Resp. Tract Infections I & II

Question 1

contrast the upper and lower respiratory tracts

Answer 1

Question 2

name the 3 enzymes that play a role in non-specific defenses of the URT

Answer 2

• S-IgA
• lysozyme
• lactoferrin

Question 3

describe situations where defenses of the respiratory system are defeated/surpassed

Answer 3

• smoking
• endotracheal intubation
• pollution
• suppression of cough reflex
• predisposing infxn
• disruption of homeostasis
  
  • age, malnutrition, immunosuppression, underlying disease, etc.

Question 4

describe the types of pathogens

Answer 4

Question 5

name an example of professional and secondary pathogen

Answer 5

• primary/professional/frank = influenza
• secondary/opportunistic = pneumococcal pneumonia

Question 6

____ are the most common cause of resp. tract infections

Answer 6

viruses are the most common cause of resp. tract infections

Question 7

name the 6 major families of viruses that cause RT infxns

Answer 7

1. adenovirus
2. rhinoviarus
3. corona virus
4. HPIV
5. RSV
6. influenza virus

Question 8

describe rhinovirus

Answer 8

• small, icosahedral, non-enveloped virus
• contain one positive-strand RNA
• labile at acidic pH

Question 9

___ infections cause up to 50% of all common cold

name the seasons it is prevalent in

Answer 9

human rhinovirus (HRV) infections cause up to 50% of all common colds

seasonality: spring, summer, fall

Question 10

the normal flora of the URT varies with ____ & _____

Answer 10

the normal flora of the URT varies with age & location

Question 11

describe other complications of rhinovirus

Answer 11

• can lead to:
  
  • secondary infxns of sinuses and middle ear
  • LRT infections such as pneumonia, bronchiolitis in young children and immuno-compromised adults

viral pneumonia

Question 12

describe the pathogenesis of rhinovirus

Answer 12

Question 13

name features of rhinovirus and how it helps its pathogenesis

Answer 13

Question 14

describe the Sketchy

Answer 14

Question 15

describe the claslsification of adenoviruses

Answer 15

• linear, ds DNA
• medium-sized (90-100 nm)
• non-enveloped, icosahedral

Question 16

describe characteristics of adenovirus

Answer 16

• virus encodes proteins to promote mRNA and DNA synthesis, including its own DNA polymerase
• human adenovirus are grouped from A through G by DNA homolgies and by serotypes (>55 human types)
  
  • serotype is mainly a result of differences in the penton base and fiber protein which determine the nature of tissue tropism and disease

Question 17

describe the outcomes of adenoviruses

Answer 17

• outcomes of adenoviral infxns:
  
  • lytic, e.g. mucoepithelial cells (killing cells)
  • latent, e.g. adenoid cells

Question 18

describe the epidemiology of adenovirus

Answer 18

• endemic throughout the year
• typically affects children from infancy to school age
• young adults in a setting of close quarters and stress may be affected

Question 19

describe respiratory diseases associated with adenoviruses and the patient population it affects

Answer 19

Question 20

describe other diseases associated with adenoviruses

Answer 20

Question 21

describe the pathogenesis of adenovirus

Answer 21

Question 22

____ enables attachment of adenovirus to the host cell receptor

Answer 22

fiber protein enables attachment of adenovirus to the host cell receptor

Question 23

___ of the adenovirus has toxic activity, and the viral genes ____ inhibit cellular _____

Answer 23

penton base of the adenovirus has toxic activity, and the viral genes E1A, E1B, E3, E4 inhibit cellular mRNA synthesis

Question 24

the survival time for adenovirus is ____

Answer 24

the survival time for adenovirus is 7 days - 3 months

Question 25

describe the Sketchy

Answer 25

Question 26

describe the biology of coronavirus

Answer 26

* single molecule of **linear positive-sense, ssRNA** * largest positive-strand RNA virus * helical nucleocapsid, **enveloped**

Question 27

describe the epidemiology of coronavirus

Answer 27

* incidence peaks in winters * transmission usually via airborne droplets * antibodies appear after initial infxn and wanes

Question 28

describe major human coronavirus proteins

Answer 28

Question 29

describe the pathogenesis of coronavirus

Answer 29

Question 30

a unique aspect of the coronavirus replicative cycle is that replication occurs in the \_\_\_\_

Answer 30

a unique aspect of the coronavirus replicative cycle is that replication occurs in the **cytoplasm**

Question 31

a unique aspect in the replicative cycle of coronavirus is that the virus obtains its envelope from the \_\_\_\_, not from the \_\_\_\_\_

Answer 31

a unique aspect in the replicative cycle of coronavirus is that the virus obtains its envelope from the **endoplasmic reticulum**, not from the **plasma membrane**

Question 32

the ___ protein of the coronavirus allows binding to host cell and fusion activity

Answer 32

the **E2 (peplomeric glycoprotein; aka spike protein)** protein of the coronavirus allows binding to host cell and fusion activity

Question 33

describe the prognosis of coronavirus

Answer 33

* prognosis: * excellent prognosis * usually mild and self-limiting illness * complete recovery is usually within 7 days for adolescents & adults; within 10-14 days for children * complications not common; very rarely causes fatal disease

Question 34

describe severe acute respiratory syndrome (SARS) (case definition and lab diagnosis)

Answer 34

* case definition * history of fever or documented fever AND * one or more symptoms of LRTI (cough, dyspnea/SOB) AND * radiologic evidence of pneumonia/ARDS or autopsy confirmation without identifiable cause * lab diagnostics: * antibodies by ELISA or IFA * viral DNA by RT-PCR

Question 35

describe the etiology of SARS

Answer 35

Question 36

describe the clinical features of SARS

Answer 36

Question 37

describe a probable clinical case of MERS

Answer 37

* febrile acute respiratory illness with clinical, radiographic, or histopathologic evidence of pulmonary parenchymal disease AND * direct epidemiological link with a confirmed MERS-CoV case

Question 38

describe the clinical features and lab diagnosis of MERS

Answer 38

Question 39

describe clinical features of MERS

Answer 39

Question 40

describe the Sketchy

Answer 40

Question 41

describe enterovirus EV-D68

Answer 41