the cdc says 'most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. children may pass the virus for longer than 7 days. ' remember that some people who get the flu may not have symptoms and can spread the virus too. good hand washing hygiene and getting the flu vaccine can help prevent getting the flu. you may be able to pass on the flu to someone else before you know you are sick as well as while you are sick. most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. some people especially young children and people with weakened immune systems might be able to infect others for an even longer time. typically during the first 72 hours whenever a fever is present or before antibiotics are administered. 2 weeks 2 days
how long is someone with the flu contagious?