Influenza infection

Uncomplicated seasonal influenza infection

Seasonal influenza is usually a self-limiting acute respiratory illness that recurs each winter season as different strains emerge. Annual influenza vaccines are available to immunise against the 3 expected strains to pass through a community.[152]Influenza Vaccine 2007-2008. Med Lett Drugs Ther. 2007 Oct 8;49(1271):81-3. http://www.ncbi.nlm.nih.gov/pubmed/17912142?tool=bestpractice.com If seasonal influenza is contracted, institution of antivirals within 36 to 48 hours of onset of symptoms will decrease days of illness by 1 to 2 days and reduce lower respiratory tract complications.[109]Fiore AE, Fry A, Shay D, et al. Antiviral agents for the treatment and chemoprophylaxis of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2011 Jan 21;60(1):1-24. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6001a1.htm http://www.ncbi.nlm.nih.gov/pubmed/21248682?tool=bestpractice.com [116]Doll MK, Winters N, Boikos C, et al. Safety and effectiveness of neuraminidase inhibitors for influenza treatment, prophylaxis, and outbreak control: a systematic review of systematic reviews and/or meta-analyses. J Antimicrob Chemother. 2017 Nov 1;72(11):2990-3007. http://www.ncbi.nlm.nih.gov/pubmed/28961794?tool=bestpractice.com

Complicated seasonal influenza: viral pneumonia

Patients considered at high risk for seasonal influenza may develop a lower respiratory tract complication of viral pneumonia. This may require more aggressive supportive care or hospitalisation.

Complicated seasonal influenza: bacterial pneumonia

Patients who have an initial improvement of their respiratory illness followed by recurrence of fever and cough with productive sputum may have a bacterial pneumonia complicating the seasonal influenza infection. This may require more aggressive supportive care, appropriate antibiotic therapy, and/or hospitalisation.