L18- Viruses and disease Flashcards
How are viruses divided morphologically?
Helical/ icosahedral
Naked/membrane bound
What are the 4 ways of virus transmission?
- Inhalation
- Ingestion
- Inoculation-> example=iatrogenic- unintentionally by doctor
- Congenital
How can aetiological diagnosis be done?
- EM- shows whole virus
- Immunilogical tests- shows virus antigen
- PCR- shows virul nucleic acid
- IgM/IgG in blood-> shows specific antibody response
What does the picornoviridae family include?
Enterovirus- CNS e.g. polio
Hepatovirus- hepatitis A
Rhinovirus- common colds
Apthovirus- Foot and mouth disease
What are the picornoviruses?
Small RNA viruses that are icosahedral. (cause colds, hep. a, polio etc.)
What is polio caused by?
enterovirus from the picornovirus family.
How is polio spread?
Faecal-oral route. Incubation period 1-2 weeks.
What does polio cause?
fever, sore throoat, vomiting. (spreads along axons)
What is interesting about Polio?
95% of individuals will be asymptomatic. 5% of the times the virus spreads to neurones, end up paralysed.
Which virus causes the common cold?
Rhinovirus (a picornavirus). There are over 100 serotypes present in a population at the same time.
When is a common cold infectious and how long is incubation?
Infectious from 1 day after infection until end of symptoms.
Incubation 2-4 days.
What’s the structure of a rhinovirus?
Icosahedral
Which family is the influenza virus from?
Orthomyxovirus
What are the types of influenza virus?
Type A- can get in many animals so worst
B- human specific
C- in humans and seals
How does influenza lead to death?
Secondary bacterial pneumonia can kill elderly and very young
