LEC-12 Enteroviruses & Polio Flashcards
What are the 4 human picornaviruses?
I. Rhinovirus
II. Enterovirus
III. Hepatovirus
IV. Parechovirus
The human picornaviruses (are/are not) ether stable.
Are ether stable (Viruses that are ether stable DO NOT have an envelope)
(T/F) The human picornaviruses do not have a viral envelope.
True.
The viral binding site of poliovirus is referred to as “The Canyon”. _______________ sites ring the canyon.
Antigenic neutralizing sites
A _____________ pocket is found at the bottom of the Canyon in poliovirus.
Hydrophobic
Poliovirus binds to the ______ receptor in the body.
PVR (Poliovirus receptor)
Coxsackievirus Group B binds to the _____ and ____ receptors in the body.
- hCAR (Human Coxsackie and Adenovirus Receptor)
- DAF (Decay Acceleration Factor)
Human rhinoviruses (major group) bind to the ______ receptor in the body.
ICAM-1
Picornaviruses have (single/double) stranded, (positive/negative) sense (RNA/DNA) genomes.
Single stranded, positive-sense RNA genomes
Which area(s) of the following RNA molecule encodes the picornavirus capsid proteins?
Area P1 (VP1, VP2, VP3, VP4)
Which area(s) of the following RNA molecules encodes nonstructural viral proteins?
Areas P2 and P3
Enteroviruses cleave the _________ protein, completely stopping host cell translation.
EIF-4G
Enteroviruses use intragenomic regions of their RNA to recruit initiation factors and begin an abnormal form of translation known as ________________.
Noncanonical translation
The _________ region of the enterovirus RNA is responsible for the recruitment of initiation factors and beginning of translation.
IRES (Internal ribosome entry site)
The most common seasons for the infection of enteroviruses are _____________ and early ____________.
Summer and early fall
The most common method of transmission for enteroviruses is ____________. Some enteroviruses may also be transmitted through ____________, but this is much less common.
- Fecal-oral = most common
- Respiratory routes = less common
The _________ strain is used in the poliovirus vaccine. It is a(n) (killed/live/attenuated) strain that induces gut and systemic immunity.
- Sabin strain
- Live strain
Poliovirus affects (motor/autonomic/both motor and autonomic) neurons.
Both motor and autonomic
The primary sites of lesions caused by poliovirus are located in the gray matter of the (anterior/posterior) horns of the spinal cord and the (sensory/motor) nuclei of the pons and medulla.
- Anterior horns
- Motor nuclei
Due to involvement of lower motor neurons, poliovirus infection most often results in (flaccid/spastic) paralysis of muscles.
Flaccid
Less than __% of people infected by poliovirus experience its more severe paralytic effects.
Less than 1%
What are the three tiers of poliovirus infection severity?
I. Minor illness (90-95% of infections)
II. Abortive poliomyelitis (4-8% of infections)
III. Paralytic poliomyelitis (<1% of infections)
(T/F) Minor poliovirus infections are usually asymptomatic.
True.
The ______________ form of poliovirus infections typically manifests in low grade fever, malaise, and anorexia. This form is most commonly asymptomatic.
Minor illness
The ____________ form of poliovirus infections usually presents with fever, headache, myalgia, hyperesthesia, paresthesia, and stiffness of neck, back, and hamstrings. CSF findings are consistent with aseptic meningitis, displaying increased cell count, increased protein, and normal glucose levels.
Abortive poliomyelitis
The ____________ form of poliovirus infections usually presents with high fever, severe myalgia, areflexia, and weakness in one or more muscle groups. It also presents with asymmetric and flaccid paralysis.
Paralytic poliomyelitis
What are the three types of paralytic poliomyelitis?
I. Spinal
II. Bulbar
III. Bulbospinal
Bulbar paralytic poliomyelitis most often affects CNs ____ and ____.
CN IX and X
The (killed/live) polio vaccine, introduced by Jonas Salk, induced systemic immunity.
- Killed
- Jonas SalK = Killed
The (killed/live) polio vaccine, introduced by Albert Sabin, induced systemic and gut immunity. This vaccine is oral.
Live
How does Nonfocal Acute Febrile Illness present?
- Common cause of fever in infants during summer and fall
- Fever, irritability, lethary, poor feeding, exanthems (widespread rash), vomiting, upper respiratory tract infections (URTI), diarrhea
- 50% of childen have viral meningitis
Enteroviruses are responsible for over ___% of identifiable cases of aseptic meningitis in the US.
85%
Enteroviruses account for up to __% of encephalitis cases caused by viruses.
22%
In cases of viral myopericarditis caused by enteroviruses, _______________ are responsible for a majority of the cases.
Group B Coxsackie viruses
What is necessary for a diagnosis of myopericarditis?
I. Echo and EKG abnormalities
II. Increased myocardial enzymes
III. Endomyocardial biopsy
Enteroviruses can cause diseases of the hand, foot, and mouth. Of the enteroviruses, ______________ is the most common cause of these conditions.
Coxsackie A-16
How does Herpangina present?
- Abrupt onset of fever and sever sore throat
- Hyperemic pharynx
- Discrete Vesicles (anter pillars of fauces, tonsils, posterior pharynx, uvula, tongue, or palate)
The ________________ group of enteroviruses are most often the cause of herpangina.
Coxsackie A1-A6, A8, A10 and A22
How dow Pleurodynia (Epidemic Myalgia, Bornholm Disease) present?
- Abrupt onset of fever/sever chest pain
- Para- or substernal chest pain (intensified by movement)
- Malaise, anorexia, and headache
- Abdominal pain in 50% of cases
Pleurodynia is most often caused by the ___________________ group of enteroviruses.
Coxsackie B
Neonatal Enterovirus Sepsis Syndrome, a viral infection passed to a newborn through infection of the mother before birth, may result in ____________, ______________, and ____________ in the newborn.
- Hepatitis
- Meningoencephalitis
- Myocarditis
What are the clinical findings associated with Chronic Enteroviral Meningoencephalitis in Agammaglobulinemia (CEMA)?
I. Chronic Meningitis
II. Dementia
III. Hepatitis
IV. Dermatomyositis
Med-Hed
The diagnostic test of choice for enteroviruses is ___________.
RT-PCR
What is the most common cause of Pleurodynia (Epidemic Myalgia, Bornholm Disease)?
Group B Coxsackieviruses
How does Hand, Foot, and Mouth Disease present?
- Fever
- Oral ulcerations
- Vesicles on palms/soles
How does meningitis present?
- Fever
- Headache
- Nausea
- Vomiting
- Irritability
- Lethary
- Photophobia
- Examthems (wide spread rash)
- Biphasic course sometimes
How does encephalitis present?
- Mental status change
- Coma
- Parital motor seizures
How does Myopericarditis present?
- Febrile (fever) URTI precede signs and symptoms in 1/3 of cases
- Fever
- Substernal chest pain
- Exercise intolerance
- Dyspnea
- Pericardial friction rub (35-80%)
- Gallop rythm
- Ventricular failure (20%)
