a few cases in India and veterans from the Gulf war.
6. The causative agent is a parasite of the reticuloendothelial system.
   1. This is not confined to the reticuloendothelial cells of the subcutaneous tissue and mucous membranes but may be found throughout the body.
7. signs and symptoms:
   1. The Visceral leishmaniasis (also known as Kala-Azar).
   2. No skin lesions are seen, rarely except a papule at the site of the bite.
   3. Fever.
   4. Weight loss (cachexia, wasting).
   5. Hepatosplenomegaly (usually, the spleen is more prominent than the liver).
      1. It returns to normal after the treatment.
   6. Bone marrow, when involved, give rise to:
      1. Pancytopenia, i.e., anemia (normocytic and normochromic), leukopenia, and sometimes thrombocytopenia.
      2. TLC is usually below 4000/cmm and is between 2000 to 3000/cmm.
      3. There is a monocytosis.
   7. High total protein level and a low albumin level, with hypergammaglobulinemia.
      1. Lymphadenopathy may be noted, particularly in some geographic regions, such as Sudan.
      2. HIV-coinfected patients may have atypical manifestations, such as involvement of the gastrointestinal tract and other organ systems.
8. Kala-azar means black (kala) fever (Azar). These are severe (advanced) cases of visceral leishmaniasis.
   1. Kala-azar or severe visceral leishmaniasis  untreated is typically  fatal due to:
      1. Directly from the disease.
      2. Indirectly from complications, such as hemorrhage or secondary bacterial infection.
      3. If left untreated, the mortality rate may reach 100% within two years (WHO).
9. Pathogenesis of the lesion:
   1. The fly, when biting the host, then amastigotes proliferate.
   2. These are taken up by the macrophages and the endothelium of the small capillaries.
   3. Macrophagic cells cause the lysis of amastigotes.
      1. The organism infects the mononuclear cells of the reticuloendothelial system.
      2. The incubation period varies from 2 weeks to more than 2 years, and mostly is 3 to 8 months.
   4. There is a chronic granulomatous reaction, leading to local nodule formation, which is due to parasite-induced damage.
   5. This may ulcerate, and there is the possibility of pyogenic infection.

Leishmania pathogenesis

Mode of spread:

1. Leishmania spread through the bite of the female sandfly (Phlebotomus).

2. Human is a natural source of a reservoir. Other reservoirs are dogs, wild canines, rodents, and humans.

Laboratory Diagnosis of  Leishmaniasis:

Procedure how to make smear for cutaneous leishmaniasis:

1. If the ulcer is on the arm or feet, then first try to put pressure to stop the blood supply to that area.
2. Now prick and try to get yellow color material or serum-like material.
3. Make a smear from this material.
4. Another method is to take a sample just like Fine needle aspiration (Author personal experience ).
5. The FNA method is done at the periphery of the ulcer and gets a good sample most of the time.

LT smear procedure

Result of cutaneous smears:

1. In a good smear, you will see a lot of LT bodies in the histiocytes and outside on the smear.

LT bodies smear

2. Also,  can find a single separate LT body.
3. Find amastigotes in:
   1. L. tropica is diagnosed by making the smear from the deeper area of the skin lesion.
      1. These smears are stained with Giemsa (or Wright’s) stains.
      2. Typical amastigotes are seen.
4. Material aspirated from the bone marrow (64% to 86% positive), spleen (95 to 98% positive), or enlarged lymph nodes (roughly 64% positive).
5. From nasal secretion.
6. From the buffy coat of peripheral blood (67 to 99% positive).
   1. The culture of aspirates or peripheral blood.
   2. Can find the Leishmania antibody using the known parasitic antigen.
7. Leishmania amastigotes (LT body) are seen in the monocytes, and a few are seen as single in the smear.
8. ELIZA and indirect fluorescent antibody assay.

LT bodies in the histiocyte

LT bodies in the histiocyte                                                                

Treatment of Leishmaniasis:

1. The best drug is Sodium stibogluconate (antimony sodium gluconate (Pentostam).
   1. Pentostam 20 mg/Kg body weight is injected I/V or I/M for 20 days for cutaneous leishmaniasis.
      1. This dose can be repeated in the resistant cases at 10 days intervals.
      2. A maximum of three courses can be given.
2. Another drug is:
   1. Meglumine antimonate (Glucantime).
      1. Initial 50 mg/Kg body weight given for 10 to 12 days for cutaneous leishmaniasis.
      2. For mucocutaneous, give treatment for 15 days and repeat after 15 to 20 days if healing is not complete.
   2.  Pentamidine.
   3. Oral Ketoconazole 400 mg daily for 4 to 8 weeks is effective in treating longstanding cutaneous leishmaniasis.
   4. Steroids