Influenza Flashcards
Most common Influenza-Like Illness causes?
-Influenza A/B/C (A & B most common)
-Parainfluenza Virus
-RSV
-M. pnemoniae
How does Influenza spread?
-Droplet Inhalation &/or direct / indirect contact with contaminated respiratory secretions.
Influenza incubation period?
1.5-2d most commonly (ranges from 1-4d)
When can adults spread Influenza virus?
1d before symptoms to ~5d after symptom onset
When is the optimal time to vaccinate for Influenza?
October (prior to the beginning of the Nov-Apr surge)
The negative stranded RNA Virus that’s responsible for Influenza is covered with a protective & antigenic envelope… What are the envelope’s sub-components?
-Haemagglutinin (HA)
-Neuraminidase (NA)
-Matrix 2 (M2) Ion Channels
Steps 1-4 of Influenza Viral Invasion & Replication?
1) HA binds host cell receptors in the respiratory tract.
2) Viral RNA released into cytoplasm & is transported to nucleus.
3-4) Complementary vRNA transcribed & is either exported into cytoplasm or stays in nucleus.
Steps 5-7 of Influenza Viral Invasion & Replication?
5) New viral proteins secreted through Golgi Apparatus onto cell surface or transported back to nucleus to form new viral genome particles.
6) vRNA & other proteins leave nucleus, bulge out of host cell membrane coated in viral surface proteins.
7) Mature virus buds off from cell & host cell dies.
Through what mechanism do AV drugs work?
Inhibition of the budding stage (Step 7)
Antigenic Shift / Drift refers to what process?
Appearance of Influenza Virus (usually Influenza A) with new HA or NA subtypes
What epidemic was declared to be the world’s worst ever?
1918-19 Influenza Pandemic
-20% world’s population infected
-2.5% - 20% mortality
-Killed up to 50mil people
Signs & Symptoms of Influenza infection?
-Sudden high fever (7-10d length ; preceded by chills)
-Cough (may persist for 2wks)
-Sore Throat
-Myalgia / Fatigue (can linger around for wks)
-Headache / Appetite Loss / Rhinitis / NVD (espec. kids)
When do most people recover from Influenza infections?
7-10d
What are some complications that may arise from Influenza infection?
-Viral / Secondary Bacterial Pneumonia
-Exacerbated Chronic Lung Disease
-Croup / Bronchiolitis (young kids)
-Otitis Media
Death from Influenza infection most often arises due to what?
Exacerbated underlying Cardio-Pulmonary Disease
What other co-morbid conditions may be exacerbated by Influenza infection?
-Febrile Seizures
-Reye’s Syndrome (Abnormal fat depositions & increased pressures on the brain)
-Encephalitis
-Guillain Barre Syndrome (Autoimmune attack on PNS)
-Myositis
-Myocarditis
In what pregnancy trimester does Influenza demonstrate its highest mortality rates?
3rd trimester
IIV3 & IIV4 stand for what?
Inactivated Influenza Vaccine Trivalent / Quadrivalent
LAIV3 & LAIV4 stand for what?
Live Attenuated Influenza Vaccine Trivalent / Quadrivalent
SD (as it pertains to vaccine terminology) refers to what?
Standard Dose, Unadjuvanted
Adj (as it pertains to vaccine terminology) refers to what?
Adjuvanted
HD (as it pertains to vaccine terminology) refers to what?
High Dose, Unadjuvanted
cc (as it pertains to vaccine terminology) refers to what?
Cell Culture Based ; Is standard dose & unadjuvanted
RIV4 (as it pertains to vaccine terminology) refers to what?
Recombinant Protein
