Paramyxo Viruses

Question 1

Species
measles virus
mumps virus
respiratory syncytial virus (RSV)
parainfluenza viruses

Answer 1

Paramyxoviruses (Family = Paramyxoviridae)

Question 2

Paramyxoviruses

Rhabdoviruses

Orthomyxoviruses

Answer 2

Negative strand RNA viruses

Question 3

Species: rabies virus

Answer 3

Rhabdoviruses

Question 4

Species: influenza viruses A, B and C

Answer 4

Orthomyxoviruses

Question 5

Helical nucleocapsid

Pleomorphic envelope (variable shape)

Hemagglutinin (measles virus) on envelope binds sialic acid on cell surface glycoproteins measles virus binds CD46 protein present on most cells

Answer 5

Paramyxoviruses

Question 6

1. Virus brings in RNA polymerase which transcribes minus RNA
   into plus RNAs (full length and mRNAs)

2.Replication is cytoplasmic

Answer 6

Paramyxovirus replication

Question 7

hemagglutinins - envelope glycoproteins
attachment proteins (bind virus to host cells) 

F protein - causes membranes to fuse together
role in viral entry into cells
expression on infected cells causes cell-cell fusion
Giant cells (syncytia)

Answer 7

Measles virus

Question 8

t/f: All paramyxoviruses can induce syncytia formation

Answer 8

true

Question 9

• caused by measles virus
• enters body through
respiratory tract
• extremely contagious

skin involvement (partly, inflammation due to host response) humoral and cellular immune responses modulate outcome

Answer 9

Measles (Rubeola)

Question 10

Kroplik Spots

Answer 10

characteristic lesions of oral cavity

Answer 11

Measles (Rubeola)

Question 12

is a word describing the symptoms of a head cold. It describes the inflammation of the mucous membranes lining the nasal cavity which usually gives rise to the symptoms of nasal congestion and loss of smell, among other symptoms.

Answer 12

Coryza

Question 13

– Pneumonia (giant cell pneumonitis)
– Bacterial superinfections of middle ear
and lung – pneumococci, staphylococci, and
meningococci

Answer 13

complications of Measles (Rubeola)

Question 14

– rare progressive degeneration of central

nervous system caused by a type of measles virus

Answer 14

subacute sclerosing panencephalitis

Question 15

– symptomatic/supportive therapy
– attenuated measles vaccine
• MMR vaccine (measles, mumps,
rubella) • Live Measles vaccine - 1993

Answer 15

treatment, prevention, and control of Measles (Rubeola)

Question 16

– Paramyxovirus
pleomorphic,
enveloped virus – helical nucleocapsid – negative strand RNA

Answer 16

Mumps

Question 17

– develop 16-18 days after infection
– fever, and swelling and tenderness of salivary glands
– complications include meningitis and orchitis
(inflammation of testis)

Answer 17

clinical manifestations of MUMPS

Question 18

– live, attenuated vaccine (MMR)

Answer 18

MUMPS vaccine

Question 19

minus stranded RNA
genome = one segment of RNA

enveloped
G protein binds host cells (instead of a hemagglutinin)

F protein - causes membrane fusion
syncytia formation

virus enter respiratory epithelial cells, then spreads downward
along the respiratory mucosa

no clinically significant spread to distant sites

• necrosis of epithelial cells
• infiltration of lymphocytes
• increased mucous production

Answer 19

Respiratory Synctial Virus

Question 20

• considered to be most dangerous respiratory infections in young children
• spread by hand contact and respiratory secretions

• clinical manifestations
– acute onset of fever, cough, rhinitis, and nasal congestion
– often progresses quickly to severe bronchiolitis and
pneumonia

• bronchiolitis - bronchiole obstruction that can lead to respiratory failure

host response may account for most serious symptoms

Answer 20

Respiratory syncytial virus (RSV)

Question 21

How is Respiratory syncytial virus (RSV) tested?

Answer 21

– rapid immunologic tests

Question 22

– negative strand RNA virus

– highly neurotropic

Answer 22

Rabies

Question 23

– bites of infected animals
– aerosols in caves where bats roost
– contamination of scratches, abrasions, open wounds, or mucous membranes with saliva of infected animals

Answer 23

Rabies Transmission

Question 24

minus stranded RNA

genome = one segment of RNA

enveloped, bullet shaped virus replication is entirely cytoplasmic

Answer 24

Rabies virus

Question 25

_____, _____, ____, ___ are four animals common associated with tranmitting the rabies virus.

Answer 25

skunk fox, bat raccoon

Question 26

incubation can be up to 12 months after virus enters body depends on size of inoculum location of bite face bite has shorter incubation

Answer 26

Rabies virus manifestations

Question 27

______ ____ ascends via the sensory fibers and spreads among the nervous system.

Answer 27

rabies virus

Question 28

masses of nucleocapsids in cytoplasm seen in brain tissue of 70-90% of infected humans

Answer 28

negri bodies

Question 29

– begin 2 to 16 weeks after exposure – pain or paresthesia at wound site, anxiety, irritability, depression, fatigue, loss of appetite, fever, and sensitivity to light and sound – Hydrophobia: contractions of muscles involved in swallowing (sometimes sight of water elicits this) – quickly progresses to paralysis – death results from destruction of regions of brain that regulate breathing

Answer 29

Clincal manifestations of Rabies Virus

Question 30

– Passive administration of antibody (antiserum or immunoglobulin) (human rabies immune globulin = HRIG collected from immunized persons) – postexposure vaccination – preexposure vaccination of individuals with high risk of exposure, dogs, and cats

Answer 30

Treatment, prevention and control of Rabies virus

Question 31

Genus: Influenzavirus - influenza virus A, B and C minus stranded RNA enveloped

Answer 31

Orthomyxoviruses

Question 32

8 segments of RNA (for influenza viruses _ and _ )

Answer 32

A and B

Question 33

7 segments of RNA (for influenza virus _)

Answer 33

C

Question 34

uses 5 end of host mRNA to prime viral mRNA synthesis

Answer 34

Cap snatching

Question 35

attachment to host cell surface (prior to entry) binds to sialic acid on epithelial cell surface promotes membrane fusion (viral-cellular) binds/aggregates RBCs elicits protective neutralizing antibody response

Answer 35

Surface Spikes (peplomers) Hemagglutinin (HA)

Question 36

release of virus from envelope cleaves sialic acid (NA has enzymatic activity)

Answer 36

neuraminidase (NA)

Question 37

Typical flu symptoms (fever, headache, muscle aches, malaise) due to ____ ____ q

Answer 37

interferon induction

Question 38

–Treat with amantidine, rimantidine (A strain only); ribavirin (A and B) –inactivated virus vaccine

Answer 38

Influenza treatments

Question 39

Changes in influenza virus surface proteins (hemagglutinin and neuraminidase) due to point mutations that occur during viral replication is called ____ _____.

Answer 39

antigenic drift.

Question 40

_____ _____ in influenza virus are caused by reassortment of viral genomic fragments during a mixed infection by two different influenza viruses

Answer 40

Antigenic shifts

Question 41

Antigenic shifts in influenza virus are caused by ________ of viral genomic fragments

Answer 41

reassortment

Question 42

_____ play an important role as a “mixing vessel” for influenza viruses from humans, birds, and pigs. This is because pigs can become infected by these different influenza viruses.

Answer 42

Pigs

Question 43

killed 50 million world-wide victims usually young and previously healthy Likely killed via a “cytokine storm” in victims with strong immune system unchecked positive feedback loop between cytokines and cellular response result: too many immune system cells activated in an single space à tissue damage

Answer 43

1918 flu pandemic: “spanish influenza”

Question 44

genome recovered in 1997 from victim in permafrost grave in Alaska Sequencing showed the virus originated in birds and mutated to be infectious in human

Answer 44

H1N1 Virus