Diagnosis comes three weeks after Liberian-American man died from virus
"We know what needs to be done," CDC director says
Experts will also help implement stronger systems to fight the disease, CDC chief says
The virus has already been confirmed outside of the three main countries.
Nigerian Minister of Health Onyebuchi Chukwu told reporters that the infected physician had been treating Patrick Sawyer, a top government official in the Liberian Ministry of Finance who died of Ebola in a Nigerian hospital July 20.
Eight other people are being quarantined and three are awaiting Ebola test results, the health minister said.
Meanwhile, the World Health Organization reports an outbreak of the virus in Liberia, Sierra Leone, Guinea and Nigeria is believed to have infected 1,603 people and killed more than 887 this year, as of Friday.
The United States is planning to send 50 health experts to West Africa to help contain the outbreak, which President Barack Obama addressed in remarks Tuesday, saying the citizens of the affected countries are in Americans’ thoughts and prayers.
“This is the biggest and most complex Ebola outbreak in history,” CDC Director Dr. Tom Frieden said in a statement.
“It will take many months, and it won’t be easy, but Ebola can be stopped. We know what needs to be done,” he said.
Frieden said the 50 experts from the CDC will work to combat the outbreak and help implement stronger systems to fight the disease.
The Ebola virus causes viral hemorrhagic fever, which affects multiple organ systems in the body and is often accompanied by bleeding.
Early symptoms include sudden onset of fever, weakness, muscle pain, headaches and a sore throat. They later progress to vomiting, diarrhea, impaired kidney and liver function – and sometimes internal and external bleeding.
An Ebola patient had not been treated within U.S. borders until last week, but the CDC has spearheaded efforts to prepare for the deadly virus.
It helped create an isolation unit at Emory University Hospital, which is being used to treat American doctor Kent Brantly, who contracted Ebola in Liberia and was evacuated to the facility in Atlanta over the weekend.
A second American patient, Nancy Writebol, arrived from Liberia on Tuesday. She will undergo treatment at the same unit.
Emory is one of four U.S. institutions capable of providing such treatment.
But in the nations hardest-hit and not as prepared, the reality is grim. Even in the best-case scenario, it could take three to six months to stem the epidemic in West Africa, Frieden said.
Ebola spreads through contact with organs and bodily fluids such as blood, saliva, urine and other secretions of infected people. It has no cure. The most common treatment requires supporting organ functions and maintaining bodily fluids such as blood and water long enough for the body to fight off the infection.
So far, the outbreak has been confined to West Africa.
Ebola also claimed the life of a medical director at a hospital in Liberia’s capital, Monrovia. Dr. Patrick Nshamdze tested positive Tuesday after being sick for two weeks. He died Saturday.
In Sierra Leone, where government officials have asked citizens to stay away from work, the military has deployed at least 750 medical officials to 13 locations, military spokesman Col. Michael Samura said.
Health officials are screening incoming and outgoing passengers at the country’s main international airport with a device that takes people’s temperature from their eyes at a distance.
People showing signs of fever are quarantined and their blood is tested.
CNN’s David McKenzie contributed to this report from Freetown, Sierra Leone. Journalist Heather Murdock reported from Nigeria. CNN’s Nana Karikari-apau and Christabelle Fombu contributed to this report.