Ebola death toll reaches 2,288, says World Health Organization
The Ebola outbreak in West Africa has killed 2,288 people, with half of them dying in the last three weeks, the World Health Organization (WHO) says.
It said that 47% of the deaths and 49% of the total 4,269 cases had come in the 21 days leading up to 6 September.
The health agency warned that thousands more cases could occur in Liberia, which has had the most fatalities.
The outbreak, which was first reported in Guinea in March this year, has also spread to Sierra Leone and Nigeria.
In Nigeria, eight people have died out of 21 cases, while one case of Ebola has been confirmed in Senegal, the WHO said in its latest update.
On Monday, the agency called on organisations combating the outbreak in Liberia to scale up efforts to control the outbreak "three-to-four fold".
Ebola spreads between humans by direct contact with infected blood, bodily fluids or organs, or indirectly through contact with contaminated environments.
However, the WHO says conventional means of controlling the outbreak, which include avoiding close physical contact with those infected and wearing personal protective equipment, were not working well in Liberia.
The reason for this remains unclear; however, experts say it could be linked to burial practices, which can include touching the body and eating a meal near it.
There are also not enough beds to treat Ebola patients, particularly in the capital Monrovia, with many people told to go back home, where they may spread the virus.
Sophie-Jane Madden, of aid agency Medecins Sans Frontieres, told the BBC that health workers at the largest treatment centre in Monrovia were completely overwhelmed: "Our teams are every day turning away people who are desperately seeking healthcare."
Meanwhile, the US says it will help the African Union mobilise 100 African health workers to the region and contribute an additional $10m (£6.2m) in funds to deal with the outbreak.
The announcement comes as a fourth US aid worker infected with the deadly virus was transported to a hospital in Atlanta for treatment.
The identity of the aid worker has not yet been revealed.
Two other aid workers who were treated at the same hospital have since recovered from an Ebola infection.
Separately on Tuesday, the UN's envoy in Liberia said at least 80 Liberian health workers had died from Ebola, according to the Associated Press.
Karin Landgren described the outbreak as a "latter-day plague" that was growing exponentially. She added that health workers were operating without proper protective equipment, training or pay, in comments to the UN Security Council.