Children may pass the virus for longer than 7 days. Symptoms start 1 to 4 days after the virus enters the body. Information about how long a person is contagious is available at How Flu Spreads.
In and around Wilmington, North Carolina. Map - 'Sleepy Hollow' filming locations in and around Wilmington, N.C. But mostly inside a sound stage: I Was An Extra On The Sleepy Hollow Set, And Here's What I Learned.
California Doubling: Double subverted. The film is set in the Ia Drang Valley in Vietnam, but was shot in northern California, which in turn is a dead ringer for the Ia Drang Valley. Not all of Vietnam was jungle or city.