Respiratory Flashcards
Guide to the Viruses of the Respiratory tract.
– Nose – Pharynx – Larynx – Middle ear – Sinuses Are known as?
Upper Respiratory tract
The lower respiratory tract includes?
The Trachea, Bronchi, and Lungs
what suffix denotes an infection (except Pneumonia) of the respiratory tract?
organ or tissue name plus the suffix –itis
True or False:
Respiratory infections are rare but often serious when contracted.
False: Very frequent and usually benign (harmless) except in elderly and very young
More than 80% of respiratory tract infections are viral.
A very small RNA virus family is called ____
Picornavirus
What kind of Virus are picornaviruses?
Naked icosahedral capsid of ss(+) RNA (Class IV)
A common member of the picornaviruses infect the noses humans?
Rhinovirus
True of False:
Rhinovirus mode of entry and dissemination is characterized by the following.
• Replicate best at 23ºC (nose and throat)
• rarely stays only in the upper respiratory tract
• Viremia
• does not cause inflammation
False
• Replicate best at 33ºC (nose and throat)
• Strictly local replication in the upper respiratory tract
• No viremia
• Cause important inflammation
True or False:
Rhino virus is both; very contagious and responsible for >50% of rhinitis.
True
Clinical symptoms of Rhinovirus are? (Common cold)
- Sneezing, runny nose, stuffed nose
- Itching and slight throat pain
- Occasional light fever
- Infectivity: for 48 hours after start of symptoms (Peaks after 48 hours, lasts < 7 days)
Best treatment for Rhinovirus include which of the following? • Rest • Symptomatic treatment and good hygiene • Light antibiotics • Vaccine
- Rest
* Symptomatic treatment and good hygiene
What is the most common Respiratory virus belonging to Orthomyxoviruses family?
Influenza
What does Orthomyxovirus mean?
In Latin ortho = Correct or normal, and Myxa = Mucus
What are the three types of Influenza and how are they different?
Classified as A, B, and C based on antigenic differences in the nucleoprotein (NP) and matrix (M1) protein
What is the structure of Orthomyxoviruses?
Spherical or filamentous Enveloped (Class V) ss(-) segmented virus containing six to eight different nucleotide segments
What are the three envelope proteins in Influenza?
2 gylcoproteins: Hemagglutinin (HA) and Neuraminidase (NA)
1 membrane protein M2
What is the importance of Hemagglutinin (HA) in influenzas envelope structure?
Viral attachment.
What is the importance of Neuraminidase (NA) in influenzas envelope structure?
Fusion
What is the importance of M2 in influenzas envelope structure?
H+ ion channel activity
What is the matrix protein in influenzas called?
M1
What are the three polymerase proteins in influenza called?
PA, PB1, and PB2
True of False:
The Nucleocapsid protein (NP) in influenza is just called NP, while Non structural protein are simply called NS1 and NS2.
True
True or False:
All three types of Influenza only infect humans..
False: B only infects humans, while C infects swine as well. moreover type A additionally infects equine, avian, and marine mammals
Which type of Influenza is mostly responsible for severe infections?
B
What is meant by genetic drift in viruses?
Random Point mutations of Antigens (Ag)
Subtypes are based on differences in the envelope proteins H and N. How many of each is there and which ones are associated with human infection the most?
– H protein: 16 varieties
– N protein: 9 varieties
H1, H2 and H3, as well as N1 and N2
What is meant by genetic shift in viruses?
Genetic shuffling usually cause by two different types infecting the same cell and recombining randomly.
What is a Pandemic and what are the Prerequisites for one?
A Pandemic is a global viral threat and must have:
• A subtype to which the general population will have low immunity.
• The new virus must be able to replicate in humans and cause serious illness.
• The new virus must be efficiently transmitted from one human to another.
Influenza enters usually as and ____
Inhaled aerosol
Influenza (increases or decreases) mucus viscosity?
Decreases
Influenza increases risk of bacterial superinfection when?
It infects the lower respiratory tract and causes inflammation
Incubation of Influenza is usually __ to __ days.
1 – 4
True or False:
Influenza clinical signs usually manifest as Fever, chills, headaches, myalgia, malaise, anorexia and last 2 to 7 days in the absence of complications
True
True or False:
11 days after fever subsides dry cough, pharyngeal pain, nasal obstruction and discharge are some lingering signs of Influenza
False:
3-4 days after fever subsides dry cough, pharyngeal pain, nasal obstruction and discharge are some lingering signs of Influenza
What are two serious/fatal complications of Influenza?
Bronchiolitis and pneumonia could be caused directly or due to bacterial superinfection
Tue or False
Influenza Diagnosis can be done by;
• Rapid tests: 30 min (A/B) ; detection of viral antigens (Sensitivity 40 –80 %)
• Serology: Complement fixation, hemagglutination inhibition
• Culture
• PCR
True
Does Influenza have a reliable prevention and treatment?
Yes, is mostly controlled by Tamiflu treatment of serious cases, Vaccination of high risk individuals, Frequent hand washing, and Covering coughs and sneezes
What kind of vaccine is the Influenza vaccine?
intra nasal live attenuated cold adapted.
What is the meaning of a Paramyxovirus?
Latin para = alternative and myxa = mucus
What is a Paramyxovirus?
A spherical enveloped (Class V) ss(-) RNA virus arranged in a Coiled helical nucleocapsid
What are the two types of envelope glycoproteins on Paramyxoviruses?
Hemagglutinnin-Neuraminidase (HN) and Fusion protein (F)
True or False:
Paramyxoviruses have 2 polymerase L (large protein) and P (phosphoprotein) as well as M matrix protein and Nucleocapsid protein (NP).
True
Paramyxoviruses attach to cells using ____ via the HN glycoprotein.
Sialic acid receptors
____ start with RNA-dependent RNA polymerase supplied by the virus and is carried out by the P and L proteins
Transcription
Enveloped viruses are released by ____.
budding from host cell membranes.
True or False:
One type of Paramyxovirus is called Parainfluenza
True
what is meant by saying Parainfluenza is Ubiquitous?
100% primary infection before the age of 5 years
Reinfections throughout life are less symptomatic because why?
Parainfluenza has weak immunity
Parainfluenza has (Viremia or No Viremia) and and incubation of (1,2,4,or 6) days?
No viremia, 4
one symptom of Parainfluenza is Laryngotracheobronchitis. What is that?
Strained breathing, wheezing, hoarse voice
True or False:
Similar to Influenza, Parainfluenza is a respiratory syncytial virus (RSV) and causes only fever
False:
UNLIKE to Influenza, Parainfluenza is a respiratory syncytial virus (RSV) and resembles a bad cold.
True or False:
Human metapneumovirus is a respiratory syncytial virus (RSV) first identified in the Netherlands.
True
True or False:
Human metapneumovirus is similar to Parainfluenza and other RSV’s in almost every way.
True
What is a meant by saying Coronavirus?
Latin corona referring to the spikes projecting from envelope
What is a Coronavirus?
A spherical enveloped (Class IV) ss(+) virus studded with clubbed spikes arranged into a coiled helical nucleocapsid.
What are the two worst illnesses associated with Coronaviruses?
SARS-CoV (Severe Acute Respiratory Syndrome) and MERS-CoV (Middle East Respiratory Syndrome)
True or False:
All Coronaviruses were benign until 2003, which was transmitted by a Rodentlike animal the Civet.
True
The Spike (S) proteins in a Corona virus exist in a (monomer, Dimer, Trimer)?
Trimer
The Dimer Protein HE (Hemagglutinin-Esterase) of a Coronavirus binds to ____ on the host cell.
Sialic acid
True or False:
Respiratory coronaviruses account for only 5% of common colds.
False:
Respiratory coronaviruses cause ~1/3 of common colds.
True and False:
Rhinovirus and Corona virus have the same symptoms but it is very easy to distinguish which virus is causing the cold.
False:
There is no reliable clinical method to distinguish coronavirus colds from colds caused by rhinoviruses or less common agents.
What is the meaning of Adenovirus?
Adenos = glandes, named for site of first isolation
out of the 100 serotypes how many infect humans?
49
True or False:
Adenoviruses are oncogenic to humans.
False:
Are only oncogenic in animals
What is an Adenovirus?
a (Class I) ds DNA virus with a Naked icosahedral capsid containing 252 subunits.
What receptor do Adenoviruses seem to use?
The viral fiber proteins interact with glycoprotein member of the Immunoglobulin superfamily some adenovirus use MHC I molecule
True or False:
The adenovirus can cause both lytic and lysogenic infections. The outcome of an infection depends on the animal species, cell type, and virus type involved
True
The Adenovirus that has entered the lysogenic cycle is usually in which cell types?
The lymphoid tissues
Transmission of an adenovirus is can be from which of the following:
• Droplets of respiratory or ocular secretions
• Close personal contact
• The air by coughing and sneezing
• Some adenoviruses can spread through an infected person’s stool
• The water (swimming pools)
All of them since Adenovirus resist drying, detergents, gastrointestinal tract secretions (acid, protease and bile) and chlorine
Which serotypes infect the most people?
Types 2, 1, 3, 5, 7, and 6 are most frequently isolated, with types 1 and 2 constituting some 60 percent of all isolates.
Adenovirus causes __% of cases of gastroenteritis that requires hospitalization
15
Why are the symptoms of an Adenovirus so hard to determine?
The signs and symptoms of the diseases they cause vary depending upon the area of the body infected.
Acute respiratory disease from an adenovirus include: fever, pharyngitis, and cervical adenitis from which serotypes?
4 and 7
What is the most common outcome of an adenoviral infection?
Acute febrile pharyngitis and pharyngoconjunctival fever. Flu like symptoms (nasal congestion, cough, coryza,, malaise, fever, chills, myalgia and headache)
A persons eye infected with adenovirus will likely exhibit?
Discharge, tearing, sore throat and itching eyes.
Serotype 40 and 42 of adenovirus can cause gastroenteritis that results in?
Watery diarrhea, fever, vomiting, headache and abdominal cramps
A complication that adenovirus can cause in young males is?
Acute hemorrhagic cystitis (bladder swelling) with dysuria (painful urination) and hematuria (blood urine)
True or False:
Not very much about bocavirus is understood yet
True
True of False:
Bocavirus infection are similar to those of a typical viral respiratory illness or atypical pneumonia.
True
When it is said Bocavirus is a co-virus what is meant by that?
Human bocavirus is often found in the presence of another pathogen or other pathogens in respiratory specimens and stool samples.
What is Bocavirus?
A small, single-molecule, linear (Class I)DNA, nonenveloped virus with a nucleocapsid.
