13 terms
Influenza
Symptoms of influenza?
Fever, cough, myalgia, malaise, sore throat, nasal discharge (sneezing makes it less likely)
What is the most sensitive/specific test for influenza?
RT-PCR (nasopharyngeal swabs)
What factors are predictive of poor outcomes from influenza?
Age >65
People who: are pregnant, have chronic diseases, are immunocompromised, obese, have Down syndrome
Aged care facility residents
ATSI
Homeless
People who: are pregnant, have chronic diseases, are immunocompromised, obese, have Down syndrome
Aged care facility residents
ATSI
Homeless
Reasons for using antivirals against influenza?
1) For individual benefit (at risk of poor outcomes, or already have poor outcomes like complications)
2) To reduce transmission (eg. inpatients, aged care facility residents, people with household contacts who are at risk of poor outcomes)
2) To reduce transmission (eg. inpatients, aged care facility residents, people with household contacts who are at risk of poor outcomes)
What two classes of antivirals are active against influenza? What are some examples?
1) Neuraminidase inhibitors (active against flu A and B)
- Oseltamavir
- Zanamivir
2) Adamantanes (flu A only)
- Amantadine
- Oseltamavir
- Zanamivir
2) Adamantanes (flu A only)
- Amantadine
Side effects of neuraminidase inhibitors?
Nausea and vomiting
How long is the incubation period for influenza? How long is viral shedding?
Incubation 1-4 days, viral shedding from 1 day before till 1 week after becoming symptomatic (longer in immunosuppressed)
What is the most common complication of influenza?
Pneumonia
- Secondary bacterial (more common), primary influenza pneumonia (less common, more severe)
- Secondary bacterial (more common), primary influenza pneumonia (less common, more severe)
What is antigenic drift?
Minor changes in the envelope glycoproteins, (haemagglutinin and neuraminidase)
What is antigenic shift?
Major changes in the envelope glycoproteins, (haemagglutinin and neuraminidase)
What is an outbreak?
An epidemic in a more limited geographic area (eg. a school)
What is a pandemic?
An epidemic that has spread over several countries or continents, usually affecting a large number of people
What is an epidemic
An increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area