When is someone contagious with the flu?

People can be contagious with the flu even before they know they are infected with the virus.

For most healthy adults, they are able to infect other people one day before flu symptoms start, according to the Centers for Disease Control and Prevention (CDC). Symptoms can start between one and four days after the virus enters your body.

An adult with the flu will still be contagious for up to five to seven days after they first became sick. A child with the flu can be contagious for more than seven days, according to the CDC.

For more information about when someone is contagious with the flu, talk with your doctor.

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