Influenza (also known as “flu”) is a contagious respiratory illness caused by influenza viruses.

It can cause mild to severe illness, and at times can lead to death. Symptoms of influenza include:

  • Fever* or feeling feverish/chills
  • cough
  • sore throat
  • runny or stuffy nose
  • muscle or body aches
  • headaches
  • fatigue (tiredness)
  • Some people may have vomiting and diarrhea. This is more common in children than adults.

*Not everyone with flu will have a fever.

person sneezing alt
The symptoms of flu and COVID-19 are very similar, and your doctor may want to test you for both. Visit the CDC’s site to learn more about the similarities and differences between flu and COVID-19
The CDC also provides information on how the Cold and the Flu are similar.

RSV(respiratory syncytial virus)

It’s a common respiratory virus that usually causes mild, cold-like symptoms. Symptoms of RSV include runny nose, decreased appetite, coughing, sneezing, fever.

It then progresses to more severe symptoms such as fast or short breathing or wheezing, and in infants and young children, grunting noises when breathing, chest caving in during breathing, and skin turning purple or blue due to lack of oxygen. While persons of any age can develop RSV, it is most common in children under age 2 and can be severe, especially for infants and older adults. Most people will recover in one to two weeks.

The CDC also provides information on how the cold and the flu are similar.

How Flu Spreads:

people icons with arrow

Person to Person

Flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. Droplets can go as far as 6 feet. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

Less often, a person might get flu by touching a surface or object that has flu virus on it and then touching their own mouth, nose, or possibly their eyes.

In addition to getting an annual flu shot, you can take steps to prevent the spread of the flu:

  • wash hands frequently with soap and water or use alcohol-based hand sanitizers
  • cover coughs and sneezes with a tissue
  • wear a face covering when in public
  • maintain 6 feet of space between others, especially those who reside outside of your own home
  • avoid touching your eyes, nose or mouth


icon of chart and medical thermometer


When Flu Spreads

People with flu are most contagious in the first three (3) to four (4) days after their illness begins. Most healthy adults may be able to infect others one day before symptoms develop and as many as five (5) to seven (7) days after becoming sick.

Children and some people with weakened immune systems may pass the virus for longer than seven days, making it very important that you stay home and practice social distancing while you are sick.

Some people can be infected with a flu virus but have no symptoms and still spread the virus to other people.


Reminder: The flu vaccine can be administered at the same time as a COVID-19 vaccine or booster.

Stats on COVID-19

For more data on Delaware COVID-19 cases including demographic breakdowns, go to My Healthy Community