Influenza mortality is greatest in those over 65 years of age. Flu onset is sudden: high fever, dry cough, headache, muscle aches, exhaustion
- Type A – causes epidemics every 1-3 years
- Type B – less likely to mutate than Type A. Epidemics seen every 5 years.
- Treatment: Mostly supportive care.
- Adamantanes: amantadine, rimantadine – no Type B activity. These are not recommended anymore.
- Neuraminidase inhibitors: oseltamivir, zanamivir, peramivir, baloxavir – Best if started within 48 hours
- Who gets neuraminidase inhibitor?
- Uncomplicated outpatient: Give if 2 days or less since symptoms or if household contact/caregiver of patients with high risk of complications.
- Complicated outpatients: Give to everyone who tests positive or has symptoms, regardless of time of exposure, for at least 5 days, consider longer if immunocompromised. Oseltamivir preferred in pregnancy or COPD/asthma.
- Inpatient: Everyone who tests positive or has symptoms, regardless of time of onset, for at least 5 days.
- Can treat high risk patients even if negative flu test. If testing won’t affect treatment, don’t need to test.
- New: Baloxavir: inhibits endonuclease activity