Michigan officials are recommending that schools and child care facilities close down for seven calendar days if they have a confirmed or probable case of swine flu.
The recommendations issued Monday come as at least 10 schools around the state are closed because of the flu outbreak. The state says approximately one-third of Michigan's 47 probable or confirmed cases involves K-12 students.
The state also wants siblings of children with probable or confirmed cases of swine flu to stay at home if they attend a different school.
The virus typically takes four or five days to incubate, though it can take as little as two days and up to seven days to incubate in some cases.
The state plans to reassess school closures after the seven-day closure period.