Nigeria's national health minister confirmed that a Liberian man who died in a Nigerian megacity on Friday tested positive for Ebola, an often fatal virus that has killed nearly 700 people in the largest outbreak on record.

Reuters reported that the man collapsed at the Lagos, Nigeria, airport on Sunday and was taken to the hospital, where he was put in quarantine. He died five days later.

Onyebuchi Chukwu, Nigeria's national health minister, said at a press conference that the diagnosis had been confirmed by the Lagos teaching hospital and by "other laboratories outside Nigeria." The state health minister and the World Health Organization, however, both said they were awaiting laboratory confirmations, Reuters reported.

Ebola is a rapidly moving virus whose symptoms include fever, weakness, and internal and external bleeding, according to the World Health Organization (WHO). The global health body says it is transmitted through contact with an infected patient's bodily fluids, or exposure to environments where those fluids have been.

There is no vaccine, and there is no cure, for Ebola. Survival rates can be as low as 1 in 10; so far in West Africa, just over 60% of recorded cases have ended in death.

The first confirmed cases appeared in Guinea in March. The disease has also spread to Liberia, where the Associated Press reported that a senior local doctor died of the disease in the capital of Monrovia and two American aid workers, including one doctor, have been infected.

The disease has also spread to Sierra Leone. Most cases in Sierra Leone are concentrated in the country's eastern region, which borders Liberia. But the capital of Freetown saw its first confirmed Ebola case this week — and a national scare yesterday when the patient's family removed her from the hospital. She died in the ambulance on her way back, government officials said today.