In malaria, mature trophozoites replicate and disrupt which cell membrane integrity and cause cell lysis?

RIMS Nursing Officer - 2022

Applied Microbiology & Infection control

Easy

Appeared in: RIMS Nursing Officer - 2022

Explanation

The malaria parasite, Plasmodium, undergoes its asexual replication phase (erythrocytic schizogony) inside erythrocytes (red blood cells).
Within the erythrocyte, the parasite matures from a ring form to a trophozoite and then into a schizont.
The mature schizont contains multiple new merozoites and eventually ruptures the host erythrocyte membrane, causing cell lysis.
This process of invasion, replication, and lysis of erythrocytes is responsible for the clinical manifestations of malaria, including anemia and cyclical fevers.

Option B: Leukocytes (white blood cells) are components of the immune system that fight infections. They are not the host cells where malaria parasites replicate and cause lysis.
Option C: Platelets are involved in blood clotting. While malaria can lead to a low platelet count (thrombocytopenia) due to mechanisms like splenic sequestration and bone marrow suppression, the parasites do not invade and lyse platelets as part of their life cycle.
Option D: Plasma is the acellular, liquid component of blood that transports cells, nutrients, and waste products. It does not have a cellular structure or membrane for the parasite to invade and lyse.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of malaria, specifically the erythrocytic stage of the Plasmodium life cycle as background academic context rather than a clinical decision trigger.
Understanding that erythrocyte lysis is the core pathology of malaria helps nurses anticipate and manage key complications like anemia, jaundice (from the breakdown of hemoglobin), and splenomegaly (from the spleen working to clear damaged RBCs).
The synchronized, cyclical rupture of erythrocytes is what causes the characteristic paroxysms of fever and chills. Recognizing this pattern is crucial for diagnosis.
Nursing care for patients with malaria includes monitoring hemoglobin levels for anemia, assessing for signs of jaundice, and managing high fevers that result from mass cell lysis.

How to Approach the Question

First, identify the key terms in the question: 'malaria', 'mature trophozoites', 'replicate', and 'cell lysis'. This points to the pathogenic mechanism of the disease.
Recall the basic life cycle of the malaria parasite, Plasmodium. Remember that it has two main stages in humans: a liver stage and a blood stage.
The question specifically mentions 'trophozoites' and 'cell lysis', which are characteristic of the blood stage (erythrocytic cycle).
Evaluate the options in the context of the blood stage. The parasite needs a host cell to replicate in.
Eliminate 'Plasma' as it is not a cell.
Consider the remaining options: Erythrocytes (RBCs), Leukocytes (WBCs), and Platelets. Recall that the defining feature of malaria's pathology is its effect on red blood cells.

Concept Tested & Keywords

Concept Tested: Pathophysiology of malaria, specifically the erythrocytic stage of the Plasmodium life cycle.
Stem keywords: malaria, mature trophozoites, replicate, cell lysis
Lead-in keywords: which cell
Negative lead-in flag: false

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