Viral Encephalitis and Poliomyelitis Flashcards
Introduction
Encephalitis is a/an (acute or chronic?) inflammatory process affecting the ___________
Acute
brain parenchyma
Causes
Herpesviruses
List 6
Flaviviruses
List 4
Togaviridae
List 3
HSV – 1, HSV – 2, VZV, CMC, EBV, HHV – 6
West Nile
Japanese encephalitis
St. Louis encephalitis
Tick borne encephalitis virus
Eastern equine encephalitis
Western equine encephalitis Venzuelan equine encephalitis virus
Causes
Enteroviruses
Measles virus
Mumps virus
Rabies virus
Lymphocytic choriomeningitis virus Colorado tick fever virus
Influenza virus
Adenoviruses
T/F
T
ARBOVIRUS
The arboviruses are a miscellaneous group of
(Naked or Enveloped?)
____RNA viruses that infect animals.
They are transmitted from one vertebrate host to another via _________
The main reservoirs are wild birds and small mammals. Man may be infected if bitten by the insect vector.
Enveloped
ss
blood sucking arthropods.
ARBOVIRUS
The main reservoirs are ______ and _______. Man may be infected if _______________
wild birds and small mammals
bitten by the insect vector.
Flaviviruses
_________, 40 - 60 nm or more in diameter
Naked or Enveloped?
_____-stranded RNA
________ sense, about 11 kb
Replication: ________.
Assembly: within ___________.
Spherical
Enveloped; single; positive
cytoplasm
endoplasmic reticulum
Flaviviruses
Envelope. _____ structural protein
•list : ___________________________________
Non structural:
•list !!!
Three
Capsid (C), Membrane (M), Envelope (E)
NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5
Togavirus
_________, 70 nm in diameter
nucleocapsid has ____ capsomeres.
Genome: ________-sense, _____-stranded RNA, 11–12 kb in size.
(Naked or Enveloped?).
Replication: ________.
Assembly: ______ through ________
Spherical; 42
positive; single
Enveloped
cytoplasm
Budding ; host cell membranes.
Togavirus
Envelope:
_____________ major structural polypeptides
______ are _________.
Three or four
two
glycosylated
Clinical features of viral encephalitis
Fever
Headache
Malaise
Anorexia
Nausea and Vomiting
____________/_________
______ aberrations: ________,_______
Altered sensorium/coma
Mental
hallucination; agitation
Clinical features of viral encephalitis
___________ change
_________ disorders
occasionally __________
personality
behavioral
frank psychosis
Clinical features of viral encephalitis
_____________ seizures in >50% severe cases.
(Mild or Severe?) focused _______ deficits
Virtually every possible ____________________ has been reported.
Focal or general
Severe; neurologic
focal neurological disturbance
Clinical features of viral encephalitis
Most Common
•______ and ______
•Hemi______ with ________ tendon reflexes
• (voluntary or Involuntary?) movements
•________ nerve deficits (_____palsies, ______ weakness)
Aphasia; Ataxia
paresis; hyperactive
Involuntary
Cranial; ocular; facial
Laboratory diagnosis of viral encephalitis
CSF
• usually _______
• __________________ pressure
•initially a _________ ________, which rapidly converts to ________
• proteins are ________
• glucose is _______
PCR
Virus culture
Serology – IgG, IgM
colorless
Slightly increased
neutrophilic pleocytosis; lymphocytes
Increased
normal
Treatment
HSV – Acyclovir
• 10mg/kgintravenouslyevery8hours. • Duration 14-21 days.
Ganciclovir can be used in CMV infections.
Fever, dehydration, electrolyte imbalances, and convulsions require treatment.
For cerebral edema severe enough to produce herniation, controlled hyperventilation, mannitol, and dexamethasone.
Patients with cerebral edema must not be overhydrated. monitoring ICP should be considered.
Treatment of viral encephalitis
HSV – _______
___________ can be used in CMV infections.
Fever, dehydration, electrolyte imbalances, and convulsions require treatment.
Acyclovir
Ganciclovir
Treatment of viral encephalitis
For cerebral edema severe enough to produce _______, controlled _____,_________, and ————-
Patients with cerebral edema must not be ————-. monitoring _____ should be considered.
herniation
hyperventilation, mannitol, and dexamethasone.
overhydrated; ICP
Prognosis of viral encephalitis
Outcomes are variable depending on _____.
———- and ______ encephalitis generally have high mortality rates and Severe neurologic sequelae among survivors.
______ is associated with significant morbidity and morality.
etiology
EEE and St. Louis
WNV
Prognosis of viral encephalitis
Mortality of HSV encephalitis before acyclovir was _____% to _____%, and with treatment approximately _____%.
_______ disability, _____, and ______ deficits are common sequelae seen among survivors
60; 70
30
Cognitive; seizures; motor
Prevention
Vaccination
List 4
Mosquito control
Use of insect repellant
Insecticide spray
Mosquito nets
VZV
Rabies virus
Japenese encephalitis virus
Tick borne encephalitis virus
Post infectious encephalitis
develop in the _______ phase, following a number of common viral infections
(Common or Uncommon?)
Measles, mumps, rubella and primary varicella-zoster virus infection.
convalescent
Uncommon
Post infectious encephalitis
Following exposure to certain vaccines, such as: ______ virus and the older ______________ vaccines.
vaccinia
neurotissue rabies
Post infectious encephalitis
(Focal or Widespread?) _______ lesions develop involving the ________ in the ________________.
Widespread; demyelinating
white matter
brain and spinal cord.
Post infectious encephalitis
Characteristic histological features include: ________ infiltration and __________ of adjacent blood vessels.
The causative agent (can or cannot?) be isolated from brain tissue or CSF.
lymphocytic; perivascular cuffing
Cannot
Post infectious encephalitis
The aetiology is somewhat obscure, but it is thought to be a ____________ auto-immune phenomenon, triggered by exposure to foreign antigens which are ______________________________________ (__________________ ).
T cell-mediated
closely related to host proteins normally present in brain tissue
molecular mimicry
Guillain Barre syndrome
Characterised by ________ which develops ________ to _____ after the _______ phase of a certain bacterial or viral infections.
The disease is due to __________ of _________ nerves.
poly-neuritis
a few days to weeks
acute; demyelination
peripheral
Guillain Barre syndrome
Patients present with ______ paralysis, associated with ______.
Like post infectious encephalomyelitis, it is believed to be __________ phenomenon.
an ascending; paraesthesia
an immunological
Guillain Barre syndrome
Patients usually recover ______________________________________ as affected nerves are _____________
spontaneously over a few weeks or months
re-myelinated.
Polio virus
Polio (poliomyelitis) mainly affects _______________________
1 in 200 infections leads to (reversible or irreversible?) paralysis.
children under 5 years of age.
irreversible
Polio virus
Among those paralysed, 5% to 10% die when their ———- muscles become immobilized.
breathing
Polio virus
The reduction in prevalence is the result of the global effort to ____________
eradicate the disease.
As long as a single child remains infected, ______________________________
~WHO 2016
children in all countries are at risk of contracting polio.
Poliomyelitis
______ stranded
(linear or circular?)
________ sense RNA
Transmission is ________
Single
Linear
positive
faeco-oral
Poliomyelitis
Primary multiplication takes place in the _________ or ________
The virus first multiplies in the _____, the _______ of the neck, ————, and the __________.
The CNS may then be invaded by way of the __________. Spread along _______ of ___________ to the CNS.
oropharynx or intestine.
tonsils; lymph nodes ; Peyer patches
small intestine; circulating blood
axons of peripheral nerves
In Poliomyelitis
Some cells that lose their function may recover completely
T/F
T
Clinical finding of poliomyelitis
Incubation period:_________ (range ___-____ days)
Could be a Mild disease
Or
____________ polio
_________ polio
.
__________ ———poliomyelitis _________
Virus shedding in stool for _________
1 – 2 weeks; 3 – 35
Non paralytic
Paralytic
Progressive post; muscle atrophy
6 – 8 weeks
Clinical finding of poliomyelitis
Non paralytic polio can lead to ___________
Paralytic polio
•(Acute or Chronic?) (flaccid or spastic?) paralysis resulting from (upper or lower?) motor neuron damage.
aseptic meningitis
Acute flaccid
Lower
Clinical finding of poliomyelitis
Progressive post poliomyelitis muscle atrophy
•A recrudescence of ____________ and _________ decades after their experience with ______________
paralysis and muscle wasting
paralytic poliomyelitis
Laboratory diagnosis of poliomyelitis
Specimen-_____,_______,_______
PCR
Virus culture
Serology
stool, throat swab, CSF
Acute flaccid paralysis (AFP) surveillance
•finding and reporting children with AFP
•transporting ——- samples for analysis
•isolating and identifying poliovirus in the laboratory
•_____the virus to determine the —————
stool
mapping
origin of the virus strain.
Global eradication strategy
Polio virus type —— was declared eradicated in ______. last case in ______.
2
2015
1999
Global eradication strategy
Nigeria was taken off the list of polio endemic countries in _____ _______ because a year had passed with no reported cases of WPV
But ____ cases this year from _____ state
September 2015
3; borno
Polio vaccines
Oral polio vaccine (OPV) by _______
in ———
Inactivated polio vaccine (IPV) by ________ in ______
Albert Sabin; 1961
Jonas Salk ; 1955
Oral polio vaccine
OPV also produces a local, mucosal immune response in the ___________________
In the event of infection, these mucosal antibodies limit the replication of the _____ poliovirus inside the _____.
This ______ immune response to OPV is thought to be the main reason why mass campaigns with OPV can rapidly stop person-to-person transmission of wild poliovirus.
mucous membrane of the intestines.
wild; intestine
intestinal
Which vaccine is cheaper??
OPV
The inactivated polio vaccine produces antibodies in the blood to all three types of poliovirus
T/F
T
The oral polio vaccine produces antibodies in the blood to all three types of poliovirus
T/F
T
In some cases it is believed that this vaccine-associated paralytic polio (VAPP) may be triggered by ________
immune deficiency.
IPV induces (very high or very low?) levels of immunity in the intestine.
Very low
WHO Region of the Americas was certified polio-free in _______ ,
the WHO Western Pacific Region in _______
and the WHO European Region in June _______.
On 27 March 2014, the WHO _______ Region was certified polio-free,
In 2020, Africa became the _______ region to be certified wild poliovirus-free.
1994,
2000
June 2002.
South-East Asia
fifth
Circulating vaccine-derived polioviruses (cVDPVs
are (common or rare?) rare strains of poliovirus that have __________ from the strain contained in the __________, and which can only emerge and circulate in __________ communities.
If the vaccine-virus is able to circulate for a prolonged period of time uninterrupted, it can mutate and, over the course of __________, reacquire infectious strength.
rare ; OPV; under-immunized
12-18 months
Circulating vaccine-derived polioviruses (cVDPVs
The (lower or higher?) the population’s immunity, the longer the cVDPV can survive.
The longer they survive, the more they replicate, change, and __________________ with other viruses as they spread.
A cVDPV can cause cases of ________ in those it circulates to.
If a population is fully immunized against polio, it will be protected against the spread of ____________________________ strains of poliovirus.
Lower
exchange genetic material
paralysis
both wild and vaccine derived
Circulating vaccine-derived polioviruses (cVDPVs
The switch from ____valent to ____valent oral polio vaccine (OPV) has dramatically reduced the risk of cVDPV. This is because the greatest risk of cVDPV arises from type ____ polio vaccine, which is _____ from ________ OPV.
trivalent ; bivalent
type 2 polio
absent
bivalent
