Viral Infections of the Upper Respiratory Tract Flashcards
What are the most common causes of common cold (in order)?
Rhinovirus, Coronavirus, Influenza Virus, Respiratory Syncytial virus, Parainfluenza virus, Adenovirus
How do viral infections reach the respiratory tract?
Virions reach resp tract via fomites or aerosols
What is the site of virus-host interaction?
Respiratory epithelium
What causes the typical symptoms of a viral infection?
Epithelial cell release of cytokines
What characteristic of the upper respiratory tract allows for viral pathogenesis?
Lower temperature (33C), therefore rhinovirus prefers URT
What age group has more severe URT infections?
Infants and elderly
What pathogens are associated with acute URT infection?
Picornavirus (rhinovirus), Coronavirus, Paramyxovirus (Parainfluenza and RSV, Orthomyxovirus (Influenza)
What viruses are associated with persistent replication in URT?
EBV, adenovirus, papillomavirus
What viruses are associated with systemic replication (dissemination) after primary replication in respiratory tract?
Paramyxovirus (Mumps, Measles), Herpesviruses (EBV, VZV, HHV6, CMV), Rubella, Picornavirus (Polio)
What are barriers to virus from resp tract to blood?
Body temperature, Basement membrane
What are the risk factors for virus dissemination into the blood?
Immunocompromised, smoking, drinking, intubation, bed-ridden
What type of virus is coronavirus? What type of Syx with infection? What are two new rare strains?
(-)ssRNA virus, Cold-like Syx, SARS 2003, MERS 2013
What are Myxoviruses?
Myxo-Greek for mucus, these viruses bind to mucin protein on RBCs
What is an Orthomyxovirus?
Straight, right, proper; Influenza virus is the “right” one
What is a Paramyxovirus?
Beside, resembling; Measles virus is similar to orthomyxoviruses, but different so classified differently
Representatives, Replication, Genome and Structure of Orthomyxoviridae
Genus - Influenzavirus Types: A, B, C; Nuclear; Segmented (-) ssRNA, Enveloped
Representatives, Replication, Genome and Structure of Paramyxoviridae
Genera: Paramyxovirus(Mumps, Parainfluenzavirus1-4) Morbillivirus (Measles, Canine Distemper), Pneumovirus (RSV); Cytoplasmic; Non-segmented (-) ssRNA, Enveloped
What are three treatments of the flu and what strains do they target?
Tamiflu - A, B; Relenza - A, B; Amantadine/Rimantadine - A
What is Fluzone?
Trivalent inactivated flu vaccine
What is Flumist?
Live attenuated flu vaccine
What are the three strains in the trivalent flu vaccine?
A/California/7/2009 (H1N1), A/Texas/50/2012(H3N2), B/Yamagata lineage
What are two common Paramyxoviridae?
Mumps and parainfluenza virus
What are characteristics of Respiratory Syncytial Virus infection? Tx? Complications?
Can cause croup; Steam and humidifiers; pneumonia and respiratory distress
How is adenovirus transmitted?
Fomites, Aerosols, Close contact
