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

Sample
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- Prepare a smear from the lesion of the patient.
- Spleen, tissue or aspirate, and (FNA) of lymph nodes.
- Splenic puncture.
- Nasal smears.
- Bone marrow aspirate.
- Culture from the above samples.
- Buffy coat of peripheral blood.
Indications
- This helps in the diagnosis of Cutaneous Leishmaniasis or oriental sore.
- For diagnosis of visceral leishmaniasis.
Pathophysiology
-
- Cutaneous Leishmania (CL) is transmitted by the sandfly.
- Genus of protozoa comprising parasites of worldwide distribution.
- Several species of which are pathogenic for humans. All species are morphologically indistinguishable.
- These are divided on the Clinical syndrome they produce:
- Visceral.
- Cutaneous.
- Mucocutaneous.
- Leishmania classified into :
- L. donovani.
- L. tropica.
- L. Mexicana.
- This is the summary of the Leishmania life cycle:
Cutaneous leishmaniasis
- Leishmania tropica:
- L. Tropica complex consists of:
- L. tropica.
- L. major.
- L. aethiopica.
- This is complex causes Oriental sore, also called as Baghdadi boil, old world cutaneous leishmaniasis, or Delhi ulcer.
- This is transmitted by sandflies belonging to the genus Phlebotomus.
- Epidemiology:
- These lesions are seen in the Mediterranean littoral, in Armenia, Azerbaijan, Uzbekistan, Turkmenistan, Afghanistan, India, Pakistan, and Iran.
- The dog may be the natural host but not looks an effective reservoir for a human.
- Incubation time is 2 months to 3 years.
- In general, cutaneous leishmaniasis causes skin lesions, which can persist for months, sometimes years.
- The skin lesions usually develop within several weeks or months after the exposure.
- These lesions are usually on the face.
- The lesions typically evolve from dry papules to nodular plaques to ulcerative lesions.
- These ulcers are usually 2 cm in Diameter or more with typical itching.
- These lesion has raised border and central depression, which can be covered by scab or crust.
- Rarely some lesions persist as nodules.
- These lesions are painless but some time may give rise to pain when these are infected.
- The healing process typically results in atrophic scarring.
- L. Tropica complex consists of:
- Leishmania Major:
- It produces an acute infection with a duration of 3 to 6 months.
- The lesion primarily occurs on the lower limbs.
- These lesions are moist and tend to ulcerate very early.
- There may secondary and lesions on other sites.
- This disease is seen in Turkmenistan, Uzbekistan, Iran, Kazakhstan, Syria, Israel, Jordan, Africa, Algeria, Sahara, Tunisia, Sudden, Nigeria, Niger, Mali, Senegal, and Kenya.
- Leishmania Mexicana:
- This causes new world cutaneous leishmaniasis
- It causes a Chiclero ulcer or Bay sore.
- It is found in the Belize, Yucatan peninsula, and in Guatemala.
- It is endemic in these areas.
- The amastigotes are found in the skin lesion of the humans, woodrats, and cats.
- Lesions are usually single and 40% involve ears.
- This may give rise to the diffuse cutaneous lesion.
- Signs and symptoms:
- The first sign of the infection is a red papule.
- There is itching and this may grow to 2 cms or more in diameter.
- In L.major infection, the papule is covered with serous exudate and ulcerates early.
- In L. tropica papules are dry and ulcerate only after several months.
- This cutaneous form may be seen as:
- Diffuse cutaneous leishmaniasis and this may be due to lake cell-mediated immunity.
- 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:
- L. braziliensis causes mucocutaneous leishmaniasis, also called espundia and uta.
- There is the formation of the ulcer on the oral-nasal mucosa.
- This is common in Brazil.
- The cutaneous lesions are multiple and large in size.
- Secondary infection plays a role in their persistence of the large size lesion.
- Sometimes it spreads to the mucous membranes.
- The entire nasal mucosa and the hard and soft mucosa are involved.
- The nasal septum will be destroyed.
- But unlike syphilis, the bone is not involved.
- The ulceration leads to loss of all soft parts of the nose, the lips, and soft palate.
- Death may occur in these patients due to secondary infection.
- A similar disease is also seen in Sudan and Ethiopia.
Visceral leishmaniasis
- Leishmania donovani:
- There are three types of L. Donovani complex:
- L. Donovani donovani.
- L. Donovoni chagasi.
- L. Donovani infantum
- It causes visceral leishmaniasis also called Kala-azar or black disease, Dumdum fever.
- This occurs in India, Burma, Bangladesh, Thailand, and Sumatra.
- Also seen in the Central African Republic, Sudan, Kenya, Gambia, Gabon, Northern Uganda, and Niger.
- This was seen in China but now it is controlled.
- Vector is Phlebotomus sandflies.
- In some cases, L.tropica has been found, in few cases in India and veterans from the Gulf war.
- The causative agent is a parasite of the reticuloendothelial system.
- This is not confined to the reticuloendothelial cells of the subcutaneous tissue and mucous membranes but may be found throughout the body.
- signs and symptoms:
- The Visceral leishmaniasis (also known as Kala-Azar).
- No skin lesions are seen, rarely except a papule at the site of the bite.
- Fever.
- weight loss (cachexia, wasting).
- Hepatosplenomegaly (usually, the spleen is more prominent than the liver).
- It returns to normal after the treatment.
- Bone marrow when involved, give rise to:
- Pancytopenia i.e., anemia, leukopenia, and thrombocytopenia.
- TLC is usually below 4000/cmm and is between 2000 to 3000/cmm.
- There is a monocytosis.
- High total protein level and a low albumin level, with hypergammaglobulinemia.
- Lymphadenopathy may be noted, particularly in some geographic regions, such as Sudan.
- HIV-coinfected patients may have atypical manifestations, such as involvement of the gastrointestinal tract and other organ systems.
- Kala-azar which means black (kala) fever (Azar). These are severe (advanced) cases of visceral leishmaniasis.
- Kala-azar or severe visceral leishmaniasis untreated are typically fatal due to:
- Directly from the disease.
- Indirectly from complications, such as hemorrhage or secondary bacterial infection.
- If left untreated the mortality rate may reach 100% within two years (WHO).
- Kala-azar or severe visceral leishmaniasis untreated are typically fatal due to:
- There are three types of L. Donovani complex:
Pathogenesis of the lesion:
- The fly when biting the host then amastigotes proliferates.
- These are taken up by the macrophages and the endothelium of the small capillaries.
- Macrophagic cells cause the lysis of amastigotes.
- There is a chronic granulomatous reaction and it leads to local nodule formation which is due to the parasite-induced damage.
- This may ulcerate and there is the possibility of pyogenic infection.
Mode of spread
1. Leishmania spread through the bite of the female sandfly (Phlebotomine).
2. Human is a natural source of a reservoir.
Laboratory Diagnosis of cutaneous Leishmania
Procedure how to make smear for cutaneous leishmaniasis:
-
- If the ulcer is on the arm or feet then first try to put pressure so that there is a stoppage of the blood supply to that area.
- Now prick and try to get yellow color material or serum like material.
- Make a smear from this material.
- Other Methods is to take a sample just like Fine needle aspiration (Author personal experience ).
- In the FNA method go into the periphery of the ulcer and most of the time get a good sample.
Result
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- In a good smear, you will see a lot of LT bodies in the histiocytes and outside on the smear.
-
- Also, can find a single separate LT body.
Diagnosis of Leishmaniasis:
- Find amastigotes in:
- L.tropica is diagnosed by making the smear from the deeper area of the skin lesion.
- These smears are stained with Giemsa.
- Typical amastigotes are seen.
- L.tropica is diagnosed by making the smear from the deeper area of the skin lesion.
- Material aspirated from the bone marrow (64 to 86% positive), spleen (95 to 98% positive), or enlarged lymph nodes (roughly 64% positive).
- From nasal secretion.
- From the buffy coat of peripheral blood (67 to 99% positive).
- The culture of aspirates or peripheral blood.
- Can find the Leishmania antibody using the known parasitic antigen.
- Leishmania amastigotes (LT body) seen in the monocytes and few seen as single in the following diagrams.
- ELIZA and indirect fluorescent antibody assay.
Treatment
- The best drug is Sodium stibogluconate (antimony sodium gluconate (Pentostam).
- Pentostam 20 mg/Kg body weight is injected I/V or I/M for 20 days for cutaneous leishmaniasis.
- This dose can be repeated in the resistant cases at 10 days interval.
- A maximum of three courses can be given.
- Pentostam 20 mg/Kg body weight is injected I/V or I/M for 20 days for cutaneous leishmaniasis.
- Another drug is:
- Meglumine antimonate (Glucantime).
- Initial 50 mg/Kg body weight given for 10 to 12 days for cutaneous leishmaniasis.
- For mucocutaneous give treatment for 15 days and repeat after 15 to 20 days if healing is not complete.
- Pentamidine.
- Oral Ketoconazole 400 mg daily for 4 to 8 weeks is effective in the treatment of longstanding cutaneous leishmaniasis.
- Steroids
- Meglumine antimonate (Glucantime).