Respiratory Tract infections 5 Flashcards
the most common cause of acute bronchitis is ______
viruses: influenza A/B, coronavirus, rhinovirus, RSV
what viral attachment proteins are on the envelope of RSV?
- fusion protein
- Glycoprotein (G protein)
- NO hemagglutinin and NO neuraminidase
what are risk factors for bronchiolitis?
- prematurity
- low birth weight
- chronic pulmonary disease
- hemodynamically significant congenital heart diseases
laryngeotracehitis is most commonly caused by _______
HPIV (larnygeotracheitis = croup)
Down syndrome is a risk factor that ↑ the chances of getting infected by __________
RSV
describe the biology of the viruses that are paramyxoviridae:
- negative sense ssRNA
- enveloped with viral attachment protein
- fusion protein (synctia formation for RSV)
- hemagglutinin and neuraminidase
syncytia formation is due to _______
Fusion factor/ F protein
vitamin _____ deficiency is associated with ↑ risk of infection by _________
A;
HPIV
describe the clinical course se of bordatella pertussis
100 day cough:
- catarrhal stage: 1-2 weeks
- paroxysmal stage: 1-6 weeks
- Convalescent stage: weeks to months
____ protein has polymerase activity in ______
L; HPIV
the “whoop” in bordatella pertussis infection occur on expiration/inspiration
inspiration (coughing on expiration to expel the mucus that is there due to the ciliary dysfunction)
which toxins released by bordetella pertussis cause localized tissue damage?
- dermonecrotic toxin
- tracheal cytotoxin (immobilizes cilia)
the P/F proteins in HPIV play an essential role inhibiting the host immune response by ____________
blocks IFN α/ β production and the signaling pathway
bordatella pertussis is a gram negative/postive ______
gram negative coccobacillus
what age group is croup seen in and what are 3 key features of this illness?
- seen in kids 6 months - 3 years
- inspiratory stridor
- barking cough
- hoarseness in older kids and adults
what is the age group associated with bronchiolitis?
kids < 2 years of age; occurs in the fall and winter
what are the components of the acellular vaccine for bordatella pertussis (aP part of DTaP vaccines)
- filamentous hemagluttinin
- pertussis toxin
“steeple sign” on X Ray is indicative of ____________
subglottic narrowing of the trachea seen with croup
name 5 predisposing factors for infection by HPIV
- malnutrition
- overcrowding
- Vitamin A deficiency
- Lack of breast feeding
- environmental smoke/toxins
child that is less than 2 years of age with prominent wheezing… what is the first thing you should think?
bronchiolitis;
virus infects terminal bronchiolar epithelial cells and the sloughed epithelia cells will obstruct small airways and cause atelectasis
what are the viral proteins and their functions associated with HPIV?
- P/F proteins: immune evasion
- F proteins: syncytium formation
- HN protein
- L protein: polymerase
- M protein: matrix structural protein
lack of breast feeding is associated with ↑ risk of infection by ________
HPIV
the class whooping cough is seen in the ______ stage of the infection
paroxysmal
how can you distinguish between acute bronchitis and pneumonia?
systemic symptoms suggest pneumonia: presence of high fever, pleuritic chest pain, SOB = pneumonia
the most common cause of croup is ______
HPIV-1 (human parainfluenza virus), in addition to RSV and Adenovirus
croup involves the inflammation in the ________
larynx and sub-glottic area
croup involves the narrowing of _____________
subglottis
HPIV is a positive/negative sense ssRNA
negative sense ssRNA
paramyoxoviridae is divided into what 2 subfamilies?
- paramyxoviriniae HPIV
- pneumoviriniae :RSV
the most common cause of bronchiolitis is _________
RSV
what is the MOA of the pertussis toxin?
↑ cAMP by inhibition of Gi → inhibiting phagocytosis
what culture would you use for Bordatella pertussis
- bordet genom aka charcoal blood agar + cephalosporin
systemic toxicity and symptoms are caused by the _____ toxin in bordatella pertussis infection
pertussis
at what stage do you see the non specific symptoms?
catarrhal
