American Ebola patient arrives at Emory in Atlanta
Atlanta, GA (CNN) -- A male U.S. citizen who contracted the Ebola virus in Sierra Leone arrived Tuesday at Emory University Hospital in Atlanta. The patient could be seen walking, apparently with some help from one person, into the facility.
The patient, whose name has not been released publicly, was taken from Africa in an air ambulance.
The State Department described the patient as a U.S. citizen.
On Monday, the World Health Organization said a doctor working for the agency in an Ebola treatment center in Sierra Leone tested positive for the virus. WHO would not reveal the doctor's nationality nor where he or she would be evacuated.
WHO officials would not say whether the doctor is the American Ebola patient, citing a confidentiality policy.
Last month, two Americans infected with Ebola were flown to Atlanta after being given an experimental drug to fight the virus in Liberia. They were treated at the Emory hospital for several weeks before being released.
Another American doctor infected with Ebola arrived in Nebraska for treatment last week.
The Ebola virus causes viral hemorrhagic fever, which refers to virus types that affect multiple organ systems in the body and are often accompanied by bleeding.
Humans contract Ebola through contact with the bodily fluids of infected animals or the bodily fluids of infected humans.
No vaccine or medicine has been proved to cure the disease, but the first human trial of an experimental Ebola vaccine began last week.
Ebola by the numbers
More than 4,200 cases of Ebola have been reported since the first documented case in December, WHO has said (pdf) Tuesday. Of those cases, there have been more than 2,200 fatalities. The official numbers are believed to be dramatically under-reported.
More than 40% of the cases have been diagnosed in the past three weeks, the agency said.
This is considered the deadliest Ebola outbreak in history. The bulk of the cases are in Guinea, Liberia, Sierra Leone. Infected people have also turned up in Nigeria and Senegal.
WHO said Monday the rapid spread of the virus in Liberia shows no sign of slowing.
"The number of new cases is increasing exponentially," WHO said, calling the situation a "dire emergency with ... unprecedented dimensions of human suffering."
It's a crisis unlike any other during previous Ebola outbreaks, according to WHO.
Taxis packed with families who fear they've contracted the deadly virus crisscross the Liberian capital, searching for a place where they can be treated, WHO said. But there are no free beds.
"As soon as a new Ebola treatment facility is opened, it immediately fills to overflowing with patients," the U.N. group said.
U.S. sending additional help
To help ease some of the burden on West Africa's already over-taxed medical system, the U.S. announced Tuesday it will send $10 million additional funds.
That's in addition to the $100 million the U.S. has already sent to help fight the outbreak. USAID also announced it will make $75 million extra available.
The new funds will pay for transportation and support to send 100 more health care workers to help fight the epidemic. The staff will run Ebola treatment units. The staff will be sent to Liberia, Nigeria, Guinea and Sierra Leone.
The WHO and several nonprofit agencies on the ground have repeatedly called for the international community to send additional trained help.
If you are a trained nurse, physician assistant or doctor who wants to help, USAID has created a website where people can sign up to help.
USAID funding has already provided 130,000 sets of personal protective equipment, 50,000 hygiene kits, and 1,000 new beds.
CNN's Miriam Falco and Debra Goldschmidt reported from Atlanta. CNN's Jamie Crawford reported from Washington. CNN's Susannah Cullinane, Madison Park, Carol Jordan, Catherine E. Shoichet and Chelsea J. Carter contributed to this report.