RNA Viruses - Negative Sense - Orthomyxoviridae; Paramyxoviridae Flashcards
Which Sketchy image represents influenzavirus?
Of what family is this virus a member?
Orthomyxoviridae
Which Sketchy image represents measles virus, mumps virus, respiratory syncytial virus, and parainfluenza virus?
Of what family are these viruses members?
Paramyxoviridae
Identify as many of the marked points in this image as you can.
Note: this is influenzavirus.
Identify as many of the marked points in this image as you can.
Note: this is measles virus, mumps virus, respiratory syncytial virus, and parainfluenza virus.
Influenzavirus is a ___________-sense _______ virus in the Orthomyxoviridae family.
Influenzavirus is a negative-sense RNA virus in the Orthomyxoviridae family.
True/False.
Orthomyxoviruses (e.g. Influenzavirus) are DNA viruses.
False.
Orthomyxoviruses (e.g. Influenzavirus) are RNA viruses.
Are orthomyxoviruses (e.g. Influenzavirus) naked or enveloped?
Enveloped
What are the main categories of influenza virus?
Type A
Type B
Type C
Which type of influenza virus is associated with epidemics?
Type B
Which type of influenza virus is associated with pandemics?
Type A
Which type of influenza virus is most associated with the seasonal flu?
Type B
Where do orthomyxoviruses (e.g. influenza virus) replicate within host cells?
The nucleus
(Note: this is unique among RNA viruses)
The genomes of orthomyxoviruses (i.e. Influenzavirus) are comprised of how many RNA segments?
8
What is here described:
- “changes in orthomyxoviruses (i.e. Influenzavirus) occurring due to point mutations in the viral genome, leading to changes in the hemagglutinin (HA) or neuraminidase (NA) glycoproteins*
- — — —*
- associated with epidemics (i.e. the seasonal flu))”*
Antigenic drift
Which is associated with epidemics (e.g. the seasonal flu), antigenic drift or antigenic shift?
Antigenic drift
What is here described:
“changes in orthomyxoviruses (e.g. Influenzavirus) occurs when segments of the genomes from different viruses (or strains of a virus) combine to form a novel genome, which results in variations of virulence factors such as hemagglutinin and neuraminidase
associated with pandemics
Antigenic shift
What segments of influenza virus are mixed and matched to result in pandemics?
Hemagglutinins
and
neuraminidases
(leading to H__N__ flus)
The antigenic variation exhibited by orthomyxoviruses (e.g. Influenzavirus) occurs as a result of what process(es)?
Antigenic drift and antigenic shift
Influenzavirus possesses the glycoprotein ____________, which promotes viral entry into host cells.
Influenzavirus possesses the glycoprotein hemagglutinin, which promotes viral entry into host cells.
The hemagglutinin (HA) of Influenzavirus binds host cell ____________ residues.
The hemagglutinin (HA) of Influenzavirus binds host cell sialic acid residues.
What determines the cell tropism seen in various influenza viruses?
Hemagglutinin variation
(H1, H2, H3)
The __________ proton channel of Influenza A virus regulates __________ ion concentration around the virus, producing the proper pH for viral uncoating.
The M2 proton channel of Influenza A virus regulates proton ion concentration around the virus, producing the proper pH for viral uncoating.
The M2 proton channel of Influenza A virus regulates proton ion concentration around the virus, producing the proper pH for viral ____________.
The M2 proton channel of Influenza A virus regulates proton ion concentration around the virus, producing the proper pH for viral uncoating.
__________ and __________ inhibit the M2 proton channel of Influenza A virus, impeding viral uncoating.
Amantadine and rimantadine inhibit the M2 proton channel of Influenza A virus, impeding viral uncoating.
Influenzavirus possesses ____________, which cleaves sialic acid residues, leading to release of the virus from host cells
Influenzavirus possesses neuraminidase, which cleaves sialic acid residues, leading to release of the virus from host cells
_________ (Tamiflu) and _________ are antiviral agents that can inhibit neuraminidase of Influenzavirus, inhibiting release of new virions.
Oseltamivir (Tamiflu) and zanamivir are antiviral agents that can inhibit neuraminidase of Influenzavirus, inhibiting release of new virions.
Oseltamivir (Tamiflu) and zanamivir inhibit which influenza protein?
Neuraminidase
(preventing the release of Influenzavirus from the host cell)
How is influenza virus transmitted?
Via respiratory droplets
How is the killed influenza virus administered?
IM
How is the live influenza virus administered?
Intranasally
__________ is a major complication of influenza.
Pneumonia is a major complication of influenza
Patients are more susceptible to pneumonia caused by __________ pathogens during or after Influenzavirus infection.
Patients are more susceptible to pneumonia caused by bacterial pathogens during or after Influenzavirus infection.
What bacterial pathogens are most likely to cause superinfection pneumonia in patients weakened due to influenza viral infection?
Staphylococcus aureus;
Streptococcus pneumoniae
Aspirin is contraindicated in children with viral illnesses, such as influenza, due to possible development of _____________.
Aspirin is contraindicated in children with viral illnesses, such as influenza, due to possible development of Reye’s syndrome.
Reye’s syndrome can present with ________pathy, _______ _______ change, and _______ failure.
Reye’s syndrome can present with encephalopathy, fatty liver change, and hepatic failure.
What vaccine is associated with Guillain-Barre syndrome (which classically presents with ascending paralysis)?
The influenza virus
Name the four major viruses of the Paramyxoviridae family.
Measles (Rubeola)
Mumps
Respiratory syncytial virus (RSV)
Parainfluenza (croup)
The measles (Rubeola) virus is a(n) _____ virus of the ________viridae family.
The measles virus is an RNA virus of the _paramyxo_viridae family.
The mumps virus is a(n) _____ virus of the _________viridae family.
The mumps virus is an RNA virus of the paramyxoviridae family.
What is an alternate term for the measles virus?
The Rubeola virus
The respiratory syncytial virus is a(n) ______ virus of the _________viridae family.
The respiratory syncytial virus is an RNA virus of the _paramyxo_viridae family.
The parainfluenza virus is a(n) ______ virus of the _________viridae family.
The parainfluenza virus is an RNA virus of the _paramyxo_viridae family.
What virus causes croup?
The parainfluenza virus
What is an alternate term for croup?
Laryngotracheobronchitis
Viruses of the Paramyxoviridae family are _________-sense RNA viruses.
Viruses of the Paramyxoviridae family are negative-sense RNA viruses.
Are viruses of the Paramyxoviridae family naked or enveloped?
Enveloped
How is the measles (Rubeola) virus transmitted?
Respiratory droplets
How is the mumps virus transmitted?
Respiratory droplets
How is the respiratory syncytial virus transmitted?
Respiratory droplets
How is the parainfluenza virus transmitted?
Respiratory droplets
The ________ vaccine is a ______________ vaccine administered to prevent measles, mumps, and rubella.
The MMR vaccine is a live-attenuated vaccine administered to prevent measles, mumps, and rubella.
____________ is a contraindication for the MMR vaccine.
Pregnancy is a contraindication for the MMR vaccine.
What are the main initial S/Sy of measles infection?
The four “C”s
Cough, coryza, conjunctivitis, and Koplik spots
The main initial S/Sy of measles infection are _______, _______, conjunctivitis, and Koplik spots.
The main initial S/Sy of measles infection are cough, coryza, conjunctivitis, and Koplik spots.
The main initial S/Sy of measles infection are cough, coryza, _______, and _______ _______.
The main initial S/Sy of measles infection are cough, coryza, conjunctivitis and Koplik spots.
How do Koplik spots appear in those infected with measles virus?
Blue-white spots on a red background
Koplik spots appear as small bluish-white spots on the _______ _______ and are pathognomonic of measles.
Koplik spots appear as small bluish-white spots on the buccal mucosa and are pathognomonic of measles.
True/False.
Measles can present with fever, which is typically low-grade (<101 °F).
False.
Measles can present with fever over 40 °C (104 °F).
Describe the progression of the maculopapular rash seen in measles.
It starts on the face and moves inferiorly.
The maculopapular rash seen in measles ________ (is / is not) likely to be confluent.
The maculopapular rash seen in measles is likely to be confluent.
The rash seen in measles infection is a ___________ rash.
The rash seen in measles infection is a maculopapular rash.
True/False.
Pneumonia is a potential complication of measles.
True.
Subacute sclerosing panencephalitis (SSPE) is a rare complication of measles characterized by what?
Progressive brain inflammation
___________________ is a rare complication of measles characterized by progressive brain inflammation.
Subacute sclerosing panencephalitis (SSPE) is a rare complication of measles characterized by progressive brain inflammation
What virulence factors does the measles (Rubeola) virus possess?
Hemagglutinin;
fusion protein
What vitamin reduces the risk of complications of measles infection?
Vitamin A
In what organ does the mumps virus replicate?
The parotid gland
What is the main S/Sy of infection with the mumps virus?
Parotitis
Mumps infection can progress to ________ in men. This inflammation is commonly ____lateral.
Mumps infection can progress to orchitis in men. This inflammation is commonly unilateral.
Mumps infection can progress to _________ in either men or women.
Mumps infection can progress to meningitis in either men or women.
What virulence factors does the mumps virus have?
Hemagglutinin;
neuraminidase;
fusion protein
What pathology can be seen in infections due to members of the Paramyxoviridae family that express fusion protein?
Syncytia
(multinucleated giant cells)
RSV commonly affects what age group?
Infants < 6 months of age
RSV infects respiratory epithelial cells via _________ attachment.
RSV infects respiratory epithelial cells via G protein attachment.
RSV is the most common cause of ___________ and _________itis in infants.
RSV is the most common cause of pneumonia and bronchiolitis in infants.
What virulence factors are expressed by respiratory syncytial virus (RSV)?
Fusion protein;
G protein
_________ and _________ can be used to treat RSV infections.
Ribavirin and palivizumab can be used to treat RSV infections
___________ (a monoclonal IgG antibody) is used to prevent RSV disease in high risk children.
Palivizumab (a monoclonal IgG antibody) is used to prevent RSV disease in high risk children
What are the main findings of croup clinical presentation?
Barking cough (‘seal bark’ cough);
inspiratory stridor
What are the main virulence factors expressed by parainfluenza virus?
Hemagglutinin;
neuraminidase;
fusion protein
Croup is associated with what X-ray finding?
“Steeple sign”
(occurs due to subglottic trachea narrowing)
A child presents with a barking cough and inspiratory stridor. X-ray shows subglottic tracheal narrowing.
What is the etiology?
Parainfluenza virus
(Croup)
What is the most common cause of pneumonia in infants?
RSV
