I do not know why people keep posting 2-4 weeks?
30 days is the minimum
quarantine for most nasty's based on a 21 day life cycle. Protozoa, Nematodes, and lots of the bacterial/fungal infections require time before symptoms will be indicated. To be as sure as possible not to infect an established system with anything ugly 45 day's should be your required stay time in isolation. Anything less includes risk period. This is not opinion its fact and easily verified with little research.