Influenza, commonly referred to as the flu, is a highly contagious viral infection that affects mainly the nose, throat, chest and lungs.

Most people who get the flu recover without having to see their health care provider. If your flu symptoms worsen, you have a high temperature for more than a few days, or if you seem better but then feel worse, call your health care provider right away.

Transmission

The flu is spread primarily by droplets made when infected people cough, sneeze, or talk. Less often, a person might become infected with flu by touching a surface or object contaminated with flu virus and then touching their own mouth, eyes, or nose. 

People may be able to infect each other one day before symptoms occur, and up to 10 days after being sick.

Symptoms

Symptoms include:

  • Body aches and pains
  • Cough and chest discomfort which may become severe
  • Early and significant exhaustion
  • Fatigue and weakness that may last up to 2-3 weeks
  • Headache
  • High fever (102-104° F) for 3-4 days
  • Occasional stuffy nose, sneezing and sore throat
Testing

Flu tests check for the most common types of seasonal flu viruses, influenza A and influenza B. Some tests are done in a health care setting, such as your health care provider’s office, pharmacies, or outpatient clinics. 

Individuals At-Risk for Severe Illness

If you have asthma or another chronic respiratory condition, it is important to regularly discuss and follow your health care provider’s recommendations to manage your existing respiratory condition. This is crucial as you may be more vulnerable to severe illness from respiratory infections.

Emergency Warning Signs of Influenza

In children, emergency warning signs that need urgent medical attention include:

  • Fast breathing or trouble breathing
  • Bluish skin color
  • Not drinking enough fluids
  • Not waking up or not interacting
  • Being so irritable that the child does not want to be held
  • Flu-like symptoms improve but then return with fever and worse cough
  • Fever with a rash

Treatment

Most people who get the flu recover without having to see their health care provider. If your flu symptoms worsen, you have a high temperature for more than a few days, or if you seem better but then feel worse, call your health care provider right away.

  • Stay home until at least 24 hours after their fever is gone without the use of fever-reducing medications, or after symptoms have improved (at least 4-5 days after flu symptoms started)
  • Consider layered apparel for body temperature changes
  • Do not share cups and eating utensils
  • Do not take aspirin products without physician approval
  • Drink plenty of fluids
  • Get plenty of rest
  • Sleep and take it easy
  • Take acetaminophen (such as Tylenol) or ibuprofen (such as Advil or Motrin) to relieve your fever and aches
  • Wash your hands frequently
Prevention

Stay home when ill. Any family member suspected of having the influenza should not attend work or school. Ill family members should be encouraged to rest and drink plenty of fluids.

  • Stay home. When you are sick, and ensure that sick children stay home as well.
  • Wash hands often. Wash hands frequently by using soap and warm water and rub your hands for 15-20 seconds (this is generally around the time it takes to sing the ABC’s). Dry hands with as clean a towel as possible. Towels should be changed frequently. Young children should be instructed and assisted to make sure they wash their hands properly. Bathrooms should be checked regularly to ensure that soap and towels are available for your family’s use.
  • Cover coughs and sneezes. Influenza can be spread by coughs or sneezes. Family members should cover their mouths using their upper arm or a tissue when coughing and use a disposable tissue when sneezing or blowing their noses. Tissues should be thrown away immediately, and then hands should be washed. (If you cannot wash hands, rub hands with an alcohol hand gel.) Make sure tissues are available in the home and cars for runny noses and sneezing.
  • Avoid close contact. Spread of the influenza in homes is likely. Families should avoid sharing of saliva by not sharing glasses, forks, spoons, toothbrushes, etc.
  • Clean surfaces frequently. Clean surfaces, such as door handles, handrails, kitchen table, and phones frequently with household cleaner or bleach solution. (Mixing ¼ cup bleach with 1 gallon of water makes a bleach solution. This should be mixed fresh daily.) If disinfectant is not available hot water and soap can be used.
  • If ill, consult a health care provider. If family members get influenza, especially if they are elderly or have other medical problems, you may wish to contact their physicians immediately. Their doctors can prescribe antiviral drugs, which may stop them from getting seriously ill. However the medications must be given within 48 hours of the onset of illness.
Resources
Novel Influenza Viruses
Data and Surveillance

Surveillance is conducted to detect changes in the flu virus to help determine the annual northern hemisphere vaccine composition and to prepare for potential pandemics. Surveillance is also conducted to identify any unusually severe presentations of flu, detect outbreaks and determine the onset, peak, and wane of the flu season to assist with prevention, particularly in high-risk populations like the very young, adults aged older 65 years, and pregnant women.

Individual cases are not reportable in Florida with the exception of novel flu A (a new subtype of flu A) and flu-associated pediatric deaths. All outbreaks are reportable in Florida.