Influenza Flashcards
1
Q
Cause
A
- Influenza virus passed on
- This can only be contracted by different types of influenza viruses
- There are 4 types of influenza viruses, types A, B, C, and D
- Influenza A and B viruses circulate and cause seasonal epidemics of disease.
2
Q
Distribution
A
- Different strains of influenza can be found worldwide
3
Q
Transmission
A
- Breathing in airborne droplets from coughs or sneezes of an infected host
- Direct contact with individuals
- Contact with contaminated objects (fomites)
- Some types of influenza are zoonotic and can be transmitted by animals
- Airborne transmission
- Direct contact
- Fomite transmission
4
Q
Life Cycle
A
- Entry into the host cell
Virus attaches to the cell surface and enters the cell (endocytosis) - Transcription and replication of the viral genome
Entry of vRNPs into the nucleus must first occur for them to be able to bind to the machinery of the host cell
RNA is used to make proteins in the cytoplasm - Export of the vRNPs from the nucleus
- Assembly and budding at the host cell plasma membrane
Viral particles are formed and released
5
Q
Impact on host
A
- Acts quickly, the host starts to feel sick about 1-7 days after coming in contact with the virus
- Symptoms appear within 2-3 days
- Fever, followed by:
- Body aches
- Headache
- Lack of energy
- Nausea and vomiting
- Dry cough
- Runny nose
- Sore throat
- Sneezing
6
Q
Treatment
A
- Most people with the flu have mild illness and do not need medical care or antiviral drugs
- Antiviral drugs can make illness milder and shorten the time someone is sick
- These can be pills, liquids, inhaled powder, or intravenous, and work best when started one to two days after flu symptoms begin
7
Q
Prevention/control
A
- The most effective prevention method is vaccination
- As immunity wanes over time, annual vaccinations are recommended
- Hand hygiene and respiratory or coughing etiquette reduce transmission
- Home isolation helps to reduce spreading
