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170 SEcTioN ii Microbiology ` microbiology—Virology Microbiology ` microbiology—Virology

Acute Also called croup. Caused by parainfluenza viruses. Virus membrane contains hemagglutinin
laryngotracheobronchitis (binds sialic acid and promotes viral entry) and neuraminidase (promotes progeny virion release)
antigens. Results in a “seal-like” barking cough and inspiratory stridor. Narrowing of upper trachea
A
and subglottis leads to characteristic steeple sign on x-ray A . Severe croup can result in pulsus
paradoxus 2° to upper airway obstruction.

T

Measles (rubeola) Usual presentation involves prodromal fever 4 C’s of measles:
virus with cough, coryza, and conjunctivitis, then Cough
eventually Koplik spots (bright red spots with Coryza
A
blue-white center on buccal mucosa A ), Conjunctivitis
followed 1–2 days later by a maculopapular “C”oplik spots
rash B that starts at the head/neck and spreads Vitamin A supplementation can reduce
downward. morbidity and mortality from measles,
Lymphadenitis with Warthin-Finkeldey giant particularly in malnourished children.
cells (fused lymphocytes) in a background of Pneumonia is the most common cause of
paracortical hyperplasia. Possible sequelae: measles-associated death in children.
B ƒ Subacute sclerosing panencephalitis (SSPE):
personality changes, dementia, autonomic
dysfunction, death (occurs years later)
ƒ Encephalitis (1:1000): symptoms appear
within few days of rash
ƒ Giant cell pneumonia (rare except in
immunosuppressed)

Mumps virus Uncommon due to effectiveness of MMR Mumps makes your parotid glands and testes as
vaccine. big as POM-Poms.
A
Symptoms: Parotitis A , Orchitis (inflammation
of testes), aseptic Meningitis, and Pancreatitis.
Can cause sterility (especially after puberty).

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