Exam 2: Disease of NS -- Viral Flashcards
What are the four viral disease we are discussing of the Nervous System?
- Viral Meningitis
- Poliomyelitis
- Rabies
- Arboviral Encephalitis (5 of them)
What is the most common type/cause of meningitis?*
viral meningitis
T/F. Viruses more readily cross the blood-brain barrier, therefore viral infections occur more frequently than bacterial and fungal infections in the nervous system.
true
What are the symptoms of viral meningitis?
similar to bacterial meningitis, but milder
- sudden high fever
- nuchal rigidity
- meningeal inflam.
- severe HA
- etc.
What genus of organism causes 90% of cases of Viral meningitis?*
Enterovirus* (Poloiovirus, Coxackie virus, Echovirus)
RNA Virus
What is an “aka” name for viral meningitis?
“aseptic meningitis” (b/c no bacteria found in CSF)
How is viral meningitis spread?
via respiratory droplets and feces
What is the Dx and Tx for viral meningitis?
Dx by absence of bacteria in CSF
Tx– non; most patients completely recover on own w/in 2 weeks
What is the official name for “polio? What organism causes it?
Poliomyelitis
Poliovirus
What percentage of cases of Poliomyelitis are asymptomatic?
almost 90% of cases
What are the three “types” of Poliomyelitis? How do they manifest?
- Minor polio –> nonspecific symptoms (flu-like)
- Nonparalytic polio–> muscle spasms and back pain
- Paralytic polio–> paralysis (~1% of cases)
What “type” of Poliomyelitis represents only about 1% of cases? What can it result in?
Paralytic polio
can result in “bulbar poliomyelitis”–> brain stem and MO are inf.–results in paralysis of muscles in limbs or respiratory muscles
What is it called when there is crippling deterioration in the function of polio-affected muscles?
Postpolio syndrome
How is Poliomyelitis transmitted?
most often by drinking contaminated water or fecal-oral route
What are the two vaccines that near elimiated polio? Which one is not given anymore in the US?
IPV– inactivated polio vaccine
OPV– oral (live) polio vaccine–> NOT given in US anymore
Who developed the polio vaccines, IPV and OPV?
IPV–> Jonas Salk
OPV–> Albert Sabin
As of 2012, where are the only 3 places that polio remains an endemic?
Nigeria, Pakistan, and Afghanistan
What president was Dx with polio?
FDR
What is the Dx and Tx for poliomyelitis?
Dx–> lab find poliovirus in stool sample or swab of pharynx
Tx–> NO CURE (focus of providing relief to symptoms)
What disease is often acquired after being bite, and one initially has pain, itching, fever, malasia, anorexia, but then once it reaches the CNS they have hyrophobia, seizures, disorientation, hallucinations, and paralysis?
Rabies
How may death results from Rabies?
respiratory paralysis and other complications
What is the organism that causes Rabies?
Rabies virus
RNA virus
Histologically, what disease will show a bullet shaped capsid and Negri bodies?
Rabies
What is the source of most cases of Rabies here in the US? How does transmission of it usually occur?
bats –main reservoir in US
transmission usually occurs via bite
T/F. When symptoms for Rabies start to show, it can then be Dx and Tx.
FALSE– by the time symptoms show it is too late to intervene and one will die
If one has been bite by an animal they suspect may have rabies, what should they do?
Timing is critical!!!– go to hospital and get:
- Injection of human rabies immune globulin
- Vaccination with human diploid cell vaccine (HDVC)
What does the viral diseases under Arboviral Encephalitis tell us about how they are transmitted?
are arthropod borne (MC mosquito-borne, but some are tick borne–but it will say “tick” in the name.)
What type of symptoms to Arboviruses USUALLY cause?
mild, coldlike symptoms
T/F. Arboviruses are zoonotic diseases, and rarely affect humans.
True
If Arboviruses cross the BBB, what do they cause?
cause encephalitis
What are the 5 types of Arboviral Encephalitis we are discussing?
- Eastern, Western, and Venezuelan Equine Encephalitis Virus
- St. Louis Encephalitis Virus
- West Nile Encephalitis virus
- California (LaCrosse) Encephalitis Virus
- Tick-borne Encephalitis virus
What is the vector for Easter/Western/Venezuelan Equine Encephalitis Virus?
What is the reservoir?
What animal is it usually found around though?
mosquito
birds
horses (not transmitted from horses to humans)
What are the symptoms for Easter/Western/Venezuelan Equine Encephalitis Virus?
fever, muscle pain, HA, vomiting, seizures 3-10 days after bite of infected mosquito
What is the dividing line b/w Eastern and Western Equine Encephalitis Virus? Which is more fatal?
Mississippi River
- EEE is east of it
- WEE is west of it
Eastern = 30-35% fatality
What organism causes:
- Eastern Equine Encephalitis
- Western Equine Encephalitis
- Venezuelan Equine Encephalitis
- Eastern Equine Encephalitis Virus
- Western Equine Encephalitis Virus
- Venezuelan Equine Encephalitis Virus
–all are Arboviruses and mosquito is the vector
What Arbovirus has mild illness symptoms including a fever and HA, but once it gets severe there is neck stiffness, stupor, disorientation, coma, tremors, and occasional convulsions and spastic paralysis?
St. Louis Encephalitis
named after outbreak in St. Louis
What organism causes St. Louis Encephalitis? What is the vector?
St. Louis Encephalitis Virus (an Arbovirus)
mosquito
What Arbovirus are 80% of people asymptomatic. but when they are they have fever, HA, body aches, nausea, vomiting, swollen lymph galnds, and a skin rash on chest, stomach, and back?
West Nile Encephalitis
What is the vector for West Nile Encephalitis? What is the reservoir?
What organism causes it?
Mosquitos
Birds
West Nile Virus
(is an Arbovirus)
How can one avoid getting West Nile Encephalitis?
avoid handling dead birds
birds are the reservoir
What Arbovirus causes initial viremia spreading the virus to target organs, leading to encephalitis, fever, and rash– but the symptoms are usually mild?
California (LaCrosse) Encephalitis
caused by California Encephalitis Virus
What is the vector for California (LaCrosse) Encephalitis? What is the reservoir?
vector–> mosquitos
reservoir–> chipmunks and squirrels
What Arbovirus causes sore muscles and a fever after 1-2 weeks, then causes encephalitis, with coma, convulsions, and paralysis? What is it carried by?
Tick-Borne encephalitis virus
carred by Ixodes ticks –> live on rodents
Besides from ticks, what else can people get Tick-Borne Encephalitis from?
from drinking unpasteurized milk containing the virus
T/F. Tick Borne Encephalitis is an emerging disease.
True
What are the symptoms like in someone who has Zika Virus infection?
most people are asymptomatic or have mild symptoms
- fever
- rash
- HA
- joint pain
- conjunctivitis
- muscle pain
What organism causes Zika virus infection ?
Zika Virus–> an arbovirus
RNA virus
How is Zika Virus transmitted? What is the vector?
spread via mosquito vector
can cross placenta
can be sexually transmitted
(get from travel–not in US)
What group of individuals do we worry about contracting Zika Virus? Why?
pregnant women, because it can cross the placenta –> leading to birth defects
What is the only Fungal infection we are dicussing of the Nervous System?
Cryptococcal meningitis
fungal meningitis
What can mushroom toxins produce?
produce hallucinations and neurological problems
How does a fungal infection spread to the CNS?
from the lungs to the CNS via the blood
Cryptococcal Meningitis has similar symptoms to bacterial meningitis, so what are they?
- HA
- dizziness
- drowsiness
- irritability
- confusion
- nausea
- vomiting
- neck stiffness
- CAN progess to loss of vision and coma*
What organism causes Cryptococcal Meningitis? What type of pathogen is it?
Crytococcus neoformans
fungus
What is the most common clinical form of Cryptococcal infection?
Cryptococcal Meningitis
How is Cryptococcal Meningitis transmitted?
opportunistic–> inhalation of spores or dried yeast cells–> often from inhaling bird droppings*
What individuals is Cryptococcal Meningitis occur in?
terminal AIDS patients and in transplant recipients
immunocompromised inds
Out of the three types of meningitis causes, bacterial, viral, and fungal, rank them most common to least and most severe to least.
MC–> Viral, Bacterial, Fungal
Most Severe–> Bacterial, Fungal, Viral
What are the two Protozoan CNS disease we are talking about?
- African Sleeping Sickeness (“trypanosomiasis”)
2. Amebic Meningoencephalopathy
What protozoan disease is characterized by three clinical stages and patient often and has severe drowsiness and dies w/in 6 months of onset of disease? What are the 3 stages?
African Sleeping Sickness
- Site of fly bite becomes lesion
- *Excessive drowsiness- fever, lymph node swelling, and HAs
- invasion of CNS = Meningoencephalitis
What is the “aka” name from African Sleeping Sickness?
trypanosomiasis
What organism causes African Sleeping Sickness (Trypanosomiasis)? What is the vector?
Trypanosoma brucei
tsetse fly*
What is caused by the tsetse fly and causes excessive drowsiness?
African Sleeping Sickness (aka trypanosomiasis)
What is more common, West African Sleeping Sickness or East African Sleeping sickness?
West = MC at 95%
East–less common at 5%
What is the treatment for African Sleeping Sickness? How fatal is it?
100% fatal if left untreated
treatment (IV medications) must begin ASAP after infection
What is a rare protozoan CNS disease that is causes usually fatal brain infections and one may experience HA, fever, vomiting, neurological tissue damage leading to hemorrhage, coma, and usually death w/in 3-7 days after onset of these symptoms?
Primary Amebic Meningoencephalopathy
How quick may death occur in someone with Primary Amebic Meningoencephalopathy?
death w/in 3-7 days after onset of symptoms due to neurological destruction
What organisms can cause Primary Amebic Meningoencephalopathy? Which is MC?
Acanthamoeba
or
*Naegleria fowleri (aka “the brain-eating amoeba”)–> MC
What does “the brain-eating amoeba” cause?
Primary Amebic Meningoencephalopathy
protozoan disease of CNS
How is Primary Amebic Meningoencephalopathy transmitted?
INHALATION of contaminated water (if drink and don’t inhale = okay)
What is the Dx and Tx of Primary Amebic Meningoencephalopathy?
antiprotozoan meds–> but by the time it is Dx, it is almost always too late for effective treatment
What must one do when using a Neti Pot in order to avoid infection that will cause Primary Amebic Meningoencephalopathy?
use distilled, sterile, or previously boiled water
pathogen = Acanthamoeba
What is a Prion Disease? What does it cause?
a prion is an infectious protein
causes Spongiform encephalopathies–> leaves the brains of victims full of holes
Prion disease cause Spongiform encephalopathies, and is a class of disease that includes what three?
- varient Creutzfeldt-Jacob disease (vCJD)**
- Bovine Spongiform Encephalopathy (BSE)– aka “mad cow disease” (cows
- scrapie (sheep/goats)
What Prion disease of the CNS is our focus?
Varient Creutzfeldt-Jakob Disease (vCJD)
Is Varient Creutzfeldt-Jakob Disease (vCJD) an emerging/reemerging disease?
yes
How does one acquire Varient Creutzfeldt-Jakob Disease (vCJD)?
most likely from eating BSE contaminated beef
BSE = Bovine Spongiform Encephalopathy
What is the Tx for Varient Creutzfeldt-Jakob Disease (vCJD)?
no Tx is available
What are the symptoms of Varient Creutzfeldt-Jakob Disease (vCJD)?
- insomnia
- weight loss
- memory failure
- progressive worsening of muscle control
- neurological tissue destruction (spongiform encephalopathy)
