Pierce County, Washington. Pierce County is a county in the U.S. state of Washington. As of the 2010 Census, the population was 795,225, making it the second-most populous county in Washington behind King County. The county seat and largest city is Tacoma.
You can be contagious from a few days up to two weeks or more, depending on which virus is causing your stomach flu (gastroenteritis). A number of viruses can cause gastroenteritis, including noroviruses and rotaviruses.
You're contagious from one day before you have any symptoms. You stay contagious for five to seven days after you start feeling sick. Kids may be able to spread the virus for even longer, until all their symptoms fade. From: How Long Is the Flu Contagious?