World leaders declared the Ebola outbreak the worst global health emergency in years, as US President Barack Obama vowed a 'much more aggressive' response to the spreading virus, which has killed nearly 4,500 people.
US President Barack Obama on Wednesday called on the world to do more, while insisting his own country would be "much more aggressive" in its response, after a second Texas hospital worker tested positive.
The fact that the newly infected Dallas caregiver took a domestic flight a day before she was quarantined magnified global fears about air travel -- concerns Obama tried to tamp down after national crisis talks.
"We are going to have to make sure that we do not lose sight of the importance of the international response to what is taking place in West Africa," Obama said after meeting with his top advisors.
Earlier, Obama called his counterparts from Britain, France, Germany and Italy to better coordinate their plan to combat the outbreak.
"Leaders agreed that this was the most serious international public health emergency in recent years and that the international community needed to do much more and faster," British Prime Minister David Cameron's office said.
Obama urged Cameron, Germany's Chancellor Angela Merkel, France's President Francois Hollande and Italian Prime Minister Matteo Renzi to "make a more significant" contribution to the fight, the White House said.
European Union health ministers are to meet in Brussels on Thursday, with member states under pressure to follow Washington in sending troops to West Africa to help fight the virus.
The United Nations Security Council urged the international community to "accelerate and dramatically expand" aid to the West African countries battling the epidemic.
In a unanimously adopted statement, the 15-member body warned that the world's response "has failed to date to adequately address the magnitude of the outbreak and its effects."
- More health checks -
France announced that it would begin carrying out health checks at airports for travelers arriving from the West African nations that have borne the brunt of the outbreak.
Airports in Britain, Canada and the United States have already introduced stepped-up screening of travelers arriving from West Africa.
On Thursday, additional screening measures are due to launch in the United States at Newark's Liberty, Chicago's O'Hare, Atlanta's Hartsfield, and northern Virginia's Dulles, the White House said. Last week, screening started at New York's JFK International.
The worst Ebola outbreak on record has so far claimed 4,493 lives, out of 8,997 recorded cases, according to the World Health Organization.
The hemorrhagic virus has ravaged West African countries Liberia, Guinea and Sierra Leone since the start of the year, and the UN health agency has warned there could be a steep rise in infections in coming months.
In Liberia, the country worst hit by the crisis, hard-pressed doctors and nurses returned to work after a two-day strike to demand hazard pay for dealing with Ebola patients.
The United States pledged $5 million to help pay the workers, many of whom have caught the virus from their patients, bringing its total commitment to the country to $142 million, Liberian officials said.
- Second US infection -
Meanwhile, the US Centers for Disease Control and Prevention (CDC) issued an alert for all passengers who traveled on an October 13 flight from Cleveland, Ohio to Texas.
Authorities want to interview 132 people who flew on a plane with an Ebola-infected nurse -- the second American to be infected within the United States -- who had not yet become symptomatic.
CDC chief Thomas Frieden said the case was "very concerning" and warned that health workers who have been exposed to Ebola patients should not use public transport.
"She was in a group of individuals known to have exposure to Ebola. She should not have traveled on a commercial airline," he said.
"The investigation is identifying additional health care workers who will be very closely monitored and we are planning for the possibility of additional cases in the coming days."
The woman was isolated at Texas Health Presbyterian hospital in Dallas late Tuesday with a fever, and the crew on the flight said she had not been symptomatic when she flew a day earlier.
Ebola is only transmitted by contact with the bodily fluids of an infected person who has fever, diarrhea or vomiting.
Both women infected in Texas treated a Liberian Ebola patient, Thomas Eric Duncan, who died in Dallas on October 8.
As fears grew about the spread of Ebola, senior US lawmakers overseeing homeland security on Wednesday joined calls for authorities to impose a temporary ban on travel from West Africa.
- 'It will get better' -
The first US case was announced Sunday -- 26-year-old nurse Nina Pham, who is currently in good condition in hospital. The second woman was transferred to Emory University in Atlanta for care.
The CDC is monitoring 75 more health care workers at Texas Health Presbyterian Hospital for signs of Ebola.
"It may get worse before it gets better, but it will get better," Dallas Mayor Mike Rawlings told a press conference.
Anthony Fauci, head of the National Institute for Allergy and Infectious Diseases, nevertheless called the second infection "unacceptable."
A Spanish nurse was said to be in stable condition, but a Sudanese doctor who had worked as a UN volunteer in Liberia died of Ebola in Germany late Monday.
The World Health Organization warned that the infection rate could reach 10,000 a week in a worst-case scenario by the first week of December.