A 5-year-old child is diagnosed with acute bacterial sinusitis. Which of the following pathogens are most commonly responsible for this condition?

Appeared in: ISRO 2024

Explanation

Acute bacterial sinusitis in children is most frequently caused by the triad of Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and Moraxella catarrhalis.
These bacteria are normal inhabitants of the nasopharynx that can cause infection when sinus drainage is obstructed, often following a viral upper respiratory infection.
Pediatric infectious disease guidelines confirm this classic triad as the primary target for empirical antibiotic therapy in community-acquired acute bacterial sinusitis.

Option A: These pathogens are not the primary cause of acute, community-acquired sinusitis in children.
Option C: These are viruses, and the question asks for bacterial pathogens.
Option D: These bacteria cause other specific respiratory infections but are not the typical agents for sinusitis.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Common pathogens of acute bacterial sinusitis in children as background academic context rather than a clinical decision trigger.
Understanding the most likely pathogens is crucial for selecting appropriate first-line antibiotics (e.g., amoxicillin or amoxicillin-clavulanate) and promoting antibiotic stewardship.
Nurses play a key role in educating parents on the clinical signs that differentiate a simple viral cold from bacterial sinusitis, such as persistent symptoms for more than 10 days, high fever with purulent discharge for 3+ days, or a 'double-sickening' course where symptoms worsen after initial improvement.
What if? If the child had cystic fibrosis or was recently hospitalized, the spectrum of likely pathogens would broaden to include Pseudomonas aeruginosa and Staphylococcus aureus, necessitating different empirical antibiotic choices.

How to Approach the Question

First, identify the core clinical entity in the question: 'acute bacterial sinusitis' in a '5-year-old child'.
The question asks for the 'most common' pathogens. This is a factual recall question requiring knowledge of microbiology for this specific condition.
Evaluate Option A: S. aureus and Pseudomonas are typically linked to chronic or hospital-acquired infections, making them less likely for an acute community case.
Evaluate Option C: Rhinoviruses and Adenoviruses are viruses. The question specifies 'bacterial' sinusitis, so this option is incorrect by definition.
Evaluate Option D: Group A Strep and C. diphtheriae are known for causing other distinct infections (pharyngitis, diphtheria), not sinusitis.
This process of elimination leaves Option B, which lists the classic triad of bacteria (S. pneumoniae, H. influenzae, M. catarrhalis) known to cause acute sinusitis in children. Confirm this is the correct choice.

Concept Tested & Keywords

Concept Tested: Common pathogens of acute bacterial sinusitis in children
Stem keywords: acute bacterial sinusitis, 5-year-old child, pathogens
Lead-in keywords: most commonly responsible
Clinical cues: Patient age (5-year-old) is typical for this condition.
Clinical cues: Diagnosis of 'acute bacterial sinusitis' specifies the type of infection.

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E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 339-341

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 1762-1764

Practise the full ISRO 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.