URTI_Viral_Infections_BrainScrape

Question 1

What are the most common viral infections of the upper respiratory tract (URT)?

Answer 1

Conjunctivitis, pharyngitis, the common cold (rhinoviruses, coronaviruses), and mumps virus.

Question 2

What are examples of lower respiratory viral infections?

Answer 2

Croup (HPIV), bronchitis (RSV, HPIV, Rhino, Influenza, Adenovirus), bronchiolitis (RSV), hantavirus infection.

Question 3

What makes strict pathogens different from opportunistic pathogens?

Answer 3

Strict pathogens cause primary infections and adhere to healthy mucosa; opportunistic pathogens need damaged tissue and cause secondary infections.

Question 4

What are the major classification systems for respiratory infections?

Answer 4

Etiology, type of infection (acute, chronic), site of infection (URT vs LRT), and exposure source (community, hospital, zoonotic).

Question 5

What are the key players in innate immunity during a viral infection?

Answer 5

Interferon-α/β, Natural Killer cells, and Cytotoxic T Lymphocytes (CTLs).

Question 6

How does adaptive immunity respond to viral infections?

Answer 6

CD8+ CTLs kill infected cells via perforins and granzymes, causing symptoms due to collateral damage.

Question 7

What virus family does Rhinovirus belong to?

Answer 7

Picornaviridae.

Question 8

What is the structure of Rhinovirus?

Answer 8

Non-enveloped, single-stranded, positive-sense RNA virus with an icosahedral capsid.

Question 9

How is Rhinovirus transmitted?

Answer 9

Aerosol, direct contact (e.g., hand-to-nose), indirect contact via fomites.

Question 10

What is the pathogenesis of Rhinovirus?

Answer 10

VP1 binds ICAM-1 on epithelial cells → replication → interferons, bradykinin, histamine → immune response causes symptoms.

Question 11

What are common risk factors for Rhinovirus infection?

Answer 11

Smoking, young or elderly age, crowded places like daycares.

Question 12

What is the genetic structure of Adenovirus?

Answer 12

Non-enveloped, double-stranded DNA virus with an icosahedral capsid.

Question 13

How does Adenovirus infect cells?

Answer 13

Binds CAR receptor → endocytosis → penton base causes cytolysis and inhibits host mRNA synthesis.

Question 14

What are common clinical manifestations of Adenovirus?

Answer 14

Pharyngo-conjunctival fever, URTI, interstitial pneumonia, keratoconjunctivitis, gastroenteritis, hepatitis.

Question 15

What populations are at high risk of Adenovirus infection?

Answer 15

Infants, children, military recruits, and those in crowded settings.

Question 16

What are symptoms of the common cold (rhinitis)?

Answer 16

Nasal congestion, sneezing, sore throat, mild cough, postnasal drip, low to no fever.

Question 17

What characterizes pharyngo-conjunctivitis (‘pink eye’)?

Answer 17

Low-grade fever, sore throat, red itchy eyes, swollen lymph nodes.

Question 18

Are there vaccines for common cold viruses?

Answer 18

No vaccines for rhinovirus and common coronavirus. Adenovirus vaccine is military-only.

Question 19

What are general preventive measures for viral URTIs?

Answer 19

Hand hygiene, avoid face-touching, cough/sneeze etiquette, masks, distancing.

Question 20

Which viral URT pathogens are vaccine-preventable?

Answer 20

Influenza, SARS-CoV-2, Mumps, Measles, Chickenpox.

Question 21

What are the classifications of respiratory infections?

Answer 21

By etiology (viral, bacterial), type (acute, chronic, primary, secondary), exposure (community-acquired, hospital-acquired, zoonotic), and site (URT vs LRT).

Question 22

What are examples of upper respiratory tract infections (URTIs)?

Answer 22

Rhinitis, sinusitis, otitis media, epiglottitis, pharyngitis, tonsillitis.

Question 23

What are examples of lower respiratory tract infections (LRTIs)?

Answer 23

Laryngotracheitis, bronchitis, bronchiolitis, pneumonia.

Question 24

Who are considered high-risk populations for respiratory tract infections?

Answer 24

Infants, elderly, immunocompromised individuals, people with pre-existing lung conditions, smokers, travelers, hospitalized individuals.

Question 25

Why are people with pre-existing lung conditions at higher risk for infections?

Answer 25

They may have scar tissue, damaged cilia, altered mucus, and disrupted immune responses that favor pathogen binding and colonization.

Question 26

Which respiratory viruses are more common in fall and winter?

Answer 26

Influenza A, common coronavirus, RSV, PIV 1 & 2.

Question 27

Which viruses are more common in spring and summer?

Answer 27

Human metapneumovirus (hMPV), PIV 3.

Question 28

Which viruses are relatively unseasonal?

Answer 28

Adenovirus, rhinovirus.

Question 29

Which viruses are common in summer?

Answer 29

Enteroviruses: Coxsackievirus, enterovirus, echovirus.

Question 30

What are the main transmission routes for respiratory viruses?

Answer 30

Person-to-person (droplets, aerosols), direct contact, indirect contact via surfaces, and environmental exposure.

Question 31

How long can respiratory viruses survive on surfaces?

Answer 31

Rhinovirus: 2 hrs–7 days, Coronavirus: ~3 hrs, Adenovirus: 7 days–3 months.

Question 32

What factors help determine the etiological agent in RTIs?

Answer 32

Lab findings, exposure history, risk factors, and clinical presentation.

Question 33

What makes Rhinovirus labile at acidic pH?

Answer 33

It is non-enveloped and has structural sensitivity to acidic environments.

Question 34

How does the body clear Rhinovirus infection?

Answer 34

Via innate immunity (interferons, NK cells) and adaptive immunity (IgA, CTLs); symptoms are mostly immune-mediated.

Question 35

What disease does Adenovirus cause in military recruits and young children?

Answer 35

Interstitial pneumonia or ARDS (acute respiratory distress syndrome).

Question 36

What are unique properties of Adenovirus?

Answer 36

Fiber protein binds CAR receptor, penton base is cytolytic, exhibits hemagglutination, and inhibits host mRNA synthesis.

Question 37

What environmental measures reduce URTI transmission?

Answer 37

Hand hygiene, avoiding touching face, cough etiquette, mask-wearing, social distancing.

Question 38

What is the general prognosis for viral URTIs?

Answer 38

Excellent. Most are self-limiting with recovery in 7-14 days; complications are rare.