ABUJA, Nigeria -- Nigerian health authorities raced to stop the spread of Ebola yesterday after a man sick with one of the world's deadliest diseases brought it by plane to Lagos, Africa's largest city with 21 million people.

The fact that the traveler from Liberia, who later died, could board an international flight also raised new fears that other passengers could take the disease beyond Africa due to weak inspection of passengers and the fact Ebola's symptoms are similar to other diseases.

Officials in the country of Togo, where the sick man's flight had a stopover, also went on high alert after learning that Ebola could possibly have spread to a fifth country.

Screening people as they enter the country may help slow the spread of the disease, but it is no guarantee Ebola won't travel by airplane, according to Dr. Lance Plyler, who heads Ebola medical efforts in Liberia for aid organization Samaritan's Purse.

The North Carolina-based organization also said yesterday that an American doctor working with Ebola patients in Liberia has tested positive for the deadly virus. Samaritan's Purse stated that Dr. Kent Brantly was being treated at a hospital in Monrovia, Liberia.

Melissa Strickland, a spokeswoman for the aid organization, says Brantly began serving in Africa as part of a post-residency program before the Ebola outbreak began.

Ebola already had caused some 672 deaths across a wide swath of West Africa before the Nigeria case was announced. It is the deadliest outbreak on record for Ebola, and now it threatens Nigeria, Africa's most populous nation.

-- AP

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Out East: Nettie's Country Bakery ... Rising beef prices ... Get the latest news and more great videos at NewsdayTV

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Out East: Nettie's Country Bakery ... Rising beef prices ... Get the latest news and more great videos at NewsdayTV

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME