The first coronavirus patient in New Hampshire — an employee of Dartmouth-Hitchcock Medical Center — defied instructions from public health officials to stay away from other people.
In a statement, the state Department of Health and Human Services said the patient attended an invitation-only private event Friday "despite having been directed to self-isolate."
The action prompted the state to issue "an official order of isolation to the first patient."
Most states have such rules. And breaking the rules may be punishable, depending on the state.
The Centers for Disease Control and Prevention says states have "police power functions to protect the health, safety, and welfare of persons within their borders."
That includes the enforcement of laws to enforce isolation (when a person is sick) or quarantine (when a person isn't sick but has been exposed to a pathogen).
The CDC says most states regard breaking a quarantine order as a criminal misdemeanor.
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New Hampshire reported Tuesday that a second person, a close contact of the first patient, has also tested positive for the coronavirus. It's unclear, however, whether the second patient, a man, attended the private event or was exposed as a result of the first person's having broken isolation.
Health officials in New Hampshire are asking anyone who attended the gathering to self-quarantine for 14 days.
Dartmouth-Hitchcock Medical Center said it was unaware of any patients' having been exposed to the individual.