Which of the following agent is least likely to cause Meningitis in the elderly?
In elderly, viral meningitis is relatively uncommon. Listeria monocytogenes, streptococcus pneumonia and gram negative bacteria are common causes of meningitis affecting the elderly. So HSV-2 is the single best answer of choice. Ref: Harrison's Principles of Internal Medicine, 16th Edition, Pages 2471-72; Manual of Practical Medicine By R Alagappan, 3rd Edition, Page 524
Listeria Monocytogenes
Streptococcus pneumonia
Gram Negative bacteria
Herpes Simplex Virus - 2 (HSV 2)