Micro: Greenberg 3

Question 1

What are the clinical hallmarks of encephalitis?

Answer 1

confusion, disorientation, acute changes in ideation and thought

Question 2

What will CSF exam of viral meningitis show?

Answer 2

elevated WBC, usually w mononuclear pleocytosis of lymphocytes, normal or elevated protein, normal glucose

Question 3

What is the microbiology of enteroviruses?

Answer 3

small nonenveloped RNA called picornaviruses
includes coxsackie A & B, echovirus, polio, enterovirus 71 (brainstem encephalitis)
humans only natural hosts, most common cause of viral meningitis

Question 4

How are enterviruses spread?

Answer 4

fecal oral - poor hygienic environments, day care
resistant to pH, detergents and disinfectants, heat and sewage treatment
household spread common
most common in SUMMER (jun-Oct)

Question 5

How is enterovirus diagnosed? Treated?

Answer 5

PCR
most resolve spontaneously, only few have sequelae, no current treatment or vaccine
maybe ISG for neonates and immunocompromised, interferon alpha

Question 6

What are the clinical manifestations of enterovirus?

Answer 6

non-specific febrile illness, respiratory illness, hematologic conjunctivitis, herpangina (mouth blisters), hand-foot-mouth syndrome, pleurodynia, myocarditis, meningitis, encephalitis, congenital/neonatal inf

Question 7

What is HSV type II meningitis?

Answer 7

sexually transmitted

pts have typical presentation and lab findings of viral meningitis

Question 8

What is Mollaret’s meningitis?

Answer 8

benign recurrent aseptic meningitis - symptoms resolve w/i 5 days and pt recovers without sequelae
LP consistent w viral meningitis
mostly caused by HSV2 - only minority have genital herpes
prophylactic acyclovir

Question 9

Which types of transmission/syndromes are caused by which type of HSV?

Answer 9

HSV type 1 = encephalitis, respiratory

HSV type 2 = meningitis, sexually transmitted

Question 10

How is HSV encephalitis diagnosed?

Answer 10

mostly in temporal lobe

CSF PCR - false negative if hemoglobin or other inhibitors present –> repeat PCR 1-3 days later

Question 11

What are the four main clinical syndromes of poliomyelitis?

Answer 11

asymptomatic: viral replication limited to oropharynx and gut
minor illness: nonspecific febrile illness, headache, malaise, sore throat, usually prompt resolution
nonparalytic aseptic meningitis: resolves w/o seqeulae
secondary viremic spread to nervous system –> flaccid paralysis

Question 12

What is the diagnosis/treatment/prevention of polio?

Answer 12

CSF findings of aseptic meningitis
no antiviral therapy - maintain fxn
2 types of vaccine - live attenuated (IgA and GALT but not used anymore) and killed (only IgG)

Question 13

What is the cycle of HSV-1 inf causing HSE?

Answer 13

after acute inf causes latent in trigeminal ganglion - reactivates and replicates - some fibers innervate meninges adjacent to temporal lobe

Question 14

What is the virology of west nile virus?

Answer 14

member of flavivirus family
+sense ssRNA
belongs to japanese encephalitis virus group - St. Louis also a member

Question 15

When does St. Louis encephalitis cause disease?

Answer 15

late summer and early fall - dz primarily in older people

Question 16

What are the clinical manifestations of St. Louis encephalitis?

Answer 16

coarse tremors (inv of substantia nigra)
muscular weakness rare
transient parkinson like tremor

Question 17

How is St. Louis encephalitis/WNV diagnosed?

Answer 17

serologically off blood and CSF, demonstrate presence if IgM

Question 18

What are the clinical syndromes associated w WNV?

Answer 18

vast majority just have asymptomatic or febrile syndrome
neuroinvasive = meningitis, ecephalitis, meningoencephalitis, or polio-like syndrome
older individuals affected predominately, acute flaccid paralysis

Question 19

What clinical manifestations help distinguish WNV from St. Louis encephalitis?

Answer 19

tremor if basal ganglia involved but mild and in minority in WNV
muscular weakness profound in WNV

Question 20

What are factors involved in neurotropic WNV?

Answer 20

upregulation of genes involved in IFN signalling, T cell recruitment, MHC class I and II antigen presentation, apoptosis
HTN and vascular dz may predispose

Question 21

What is the vector control for WNV?

Answer 21

aerosols don’t affect aquatic stages of mosquitos
mortality restricted to “adults” in flight
graded drainage systems
fix poorly constructed apts

Question 22

What is the treatment and prevention for WNV?

Answer 22

no effective vaccines for humans or antiviral agents
looking for protease inhibitors
MyD88 inhibits by inhibiting replication in subset of cells
vaccine for horses

Question 23

What kind of virus is the rabies virus?

Answer 23

RNA rhabdovirus

Question 24

What is the cycle of the rabies virus once it enters the body?

Answer 24

binds to peripheral nerves - spreads retrograde back up to the brain - affects hippocampus, brainstem, pons, Purkinje cells of cerebellum - disseminates along nerves to salivary glands and other cells

Question 25

What is the clinical progression/stages of inf with rabies?

Answer 25

incubation period - most variable in length
prodromal phase - fever, lethargy, vomiting, anorexia, headache, pain at bite - 2-10 days
neurological stage - loss of coordination, paralysis, delirium, confusion (hypersalivation, hydrophobia)
coma and death - almost invariably fatal

Question 26

How is rabies diagnosed?

Answer 26

late, viral antigen in CNS
can be isolated and cultured but only after neurological dz
brain biopsy - Negri body = intracytoplasmic inclusions of viral nucleocapsid

Question 27

What are the two cycles of reservoirs of rabies? the two forms?

Answer 27

urban - dogs main transmitters
sylvatic - large number of hosts
encephalitic, paralytic

Question 28

What is the prevention of rabies?

Answer 28

vaccine - pre-prophylactic for high risk, prophylactic post-exposure - also give hyper-rabies immunoglobulin (HRIG) - *not effective once symptoms develop

Question 29

How is anti NMDA receptor encephalitis diagnosed?

Answer 29

mild CSF lymphocytic pleocytosis
T2 FLAIR hyperintensities
tumors often found

Question 30

What are the treatment and prognostic factors for anti NMDA receptor encephalitis?

Answer 30

most respond to immunotherapy (steroids, IVIG, plasmapheresis)
second line (rituximab, cyclophosphamide)
recovery can take up to 10 months, 3/4 do recover

Question 31

What is postinfectious encephalitis?

Answer 31

after viral inf (VZV), most commonly children, winter or spring
characterized by multi-focal perivenous demyelination (CD8 cells, autoimmune)
ADEM not consequence of specific inf or immunization
outcome usually favorable, 30% will develop MS

Question 32

What are signs and symptoms of postinfectious encephalitis?

Answer 32

meningeal signs
multi focal neurologic signs raise suspicion of ADEM
MRI w gadolinium enhancement

Question 33

What is the virology of JC virus and PML?

Answer 33

polyoma family (includes BK and SV40)
predominately in pts w advanced AIDs
related to papillomaviruses

Question 34

What is subacute sclerosing panencephalitis?

Answer 34

associated w prior measles inf
recover, then 6-15 yrs later progressive neurological degeneration
intact viral particles not present, but particles lacking M protein and viral nucleic acids detected
no treatment, usually death

Question 35

What is Reye’s syndrome?

Answer 35

encephalopathy (not encephalitis) associated with inf viral illness
influenza B and varicella mostly
has acute fatty liver
linked to use of aspirin