As influenza is both more difficult to diagnose and deadlier in older adults, there are several nuances to consider.

• Isolation precautions:  
  • Provide a mask for the patient. Isolation should continue during the initial diagnostic testing and assessment.  A face mask and hand hygiene should be used by providers.  Likewise, the patient should wear a mask when being transported outside of their room.
• Influenza key features:
  • Abrupt onset of fever, cough, and muscle aches. 
  • Additional features may include: sore throat, runny nose, headache and fatigue.
  • Influenza testing is not required to confirm the clinical diagnosis when influenza viruses are circulating in the community.
• Atypical influenza presentations in older adults:
  • Older adults may be afebrile, when defined as a temperature of 38C.
  • Upper respiratory symptoms may be absent.
  •  During flu season, consider influenza when evaluating older adults without an obvious cause of fever, delirium, COPD exacerbation, pneumonia, generalized weakness, and accelerated functional decline. 
• Influenza testing may be helpful when it will change clinical management decisions:
  • When influenza is not yet circulating in the community
  • When the patient lives in an institutional setting, to define an outbreak
  • To determine need for antibiotics/antivirals
• What is the initial testing for influenza?
  • A nasopharyngeal swab is the initial test for influenza. A negative test may not rule out influenza.    
  • Molecular assays are recommended for hospitalized patients with suspected influenza. Proper technique of nasopharyngeal swab collection is key, as test accuracy depends on good specimen collection.
• What is the initial treatment for influenza?
  • Oseltamivir 75 mg orally twice daily for five days (adjust for creatinine clearance < 60). 
  • Peramivir is also available at 600 mg IV infused over 15-30 minutes as a single dose, with dose adjusted for renal disease.  The cost for this medication is ten times that of oseltamivir.  The duration can be continued for 5 days in severe cases.
  • Prompt treatment shortens symptom duration by one day. 
• “Red Flag” symptoms include:
  • Dyspnea, pain or pressure in the chest, abdominal pain, sudden dizziness or confusion. 
  • Flu-like symptoms that improve but then return with fever and respiratory distress should prompt consideration of secondary bacterial pneumonia. 
  • Serious complications include: pneumonia, respiratory failure, myocarditis, acute myocardial infarction, encephalitis, rhabdomyolysis, multi-organ failure, sepsis, and worsening of chronic conditions.
• Considerations for hospital admission of older influenza patients include:
  • Dehydration or poor ability to take oral fluids
  • Mental status changes/delirium
  • Decline in function
  • Frail patients and those patients with multiple co-morbidities