Influenza: Prevention, Diagnosis, and Treatment

Influenza is typically a self-limiting viral infection that causes symptoms such as fever, chills, cough, rhinitis, headache, sweats, myalgias, and malaise. However, serious illness and complications (eg, pneumonia, death) can occur, particularly in individuals with risk factors. Annual influenza vaccination is recommended for people 6 months and older, including pregnant individuals, who do not have a contraindication to the vaccine. Rapid diagnosis of influenza using point-of-care testing in select patients increases antiviral prescribing and decreases antibiotic prescribing in those with a positive result. However, a negative rapid test result does not exclude influenza. Although most patients do not require treatment for influenza, antivirals should be initiated as soon as possible for patients who are hospitalized, have severe or progressive illness, or are at high risk of complications. Treatment can be considered in symptomatic patients who are household contacts of individuals at high risk of complications or in symptomatic health care professionals who care for patients at risk. Postexposure chemoprophylaxis with antiviral therapies can be considered in individuals who are at risk for influenza complications. Oseltamivir and baloxavir marboxil are commonly recommended antiviral treatment options for influenza. Antiviral treatment is most effective if taken within 24 to 36 hours of symptom onset and reduces symptoms by approximately 20 hours. However, there is little to no evidence that it reduces complications of influenza.