Influenza, or flu, is a respiratory infection caused by a variety of flu viruses. The "flu" is a common catch-all term used for a variety of illnesses, but it correctly applies only to the upper respiratory disease caused by the influenza virus.
Estimates are that between 15% and 40% of the population will develop illness from influenza every year. An average of about 36,000 people per year in the United States die from influenza, and 114,000 per year have to be admitted to the hospital as a result of influenza infection. Anyone can get the flu (even healthy people), and serious problems from influenza can happen at any age. People age 65 years and older, people of any age with chronic medical conditions, and very young children are more likely to get complications from influenza.
For the most current information about influenza in Florida, please see Florida's Weekly Surveillance Report, the Florida Flu Review.
Week 2 2015 Florida Flu Review Surveillance Summary
National Influenza activity
- Influenza activity is elevated nationally.
- The Centers for Disease Control and Prevention (CDC) has identified an antigenically drifted influenza A (H3N2) strain circulating nationally and in Florida that is different from the strain of influenza A (H3N2) contained in the current 2014-15 influenza vaccine formulations.
- The CDC indicates this season's vaccine is offering reduced protection, as such, use of neuraminidase inhibitor antiviral medications, for treatment and prevention of influenza, is more important than ever. High risk individuals with suspected flu should be treated with antivirals as early as possible (even prior to laboratory confirmation). For more information read the letter for health care providers.
- The CDC indicates that antiviral medications are underutilized; one study estimates antivirals were only used one out of five times where antivirals use would be recommended.
State Influenza and influenza-like illness (ILI) activity
- Flu activity remains high in Florida and is widespread.
- The 2014-15 flu season began early and is in full swing in Florida.
- Although influenza activity has decreased in recent weeks in some surveillance systems, overall activity levels remain high and it is too early to tell if the season has peaked.
- Seasons like this one, where influenza A (H3) is the predominantly circulating strain, are typically associated with higher morbidity and mortality, particularly in the 65+ age group.
- More hospitalizations and deaths are typical of H3N2-seasons, which hit young children and older people harder.
- While biggest increases in ED visits for ILI have most recently been identified in the 65+ age group, activity is still greatest in children..
- Forty-seven (66%) of reported outbreaks of ILI have been in facilities that primarily serve the 65+ years old age group.
- In the past week, the number of pneumonia and influenza associated deaths, particularly in those over the age of 65 have increased to above levels seen during previous years at this time. Increases in hospitalizations and deaths at this point in the season are expected during severe flu years, like this one.
- During flu season, increases in ED visits typically come before increases hospitalizations and deaths.
- It is likely that flu deaths will reach higher levels later this season since mortality tends to lag behind other indicators.
- In Florida, the most common influenza subtype detected at the Bureau of Public Health Laboratories (BPHL) in recent weeks has been influenza A (H3).
- In the past week, 24 of 37 (64.9%) specimens submitted for influenza testing at BPHL were PCR positive for seasonal strains of influenza: 13 were positive for influenza A (H3), nine were influenza A not yet subtyped, and two influenza B not yet subtyped.
- Eight outbreaks of influenza (two or more cases of influenza or ILI in a specific setting) were reported to EpiCom in week 2.
- No pediatric influenza-associated deaths were reported in week 2.
For more information about Avian Influenza (H7N9), please click here: Avian Influenza (Bird Flu)
New! Long-Term Care Facility Administrators Letter
New! Long-Term Care Faciltiy Administrators Guidance
New! 2014-15 Letter and Guidance to Physicians(December 5, 2014)
New! Guidance for Health Care Providers (December 5, 2014)
New! Sample Letter To Parents (December 5, 2014)
New! Letter to Schools (December 5, 2014)
Letter to Providers: Influenza Prevention (March 14, 2014)
Letter to Providers: Pregnant Women and Influenza Vaccination Recommendations (December 17, 2013)
Press Release: DOH Reminds Pregnant Woman that Flu Vaccination is Important (December 12, 2013)
Antiviral Usage: Influenza
Influenza Fact Sheet for Home
Influenza General Public Fact Sheet
Florida Influenza Weekly Surveillance (Flu Review)
Florida Influenza-like Illness Surveillance Network
Guidelines for the Flu Lab Report in Merlin
The Flu In the United States (CDC
Press Release (December 28, 2010)
Respiratory Syncytial Virus (RSV)
Severe Acute Respiratory Syndrome (SARS)
Information for Directors of Long-Term Care Facilities
Novel Influenza A H1N1 Outbreak: Florida Response Satellite Broadcast
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