Leishmaniasis: Kinetoplastids, Life Cycle, Clinical Forms and Vectors

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What phylum do Leishmania and Trypanosoma belong to?

Phylum Euglenista

What order is associated with Leishmania and Trypanosoma?

Order Kinetoplastida

What family includes Leishmania and Trypanosoma?

Family Trypanosomatidae

What is a kinetoplast?

A DNA-containing organelle from which a mitochondrion arises.

What unique organelles do Leishmania and Trypanosoma possess?

Glycosomes for glycolysis and a subpellicular microtubular network.

How many flagella do Leishmania and Trypanosoma have?

1 flagellum

What type of life cycle do Leishmania and Trypanosoma exhibit?

Heteroxenous, requiring a blood-feeding insect vector.

What are the stages of Leishmania and Trypanosoma?

Trypomastigote, Epimastigote, Promastigote, Amastigote.

What is the infective form of Leishmania in the insect vector?

Promastigote

What is the intracellular form of Leishmania in the vertebrate host?

Amastigote

What disease is caused by Leishmania donovani?

Visceral Leishmaniasis (Kala-azar)

Which Leishmania species is associated with Cutaneous Leishmaniasis?

Leishmania tropica, Leishmania major, and Leishmania aethiopica.

What is the primary vector for Leishmania?

Sandflies (Phlebotomus and Lutzomyia species)

What is the estimated incidence of visceral leishmaniasis cases worldwide?

300,000 new cases annually.

What is the role of macrophages in Leishmania infection?

Macrophages are infected by Leishmania and replicate as intracellular amastigotes.

How does Leishmania evade destruction by macrophages?

By preventing the formation of the fully functional Membrane Attack Complex (MAC).

What is opsonization in the context of Leishmania?

The process by which Leishmania binds elements of the complement system to its surface, tagging it for phagocytosis.

What are the characteristics of the Leishmania life cycle stages in sandflies?

The parasite lives as extracellular promastigotes in the digestive tract of sandflies.

What factors contribute to the breeding grounds of sandflies?

Heat, humidity, and poor sanitation.

What is the size range of sandflies?

2-3 mm in size.

What is the significance of a TH1 response in Leishmania infections?

A TH1 response is required for parasite control and healing.

What is the impact of Leishmania infections globally?

Affects up to 12 million people, with 1 million new cases and 20,000-65,000 deaths per year.

What is the primary vector for Leishmania transmission?

Sand flies

What regions are referred to as the 'Old World' for Leishmaniasis?

Eastern Hemisphere

In urban environments, how is Leishmaniasis primarily transmitted?

Human to human

What is a common zoonotic reservoir for Leishmaniasis in rural areas?

Dogs

What is the incubation period for Visceral Leishmaniasis?

Usually 2-4 months (range 10 days - 1 year)

What are the main symptoms of Visceral Leishmaniasis?

Low-grade fever, malaise, anemia, leukopenia, drastic weight loss, darkening of the skin, abdominal swelling

What is another name for Visceral Leishmaniasis?

Kala-azar or DumDum Fever

What is Post Kala-azar Dermal Leishmaniasis (PKDL)?

A skin condition that may occur after inadequate treatment of Visceral Leishmaniasis

What are the two types of Cutaneous Leishmaniasis?

Chronic dry ulceration (urban type) and acute moist ulceration (rural type)

What is a common name for Cutaneous Leishmaniasis?

Oriental Sore, Jericho or Delhi Boil

What are the primary species causing Mucocutaneous Leishmaniasis?

L. braziliensis

What percentage of Mucocutaneous Leishmaniasis cases occur in Bolivia, Brazil, and Peru?

90%

What is the mortality rate of untreated Visceral Leishmaniasis?

75-95% in 2-3 years

What factors have contributed to the increased prevalence of Leishmaniasis since 1993?

Rural-urban migration, agro-industrial projects, environmental impacts, and deforestation

What is the gold standard for diagnosing Leishmaniasis?

Demonstration of parasites in blood or lymph, or in scrapings of ulcers

What is the treatment for Visceral Leishmaniasis?

Pentavalent antimonials or Miltefosine (Impavido®)

What complications arise in treating Leishmaniasis with HIV co-infection?

Treatment is complicated due to drug resistance and increased severity of symptoms

What are the vectors for Cutaneous Leishmaniasis in the Old World?

Phlebotomus spp.

What are the vectors for Cutaneous Leishmaniasis in the New World?

Lutzomyia spp.

What is a significant characteristic of Mucocutaneous Leishmaniasis lesions?

They can lead to extensive and disfiguring destruction of mucous membranes

What is the typical reservoir for Leishmania in the New World?

Wild animals such as rodents and monkeys

What is the primary symptom of Post Kala-azar Dermal Leishmaniasis?

Reddish dermal lesions containing parasites

What is the role of vector control in managing Leishmaniasis?

Use of insecticides and bed nets to reduce transmission

What is the main challenge in treating Cutaneous Leishmaniasis?

Available drugs have significant side effects and resistance has emerged

What is the significance of the term 'sylvatic' in relation to Leishmaniasis?

It refers to wild animal reservoirs for the parasite

What are the common names for Cutaneous Leishmaniasis caused by L. tropica?

Oriental Sore, Jericho or Delhi Boil