Margaret Trexler Hessen, MD
Comparison of Inactivated TIV with LAIV
Antiviral Drugs for Treatment and Prophylaxis of Influenza in Adults
Susceptibility of Prevailing Strains to Antiviral Agents*
Influenza vaccine is effective in preventing influenza and its complications, including hospitalization and death. Vaccine against seasonal influenza should be given to children between 6 months and 19 years old, to adults older than 50 years, and to persons with chronic medical conditions that increase risk for complications. Vaccination should be encouraged in persons, such as health care workers, who have close contact with high-risk persons. Prophylaxis with antiviral medication may serve as a substitute or an adjunct under some circumstances.
Differential Diagnosis of Influenza
Clinical diagnosis of influenza on the basis of fever, cough, rhinorrhea, and symptom severity is usually reliable when influenza is present in the community. Viral cultures can be useful to determine the cause of an outbreak and rapid testing can guide management decisions in individual patients with an atypical presentation.
The mainstay of influenza treatment is supportive care with hydration and antipyretics. Initiate antiviral treatment in hospitalized patients and in those at risk for complications. Consider treatment of others who present early in the course of disease, because early treatment can reduce duration of disease. Hospitalization and subspecialty consultation should be considered for severe illness, uncertain diagnosis, or complications.
All children aged 6 mo to 18 y
All persons aged ≥50 y
Women who will be pregnant during influenza season
Adults and children with chronic pulmonary (including asthma and any condition that causes difficulty handling respiratory secretions), cardiovascular (excluding hypertension), renal, hepatic, hematologic, or metabolic (including diabetes mellitus) disorders, or immunosuppression (including related to medications or HIV)
Residents of long-term care facilities
Persons aged 6 mo to 18 y receiving long-term aspirin therapy who are at risk for the Reye syndrome
Contacts of high-risk persons, including health care workers involved in direct patient care, out-of-home caregivers, and household contacts.
Household contacts and caregivers of children aged ≤5 y
Any other person who wants to reduce their risk for influenza or for transmitting it to others
Household contacts and caregivers for children aged <6 mo
Health care and emergency medical services personnel
All persons aged 6 mo to 24 y
Persons aged 25 to 64 y at high risk for flu complications
What is influenza?
Influenza (flu) is an illness caused by infection with the influenza virus.
Flu symptoms include fever, cough, body aches, tiredness, sore throat, and runny nose.
Usually, flu is not serious and persons recover completely. However, older persons, very young children, and persons with long-term conditions can get very sick or even die of flu or its complications.
What is the difference between regular flu and novel H1N1 (swine) flu?
Novel H1N1 (referred to as "swine flu" early on) is a new influenza virus causing illness in people.
Novel H1N1 spreads from person to person worldwide, probably in much the same way that regular seasonal influenza viruses spread, but occurs outside the regular flu season.
Although regular flu is most serious in older persons, novel H1N1 seems to affect younger persons more than older persons.
Symptoms of novel H1N1 are similar to regular flu, but many patients also have diarrhea, which usually doesn't occur in regular flu.
How can you keep from getting the flu or spreading it to other people?
Get a flu shot every fall if you are aged 6 months to 18 years or 50 years or older; have diabetes, heart or lung disease, or other health problems; or live with or take care of an older person, someone with health problems, or children younger than 5 years.
Wash your hands often with soap and water and try not to touch your eyes, nose, or mouth.
Stay away from people who are sick.
If you get sick, stay home from work or school.
How will I know if I have the flu or something else?
Doctors usually can make the diagnosis without special tests, especially when symptoms occur during a local outbreak.
Your doctor may need to do tests to rule out other illnesses.
Call your doctor if you have the flu and you:
Have a high fever for more than 3 days
Are short of breath
Cannot eat or drink
What can I do for the fever, cough, and aches of the flu?
Fluids and medicines to lower fever are helpful.
Flu medicines do not cure the flu, but they may shorten the time you are sick. They are most effective when started within 1 to 2 days of the first symptoms.
Centers for Disease Control and Prevention
American Lung Association
National Institute of Allergy and Infectious Diseases
American Thoracic Society
Access the PIER module on influenza. PIER modules provide evidence-based, updated information on current diagnosis and treatment in an electronic format designed for rapid access at the point of care.
Download copies of the Patient Information sheet that appears on the following page for duplication and distribution to your patients.
Access MEDLINE Plus information about influenza for patients, including an interactive tutorial available in both English and Spanish.
Current information on seasonal influenza, vaccine and treatment recommendations, vaccine availability, and influenza activity. Includes information for health professionals and patients.
Current information for clinicians and patients on pandemic influenza due to the novel H1N1 strain.
Access information about CLIA-waived tests for rapid diagnosis of influenza.
Access information on 2009 Physicians Quality Reporting Initiative measures relating to influenza.
Access information on Joint Commission on the Accreditation of Healthcare Organizations' requirements related to influenza vaccination for staff of health care organizations.
Hessen MT. Influenza. Ann Intern Med. 2009;151:ITC5–1. doi: https://doi.org/10.7326/0003-4819-151-9-200911030-01005
Download citation file:
Published: Ann Intern Med. 2009;151(9):ITC5-1.
Infectious Disease, Influenza, Prevention/Screening, Pulmonary/Critical Care.
Results provided by:
Copyright © 2020 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use