Upper Respiratory Tract Flashcards
upper respiratory tract
nasal cavity, Eustachian tube, pharynx
respiratory defenses
mucociliary clearance: cilia forces mucus towards pharynx
alveolar macrophages remove pathogens that reach alveoli
transmission of respiratory disease
fomite (influenza, picornaviruses, adenovirus)
droplets and aerosols
measles can stay in a room for 2h
what affects transmission
-generation and exhalation (viral load, distribution, number of virions)
-transport (settling velocity, persistence)
-inhalation, deposition and infection (size distribution, deposition mechanisms)
how long do particles stay in the air
small droplets (<1 um): hours
droplets <5 are important for virus infection
inertia
removes most large particles in nasal passage
turbulent airflow
helps to increase contact between particles and mucus
syndrome
a set of connected/co-occurring signs and symptoms with an unclear cause
common cold syndrome
2-4 day incubation
common cold syndrome viruses
picornavirus
adenovirus
coronavirus
parainfluenze
rhinovirus and enteroviruses characteristics
picornavirus (small RNA)
small, non-enveloped viruses
have an IRES (internal ribosome entry site)
replicate at 33C
rhinovirus and enteroviruses spread and vaccine
spread through aerosols or fomites
remains infectious on surfaces in the environment
no antivirals and no vaccines available
there are very effective ______ vaccines
poliovirus
streptococcal pharyngitis
streptococcus pyogenes
respiratory droplets
swollen lymph noses, tonsil abscesses, reddening of pharynx
fever, malaise, headache
can spread to trachea, larynx, bronchi
no vaccine
strep throat complications
scarlet fever
rheumatic fever
acute glomerulonephritis
scarlet fever
blanching, papular rash on chest, strawberry red tongue, headache, chills, muscle pain
expression of exotoxin
exotoxin acts as a super antigen
rheumatic fever
fever joint swelling, pancarditis 2-5 weeks after sore throat
antibody mediated - antibodies (S. pyogene) cross react with self antibodies
Type II hypersensitivity
acute glomerulonephritis
haematuria, albuminuria, oedema
spontaneous recovery 1-3 weeks after infection can cause kidney damage
Type III hypersensitivity
immune complexes of S. pyogenes antigens or self-antigens
diptheria
corynebacterium diphtheriae
sore throat, localized pain, fever, pharyngitis
pseudomembrane adhered to tonsils, pharynx, larynx
bullneck
diphtheria toxin destroys
a eukaryotic elongation factor - a protein required for translation of polypeptides
C. diphtheriae is transmitted
from person to person via respiratory droplets or skin contact
diptheria prevention
by immunization with DTaP vaccine
