The most common cause of acute bacterial meningitis in the age group of 6 months to 5 years which has been virtually eradicated by the effective vaccine, is?

1. A

   Haemophilus influenza type b

2. B

   N. meningitides

3. C

   Cryptococcus neoformans

4. D

   Streptococcal pneumonia meningitis

Appeared in: NVS Staff Nurse - 2019

Explanation

• Before the introduction of its conjugate vaccine, Haemophilus influenzae type b (Hib) was the leading cause of bacterial meningitis in children under the age of 5.
• The Hib vaccine is highly effective, leading to a greater than 99% reduction in invasive Hib disease in countries with routine immunization.
• This dramatic success is why the disease is considered 'virtually eradicated' in vaccinated populations, directly matching the question's description.
• While other bacteria on the list are causes of meningitis and have vaccines, none have been as close to eradication as Hib.

Why Other Options Were Wrong

• Option B: While a major cause of bacterial meningitis, and despite the availability of effective vaccines, Neisseria meningitidis has not been 'virtually eradicated'. It continues to cause sporadic cases and outbreaks.
• Option C: Cryptococcus neoformans is a fungus, not a bacterium. The question specifically asks for a cause of 'bacterial' meningitis.
• Option D: Streptococcus pneumoniae is a leading cause of bacterial meningitis now that Hib is rare. However, while the pneumococcal vaccine (PCV) has reduced its incidence, it has not been 'virtually eradicated' due to the existence of many serotypes.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of pediatric bacterial meningitis and the impact of vaccination as background academic context rather than a clinical decision trigger.
• This question highlights one of the greatest public health successes: the power of routine childhood vaccination to nearly eliminate a deadly disease.
• A nurse's role is critical in educating parents about the importance, safety, and timing of the Hib vaccine as part of the standard immunization schedule.
• Prompt recognition of meningitis symptoms (fever, nuchal rigidity, altered mental status) remains vital, as a delay in treatment can lead to severe neurological sequelae or death.

How to Approach the Question

• First, break down the question into its key components: 1) a bacterial cause, 2) affecting the 6-month to 5-year age group, and 3) has been 'virtually eradicated' by a vaccine.
• Evaluate each option against these three criteria.
• Eliminate Option C, Cryptococcus neoformans, immediately because it is a fungus, not a bacterium.
• Consider the remaining bacterial options. All three can cause meningitis in this age group and have associated vaccines.
• Focus on the most specific clue: 'virtually eradicated'. Recall or reason that while vaccines for N. meningitidis and S. pneumoniae have reduced cases, the Hib vaccine has had the most dramatic impact, leading to a near-disappearance of the disease.
• This unique level of vaccine success points directly to Haemophilus influenzae type b as the correct answer.

Concept Tested & Keywords

• Concept Tested: Etiology of pediatric bacterial meningitis and the impact of vaccination.
• Stem keywords: acute bacterial meningitis, 6 months to 5 years, virtually eradicated, vaccine
• Lead-in keywords: most common cause
• Clinical cues: The phrase 'virtually eradicated by the effective vaccine' is the key differentiator.

Question ID

Q_lqFPT-2hNvWp6xwVJahV

Copy ID

Reference Book

E6 Medicine Harrison 22e Part 1 p. 1160-1162

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 708-710