FORT KENT, Maine - Insisting she is perfectly healthy, nurse Kaci Hickox again defied the state's Ebola quarantine Thursday by taking a bike ride with her boyfriend, and Maine health authorities struggled to reach a compromise that would limit her contact with others.

Hickox, 33, stepped out of her home on the northern edge of Maine for the second day in a row, practically daring authorities to make good on their threat to go to court to have her confined against her will. Wednesday evening, she went outside for an impromptu news conference and shook a reporter's outstretched hand.

By evening, it was unclear whether the state had gone to court. The governor's office and Hickox's attorneys would not comment.

Hickox, who returned to the U.S. last week from treating Ebola victims in West Africa as a volunteer with Doctors Without Borders, has been under what Maine is calling a voluntary quarantine at her home in this town of 4,300.

She has rebelled against the restrictions, saying she is no threat to others because she has no symptoms. She tested negative last weekend for Ebola, though it can take days for the virus to reach detectable levels.

Her 21-day quarantine - the incubation period for the Ebola virus - is scheduled to end Nov. 10.

Gov. Paul LePage said state attorneys and Hickox's attorneys had discussed a scaled-down quarantine that would have allowed her to go for walks, runs, and bike rides while preventing her from venturing into populated public places or coming within 3 feet of others.

Around midday, however, LePage said that the hours of negotiations had gone nowhere, and that he was prepared to use the full extent of his authority to protect the public.

Word made its way quickly around the town about Hickox. Priscilla Staples said that some were fearful of Hickox's presence, but Hickox "has done nothing wrong, and she has every right in the world to go for a bike ride."

In other developments:

Ebola fears infected a medical conference on the subject. Louisiana health officials told thousands of doctors planning to attend a tropical-diseases meeting this weekend in New Orleans to stay away if they have been to certain African countries or have had contact with an Ebola patient in the last 21 days.

Liberia continued making progress in containing the outbreak, while Sierra Leone is "in a crisis situation which is going to get worse," the top anti-Ebola officials in the two countries said.

New York City Mayor Bill de Blasio and Gov. Andrew Cuomo announced a plan Thursday to encourage health-care professionals to travel to West Africa to treat patients by guaranteeing they won't lose their jobs or benefits while overseas. The state will reimburse health workers and their employers for any quarantine time when they return, they said.

Craig Spencer, the New York doctor who contracted Ebola while serving in West Africa, remains in serious but stable condition.

At a medical conference in Chicago, attendees swapped stories on the number of people turning up at emergency rooms thinking they have Ebola, including a New Mexico woman who sought testing because she had visited Africa two years ago.

The World Bank will give an additional $100 million to help bring in more foreign health workers. That raises the money it has given to $500 million.

A Dallas nurse who recovered from Ebola will soon be reunited with her dog, Bentley, sequestered since his owner became ill. The King Charles Cavalier spaniel's 21-day quarantine period at an abandoned Navy base in Dallas ends Saturday.