Influenza Flashcards
symptoms of influenza
the virus attacks the respiratoery system. sudden onset of high fever, cough, muscle aches and pains, sore throat, runny nose. These symptoms usually last up to 2 weeks.
incubation period for influenza
average of 1-4 days
why cant a viral pathogen such as influenza be treated with antibiotics
influenza is caused by a virus
antibiotics mainly used to treat bacterial infection
antivirals used to treat viruses
influenza pathogen type
RNA virus
influenza pathogen name
Influenza A, B or C
Influenza mode of transmission
Direct, close contact via airborne droplets when infected person coughs
Indirect via formites
influenza life cycle specificiations
Entry and exit via respiratory system
Replication inside epithelial cells in the respiratory tract; human host reservoir.
method of invasion
Contains genome of single stranded RNA segments, enzymes for viral replication in host cell + shell of matrix proteins
Has phospholipid envelope embedded with proteins
Binds to host cell receptor proteins found within respiratory tract
Host cell takes up virus by endocytosis
Directs host cell to make multiple copies of viral RNA, enzymes + proteins
All assembled together + released from cell
evolutionary adaptations
Reassortment
2 different viral strains come in contact + transfer some genetic information (becomes a hybrid)
Can do this with strains that infect different species (ie. Bird flu)
High mutation rates
High evolution rates
Factors Affecting Spread
Pre-existing conditions can correlate with enhanced influenza infection
So can chronic smoking / alcohol
Vaccination / good hygiene has decreased spread
Children spread it more
More with high population density + poor conditions
Management Strategies - Treatment
Antiviral drugs
Do not destroy target pathogen (like most antibiotics) but inhibit development
Eg. Before cell entry, entry inhibitor, stopping synthesis, stopping assembly, stopping release
Targets should be different to any regular human proteins to limit side effect
Management Strategies - Prevention
Flu vaccine
Causes antibody development against viruses in vaccine
Seasonal vaccines protect against the influenza strain that research indicates will be most common
Needed every year
Hygiene measures