Is it true that after 4days a cold or flu virus is no longer contagious?

4 days a cold or flu virus is no longer contagious ? Here's something you must know about the flu and how long its contagious and the flu viruses are thought to spread mainly from person to person through coughing or sneezing of people with influenza. Sometimes people may become infected by touching something with flu viruses on it like a door knob or any thing other people touches and then touching their mouth or nose. Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5-7 days after becoming sick. That means that 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.now little children stay infectious for up to 10 to 12 days and can give this very easy to someone. so i would not go around someone for a long time like in the 2 weeks cycle before this time to be very careful about the flu.