Viral Infections of the Upper Respiratory Tract

Question 1

How do viruses reach the respiratory tract?

Answer 1

Fomites or aerosols

Question 2

What causes the typical syx of a viral disease?

Answer 2

Infected epithelial cells give off cytokines that cause fever, aches.

Dead epithelial cells result in sore throat

Question 3

What in the upper respiratory tract is attractive to viruses?

Answer 3

URT is approx 33 oC while the body is 37 oC

Question 4

What age groups typically have more severe resp infections?

Answer 4

Infants and elderly

Question 5

What bugs are confined to the respiratory mucosal surface?

Answer 5

• Picornavirus (rhinovirus)
• Coronavirus
• Paramyxovirus (parainfluenza and RSV)
• Orthomyxovirus (Influenza)

Question 6

What bugs persistently replicate on respiratory mucosal surface?

Answer 6

• EBV
• Adenovirus
• Papillomavirus

Question 7

What are the two barriers to virus dissemination from the respiratory tract to the blood?

Answer 7

• Flu replicates in epithelium b/c the proteins are focused on apical side
• Basement membrane is acellular

Question 8

What risk factors contribute to virus dissemintation?

Answer 8

Damage to epithelium, retarded cilia

Question 9

Describe the Coronavrius characteristics

Answer 9

• Crown of spikes
• (-) ssRNA virus
• Strains cause cold-like Syx
• SARS, MERS

Question 10

Describe the characteristics of orthomyxoviruses

Answer 10

• Nuclear replication
• Segmented (-) ssRNA
• Enveloped

Question 11

What is the Genus and Types of orthomyxoviridae?

Answer 11

Genus: Influenza

Types: A, B, C

Question 12

What are the Paramyxoviridae?

Answer 12

• Paramyxovirus - Mumps, Parainfluenzavirus 1-4, Newcastle disease viruse
• Morbilivirus - Measles
• Pneumovirus -RSV

Question 13

Characteristics of Paramyxoviridae

Answer 13

Cytoplasmic replication, non-segmented (-) ssRNA, enveloped

Question 14

What are serious complications of influenza virus?

Answer 14

Secondary bacterial infection, Primary viral pneumonia, CNS/muscle involvement

Question 15

What are the two antivirals that are typically used for Influenza A and B?

Answer 15

Oseltamivir, zanamivir

Question 16

What vaccines are used for the flu?

Answer 16

(injectable and inhalable) Trivalent inactivated vaccines, live attenuated vaccine

Question 17

What are the two bugs that cause croup?

Answer 17

Parainfluenza (but also RSV for Moffat)

Question 18

What is a serious concern about croup?

Answer 18

Can progress to deadly/complicated pneumonia and respiratory distress

Question 19

Why can you be repeatedly infected with Adenovirus?

Answer 19

47 serotypes that can infect humans

Question 20

What are the typical sites of adenovirus infection?

Answer 20

Resp tract, GI tract, eye (Bob Costas)

Question 21

Who are typically at highest risk for adenovirus infection?

Answer 21

Children, army personnel, people in tight quarters

Question 22

What vaccines are available for adenovirus?

Answer 22

Only for military!

Question 23

Where is the first site of virus and host interaction?

Answer 23

Respiratory epithelium

Question 24

Which of the bugs talked about in lecture can cause mild respiratory infections?

Answer 24

• Adeno
• Corona
• Flu
• Rhino

Question 25

Most common cause of acute respiratory viral infection?

Answer 25

Rhinovirus

Question 26

A woman age 20 in college was suffering from sore throat, fatigue, lack of appetite, chills, and body aches. She had just returned from bootcamp w/ her ROTC group. 2 most likely bugs?

Answer 26

Adeno or inluenza

Question 27

9 yo complaining of congestion, fatigue, cough when lying down, and ear pressure. Two most likely bugs?

Answer 27

Rhinovirus and coronavirus