Viruses: RNA Negative Sense Viruses Flashcards
List the RNA negative sense viruses
- Influenza
- Measles
- Mumps
- RSV
- Parainfluenza
- Rabies
- Ebola
- Hantavirus
- California Encephalitis Virus
- Rift Valley Fever Virus
- Lymphocytic Choriomeningitis Virus
- Rotavirus
- Colorado Tick Fever Virus
List the RNA negative sense virus families
- Orthomyxoviridae
- Paramyxoviridae
- Rhabdoviridae
- Filoviridae
- Bunyaviridae
- Arenaviridae
- Reoviridae
Influenzavirus
- negative sense
- RNA virus
- Orthomyxoviridae
- enveloped
viruses in the Orthomyxoviridae family
Influenzavirus A, B, and C
orthomyxoviruses (i.e. Influenzavirus) replicate
inside the nucleus of host cells
the genomes of orthomyxoviruses (i.e. Influenzavirus) are comprised of
8 RNA segments
antigenic drift of orthomyxoviruses
antigenic drift of orthomyxoviruses (i.e. Influenzavirus) occurs due to point mutations in the viral genome, leading to changes in the hemagglutinin (HA) or neuraminidase (NA) glycoproteins (antigenic drift is associated with epidemics (i.e. the seasonal flu))
antigenic shift of orthomyxoviruses
antigenic shift of orthomyxoviruses (i.e. 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 (antigenic shift is associated with pandemics)
the genomes of orthomyxoviruses (i.e. Influenzavirus) can
the genomes of orthomyxoviruses (i.e. Influenzavirus) can undergo significant genetic changes due to reassortment of the RNA segments (antigenic shift), resulting in variations of virulence factors such as hemagglutinin and neuraminidase
the antigenic variation exhibited by orthomyxoviruses (i.e. Influenzavirus) occurs as a result of
genetic drift and genetic shift
Influenzavirus possesses
the glycoprotein hemagglutinin (HA), which promotes viral entry into host cells
the hemagglutinin (HA) of Influenzavirus
the hemagglutinin (HA) of Influenzavirus binds host cell sialic acid residues
a variety of hemagglutinin (HA) glycoproteins are expressed by influenza viruses
a variety of hemagglutinin (HA) glycoproteins are expressed by influenza viruses; H1, H2, and H3 are seen in influenza viruses that infect humans (the hemagglutinin (HA) glycoprotein determines cell tropism (or what cells influenza viruses are able to infect))
the M2 proton channel of Influenza A virus
the M2 proton channel of Influenza A virus regulates hydrogen ion concentration around the virus, producing the proper pH for viral uncoating
amantadine/rimantadine
amantadine/rimantadine inhibit the M2 proton channel of Influenza A virus, impeding viral uncoating
Influenzavirus possesses neuraminidase (NA)
Influenzavirus possesses neuraminidase (NA), which cleaves sialic acid residues, leading to release of the virus from host cells
nfluenzavirus possesses the _________ enzyme
neuraminidase
oseltamivir/zanamivir (Tamiflu)
oseltamivir/zanamivir (Tamiflu) (an antiviral agent that can inhibit neuraminidase (NA) of Influenzavirus)
oseltamivir/zanamivir (Tamiflu) inhibit
neuraminidase (NA), preventing the release of Influenzavirus from the host cell
Influenzavirus is transmitted via
respiratory droplets
______ vaccine can be administered to prevent Influenzavirus infection
- a killed injectable vaccine
2. intranasal live vaccine
______ is a major complication of influenza
pneumonia
patients are more susceptible to _________ during or after Influenzavirus infection
patients are more susceptible to pneumonia caused by bacterial pathogens (such as Staphylococcus aureus and Streptococcus pneumoniae) during or after Influenzavirus infection
_______ is contraindicated in children with viral illnesses, such as influenza, due to possible development of Reye’s syndrome
aspirin
Reye’s syndrome can present with
encephalopathy, fatty liver change, and hepatic failure
Reye’s syndrome has been linked with
aspirin use during a viral illness, such as influenza
the influenza vaccine is associated with
Guillain-Barre syndrome, which classically presents with ascending paralysis
Paramyxoviridae
- negative sense
- RNA viruses
- enveloped
paramyxoviruses include
- measles virus
- mumps virus
- respiratory syncytial virus
- parainfluenza virus
paramyxoviruses (i.e. measles virus, mumps virus, respiratory syncytial virus, parainfluenza virus) are transmitted via
respiratory droplets
the MMR vaccine is a live attenuated vaccine administered to prevent
measles, mumps, and rubella
________ is a contraindication for the MMR vaccine
pregnancy
measles virus
- negative sense
- RNA viruses
- enveloped
- paramyxoviridae
measles is sometimes referred to as
rubeola
measles can present with
- cough
- coryza
- conjunctivitis
- Koplik spots
- fever over 40 °C (104 °F)
Koplik spots appear as
small bluish-white spots on the buccal mucosa and are pathognomonic of measles
the maculopapular rash seen in measles
- starts on the face and moves inferiorly
2. likely to be confluent
______ is a complication of measles
pneumonia
subacute sclerosing panencephalitis (SSPE) is
subacute sclerosing panencephalitis (SSPE) is a rare complication of measles characterized by progressive brain inflammation
subacute sclerosing panencephalitis (SSPE) is a serious complication of the
measles
measles virus possesses
- the glycoprotein hemagglutinin (HA), which promotes viral entry into host cells
- fusion protein, which plays a role in the formation of syncytia (or multinucleated giant cells)
________ reduces the risk of complications of the measles
Vitamin A
mumps virus
- negative sense
- RNA viruses
- enveloped
- paramyxoviridae
mumps virus replicates in the
parotid salivary glands, which results in parotitis
mumps infection can progress to
- orchitis in men (the testicular inflammation is more commonly unilateral)
- meningitis
the MMR vaccine includes
live attenuated mumps virus
mumps virus possesses
- the glycoprotein hemagglutinin (HA), which promotes viral entry into host cells
- fusion protein, which plays a role in the formation of syncytia (or multinucleated giant cells)
- neuraminidase, which cleaves sialic acid residues, leading to release of the virus from host cells
respiratory syncytial virus (RSV)
- negative sense
- RNA viruses
- enveloped
- paramyxoviridae
RSV commonly affects
infants less than 6 months of age
RSV infects
respiratory epithelial cells via G protein attachment
RSV is the most common cause of
pneumonia and bronchiolitis in infants
respiratory syncytial virus possesses
usion protein, which plays a role in the formation of syncytia (or multinucleated giant cells)
_______ can be used to treat RSV infections
ribavirin
__________ is used to prevent RSV disease in high risk children
palivizumab (a monoclonal IgG antibody)
parainfluenza virus
- negative sense
- RNA viruses
- enveloped
- paramyxoviridae
parainfluenza virus is the cause of
croup, which is characterized by a “barking” cough (often compared to the call of a seal)
parainfluenza virus possesses
parainfluenza virus possesses the virulence factors hemagglutinin (HA), neuraminidase (NA), and fusion protein
chest X-ray of patients with croup may show
chest X-ray of patients with croup may show the “steeple sign,” which occurs due to subglottic trachea narrowing
______ is a common cause of inspiratory stridor
croup
rabies virus
- negative sense
- RNA
- Rhabdoviridae
- enveloped
the capsule of viruses in the Rhabdoviridae family (i.e. rabies virus) appears
bullet-shaped on electron microscopy
the capsid of viruses in the Rhabdoviridae family (i.e. rabies virus) is
helical
______ are the number one carrier of the rabies virus in the United States
bats
_____ are common carriers of the rabies virus
- skunks
- raccoons
- foxes
a rhabdovirus glycoprotein binds
nicotinic acetylcholine receptors
a rhabdovirus glycoprotein binds nicotinic acetylcholine receptors in the
postsynaptic membrane of the neuromuscular junction
the rabies virus travels
- retrograde along peripheral nerves to the CNS
2. to the dorsal root ganglia before spreading to the brain
the rabies virus replicates in
motor neurons
rabies can present with
fever, foaming of saliva, and encephalitis
eosinophilic Negri bodies are pathognomonic for
rabies and can be seen in neural tissue upon microscopy
Negri bodies are commonly found in
hippocampal pyramidal nerve cells infected with the rabies virus
Negri bodies can be found in
Purkinje cells infected with the rabies virus
eosinophilic Negri bodies can be found in
Purkinje cells infected with the rabies virus
_______ should be administered after exposure to the rabies virus
passive immunization should be administered after exposure to the rabies virus
_______ should be administered after exposure to the rabies virus for development of active immunity
an inactivated (killed) vaccine should be administered after exposure to the rabies virus for development of active immunity
Filoviruses
- ebolavirus
2. marburgvirus
Filoviruses
- RNA Virus
- Negative Sense virus
- enveloped
the capsids of filoviruses (i.e. Ebolavirus, Marburgvirus) are
helical
Marburg virus
- RNA Virus
- Negative Sense virus
- enveloped
- Filoviridae
Ebola virus
- RNA Virus
- Negative Sense virus
- enveloped
- Filoviridae
Marburg virus and Ebola virus infections may present with
petechial rash and fever
Marburg virus and Ebola virus can cause
hemorrhagic fever
hemorrhagic fever caused by Marburg virus or Ebola virus can result in
end-organ failure
Marburg virus and Ebola virus infections can lead to
hypovolemic shock
Marburg virus and Ebola virus are likely transmitted via
primates
_____ may be a reservoir for Marburg virus and Ebola virus
Symbols
bats
healthcare workers who care for patients infected with Marburg virus or Ebola virus are at a high risk of
infection
bunyaviruses include
- hantavirus
- California encephalitis virus
- Rift Valley fever virus
bunyaviruses (i.e. hantavirus, California encephalitis virus, Rift Valley fever virus) are
- RNA viruses
- Negative sense
- enveloped
bunyaviruses (i.e. hantavirus, California encephalitis virus, Rift Valley fever virus) obtain their envelopes from
the Golgi body membrane of host cells
the genomes of bunyaviruses (i.e. hantavirus, California encephalitis virus, Rift Valley fever virus) are comprised of
three circular RNA segments
hantavirus
- RNA viruses
- Negative sense
- Bunyaviruses
- enveloped
hantavirus (an RNA virus in the Bunyaviridae family) is transmitted via
the feces, urine, and saliva of rodents
hantavirus infection may lead to
pulmonary edema due to increased capillary permeability
hantavirus infection may cause
hypotension leading to prerenal azotemia or acute renal failure
hantavirus may cause
hemorrhagic fever
California encephalitis virus and Rift Valley fever virus
- RNA viruses
- Negative sense
- Bunyaviruses
- enveloped
California encephalitis virus and Rift Valley fever virus infections can lead to
encephalitis and seizures
_______ is the vector of California encephalitis virus and Rift Valley fever virus
the Aedes mosquito
most bunyaviruses (i.e. California encephalitis virus, Rift Valley fever virus) are
arboviruses (viruses that are arthropod-borne); an important exception is hantaviruses, which are rodent-borne
arenaviruses include
are RNA viruses
arenaviruses
- RNA virus
- Negative Sense
- enveloped
- helical capsid
arenaviruses (i.e. lymphocytic choriomeningitis virus) are often classified as
negative-sense RNA viruses (but also harbor sections of positive-sense RNA)
arenaviruses (i.e. lymphocytic choriomeningitis virus) possess both positive and negative-sense RNA sections, making them
ambisense
the genomes of arenaviruses (i.e. lymphocytic choriomeningitis virus) contains
two RNA segments
arenaviruses (i.e. lymphocytic choriomeningitis virus) appear
grainy when visualized by electron microscopy
_____ are the reservoir for arenaviruses (i.e. lymphocytic choriomeningitis virus)
rodents
lymphocytic choriomeningitis virus
an ambisense RNA virus in the Arenaviridae family
lymphocytic choriomeningitis virus infection may lead to
aseptic meningoencephalitis
lymphocytic choriomeningitis virus infection may present with
fever
arenaviruses (i.e. lymphocytic choriomeningitis virus) can be inactivated by
- heat
2. irradiation
reoviruses include
- Rotavirus
2. Colorado tick fever virus
Reoviruses
- RNA
- Negative sense
- naked viruses
the genomes of reoviruses (i.e. Rotavirus, Colorado tick fever virus) is comprised of
an average of 11 RNA segments (but can be anywhere between 9-12)
reoviruses (Rotavirus, Colorado tick fever virus) are
double-stranded RNA viruses (and therefore are both positive- and negative-sense)
Rotavirus
a double-stranded RNA virus in the Reoviridae family
Rotavirus infection can present with
watery diarrhea
the NSP4 enterotoxin of Rotavirus
- causes secretory (watery) diarrhea
2. increases chloride permeability, which results in secretory diarrhea
the peak incidence of Rotavirus gastroenteritis occurs in
winter
____ are at increased risk for Rotavirus infection
children
Rotavirus is the number one cause of
severe diarrhea in young children
Colorado tick fever virus
a double-stranded RNA virus in the Reoviridae family
Colorado tick fever virus infection can present with
vomiting, fever, and myalgias
the treatment for Rotavirus gastroenteritis is
oral rehydration therapy and supportive care
the rotavirus vaccine
the rotavirus vaccine is a live attenuated vaccine that is administered orally
the rotavirus vaccine can cause
the rotavirus vaccine can cause intussusception (telescoping of the bowel) that can lead to bloody diarrhea and bowel necrosis
