RTI V

Question 1

describe acute bronchitis

Answer 1

• inflammation of the bronchi due to upper airway infxn
• cough lasting more than 5 days (1-3 weeks)
• indistinguishable from URI in the first few days

Question 2

describe croup (laryngotracheitis/laryngotracheobronchitis)

Answer 2

• symptoms of common cold PLUS:
• resp. illness characterized by:
  
  • inspiratory stridor
  • cough (barking cough - infants and young children)
  • hoarseness (predominant in older children and adults)
• inflammation in the larynx and sub-glottic area

Question 3

the most common cause of croup is ____

Answer 3

the most common cause of croup is viruses - HPIV-1

Question 4

describe the image

Answer 4

Question 5

describe the paramyxoviridae and pneumoviridae subfamilies

Answer 5

Question 6

describe the classification of paramyxoviridae

Answer 6

• negative sense, ssRNA genome in helical nucleocapsid
• enveloped

Question 7

describe the role of the F protein in human parainfluenza viruses (HPIVs) which is part of the paramyxoviridae family

Answer 7

• fusion factor (F) - F protein
  
  • involved in viral entry
  • antibodies against F protein = neutralizing
  • syncytia formation

Question 8

name predisposing factors to HPIV infection

Answer 8

• predisposing factors
  
  • malnutrition
  • overcrowding
  • vit. A def.
  • lack of breastfeeding
  • environmental smoke or toxins

Question 9

name the disease and the type of HPIV associated with it

Answer 9

Question 10

describe the key viral proteins found in HPIV

Answer 10

HPIV = linear ss (-) sense RNA

• key viral proteins:
  
  • P and F = immune evasion
  • F protein = role in syncytium formation
  • HN protein = structural hemagglutinin and neuraminidase activity
  • L protein = multifunctional polymerase
  • M = matrix structural protein

Question 11

describe the role of P and F protein

Answer 11

P and F protein (non-structural protein): role in evasion of immune response

• functions:
  
  • plays an essential role in the inhibition of host immune response
  • prevents the establishment of cellular antiviral state by blocking interferon-alpha/beta (IFN-alpha/beta) production and signaling pathway

Question 12

describe bronchiolitis

Answer 12

inflammation of the bronchioles and small bronchi

• < 2 years of age; fall and winter
• URI symptoms followed by LRT infxn with inflammation, resulting in wheezing and/or crackles (rales)
• causative pathogen (virus) infects terminal bronchiolar epithelial cells → direct damage and inflammation
  
  • edema, excessive mucus, sloughed epithelial cells → obstruction of small airways and atelectasis

Question 13

the most common cause of bronchiolitis is _____

Answer 13

the most common cause of bronchiolitis is respiratory syncytial virus (RSV)

Question 14

name risk factors for bronchiolitis

Answer 14

• risk factors:
  
  • prematurity, low birth weight, congenital heart disease, chronic pulm. disease
  • passive smoking, overcrowding, day care

Question 15

describe clinical features of bronchiolitis

Answer 15

• begins with URT symptoms, followed by LRT signs and symptoms
• symptoms and signs:
  
  • fever
  • cough
  • resp. distress (increased RR, retractions, WHEEZING, crackles)
  • preceding history of URI (nasal congestion and/or discharge)

Question 16

____ is the leading cause of LRTIs in infants and young children

Answer 16

respiratory syncytial virus (RSV) is the leading cause of LRTIs in infants and young children

Question 17

describe the biology of RSV

Answer 17

• family = Pneumoviridae (formerly paramyxoviridae)
  
  • genetic material = linear ss (-) sense RNA
• enveloped
• helical nucleocapsid
• virally-encoded surface proteins:
  
  • fusion factor (peplomer): main viral antigen
  • G glycoprotein: involved in attachment
    
    • 2 subgroups: A & B
• lacks glycoprotein with HN activity

Question 18

name risk factors for RSV

Answer 18

similar to bronchiolitis

• underlying lung disease
• premature birth (<35 weeks)
• congenital heart disease
• passive smoking
• Down syndrome

Question 19

describe the pathogenesis of RSV

Answer 19

• entry is via epithelia of nose and eye
• F & G proteins mediate attachment; F mediates membrane fusion
• primary site of replication = nasopharyngeal epithelium
  
  • direct cytopathic effect → loss of function

Question 20

the primary site of replication of RSV is the ____

Answer 20

the primary site of replication of RSV is the nasopharyngeal epithelium

Question 21

Bordatella pertussis is a (G+ve/G-ve) ____ (shape)

Answer 21

Bordatella pertussis is a G-ve coccobacillus

Question 22

Bordatella pertussis typically occurs in _____ and ___ are important as reservoirs

Answer 22

Bordatella pertussis typically occurs in unvaccinated children and adults are important as reservoirs

Question 23

describe the clinical course of whooping cough

Answer 23

Question 24

describe the pathogenesis of Bordatella pertussis

Answer 24

Question 25

describe lab diagnosis of *Bordatella pertussis*

Answer 25

Question 26

describe the types of vaccines against *Bordatella pertussis*

Answer 26

Question 27

describe the Sketchy

Answer 27