Respiratory Viruses Flashcards
Transmission of respiratory viruses?
Virus particles.
Sneezing/Coughing.
Release of salivary droplets.
Inhalation of contaminated air.
Viruses that cause the common cold?
Rhinoviruses >50%
Coronaviruses 10-30%
Symptoms of a common cold?
Sneezing, rinorrhoea, congestion, sore throat, malaise, cough.
Characteristics of Rhinovirus?
Picornaviridae! (+)ssRNA, naked icos NC, Genus: Enterovirus, Species: human rhinovirus A,B,C
Transmission of Rhinovirus?
Respiratory droplets, in air or deposited on fingers, delivered to nose, eyes.
Treatment and prevention of rhinovirus?
Treatment: Supportive, Pleoconaril to asthmatics.
Prevention: Hand antisepsis
Characteristics of Coronavirus?
Coronaviridae, Alphacoronavirus. (+)ssRNA, helical NC, buds from ER.
Characteristics of coronavirus infection?
Occurs spring, early winter, cause respiratory and enteric disease. SARS
What is Paramyxovirus?
Measles virus! (+)ssRNA, envelope - F protein, H protein.
Measles infection involves:
Prodrome of Fever, conjunctivitis, coryza, cough -> rash of flat macules, descending from head to limbs.
Vaccine for measles?
Live attennuated!! widely administered.
Orthomyxoviridae?
Influenza A, (-)ssRNA, 8 segments, helical NC, enveloped, contains RNAdepRNApol.
Characteristics of influenza infection?
incubation: 1-3 days, high fever, cough, chills, sweating, sore throat, severe headache, muscle and joint pains, weakness, can caause pneumonia.
Differences between influenza types A B and C?
A causes pandemics (severe), B is milder than A, and C has only minor symptoms.
Explain antigenic drift
One subtype can have spontaneous mutations which cause it to alter proteins, leading to immune evasion and possibility of re-infecting the original host.
Explain antigenic shift
Two subtypes infecting the same host causes genomic segments to mix and create new viruses with potentially higher virulent capabilities.
Different influenza Vaccine types?
- While virus vaccines - high side effects, inactivated with formalin. (-CTL+Ab)
- Split virus vaccine - disrupted with detergent, fewer side effects (-CTL+Ab)
- Subunit Vaccine, only antigens (-CTL+Ab)
- Live attenuated vaccine, may revert to virulent, time intensive production (+CTL+Ab).
Treatments of Influenza?
Relenza/Tamiflu - inhibit neurominidase.Do not prevent infection, but prevent spread in lungs.
