Virology4 Flashcards
H1N1 is the —– flu caused a pandemic in ——(year)
Spanish in 1918 (50-100 mill deaths)
Swine in 2009
Orthomyxoviruses
Genome:
Shape:
Envelope:
RNA polymerases:
Genome: single stranded (-)segmented(7-8) - RNA
Shape: helical
Envelope:present
Polymerases: PB1, PB2, PA
M2 is a —— protein (location) works as an——
Matrix protein
Ion channel
Glycoproteins of influenza:
1-
2-
1- NA : neuraminidase
2- HA: hemagglutinin
Hemagglutinin role:
Induce agglutination of red blood cells
T or F
Influenza C makes mutation
False
Influenza A viruses are named according to their glycoproteins
How many H do we have?
How many N do we have?
How we have antigenic variability in influenza?
18 H
11 N
Genetic reassortment
Hemagglutinin uses the proteases of —— or —— once it’s cleaved by —- and —-, —— fuses with the membrane then the virus is ——-
Respiratory tract Plasmin HA1 and HA2 Second subunit Endocytosed
Neuraminidase is important in the —— mechanism, where the virus is still attached till a protease will cut.
Release
Replication of influenza: 1- 2- 3- 4- 5- 6- Caps are gained from-----
1- -ve RNA with RNA polymerase of the virus will go to the nucleus.
2- + RNA is formed
3- PB1 will copies + templates to make -
4- some + rna will go to cytoplasm as mRNA to make the viral proteins
5- viral proteins will go to ER-golgi to budd out as vesicles and insert in PM
6- budding (out of the cells)
Host cell ( non structural proteins)
T or F
Covid is - sense RNA
False
Antigenic shift:
Antigenic drift:
No shift in —- and —–
Shift : RNA gene reassortment to make new strains
Drift : caused by mutation, no repair system in viruses
B and C
Neuraminidase —— the viscosity of the mucus thus allowing it’s spread in the ——
Once one cell gets infected it will move to the—-
IP for influenza
Decreases
Respiratory tract
Near by cells
1-2 days
Mode of transmission of influenza
Effect of cough:
Airborne droplets
Contact with surfaces
Fomites
Cough reflex may reduce the advancement of the disease by reducing the inoculum
IP for influenza:
Factors affecting:
Infectious window:
Few days
Depends on the infectious dose and immune status
After sneezing and coughing by 1 week(5 days)
Cell destruction causes —— release
Interferon
T or F
Destruction of cells will cause lifelong damage because basal layer is destroyed
False
We will have regeneration because basal layer is not destroyed
Uncomplicated inlfuenza symptoms:
Location:
- abrupt
- chills headache(frontal) and dry cough
- fever(mesh fu2 41) myalgia malaise and anorexia
URT
T or F
Influenza B causes the common cold
False
C
In pediatrics influenza may cause: 1- 2- 3- 4-
1- febrile seizures (higher fever)( disturbance of brain electricity)
2- GI problems (proximity)
3- higher fever
4- croup (laryngitracheobronchitis)
High risk patients: khuf mn l pneumonia
1-
2-
3-
Elderly
Pregnant
People with comorbidities
Viral infections can cause —— which is also caused by—–
ARDS (acute respiratory distress syndrome)
Burns
Lethal impact of influenza:
Cardiopulmonary deaths
Reye syndrome:
Affected group: mainly—–
Cause:
Complications:
-Children
-Took aspirin ( saliciyic acid ) with infection (varicella or FLu A and B)
-acute liver failure and encephalopathy
(Reye’s syndrome)
Avoiiiiiddddd —— in young children
Aspirinnn
Swine flu reassortment: 1- 2- 3- 4- Have --- to --- transmission
North america
Eurasian swine
Avian
Human
Human to human
Swine flu have same severity as —–
Seasonal flu
MR of corona is —–
2.2
Herald wave:
Spring influenza wave that makes us predict what will be the next strain
The problem in influenza pandemics is ——-
Overwhelming the healthcare system
Lung attachment by— virus will go inside , there is a release of —- and —-
When the WBC reach the site the —- will make damage that facilitates the growth of —–
Then we will have—-
HA Cytokines and interferons Cytokines Bacteria Another cytokine storm
T or F
Bacterio-influenzal pneumonia is more common that influenzal
True
Bacterial protease from —–are capable of cleaving —-
S aureus
HA
T or F
We may have bacterial infection even after recovery from the virus
True
T or F
Most will not have disease if they are infected with the same strain
True
Spanish flu Year: Deaths: Deadly for : Reservoir of assortment: Complications in:
1918 50 mill to 100 mill (3-5% of whole pop) 20 - 40 year Pig 48 hrs
Inactivated influenza vaccine is done by—-(1938)
The virus was discovered —-
In first wave spanish flu did—–cause infectivity increase in second wave.
Salk and francis
1930
Drift mutation
Drift mutation (one mutation)
T ir F
Avian was the ancestor of all the following
True
Sick birds are —— of avian influenza (—)
—-borne
Causes —– infection in humans and lethal in —–
Mobile reservoir for avian influenza H5N1 (Laanu ma by2telun) Water borne Inaperant Chicks and turkey
All human pandemic strains are ——
In humans influeza that reached humans are of strains:
Intermediate host of avian:
Reassortants between animal anf human viruses
H18: 1-2-3-5-7-9
N11: 1-2
Swine
How to recognize sick bird?
Slide 15
How infected poultry could spread the virus?
Slide 16
1997 H5N1 oandemic
Immunity against inluenza
Subtype:
Immunity agaisnt HA:
Immunity agaisnt NA:
Specific
Prevention of initiation
Prevents transmision and severity(mucous)
Every 10-40 years no enough people will have ——
Immunity that the pandemic had risen
Pandemic kl —— beseru
Baynama l epidemics every —-
10-20-30 years
2-3-5 years
T or F
No long life immunity in influenza
True
Always reinfections
But milder presentations
T or F
There is a cross protection of A B and C
Falseeeee ma khasun
Kl hada eendu antigens gher
Diagnosis:
Tx
Swab after 3 days of symptoms (mtl l pcr l matrah)
M2 ion channel inhibitors (amantadine and rimantadine (ma mnstaamln)
NA inhibitors : -mivir for A and B for new borns masaln
Oseltamivir prevents cleavage of NA to be released
Circulating strains are resistant to M2 channel inhibitors
After symptoms by 4 days the antiviral drugs are useless
True
After 2 kamen
T or F
Ma fe live attenuated vax lal influenza
False fe
Bs manu recommended
Vax for : 1- 2- 3- 4- 5- 6-
Chronic cardiopulmo disease
Children with asthma metabolic and renal disorders
Nursing homes
HIV
65 and older
Transmitters to the high risk groups (drs , nurses and security….)
