World Bank chief Jim Yong Kim made an impassioned plea Tuesday for thousands more medics to volunteer in the fight against Ebola in West Africa, calling the epidemic a global crisis that required a global response. The call to action comes as U.S. health officials warn that state policies to quarantine travellers from the region will hamper relief efforts.

Kim warned against knee-jerk panic in response to the highly contagious virus, which has killed nearly 5,000 people in the outbreak.

"This is not an African crisis... it is a global crisis," said Kim, who is visiting Ethiopia along with United Nations Secretary General Ban Ki-moon and African Union Chairwoman Nkosazana Dlamini-Zuma.

"We'll need a steady state of at least 5,000 health workers from outside the region. Those health workers cannot work continuously. There needs to be a rotation," Kim said. "So we will need many thousands of health workers over the next months to a year to bring this epidemic under control."

The death toll from the Ebola epidemic has risen to 4,922 out of 10,141 known cases in eight countries, the World Health Organization (WHO) said on Saturday.

Liberia has been hardest hit, with 4,665 recorded cases and 2,705 deaths, according to the WHO. Sierra Leone and Guinea have also been badly affected by the outbreak.

"We have done as much as we could up till now but I guarantee you we will do more," Kim said. "The way to fight the Ebola epidemic is clear...the key is to get high quality services to both prevent new infections and treat those who are ill at the source of the epidemic."

Kim said medics should remember their vocation and the Hippocratic oath and not shy away from going to a problem area.

"Right now, I'm very much worried about where we will find those health workers," he said, adding that the "fear factor" was getting "out of control."

His warning comes amid debate in the U.S. as to how to treat those returning from West Africa, including health care professional.

Officials in the U.S. on Monday unveiled new guidelines that outline increasing levels of monitoring and quarantine for travelers from the region depending on their level of risk for developing the disease.

But the treatment of those deemed to be at risk has been a source on controversy.

Over the weekend, the White House criticized state policies that quarantine passengers who exhibit no Ebola symptoms, and as such pose no risk to others.

But officials appeared to tone down criticism on Tuesday while still defending the new guidelines.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease at the National Institutes of Health, defended the Washington policy Tuesday, but he said that states have a right "to go the extra mile" if they wish.

In an appearance on ABC's "Good Morning America," Fauci declined to criticize the more stringent quarantine policies implemented in New York and New Jersey. “They're doing it in good faith."

New Jersey Gov. Chris Christie said Tuesday he feels the Centers for Disease Control and Prevention’s (CDC) latest guidance is "incredibly confusing."

"The CDC is behind on this," he said on NBC's "Today" show. "Governors ultimately have responsibility to protect the public health of people within their borders."

Christie faced criticism over the weekend for ordering the mandatory quarantine of a nurse who had returned from treating victims of the disease in Sierra Leone. Her flight landed at Newark International Airport and she briefly exhibited one of the symptoms of the disease, a fever, but soon found herself in an isolation tent at Newark University Hospital.

On Monday, state health officials allowed Kaci Hickox to leave the hospital after she tested negative twice for the illness, exhibited no symptoms and threatened to file a federal lawsuit over her detention. She had chronicled her ordeal with a series of photographs showing her conditions: an unheated tent at the hospital with a chemical toilet and a hospital bed.

Experts on managing outbreaks say that people who must endure quarantining should be able to do so in comfortable accommodations provided by the government demanding they stay put.

Illinois, Florida, Connecticut and Maryland have instituted similar orders as New Jersey, which allows state residents who have traveled to the region to complete their mandatory quarantine at home. For people traveling on to other destinations, however, state rules complicate the ability for a person to travel through the Garden State easily.

Meanwhile, the U.S.’s Ebola efforts received some good news on Tuesday. Amber Vinson, 29, a Dallas health care worker who contracted the disease after treating a Liberian patient, has been released from the Emory University Hospital in Atlanta. The Liberian patient, Thomas Eric Duncan, is the only person in the U.S. to have died from the virus to date.

Vinson becomes the fourth patient successfully treated for Ebola at Emory's hospital. Another health care worker, Craig Spencer, 33, who came down with the disease after returning from Liberia, remains in isolation undergoing treatment at Bellevue Hospital in New York City.

Vinson's case gained increased attention after it was revealed she flew from Texas to Ohio and back before she was diagnosed with the virus. Officials were monitoring the health of 164 people in Ohio who were believed to have had contact with her or to have been near her.

Al Jazeera and news services