Microbiology and Immunology - Viral Meningitis - Jennifer Moffat

Question 1

Is aseptic meningitis caused by bacteria?

Answer 1

No

Causes: viruses, funghi, TB, infections near the CNS

Question 2

What is the most common cause of aseptic meningitis?

Answer 2

Enteroviruses (80%)

then HSV 1 and 2 and arboviruses

Question 3

What is the distinguishing feature between encephalitis and meningitis?

Answer 3

Mental status remains normal in meningitis;
Intracerebral hemorrhage can happen in encephalitis but not meningitis

Symptoms of meningitis:
photophobia, headache, fever, malaise, stiff neck, chills, sore throat, nausea, vomiting, abdominal pain, rash, muscle pain

Question 4

What WBC count is expected in aseptic meningitis?

Answer 4

Elevated WBC
glucose normal
viruses may be detected in CSF

Question 5

What is Brudzinski’s sign?

Answer 5

Sign of meningitis

Neck is so stiff that knees flex when neck is flexed

Question 6

CNS infections include alphaherpesviruses and rabies, which spread in what way?

Answer 6

Neuronal spread ie trigeminal nerve in HSV-1

Question 7

CNS infections include enteroviruses (a kind of picornavirus) which spread in what way?

Answer 7

Fecal-oral

Question 8

CNS infections include arboviruses (flaviviruses, togaviruses) which spread in what way?

Answer 8

Insect vectors

Question 9

Which herpvesvirus is most likely implicated in meningitis?

Answer 9

Primary HSV-2

Question 10

How would you best diagnose HSV-1 encephalitis?

Answer 10

PCR of CSF

MRI shows predominantly unilateral temporal lobe abnormalities

Question 11

How does rabies travel neuronally?

Answer 11

Replicates at bite site in muscle
Infects peripheral nerves and travels to the brain
Spreads to salivary glands

Question 12

Why is post-exposure immunization preventative against rabies?

Answer 12

Rabies has a long incubation period, weeks to months

Question 13

Where does poliovirus replicate?

Answer 13

tonsils and Peyer’s patches (lymphoid tissue)

Question 14

(+) sense
RNA virus
naked
acid stable

These are characteristics of what virus?

Answer 14

Poliovirus AND Coxackie A and B, all picornaviruses

Question 15

What is the only picornavirus not spread fecal-orally?

Answer 15

Rhinovirus (droplets/fomites)

**is acid labile, can’t get through GI tract

Question 16

How does rhinovirus enter host cells?

Answer 16

ICAM-1 receptor

Question 17

What are the distinguishing symptoms of coxsackie B virus?

Answer 17

Dilated cardiomyopathy
“Devil’s grip” / Bornholm’s disease/ Pleurodynia - unilatera, trouble breathing
Can cause aseptic meningitis, encephalitis
common in summer months

Question 18

What are the distinguishing symptoms of coxsackie A virus?

Answer 18

hand, foot and mouth disease - red vesicular rash
common in summer months
Can cause aseptic meningitis, encephalitis

Question 19

What is ADEM (Acute disseminated encephalomyelitis)?

Answer 19

• -Postinfectious encephalitis following viral viral infection by 1-2 weeks
• -Associated with measles, mumps, VZV, influenza, parainfluenza viruses
• -can be associated with autoimmune disorder

Question 20

VEE
EEE
WEE
are all examples of:

Answer 20

Togaviruses that cause encephalitis

Question 21

Japanese encephalitis and St. Louis encephalitis are examples of:

Answer 21

Flavaviruses

Question 22

West Nile patients who are at higher risk of developing WNV meningoencephalitis include:

Answer 22

Cancer
Diabetics
HTN
Kidney disease

Question 23

Viral infections of the CNS cause meningitis, encephalitis, or both, and have many common symptoms. What is a distinguishing characteristic of encephalitis?

A. Virus detected in CSF by culture or PCR
B. Intracerebral hemorrhage
C. Stiff neck, aka Brudzinski’s sign
D. Headache
E. Prognosis may be good, with few sequelae

Answer 23

B. Intracerebral hemorrhage

Question 24

A patient diagnosed with viral encephalitis in the summer is most likely infected with what type of virus?

A. Enterovirus
B. CMV
C. HSV-2
D. Rabies virus
E. Mumps

Answer 24

A. Enterovirus

Question 25

Viremia can result in skin rashes, congenital infections, and CNS infections. What is an alternate route for viruses to enter the CNS?

A. Extravasation through the meningeal or cerebral capillaries
B. Implantation of an organ from a donor infected with HSV-1
C. Retrograde transport from peripheral nerve endings or nasal mucosa
D. Bites from Aedes, Culex or Culiseta mosquitos carrying togaviruses

Answer 25

C. Retrograde transport from peripheral nerve endings or nasal mucosa

Question 26

Which type of HSV-1 is more likely to be associated with meningitis, HSV-1 primary or recurrent infection?

Answer 26

Recurrent HSV-1 infection