Respiratory Infections 3

Question 1

Mumps viral epidemiology

Answer 1

• Paramyxoviridae family
• Enveloped ss(-)RNA virion
• 2 glycoproteins
• HN – mediates hemagglutination and neuraminidase activity
• F – fusion to the host cell

Question 2

How is mumps transmitted

Answer 2

Aerosol transmission

Question 3

Mumps Pathogenesis

Answer 3

Question 4

Mumps parotitis clinical presentation

Answer 4

• Low grade fever, malaise, myalgia, headache and anorexia
• Parotitis may be unilateral or bilateral
• Swelling of the parotid and tenderness
• Earache
• difficulty eating, swallowing, talking

Question 5

Complications from Mumps

Answer 5

• Orchitis – most common complication after parotitis • Sterility is rare but subfertility may occur
• Oophoritis
• Meningoencephalitis
• Rare: Loss of hearing, Pancreatitis & Thyroiditis
• Most patients experience complete recovery with no long term effects

Question 6

How to prevent mumps

Answer 6

MMR/MMRV Vaccine
• Vaccine is ~88% protective with 2 doses
• Reduces severity of symptoms if infection occurs
• Outbreaks among vaccinated groups are linked to waning immunity

Question 7

Bacterial pharyngitis

Answer 7

• Acute onset
• Sore throat, fever
• Nausea, vomiting and headache often present
• Erythematous posterior pharynx and palatine
tonsils
• Tender cervical lymphadenopathy
• While or yellow exudate in tonsillar crypts

Question 8

Viral pharyngitis

Answer 8

• Gradual onset
• Low-grade fever
• Less erythema and swelling of the pharynx
• Discrete ulcerative lesions
• Tonsils generally not involved
• conjunctivitis, coryza, cough may be present

Question 9

S. pyogenes: Biology

Answer 9

• Gram positive cocci
• Usually arranged in chains
• Grow in solid media as discoid colonies
• β-hemolytic
• Lancefield Group A
• Important for Rapid Strep test • PYR positive
• detection of pyrolidonyl arylamidase
(hydrolysis of L-pyrrolidonyl-β-naphthylamide) • Bacitratin sensitive
*GABHS - Group A β-hemolytic streptococcus