All cause meningitis in the elderly except –
**Core Concept**
Meningitis in the elderly can be caused by various pathogens, including bacteria, viruses, and fungi. The elderly are more susceptible to meningitis due to decreased immune function and increased exposure to pathogens.
**Why the Correct Answer is Right**
Meningitis in the elderly is often caused by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b (Hib). These bacteria commonly cause community-acquired meningitis. In contrast, Listeria monocytogenes is more commonly associated with meningitis in neonates and immunocompromised individuals.
**Why Each Wrong Option is Incorrect**
**Option A:** _Listeria monocytogenes_ is indeed a cause of meningitis, particularly in the elderly, especially those with weakened immune systems. However, it is not the correct answer since the question asks for an exception.
**Option B:** _Cryptococcus neoformans_ is a type of fungus that can cause meningitis, particularly in immunocompromised individuals, including the elderly. Therefore, it is not the correct exception.
**Option C:** _Mycobacterium tuberculosis_ can cause meningitis, especially in immunocompromised individuals, including the elderly. Therefore, it is not the correct exception.
**Clinical Pearl / High-Yield Fact**
The elderly are more susceptible to meningitis due to decreased immune function and increased exposure to pathogens. The most common causes of meningitis in the elderly are Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b.
**Correct Answer:** D.