SM 179 Viral Infections

Question 1

Where do respiratory viruses have the greatest mortality rates?

Answer 1

The developing world

Question 2

Why do some respiratory viruses show seasonal variation?

Answer 2

Favorable environmental conditions and potential human behavior changes, such as indoor crowding

Question 3

Which respiratory viruses lack seasonality?

Answer 3

Coronavirus and Adenovirus, which are active year-round

Question 4

Which viruses tend to cause the common cold?

Answer 4

Rhinovirus and coronavirus

Question 5

Which viruses cause pharyngitis?

Answer 5

Adenovirus, influenza

Question 6

Which viruses cause croup?

Answer 6

Parainfluenza Viruses 1 and 2

Question 7

Which virus tends to cause bronchiolitis?

Answer 7

RSV

Question 8

Which viruses cause pneumonia in children?

Answer 8

RSV, PIV, influenza

Question 9

Which viruses cause pneumonia in adults?

Answer 9

Influenza, adenovirus

Question 10

Which viruses cause pneumonia in the immunocompromised?

Answer 10

CMV, HSV

Question 11

How long does the common cold last?

Answer 11

Typically lasts 10 days, via multiple viral agents

Question 12

How does respiratory virus induced pharyngitis present?

Answer 12

Sore throat and nasal congestion suggest respiratory viral causes of pharyngitis

Question 13

Which group tends to get Croup?

Answer 13

Young children infected with PIV1 and PIV2

Question 14

How does Croup manifest and why?

Answer 14

Presents as a typical cold that worsens to a deep, barking cough due to inflammation and obstruction of the subglottic structures

Question 15

How does Croup affect respiration?

Answer 15

Inflammation and swelling of the subglottic structures may obstruct airflow and lead to cyanosis

Question 16

What differentiates tracheobronchitis from the common cold, and what causes it?

Answer 16

Non productive cough that lasts for more than one week, due to Influenza and PIV

Question 17

What is bronchiolitis?

Answer 17

Viral infection of the terminal bronchiolar epithelial cells that leads to edema and mucus obstructing the small airways

Question 18

What type of virus is Influenzavirus?

Answer 18

Influenza is a negative ssRNA virus

Question 19

What are the 3 types of Influenzavirus and which one causes pandemics?

Answer 19

The 3 types are A, B, and C; only A causes pandemics

Question 20

What surfaces antigens does Influenza A have?

Answer 20

Hemaglutinin and Neuraminidase

Question 21

How does Influenza A cause pandemics?

Answer 21

Influenza A is able to undergo Antigenic Shift, which causes major reassortments of its Hemaglutinin and Neuraminidase, within and between species, leading to pandemics

Question 22

Why does Influenza B not cause pandemics?

Answer 22

Influenza B predominantly experiences Antigenic Drift, which are minor mutations due to errors in RNA Polymerase

Question 23

What is the difference between Antigenic Drift and Antigenic Shift?

Answer 23

Antigenic Drift is due to errors in RNA replication by RNA Poly and leads to minor changes; Antigenic Shift is due to reassortment of genes between viruses and leads to major changes

Question 24

What caused H1N1?

Answer 24

A quadruple reassortment (antigenic shift) between swine (2), avian, and human influenza

Question 25

Is Influenza seasonal in the US?

Answer 25

Yes, during the colder months

Question 26

How does Influenza spread?

Answer 26

Droplets and fomites after invading the epithelial cells of the upper respiratory tract

Question 27

When can Influenza be spread between people?

Answer 27

Virus sheds 2 days prior to symptoms and 5 days after symptoms abate

Question 28

What are the complications of influenza?

Answer 28

Secondary S. aureus pneumonia and exacerbation of cardiopulmonary conditions

Question 29

Who tends to die of Influenza?

Answer 29

The elderly

Question 30

When can a clinical diagnosis of Influenza be made?

Answer 30

A clinical diagnosis of sx like fever, sore throat, etc. can only be made during flu season due to low sensitivity = 60%

Question 31

What is the ideal way to diagnose Influenza

Answer 31

PCR, due to high sensitivity and specificity

Question 32

When should Influenza be tested for?

Answer 32

Only test for Influenza if it impacts patient care or puts the patient in a hospital

Question 33

What should be done while waiting for Influenza test results?

Answer 33

Start empiric antivirals of Neuraminidase inhibitors and CAP dependent endonuclease inhibitors

Question 34

What class of Influenza drugs is no longer used?

Answer 34

M2 inhibitors like Amantadine, DO NOT USE THEM

Question 35

How do Neuraminidase inhibitors work?

Answer 35

Oseltamivir prevents release of viruses from cell and therefore prevent other cells from being infected

Question 36

How do Neuraminidase inhibitors affect the course of the disease?

Answer 36

Decrease symptom and shedding duration

Question 37

How do CAP dependent endonuclease inhibitors work?

Answer 37

Baloxavir blocks mRNA synthesis and prevent the formation of new virus

Question 38

What is Oseltamivir?

Answer 38

An Influenza Neuraminidase inhibitor

Question 39

What is Balozavir?

Answer 39

A CAP dependent endonuclease inhibitor

Question 40

Who should be treated for Influenza?

Answer 40

Anyone with severe sx/hospitalization, young children, older adults, pregnant women, medically complicated, and immunosuppressed px

Question 41

Who should be vaccinated for Influenza?

Answer 41

Everyone

Question 42

Is the Influenza vaccine effective?

Answer 42

Up to 50% effective for all strains

Question 43

What are the antigens of RSV?

Answer 43

SH and F protein

Question 44

What does RSV's SH protein do?

Answer 44

Inhibits apoptosis of the infected cell

Question 45

What does RSV's F protein do?

Answer 45

Mediates fusion of infected cells together

Question 46

What infection does RSV cause?

Answer 46

Pneumonia and bronchiolitis in young children and immunocompromised

Question 47

How does RSV spread?

Answer 47

Respiratory droplets and fomites

Question 48

Why is re-infection common in RSV?

Answer 48

Immunity to RSV does not persist

Question 49

How is RSV treated?

Answer 49

Supportive care (oxygen, bronchodilators, saline), Ribavirin in adults

Question 50

What antigen does PIV have?

Answer 50

Fusion protein that mediates formation of

Question 51

How can PIV infectivity be stopped?

Answer 51

Antibodies to Fusion protein

Question 52

What radiographic sign is associated with PIV?

Answer 52

Steeple Sign on CXR

Question 53

What group is most affected by Adenovirus?

Answer 53

People in close quarters like Adenovirus

Question 54

What epidemic can Adenovirus cause?

Answer 54

Epidemic keratoconjuctivitis

Question 55

Which form of Adenovirus causes serious outbreaks?

Answer 55

Adenovirus 14

Question 56

Who gets treated with Adenovirus and how?

Answer 56

Most adenovirus infections are self limiting, so treatment with Cidofovir is reserved for seriously ill px

Question 57

Does Adenovirus have a vaccine?

Answer 57

Yes, for Type 4 and 7

Question 58

What type of virus is Rhinovirus?

Answer 58

Non-segmented Positive ssRNA

Question 59

What type of virus is Adenovirus?

Answer 59

Nonenveloped dsDNA

Question 60

Why is Rhinovirus so hard to vaccinate against?

Answer 60

More than 100 serotypes

Question 61

Where does Rhinovirus reproduce and why?

Answer 61

Nose and conjunctiva because it replicates poorly at body temperature

Question 62

How does Rhinovirus spread?

Answer 62

Aerosol droplets and contaminated surfaces

Question 63

What does Rhinovirus bind?

Answer 63

ICAM-1 on respiratory epithelial cells, leading to cell lysis

Question 64

How is Rhinovirus treated?

Answer 64

Symptom management only

Question 65

What is Coronavirus?

Answer 65

A nonsegmented ssRNA virus

Question 66

What does SARS Coronavirus bind to?

Answer 66

ACE-2 Receptor

Question 67

What can Coronavirus cause?

Answer 67

SARS, MERS

Question 68

What is Hantavirus?

Answer 68

An emerging virus spread by deer excretion

Question 69

What Is HCPS?

Answer 69

Initial fever followed by abrupt pulmonary edema and shock

Question 70

Where did SARS Coronavirus come from?

Answer 70

Zoonosis via the Palm Civet

Question 71

Where did MERS Coronavirus come from?

Answer 71

Zoonosis via Camel contact