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 10 2015 Florida Flu Review Surveillance Summary
National Influenza activity
- Influenza activity is decreasing 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, so the use of neuraminidase inhibitor antiviral medications for treatment and prevention of influenza is more important than ever. Individuals at high risk of complications from influenza infection with suspected influenza 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
- Due to declining influenza activity around the state, Florida reported regional activity to the CDC in week 11. Regional refers to the geographic spread of influenza across Florida.
- The 2014-15 influenza season began early.
- Influenza and ILI continue to decline statewide in all surveillance systems, and data suggest that the season peaked in week 52.
- Influenza activity in Region 2 is elevated in relation to previous years but has decreased in the past two weeks.
- Seasons like this one, where influenza A (H3) is the predominantly circulating strain, are typically associated with higher morbidity and mortality, particularly in adults ≥65 years old.
- Visits for ILI to emergency departments (ED) have declined and are at similar levels to those seen during previous years at this time. Visits in adults ≥65 years old have declined overall but remain slightly above levels seen in previous years at this time.
- 73 (72%) of reported outbreaks of ILI have been in facilities that primarily serve adults ≥65 years old.
- The number of pneumonia and influenza (P&I) associated deaths have declined in recent weeks but are above levels seen during previous years at this time. Increases in deaths at this point in the season are expected during severe influenza years where vaccine effectiveness is reduced, like this one.
- In Florida, the most common influenza subtype detected at the Bureau of Public Health Laboratories (BPHL) in recent weeks has been influenza B. The increase in influenza B late in the season follows previous yearly trends and may also be responsible for increased influenza activity in the north region of the state.
- In the past week, 26.7% of 30 specimens submitted to BPHL for influenza testing were PCR positive for seasonal strains of influenza: one was positive for influenza B Yamagata lineage, two were influenza B Victoria lineage, two were influenza B not yet subtyped, two were influenza A (H3), and one was influenza A not yet subtyped.
- Two outbreaks of influenza (two or more cases of influenza or ILI in a specific setting) were reported to EpiCom in week 11.
- No pediatric influenza-associated deaths were reported in week 11.
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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