The micro-organism which is most commonly responsible for rheumatic fever is?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Applied Microbiology & Infection control

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Explanation

Rheumatic fever is an inflammatory, post-infectious syndrome, not a direct infection.
It develops as a delayed autoimmune reaction following an untreated or inadequately treated pharyngitis (sore throat) caused by Group A beta-hemolytic Streptococcus (GAS).
The immune system creates antibodies against the streptococcal bacteria, which then cross-react with and attack the body's own tissues, particularly the heart valves, joints, and brain.
This phenomenon, known as molecular mimicry, is the underlying cause of the inflammation and symptoms seen in rheumatic fever.

Option A: Staphylococcus aureus is a major cause of skin infections, abscesses, and acute infective endocarditis, but it does not trigger the specific autoimmune cascade that leads to rheumatic fever.
Option C: Haemophilus influenzae is a bacterium that primarily causes respiratory tract infections, such as pneumonia and epiglottitis, as well as meningitis. It is not associated with rheumatic fever.
Option D: Escherichia coli is a bacterium commonly found in the gut. It is the most frequent cause of urinary tract infections (UTIs) and a common cause of traveler's diarrhea and neonatal sepsis. It has no link to rheumatic fever.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Causative agent of Rheumatic Fever as background academic context rather than a clinical decision trigger.
The primary clinical relevance is prevention. Nurses play a key role in educating patients about the importance of seeking medical care for severe sore throats.
Prompt diagnosis (e.g., via rapid strep test or throat culture) and completion of the full course of prescribed antibiotics (usually penicillin) for strep throat is crucial to prevent the initial development of rheumatic fever.
For patients who have had rheumatic fever, long-term secondary prophylaxis with antibiotics is necessary to prevent recurrences and the development or progression of rheumatic heart disease, a serious long-term complication.

How to Approach the Question

This is a factual recall question that tests your knowledge of microbiology and associated diseases.
First, identify the key terms in the question: 'micro-organism' and 'rheumatic fever'.
The core task is to link the specific disease (rheumatic fever) to its causative agent.
Systematically review the options, recalling the primary diseases associated with each bacterium.
Recall or deduce that rheumatic fever is a well-known post-streptococcal syndrome.
Eliminate the other options based on the diseases they are known to cause (e.g., Staphylococcus -> skin infections; E. coli -> UTIs; H. influenzae -> respiratory infections/meningitis).

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 1 Part 3 p. 16-18

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 368-370