RT4 Flashcards by Vanessa Nwaokocha

viral agents of infectious bronchitis and bronchiolitis

AIR - adenovirus, influenza virus, respiratory syncitial virus

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bacterial agents of infectious bronchitis and bronchiolitis

bordatella pertussis, mycoplasma pneumonia, chlamydophilia pneumonia

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clinical syndrome of bordatella pertussis

whooping cough (chronic bronchitis)

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population susceptible to bordatella pertussis

unvaccinated children

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reservoir of bordatella pertussis

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

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what are bordatella toxins

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

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pathogenesis of bordatella pertussis

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

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stages of whooping cough

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

all this happens in a matter of days

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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

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how to prevent bordatella pertussis

DaPT – acellular Pertussis

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what happens over time with bordatella pertussis vaccine

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

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what culture is used for bordatella pertussis

charcoal blood agar (bordet-gangou) with cephalosporin

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

laryngotracheobronchitis, bronchitis

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physical feature of HPIV

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

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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

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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

how many H types and N types are found in ducks

all 15Hs and 9Ns

can immunity for H1 give immunity for H2

no, one has to develop immunity for each type separately

which human hemagglutinin types have not been associated with a human disease

H6 through H15 with the exception of H7N9 | it is possible that H4 may not exist

how many segments of RNA are needed for influenza

A and B must have 8 segments C must have 7 segments all segments must all be different

features of hemagglutinin

- rod shaped - it's 25% of the viral protein - major antigen - neutralizing Ab directed at it - highly variable - 4 subtypes - H1-3, H5 - requires cleavage by cellular proteases to be active - changes in structure of protein that alters it length so that it can grab on to the target host cell

features and function of neuraminidase

- sialidase enzyme (removes terminal sialic acid from glycoproteins and glycolipids) - enables release of newly budding viruses from host - helps virus move through the mucin layer - two subtypes N1 and N2??? - no stimulation of neutralizing antibodies