Viral Infections of the Upper Respiratory Tract Flashcards
How do viruses reach the respiratory tract?
Fomites or aerosols
What causes the typical syx of a viral disease?
Infected epithelial cells give off cytokines that cause fever, aches.
Dead epithelial cells result in sore throat
What in the upper respiratory tract is attractive to viruses?
URT is approx 33 oC while the body is 37 oC
What age groups typically have more severe resp infections?
Infants and elderly
What bugs are confined to the respiratory mucosal surface?
- Picornavirus (rhinovirus)
- Coronavirus
- Paramyxovirus (parainfluenza and RSV)
- Orthomyxovirus (Influenza)
What bugs persistently replicate on respiratory mucosal surface?
- EBV
- Adenovirus
- Papillomavirus
What are the two barriers to virus dissemination from the respiratory tract to the blood?
- Flu replicates in epithelium b/c the proteins are focused on apical side
- Basement membrane is acellular
What risk factors contribute to virus dissemintation?
Damage to epithelium, retarded cilia
Describe the Coronavrius characteristics
- Crown of spikes
- (-) ssRNA virus
- Strains cause cold-like Syx
- SARS, MERS
Describe the characteristics of orthomyxoviruses
- Nuclear replication
- Segmented (-) ssRNA
- Enveloped
What is the Genus and Types of orthomyxoviridae?
Genus: Influenza
Types: A, B, C
What are the Paramyxoviridae?
- Paramyxovirus - Mumps, Parainfluenzavirus 1-4, Newcastle disease viruse
- Morbilivirus - Measles
- Pneumovirus -RSV
Characteristics of Paramyxoviridae
Cytoplasmic replication, non-segmented (-) ssRNA, enveloped
What are serious complications of influenza virus?
Secondary bacterial infection, Primary viral pneumonia, CNS/muscle involvement
What are the two antivirals that are typically used for Influenza A and B?
Oseltamivir, zanamivir
What vaccines are used for the flu?
(injectable and inhalable) Trivalent inactivated vaccines, live attenuated vaccine
What are the two bugs that cause croup?
Parainfluenza (but also RSV for Moffat)
What is a serious concern about croup?
Can progress to deadly/complicated pneumonia and respiratory distress
Why can you be repeatedly infected with Adenovirus?
47 serotypes that can infect humans
What are the typical sites of adenovirus infection?
Resp tract, GI tract, eye (Bob Costas)
Who are typically at highest risk for adenovirus infection?
Children, army personnel, people in tight quarters
What vaccines are available for adenovirus?
Only for military!
Where is the first site of virus and host interaction?
Respiratory epithelium
Which of the bugs talked about in lecture can cause mild respiratory infections?
- Adeno
- Corona
- Flu
- Rhino
Most common cause of acute respiratory viral infection?
Rhinovirus
A woman age 20 in college was suffering from sore throat, fatigue, lack of appetite, chills, and body aches. She had just returned from bootcamp w/ her ROTC group. 2 most likely bugs?
Adeno or inluenza
9 yo complaining of congestion, fatigue, cough when lying down, and ear pressure. Two most likely bugs?
Rhinovirus and coronavirus
