The deadliest Ebola outbreak in history has killed more than 700 people across West Africa, according to the World Health Organisation.
The disease is responsible for 729 deaths across West Africa, according to the figures, which show at least 57 deaths have been reported in recent days.
Nearly half of the new deaths were reported in Liberia.
That nation’s president, Ellen Johnson Sirleaf, ordered the nation’s schools to close on Wednesday and also demanded that most government employees stay at home in a bid to stop the disease’s spread.
Sierra Leone, where nine new deaths were reported, has declared a public health emergency and is trying to quarantine sick people at home who have refused to go to isolation centres.
Ebola cases first emerged in Guinea back in March, although the crisis has dramatically deepened in the last week.
The president of Sierra Leone, Ernest Bai Koroma, has also vowed to conduct house-to-house searches for people who may have been exposed to the virus,.
As part of the new measures to contain the viral haemorrhagic fever, travellers at airports will have to wash their hands with disinfectant and have their temperatures checked, President Koroma said.
All deaths must also be reported to the authorities before burial, he said
The US Peace Corps is also evacuating hundreds of its volunteers in the affected countries. Two Peace Corps workers are under isolation outside the US after having contact with a person who later died of the Ebola virus, a State Department official said.
Ebola has shown no signs of slowing down, particularly in Liberia and Sierra Leone. Among the dead was the chief doctor treating Ebola in Sierra Leone.
The government said Dr Sheik Humarr Khan’s death was “an irreparable loss of this son of the soil”.
The 39-year-old was a leading doctor on hemorrhagic fevers in a nation with very few medical resources.
The ebola outbreak is now the largest recorded in world history, and has infected three African capitals with international airports.
Officials are trying to step up screening of passengers, although an American man was able to fly from Liberia to Nigeria, where authorities say he died days later from ebola.
He was working for the Liberian government.
There is no vaccine for ebola and no specific cure or treatment, resulting in a fatality rate of about 60 per cent, although many of the infected are poor rural Africans who may not get immediate or adequate care.
But experts say the risk of travellers contracting it is considered low because it requires direct contact with bodily fluids or secretions.
Ebola cannot be spread like flu through casual contact or breathing in the same air. Initial flu-like symptoms can lead to external haemorrhaging from areas like eyes and gums, and internal bleeding which can lead to organ failure.
Patients are contagious only once the disease has progressed to the point they show symptoms, according to the World Health Organisation. The most vulnerable are health care workers and relatives of the sick.