Medical workers potentially exposed to Ebola while treating patients in West Africa will be confined to their homes for 21 days on returning to Minnesota, state officials said Monday as authorities across the nation continued to seek appropriate safeguards against the deadly virus.

Joined by experts including the Health Department’s chief attorney and a leading University of Minnesota bioethicist, Gov. Mark Dayton said this and other new restrictions were scientifically based solutions that would protect the state without restricting too many personal liberties or inciting panic.

“In the Dark Ages, people had to flee civilization to try to protect themselves and their families from ravaging disease,” Dayton said. “Fortunately, we do not live in those conditions today.”

Home quarantine would apply only to medical personnel returning from the affected countries — Liberia, Guinea and Sierra Leone — who believed they might have been exposed to Ebola by a mishap such as a needle stick or contact with bodily fluids from an infected patient.

It would not apply to travelers who simply visited relatives or to medical workers who treated Ebola patients but didn’t have a known exposure to the virus — a step designed to differentiate Minnesota from controversial measures imposed over the weekend in New Jersey and New York. Those individuals would instead monitor their own symptoms and temperatures, and check in twice daily with state health officials.

A blanket quarantine would exceed what science says is necessary to protect the public and could discourage American medical workers from providing medical aid in West Africa, said Dr. Ed Ehlinger, state health commissioner. Ebola has infected more than 10,000 people in Africa and caused more than 4,900 deaths.

“That is a program that will protect Minnesotans [and] respect the work that humanitarian aid workers are doing,” Ehlinger said.

Since last week, federal officials have informed Minnesota of 26 travelers returning to the state from West Africa. State health officials now are contacting them to determine their risk categories for Ebola exposure and inform them of any restrictions.

Ehlinger said that the restrictions in Minnesota are voluntary but that full compliance is expected. He added that he does have legal authority to impose such restrictions and that he could exercise it later, if necessary.

In addition, state officials said travelers returning from Africa with high risks of Ebola exposure would be banned from public transportation. Returnees at lower risks would be asked to refrain from trips on public transportation lasting three or more hours. The goal is that such travelers would be able to remove themselves quickly from contact with others if they develop Ebola-like symptoms, said Kris Ehresmann, infectious disease director for the state health department.

“You can’t isolate yourself on a plane,” she said.

All of the restrictions announced Monday would last 21 days — the maximum time in which Ebola symptoms emerge — or until the returning travelers developed fever or other suspect symptoms. In the latter event, the patients would be assessed at hospitals and placed in isolation.

An early warning

While Ebola has proved a lethal virus, killing half of the people in Africa it has infected, it spreads only through contact with infected bodily fluids such as blood or saliva — and people carrying the virus aren’t contagious until they suffer fevers or other symptoms. That gives health officials an early warning to remove infected patients from contact with others before the virus can spread.

But what to do with suspected patients while waiting for symptoms to emerge — or not — has been a topic of intense debate. New Jersey’s plan to quarantine all returning health care workers from West Africa was undermined over the weekend when a nurse complained that her isolation in a hospital was inhumane. She was discharged Monday.

Minnesota’s new restrictions were developed Sunday, when Dayton conferred with top medical, legal and ethics experts, but they also mirror new guidance issued Monday by the U.S. Centers for Disease Control and Prevention (CDC).

In a briefing, CDC officials said 807 returning travelers from the three West African countries underwent health exams at five U.S. airports between Oct. 11 and 25. Of them, 46 were health care workers who had modest risk of exposure to Ebola and needed daily monitoring for symptoms, said CDC Director Dr. Tom Frieden.

The aggressive restrictions in New York and New Jersey were imposed last week after the discovery that Dr. Craig Spencer, a New York physician, suffered an Ebola infection following a medical aid trip to Guinea. Spencer monitored his symptoms and reported them immediately to New York authorities, but he has been criticized because he didn’t voluntarily quarantine himself to his home and visited public places such as a bowling alley.

However, the quarantines imposed in New York and New Jersey have been criticized as excessive by federal leaders such as Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases.

Dr. Steven Miles, a U bioethics expert consulted by Dayton, said Minnesota’s new guidelines are based on scientific understanding of how Ebola spreads and not the public fear of the disease that has caused some officials to overreach. “Of course the policy will change with the science,” Miles said. “But it is not built from the fear.”

About 70 percent of travelers returning from the three West African nations are going to six states other than Minnesota, but state officials have nonetheless been concerned because the Twin Cities is home to more than 30,000 residents from Liberia.

State officials hope the new restrictions will give people confidence that they are protected and also eliminate any stigma against healthy Liberians in the community who present no risk of transmitting the virus.

Dayton issued rebukes to anyone stigmatizing Liberians in Minnesota or discriminating against them due to Ebola fears.

“Its illegal and un-American,” Dayton said, “certainly un-Minnesotan.”