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Flashcards in RT4 Deck (36)
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viral agents of infectious bronchitis and bronchiolitis

AIR - adenovirus, influenza virus, respiratory syncitial virus


bacterial agents of infectious bronchitis and bronchiolitis

bordatella pertussis, mycoplasma pneumonia, chlamydophilia pneumonia


clinical syndrome of bordatella pertussis

whooping cough (chronic bronchitis)


population susceptible to bordatella pertussis

unvaccinated children


reservoir of bordatella pertussis

adults (part of their normal flora) -- who can pass it to children


what are bordatella toxins

􏰀TCT = tracheal cytotoxin
􏰀PT = pertussis toxin
􏰀ACT = adenylate cyclase toxin
􏰀DNT = dermonecrotic toxin
􏰀LOS = lipooligosaccharide
􏰀Filamentous haemagglutinin (FhA)


pathogenesis of bordatella pertussis

transmission --> adhesion --> growth and toxin release --> local and systemic pathology --> bacterial clearance (if the patient survives)


stages of whooping cough

incubation --> catarrhal (symptoms of common cold) --> paroxysmal (coughing vomiting) --> convalescence

all this happens in a matter of days


sample used for bordatella pertussis and what type of sampling to avoid?

-get a nasopharyngeal swab then do PCR
-avoid cotton swab because they contain lipids and bordatella pertussis is easily killed by lipids/inhibits its growth


how to prevent bordatella pertussis

DaPT -- acellular Pertussis


what happens over time with bordatella pertussis vaccine

immunity decreases over time -- vaccine does not last a lifetime so must give boosters


what culture is used for bordatella pertussis

charcoal blood agar (bordet-gangou) with cephalosporin


clinical syndrome of HPIV (human parainfluenza virus) (paramyxovirinae)

laryngotracheobronchitis, bronchitis


physical feature of HPIV

-ssRNA, hemagglutinin and neuraminidase on surface, F spike (fusion protein), enveloped


pathogenesis of HPIV

important proteins/enzymes are HA, NA, F-protein, V protein

-V protein is also a fusion protein which is needed for evasion of host immune response; also will alter cell cycle, prevent apoptosis, inhibit synthesis of interferon and dsRNA signaling


what is Croup

aka laryngotracheobronchitis commonly caused by respiratory viruses (HPIV, pneumovirus, RSV)


symptoms of Croup

􏰀-Happens mostly in young children and infants -􏰀Swelling and narrowing of the airway
-􏰀Distinctive cough, sounds like the barking of a seal.
􏰀-Can rarely be fatal, especially if case is mishandled


what infection tends to be worse if vaccinated against using heat-killed vaccine

RSV infection (Respiratory Syncitial Virus)


what leads to clinical outcome of RSV infection

tropism of respiratory epithelium, anatomy of airways, immunologic response


how is epidemic flu transmitted

from man to man (even though it is zoonotic)


how is influenza transmitted

inhalation of respiratory droplets


adult symptoms of flu

-Rapid onset after short incubation of 1 to 4 days
-Sudden malaise and headache lasting a few hours
-Abrupt rise of fever, chills, severe muscle aches. Loss of appetite, non-productive cough. This can last from 3 to 8 days
-Recovery is complete in 7 to 10 days
-Patient is contagious from before symptoms appear (end of day 1) for the next 7 days
-Risk of secondary infection highest in time from 6 to 12 days after infection


children's symptoms of flu

-symptoms in adult flu plus the following:
-􏰀Higher fever
-􏰀G.I symptoms: (Vomiting, Abdominal pain)
-􏰀Ear ache (Otitis Media)
􏰀-Muscle pain and sometimes swelling
􏰀-Croup often but not always
-􏰀􏰀Febrile Convulsions (Children under 3: Rare)


describe the symptoms in a common cold: fever, headache, general malaise, nasal discharge, sore throat, vomiting/diarrhea

rare fever and headache, slight general malaise, abundant nasal discharge, common sore throat, rare vomiting/diarrhea


describe the symptoms in a flu: fever, headache, general malaise, nasal discharge, sore throat, vomiting/diarrhea

common fever and headache, severe general malaise, less common nasal discharge, less common sore throat, common vomiting/diarrhea


complications of flu

Primary Viral Pneumonias
􏰀Secondary Bacterial Pneumonias
􏰀Muscle inflammation – Cardiac involvement
􏰀Rare Neurological syndromes


which types of influenza are hemagglutinin and neuraminidase present

all except for type C


which influenza type is most important

type A because it infects both humans and animals and can cause epidemics and pandemics

while type B and C are only in humans
type B can cause only epidemics
type C cannot do either


two surface glycoprotein on influenza and their function

hemagglutinin - helps virus get into the host cell by adhering to the respiratory tissues
neuraminidase - helps virus get out of the host cell

M2 protein is on A only (ion channel)
all three are where antigenic variation can occur


animals that are reservoir for influenza type A

ducks and pigs