Lecture 10: Respoiratory Viruses, Corona, Influenza Flashcards
What are the top 2 viruses that constitutes for the majority of the cases for the common cold?
What are all the viruses that are considered part of the common cold?
-Rhinovirus A,B,C (MOST)
-Coronavirus (second most)
-adenovirus
-RSV
Why do we get so many colds?
-many different viruses can cause the common cold
-new cold viruses constantly develop
-the body never builds up resistance against all of them
Common cold transmitted by
-inhaling airborne virus
-direct contact with infected secretions
Rhinovirus A,B,C
Capsid
Genome
Envelope
Icosahedral
SsRNA (+)
Naked
Rhinovirus are distinguished from enteroviruses by?
-being acid-labile
-optimum growth temperature of 33
-causes mild URT
Rhinovirus spread through?
-respiratory secretions
-direct contact with fomites
Viral replication of Rhinovirus?
What is the cell receptor?
Do Rhinoviruses damage epithelial cells?
“Rhino” = nose
Replication is initiated in the nose to the receptor ICAM-1 at 33 degrees Celsius
-no!!!! Symptoms are thought to be to be immunopathological
Initial symptoms for the common cold?
Followed common symptoms?
Less common symptoms?
INITAL
-sore throat
-runny nose
FOLLOWED
-coughing
-sneezing
LESS COMMON. (More common in the flu)
-headaches
-body aches
Diagnosing and treatment for the common cold
-RT-PCR of the nasopharyngeal specimens
-BioFire film array
(Avoids unnecessary antibiotics prescriptions)
TREATMENT
=supportive care only
Coronavirus
Capsid
Genome
Envelop
Helical
SsRNA (+)
Enveloped
Which Human coronavirus account for 15% if annual colds?
Which animals serve as reservoirs for SARS( severe acute respiratory syndrome)
Coronavirus
-HKU1
-NL63
-OC43
-229E
*primarily spread person-to-person
Zoonosis
-Raccoon dog
-Chinese ferret badgers
-Masked-palm civet
Which animals serve as a reservoirs for MERS (Middle East Respiratory syndrome?
Zoonosis with:
-Dromedary Camel
-Egyptian Tomb Bat
Coronavirus virus transmission
-Respiratory droplets
-direct contact with fomites
Differentiate the symptoms b/w human coronavirus, SARS, and MERS
-similarities b/w all?
-similarities b/w Human coronavirus & SARS?
-similarities b/w SARS & MARS?
-differences
Similarities b/w all:
-fever
-cough
Similarities b/w human corona and SARS
-headache
Similarities b/w SARS and MERS
-Shortness of breath
-human corona = runny nose/sore throat
-SARS = myalgias, lymphopenia, Pneumonia
-MERS = nausea/vomitting (sometimes), pneumonia/kidney (only if other medical conditions)
Coronavirus pathogenesis
-human coronavirus vs. SARS vs. MERS
HUMAN CORONA VIRUS
Localized in URT (33-35)
SARS & MERS
Systemic (37)
COVID-19
-caused by?
-capsid
-genome
-envelope
-SARS-CoV2
-spherical
-(+) ssRNA
-yes
SARS-CoV-2 transmission
-zoonotic disease (bats)
-respiratory droplets (had to wear mask)
-lungs or eyes
-direct contact with fomites
SARS-CoV: (Raccoon dog, Chinese ferret badgers, masked-palm civet)
SARS-CoV2 has tropism for?
Describe the process for binding
-oral mucosa, Lungs, GI tract, kidney, heart, blood vessels)
Require 2 proteins for entry (our cell receptors)
-ACE2
-TMPRSS2 = protease (its going to cleave the ACE2 cell receptor thus activating viral s-protein to bind)
Antigen = s-protein (S1)
*SARS + MERS = systemic
Covid-19 clinical manifestations
-may be asymptomatic
-presymptomatic
-symptoms:
——-fever/chills **
——-cough **
——-shortness of breath ***
——- headache
——-myalgias
COVID-19 diagnosis
approved sample types
-nasalpharyngeal swab
-saliva collection
-blood draw
Emergency situations
-RT-PCR
-ELISA
-LFA
Influenza (FLU)
Caused by:
Capsid:
Genome:
Envelope:
-influenza A, B, and C
-helical
-(-) ssRNA
-yes
Influenza virus A, B, and C:
Name their respective protein and genome
A:
-H, N, M2 protein
-8 genome segmented
B:
-H, N
-8 genome segmented
C:
-H,N,
-7 genome segmented
*H/N: are the 2 major antigens on the spike proteins
M2 protein = ion channel
Influenza virus
-envelope glycoproteins (entry/release)
-serotypes
ENTRY
-Hemagglutinin (HA, H)
RELEASE
-Neuraminidase (NA, N)
18 = H
11 = N
Reservoirs for Influenza A,B, and C
the virus can infect different species
A:
-humans, pigs, birds
B:
-humans
C:
-humans & pigs
Pathogenesis for Influenza A,B, and C
epidemics/pandemics are due to changes in the structure of H/N proteins (antigenic shift/drift)
SHIFT:
Influenza A only
DRIFT:
Influenza A and B
Which type of influenza are genetically more stable?
Influenza B
only reservoir for influenza B are humans
Seasonal vs. Pandemic Flu (influenza)
Seasonal influenza strains
-antigenic DRIFT
-change gradually
-allows for specific influenza vaccines
Pandemic influenza strains
-antigenic SHIFT in viral envelope proteins
-cause illness and death in a large portions
Antigenic drifts
-when does it happen
-happens over what time frame
-caused by
-results in
-needs
-H(mostly) and N genes
-2-3 aa/yr
-caused by mutations during replication of the RNA genome
-results in epidemics
-needs yearly flu vaccination
Antigenic Shift
-when does it happen
-happens over what time frame
-caused by
-results in
-acquiring new H/N gene via reassortment
-quickly (w/n season)
-simultaneous infection with 2 strains of influenza A
-pandemics
Influenza diagnosing
-often made clinically
-Rapid flu test
:Lateral Flow assay
-ELISA
:not useful
-RT-PCR
:BioFire film array
:differentiates b/w flu types
Influenza treatment
-Oseltamivir
—Neuraminidase inhibitor
—FLU A/B w/n 48 hrs
-Baloxavir
—polymerase inhibitor
—-FLU A/B w/n 48 hrs
BioFire Respiratory Panel
Viruses:
-Influenza A
-Influenza A/H1
-Influenza A/H3
-Influenza A/H1-2009
-Influenza B
RT-PCR= BioFire = differentiate b/w Flu types
Influenza Prevention
each vaccine contains the two most prevalent strains of Influenza A + one/two of the most prevalent B strains
Two types of vaccines available for seasonal influenza
-killed virus = injected
-live virus = inhaled (non-preggo, healthy 2-49)
Respiratory syncytial virus
-capsid
-genome
-envelope
-variable shape
-SS RNA (-)
-yes
RSV transmitted person to person via:
-coughing and sneezing
-fomites
-direct contact (kissing)
RSV Symptoms
-appear first
-later
-symptoms
appear first:
=Runny nose
=Decrease appetite
1-3 days later
=coughing
After coughing
=sneezing
=fever
=wheezing
RSV- severe presentation
CAUSE IN INFANTS/CHILDREN <1yoa
-bronchiolitis
-Pneumonia
RSV diagnosis
-RT-PCR
-LFA for RSV antigen
— effective only in young children only b/c viral loads are too low in adults to be detected
RSV treatment
Mild/severe
MILD
-supportive care
SEVERE
- O2 therapy
-Ribavirin
-Palivizumab is an anti-RSV mAb
RSV Prophylaxis
Prophylaxis = attempts to prevent disease
-mABS (Beyfortus, Palivizumab)
-vaccines (Arexvy, Abrysvo)
Which virus does NOT provide immunity when infected?
RSV may cause repeated infections
RSV pathogenesis
-infects respiratory epithelium
-syncytium formation is how RSV spreads to adjacent cells avoiding the immune system
-the immune system responds to infected cells by causing swelling and formation of plugs
———bronchiolitis
———Issue for small airways of newborns
