URTIs- Cross Flashcards
What kind of virus is the Rhinovirus?
Icosahedral, non-enveloped (+)sense single-stranded linear RNA virus
What is the most common cause of URTIs?
Rhinovirus
Does Rhinovirus cause GI illness?
No, the virus is acid labile (helps to distinguish between rhinovirus and coronavirus)
Transmission of Rhinovirus?
Respiratory droplets; person to person or indirectly by droplets being deposited on surfaces or hands
Pathogenesis of Rhinovirus?
Binds to ICAM-1 on respiratory epithelium–> infects the cells
Treatment for Rhinovirus?
Supportive
What kind of virus is Coronavirus?
Helical, enveloped, (+)sense single-stranded linear RNA virus
What disease(s) can Coronavirus cause?
URTI, GI illness, MERS, and SARS
Clinically with a URTI, can you distinguish between Rhinovirus and Coronavirus?
No, identical symptoms
Describe Bordetella Pertussis (the organism)
Small coccobacillarym, encapsulated gram(-) rod
What does Bordetella Pertussis cause?
Whooping Cough
Pathogenesis of Bordetella Pertussis?
A-B toxin stimulates adenylate cyclase by catalyzing the addition of ADP-ribosylation to the inhibitory subunit of the G protein complex (Gi)–> overactive adenylate cyclase leads to a rise in cAMP levels and thus overactive cyclic AMP-dependent protein kinase activity–> impaired phagocytosis and cilia activity
Transmission of Bordetella Pertussis?
Airborne droplets, highly contagious
3 stages of Bordetella Pertussis?
Catarrhal- 2 weeks of mild URT symptoms
Paroxysmal- 2-3 months of severe cough (whooping sound)
Convalescent- 1-2 weeks of reduction in coughing
Notable finding on CBC in Bordetella Pertussis?
Lymphocytosis; Bordetella toxin impairs lymphocytic transmigration into lymphoid tissues
Diagnosis of Bordetella Pertussis?
Nasopharyngeal swab (PCR) or culture
Treatment of Bordetella Pertussis?
Azithromycin for all individuals with (+) lab diagnosis regardless of age/symptoms
Prevention of Bordetella Pertussis?
DTaP vaccine
Description of Corynebacterium Diphtheriae (organism)
Gram(+) bacillus, pleomorphic, club-shaped, arranged in palisades
What does Corynebacterium Diphtheriae cause?
Diphtheria
Pathogenesis of Corynebacterium Diphtheriae?
A-B toxin blocks protein synthesis by inactivating EF-2–> decreased protein synthesis (think “DEF-theria)
Why will Rhinovirus NOT cause pneumonia?
It doesn’t grow at 37 degrees; that’s why it infects the URT
Why isn’t there a vaccine for Rhinovirus?
There are too many serotypes (over 100)
Generalized symptoms of Diphtheriae?
Sore throat getting progressively worse; Malaise/fatigue/low-grade fever
2 most distinct features of Diphtheriae?
“Bull Neck” (Cervical lymphadenopathy) and pseudomembrane formation in the pharynx
Why is the pseudomembrane formation a concern in Diphtheria?
It can cause mechanical obstruction of the airway; it also serves as a platform for bacterial growth and toxin production
Diagnosis of Diphtheria?
Throat swab culture on Loeffler’s medium, tellurite plate–> will turn grey black; Blood agar also used
2 more specific symptoms seen in Diphtheria (not bull neck or pseudomembrane)
Cardiac dysfunction (Myocarditis) and Neurologic toxicity (especially in cranial nerves) (I know that’s a shitty question)
Treatment of Diphtheria?
Antitoxin administration AND either PCN/erythromycin
Why are children more at risk for Acute Otitis Media?
Their eustachian tubes are shorter, more narrow, and more horizontal than adults (perfect for bacterial incubation)
3 bacteria that cause Acute Otitis Media (in decreasing order of prevalence)?
Strep Pneumoniae; Haemophilus Influenzae; Moraxella Catarrhalis
Treatment of Acute Otitis Media?
Amoxicillin is 1st line; if patients are unresponsive or had recent abx–> Augmentin
What is Epiglottitis?
Acute inflammation in the supraglottic region of the oropharynx
What causes Epiglottitis (decreasing order of prevalence)?
Haemophilus Influenza–> H.parainfluenzae–> S.pneumoniae–>GAS
Typical patient that gets Epiglottitis?
Urban male in his 40s
Prognosis of Epiglottitis?
Good, unless it goes unrecognized, then airway obstruction can ensue–> death risk is high
Treatment of Epiglottitis?
Ceftriaxone
What do you seen on X-ray with Epiglottitis?
Thumb sign; swelling of the larynx
