Leishmania donovani Lifecycle ( Hindi ) | Kala-azar | Dumdum fever

Summary

The transcript delves into the life cycle of Leishmania donovani, the causative agent of visceral leishmaniasis or kala-azar. It explains how the parasite enters the human body through sandfly bites, infecting macrophages and multiplying within them. The discussion covers the process of parasite transformation, its spread through the bloodstream, and its impact on human health. The video further details the symptoms, including fever and pigmentation changes, and traces the discovery of kala-azar in Kolkata. This informative content offers insights into the transmission, pathogenesis, and clinical manifestations of Leishmania donovani infection.

Takeaways

• 😀 Leishmania donovani is a parasitic organism responsible for visceral leishmaniasis (Kala-azar).
• 😀 The parasite is transmitted through the bite of an infected sandfly, which introduces its infective form into the human body.
• 😀 Once inside the body, the parasite is carried by macrophages, which attempt to destroy the parasite through phagocytosis.
• 😀 Leishmania donovani undergoes transformations inside macrophages, changing form to increase its infection potential.
• 😀 The parasite multiplies within macrophages and can burst out, releasing infective forms into the bloodstream, spreading the infection.
• 😀 The spread of Leishmania donovani is facilitated when an infected individual is bitten by a sandfly, which picks up the parasite from the bloodstream.
• 😀 Infected macrophages and blood particles can also be transferred to other individuals via the sandfly bite, completing the transmission cycle.
• 😀 Kala-azar causes hormonal imbalances in the human body, which can lead to pigmentation changes, especially on the face.
• 😀 The disease was first discovered in Dum Dum, Kolkata, which is why it’s sometimes referred to as Kala-azar.
• 😀 Key symptoms of Kala-azar include fever, weight loss, liver and spleen enlargement, and skin changes like pigmentation.

Q & A

What is the primary focus of the video script?

The video script primarily focuses on explaining the life cycle of *Leishmania donovani*, its transmission, and the impact it has on the human body, leading to the disease Kala-azar.

How does *Leishmania donovani* infect the human body?

*Leishmania donovani* enters the human body when a sandfly bites, injecting the infective form of the parasite into the bloodstream, which then spreads to various parts of the body.

What role do macrophages play in the infection process?

Macrophages are immune cells that attack and attempt to eliminate the parasite, but *Leishmania donovani* survives within these cells, reproducing and spreading further in the body.

What happens when *Leishmania donovani* is inside the macrophages?

Once inside the macrophages, the parasite alters its form and survives by multiplying within the cell, eventually causing the macrophage to burst and release more infective parasites into the bloodstream.

What is Kala-azar, and how is it related to *Leishmania donovani*?

Kala-azar, also known as visceral leishmaniasis, is a disease caused by *Leishmania donovani*. It leads to symptoms such as fever, weight loss, and liver and spleen enlargement. It is spread by sandflies carrying the parasite.

How does the *Leishmania donovani* parasite change form throughout its life cycle?

*Leishmania donovani* changes its form depending on the host. In sandflies, it exists in a flagellated form, while in human hosts, it transforms into an amastigote form to survive within macrophages.

What is the connection between sandflies and the transmission of *Leishmania donovani*?

Sandflies act as vectors for *Leishmania donovani*. They bite infected humans or animals, ingesting the parasite, and later transmit it to new hosts during their subsequent bites.

What are the symptoms of Kala-azar caused by *Leishmania donovani* infection?

Symptoms of Kala-azar include fever, weight loss, enlargement of the liver and spleen, and the presence of pigmented spots on the skin, often leading to significant health issues if untreated.

How does the parasite *Leishmania donovani* affect the human immune system?

The parasite suppresses the immune system by surviving inside macrophages, avoiding destruction. This leads to an imbalance in the immune response, making it difficult for the body to fight the infection effectively.

Why is *Leishmania donovani* resistant to the body's immune defenses?

*Leishmania donovani* has evolved to evade the immune system by surviving and multiplying within macrophages. This process prevents the immune system from recognizing and eliminating the parasite.