Chapter 34-35-36 Paramyxo- Rabies and Influenza

Question 1

what do paramyxoviruses cause

Answer 1

• measles virus
• mumps virus
• respiratory syncytial virus
• parainfluenza virus

Question 2

what do rhabdoviruses cause

Answer 2

rabies

Question 3

what do orthomyxoviruses cause

Answer 3

influenza viruses A B and C

Question 4

describe the structure of paramyxoviruses

Answer 4

• helical nucleocapsid
• pleomorphic envelope
• hemagglutinin binds sialic acid
• minus stranded RNA

Question 5

describe paramyxovirus replication

Answer 5

• virus brings in RNA polymerase which transcribes minus RNA into plus RNAs
• replication is cytoplasmic

Question 6

describe measles viruses features

Answer 6

• hemagglutinings
• F protein

Question 7

what does F protein do

Answer 7

causes membranes to fuse together to allow viral entry into cells

Question 8

how does measles enter body

Answer 8

through respiratory tract

Question 9

what responses modulate the outcome of measles

Answer 9

humoral and cellular immune

Question 10

what are the characterisitc lesions of the oral cavity in measles caleld

Answer 10

koplik spots

Question 11

what are the 3 C’s of measles

Answer 11

cough , coryza, and conjunctivitis

Question 12

what is coryza

Answer 12

describes symptoms of a head cold

Question 13

what are the complications of measles

Answer 13

• pneumonia
• bacterial superinfections of middle ear and lung
• pneumococci, staphylococci, and meningococci

Question 14

what is subacute sclerosing panencephalitis in measles

Answer 14

rare progressive degeneration of CNS caused by measles

Question 15

what is the treatment, prevention and control of measles

Answer 15

• symptomatic therapy
• attenuated measles vaccine: MMR

Question 16

describe mumps virus

Answer 16

• paramyxovirus, pleomorphic, enveloped virus
• helical nucelocapsid
• negative strand RNA

Question 17

what are the clincial manifestations of mumps and when do they develop

Answer 17

• develop 16-18 days after infection
• fever and swelling and tenderness of salivary glands
• complications include meningitis and orchitis

Question 18

describe respiratory syncytial virus

Answer 18

• minus stranded RNA
• enveloped
• G protein binds host cells
• F protein causes membrane fusion

Question 19

how does respiratory syncytial virus infect

Answer 19

• enters respiraotry epithelial cells then spreads downward along mucosa
• no clinically significatn spread to other sites

Question 20

how is RSV spread

Answer 20

hand contact and respiratory secretions

Question 21

what are the clinical manifestations of RSV

Answer 21

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

Question 22

what is bronchiolitis

Answer 22

bronchiole obstruction that can lead to respiratory failure

Question 23

what is the treatment for RSV

Answer 23

rapid immunologic tests

Question 24

describe rabies viruses

Answer 24

• negative strand RNA virus
• highly neurotropic
  -enveloped

Question 25

how is rabies transmitted

Answer 25

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

Question 26

how long can incubation of rabies be

Answer 26

up to 12 months depending on size of inoculum and located of bite

Question 27

what are negri bodies

Answer 27

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

Question 28

what are the clinical manifestations of rabies and when does it begin

Answer 28

- 2-16 weeks after exposure - pain or parasthesia at wound site, axiety, or irritablitie, depression , fatigue, loss of appetite, fever, and sensitivity to light and sound - hydrophobia: contractions of muscles involved in swallwoing - quickly progresses to paralysis - death from destruction of regions of brain that regulate breathing

Question 29

what is the treatment, prevention and control of rabies

Answer 29

- passive administration of antibody - postexposure vaccine - preexposure vaccine of individuals with high risk of exposure

Question 30

describe orthomyxoviruses

Answer 30

- minus stranded RNA - enveloped

Question 31

what does neuraminidase do

Answer 31

release of virus from envelope - cleaves sialic acid

Question 32

what are typical flu symptoms due to

Answer 32

interferons

Question 33

what is the treamtent for flu

Answer 33

- amantidine - rimantidine (A strain only) - ribavirin (A and B strain)

Question 34

what is the flu vaccine

Answer 34

inactivated virus vaccine

Question 35

what is antigenic shift

Answer 35

- caused by reassortment of viral genomic fragments during a mixed infection by two different flu viruses

Question 36

what is antigenic drift

Answer 36

changes in influenze virus surface proteins due to point mutations that occur during viral replication

Question 37

why was the spanish flu so deadly

Answer 37

killed from a cytokine storm from unchecked positive feedback loops