NEW YORK (AP) — Officials in three states have enacted 21-day quarantines for any travelers arriving back in the United States after having contact with Ebola patients in West Africa. But they’ve said little about exactly how they’ll enforce such strict rules.

In Illinois, health officials say such travelers are subject to a mandatory home quarantine. In New York and New Jersey, the three-week quarantine is also in effect because that’s the incubation period of the deadly virus.

All three states announced the quarantine requirements on Friday. But no health officials from those states responded to requests Saturday about how such a quarantine will work.

A nurse who worked in Sierra Leone tested negative for Ebola at a New Jersey hospital after being the first traveler subject to quarantine there. But hospital officials won’t say if she’ll be allowed to leave.

(Copyright 2014 The Associated Press. All rights reserved.)