More than 10,000 people have now been infected with Ebola in the latest outbreak in West Africa, according to World Health Organization figures released Saturday as the deadly virus continues to spread.
Of those cases, 4,922 people have died.
The Ebola epidemic in West Africa is the largest-ever outbreak of the dangerous hemorrhagic fever with a rapidly rising death toll in Guinea, Liberia and Sierra Leone. There have also been a few cases in three other West African countries, as well as Spain and the United States.
The U.N. health agency said Saturday that the number of confirmed, probable and suspected cases has risen to 10,141. Its figures show about 200 new cases since its last report four days earlier.
Even those sharply rising numbers are likely an underestimate, WHO has warned, as many people in the hardest-hit countries have been unable or too frightened to seek medical care. A shortage of labs capable of handling potentially infected blood samples has also made it difficult to track the outbreak.
WHO said the true toll may be three times as much: by a factor of 1.5 in Guinea, 2 in Sierra Leone and 2.5 in Liberia, while the death rate is thought to be about 70 percent of all cases. But the latest figures show no change in Liberia's case toll, suggesting the numbers that have been released may be lagging behind reality.
On Thursday, authorities confirmed that the disease had spread to Mali, the sixth West African country affected, and on the same day a new case was confirmed in New York, in a doctor recently returned from Guinea.
Mali had long been considered highly vulnerable to the disease, since it shares a border with Guinea. The disease arrived there in a 2-year-old, who had traveled from Guinea with her grandmother by bus and died Friday.
The toddler, who was bleeding from her nose during the journey, may have had high-risk contact with many people, WHO warned. So far, 43 people are being monitored in isolation for signs of the disease, and WHO said Saturday that authorities are continuing to look for more people at risk.
To help fight Ebola, the U.N. humanitarian flight service airlifted about 1 ton of medical supplies to Mali late Friday. The seats of the plane were removed to make room for the cargo, which included hazard suits for health workers, surgical gloves, face shields and buckets, according to the World Food Program, which runs the flights.
"Speed is of the essence in this Ebola crisis. Agencies such as WFP and WHO are working every hour to confront together the virus as a matter of priority," said Denise Brown, the West Africa regional director for the U.N. food agency.
In the U.S., a medical worker in New Jersey quarantined after arriving at an airport after treating Ebola victims in West Africa has tested negative for the virus, the state's health department said Saturday.
The worker, who has not been identified, was the first to be quarantined under a new policy announced Friday making this mandatory for anyone arriving at a New York City-area airport after working with Ebola patients in three West African countries.
The worker continues to be under a mandatory 21-day quarantine, the department said in its statement.
Isolation wards have been used for medical personnel returning from Ebola zones since Craig Spencer, a doctor who treated patients in Guinea for a month, came back to New York City infected.