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Question #46500
The Question
A patient presents with paroxysms of high fever and chills recurring every 3 to 4 days. While a systemic bacterial infection like Typhoid is classically confirmed by the Widal test (an antibody-based agglutination assay), the definitive diagnosis of active infection and the exact physiological trigger for the cyclical pyrexia in this patient's condition are best described by:
Options
- A.
Serological detection of circulating antibodies; pyrexia is triggered by the rupture of hepatocytes releasing merozoites during exo-erythrocytic schizogony.
- B.
Microscopic visualization of intracellular parasite stages in blood smears; pyrexia is triggered by the cyclical release of haemozoin upon the synchronous rupture of infected erythrocytes.
- C.
Agglutination assay detecting protozoal O and H antigens; pyrexia is triggered by the release of toxic haemozoin during the formation of the liver schizont.
- D.
Rapid antigen capture of extracellular sporozoites in plasma; pyrexia is triggered by the synchronous lysis of erythrocytes releasing gametocytes into the bloodstream.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Widal Test Specificity|Haemozoin Release|Life Cycle of Plasmodium
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the stages of the Plasmodium life cycle that cause clinical symptoms.
The trap lies in distinguishing the asymptomatic liver stage (exo-erythrocytic) from the symptomatic blood stage (erythrocytic).
Furthermore, it tests the diagnostic distinction between detecting an immune response (antibodies in Widal) versus detecting the actual intracellular pathogen (blood smear for Malaria) responsible for the cyclical release of metabolites.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Widal Test Specificity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |