Influenza Flashcards
What are the three subtypes of influenza?
A,B,C
What is affected by each of the three subtypes of influenza?
A- mammals and birds
B,C- humans
Differentiate antigenic drift from antigenic shift
Drift: normal shift in viral makeup, occurs naturally over time, makes gradually harder for immune system. Causes worse than normal epidemics and vaccine mismatch
Shift: major abrupt change to viral genetics, allows jump form one animal species t another, two or more strains can combine to form new subtypes. Can lead to pandemics
What is the normal and range incubation period for influenza in humans?
2-4 days (1-5 range)
Describe the fever indicative of influenza including max temp, range and duration
41 degrees max
normal range 38-40
lasts for 3 days
List symptoms, two or more of which, are required to satisfy a diagnosis of influenza
cough sore throat rhinorrhoea myalgia headache malaise
What are the two most common complications of influenza?
Actue Bronchitis
Secondary Bacterial Pneumonia (20%)
What investigation should be done in a patient suffering from flu symptoms and fever for 4 days or more? Why?
Urgent CXR
To look for secondary bacterial pneumonia
What are the component parts of the CURB65 screening test?
Confusion Urea >7mmol/l RR >30 BP diastolic <60 OR systolic >65 years of age
Give 8 investigations for a patient where influenza is suspected
RR FBC CXR Nose and mouth swabs Pulse oximetry - if <92 need 02 and do ABG CRP U+E's Blood cultures
What are the two main antivirals which may be used for influenza? When can they be used? Which is preferable for breastfeeding mothers?
Oseltamivir (Tamiflu) and Zanamivir (Relenza)
In complicated cases/patients or where the senior physician feels that the patient is at a high risk of complications
Oral Oseltamivir
