T/F: Viral meningitis and viral encephalitis are both typically self-limiting illness
True
T/F: Profound altered mental status and focal neurological deficits are symptoms found in viral meningitis
False; these are symptoms for viral encephalitis, viral meningitis (like bacterial meningitis), presents frequently with nuchal rigidity and only variable degrees of altered mental status
T/F: Viral cause of newborn meningitis is common
False; it is really rare, newborn meningitis is typically caused by Group B strep, NMEC and/or listeria. Same thing goes for 60 year + adults too
What are common causes of viral Encephalitis?
HSV-1
And arboviruses i.e EEE, WEE, StLouisE, LaCrosse, California encephalitis, WNV
T/F: Treatment for all viral encephalitis is the use of IV Acyclovir
False; acyclovir is only used for HSV-1 infections (because it is a DNA virus), other causes of viral encephalitis is supportive care
Viral infection CSF: pressure _____, CSF appearance ____, cell counts ___, dominant cell type ____, glucose ____, protein ____
Normal pressure
Clear CSF
Normal cell count
Late lymphocytes
Normal glucose
Normal protein
If blood is present in the CSF and traumatic spinal tap is ruled out, what does this suggest?
HSV-1 encephalitis
80-85% of viral meningitis is caused by _____
Coxsackie A and B
Echovirus is the second most common
These are enteroviruses
Enteroviruses: Coxsackie A/B and echovirus (and poliovirus)- genetic makeup:
Single-stranded RNA (+)
non-enveloped
Picornaviridae family
replicate in the cytoplasm
Coxsackie ___ can cause hand-foot-mouth disease, hemorrhagic conjunctivitis and respiratory disease
A
While coxsackie B can cause pericarditis, pleurodynia
Both of them can cause paralytic, encephalitis and meningitis
Enterovirus enter ____ route, and replicate in the ____ or in the ____. Later enter the bloodstream and infect other cell types
Fecal-oral/ ENT
Oropharynx
Intestines
Which virus has biphasic virulent cycle?
Enterovirus – first peak when the virus replicate in the intestinal mucosa, affected individual starts to feel a little better but then struck with next round of viremia that could possibly get to the CNS
Diagnosing enteroviral, HSV, West Nile CNS infection:
PCR
HSV is of the ____ family, and its genome is ______, (with/without) envelope and replicates in the _____
Herpesviridae
Double-stranded linear DNA
with envelope
replicates in the nucleus
Herpesviridae virus gets their envelope from ____
The nuclear membrane when it buds off
Where does Herpesvirus establishes latency?
In the neuron, in trigeminal ganglia
Then it’s reactivated when there’s stress, fever, trauma, and spreads via peripheral nerves
T/F: HSV-1 causes encephalitis, and HSV-2 usually meningitis
True, though HSV-2 can also cause encephalitis but that’s seen more in neonates
What is whitlow?
Herpetic whitlow, hand/finger lesions seen in a lot of healthcare provider form having contact with the herpesvirus
What is gingivostomatitis?
Primary HSV-1 oral lesion that supposedly Honsa had and said that most of us have had it too as a child
If adult gets exposed to oral HSV-1 for the first time, it can present as ___
Severe pharyngitis
This is why you should ideally get gingivostomatitis as a child so as an adult you won’t have to get this
Cold sores is aka____
Herpes labilais
Primary infection can be asymptomatic and usually occurs in childhood
When CSF shows _____, it is suggestive of HSV-1 encephalitis reactivation, which attacks what part of the brain?
Blood
Temporal lobe
Most common cause of sporadic acute necrotizing encephalitis in the USA is _____, and there is a high mortality if untreated.
HSV-1 encephalitis
Treated pt will likely have neurological sequelae and 20% mortality
Cowdry type A inclusions, think:
Herpes; HSV-1
What is Cowdry type A inclusions?
Intranuclear eosinophilic bodies surrounded by a clear halo with margination of chromatin on the nuclear membrane, suggestive of the Herpesviridae family
______ shows Multinucleated giant cells of HSV or VZV
Tzanck smear
Which is the most common arboviral infection in the US?
West nile virus
T/F: Eastern Equine Encephalitis (EEE) and Western Equine Encephalitis (WEE) have horse as its reservoir
False; horses are dead-end HOSTS, not reservoir.
Reservoir: wild birds; Vector: mosquitoes
T/F: California encephalitis is commonly seen in Kern County, Central California
False; instead it is found in northcentral states, think Illinois, Minnesota and Iowa
Reservoir and vector for California Encephalitis/ La Crosse Virus
Reservoir: rodents
Vector: mosquito
T/F: Colorado tick fever virus (reovirus), is commonly found in the northcentral states
False; Colorado tick fever virus is aptly named, unlike California Encephalitis, in that this virus is actually found in the Rocky Mountains region, and clinical vignette may often involve a hiker
Dermacentor tick is the vector for which virus causing viral encephalitis?
Colorado tick fever virus
(this tick is also a vector in the Gr negative coccobacilli bacteria Franciscella tularensis!)
T/F: all the arboviruses causing viral encephalitis have mosquito as their vectors and wild birds as their reservoir
False; while it is ALMOST true, but Colorado Tick fever virus as Dermacentor tick as vector
And both California Encephalitis and Colorado Tick fever have “small mammals” as their reservoir instead of wild birds
Which viruses are part of the Flaviviridae family?
West Nile Virus
St. Louis encephalitis Virus (and Japanese encephalitis virus but we didn’t really learn that)
(from hemorrhagic fever lecture: also Dengue and Yellow fever)
Which viruses are part of Togaviridae family?
Eastern Equine Encephalitis virus
Western Equine Encephalitis virus
Which viruses are part of bunyaviridae family?
California encephalitis virus, including La crosse virus
(also from hemorrhagic fever: Hantavirus)
Which viruses are part of reoviridiae family?
Colorado tick fever virus
Which viruses are part of arenaviridae family?
Lymphocytic choriomeningitis virus (not an arbovirus!)
(from hemorrhagic fever: Lassa fever virus)
T/F: All of the viral encephalitis viruses are ssRNA, enveloped virus
False; almost all are ssRNA enveloped, except for Reoviridae (Colorado tick fever) it is not enveloped and it is actually dsRNA
Which two family have segmented enveloped ambisense ssRNA?
Bunyaviridae (somehow this was not specified in the hemorrhagic fever lecture though)
Arenaviridae
T/F: both Flaviviridae and togaviridae families have positive-sense ssRNA, enveloped genome
True
Which mosquito-borne viral encephalitis can be found in California?
Western Equine Encephalitis virus
St. Louis Encephalitis
West Nile Virus
Culex mosquito is a vector for _____ virus
West Nile
St. Louis Encephalitis vrus
West Nile virus most often cause encephalitis in which age group?
Over 60 years
Which family of virus has 3 circular segments of RNA?
Bunyaviridae – California encephalitis virus, La crosse virus, hantavirus
Aedes mosquitoes are vector for ____ virus
California encephalitis and La Crosse
Chipmunks, squirrels are reservoirs for ____ virus
California Encephalitis virus and La crosse
California encephalitis and La crosse virus most often affect which age group?
Children 5 to 18 years old
A squirrel-chasing teenager from rural Iowa presents with altered mental status and multiple mosquito bites, think:
California Encephalitis and La Crosse virus
T/F: St. Louis Encephalitis virus is seen more in urban setting, while California encephalitis/ La Crosse is seen more in suburban and rural environments
