Abuja, Nigeria - Nigeria said Tuesday it had recorded its first Ebola case of Africa's latest outbreak, as Kenya declared its ninth case, prompting a regional health official to warn of "an extremely serious threat."

The case in Nigeria, Africa's most populous country, was detected in a woman who had traveled from Uganda to the capital Abuja, the government confirmed.

Since a major Ebola outbreak was declared in the Democratic Republic of Congo in May, the deadly viral hemorrhagic fever has spread to several countries across the continent, including to neighboring Uganda.

Kenya's health ministry, meanwhile, reported its ninth Ebola case of the outbreak on Tuesday.

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"This Ebola Bundibugyo outbreak has already become the most geographically widespread Ebola outbreak in history, affecting multiple countries across three regions of Africa," said the director general of Africa CDC, Jean Kaseya.

In several months, the DRC's Ebola epidemic has become the deadliest in the country's history, killing 4,381 people out of more than 9,000 confirmed cases, according to the health authorities.

Kaseya, who heads the African Union health agency, urged the international community to send money, medical supplies, and health workers to help.

"With mortality approaching 50% in DRC, we face an extremely serious threat," he posted on X. "My appeal to the international community is urgent: ACT NOW."

The outbreak has now spread from central Africa to the continent's east and west.

Kenya reported its first Ebola case on October 6 – a businessman in his forties who had lived in the DRC.

Most of the eight cases reported since in the east African country have been among people with a close connection to the first victim, who died in the capital Nairobi on October 5.

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The ninth case is a 24-year-old man, described as "a close family member of the first case," and confirmed positive on Monday, the health ministry said.

"He was isolated at the first sign of illness, tested and started on treatment immediately upon confirmation of his positive test result," it said, adding he "was already in quarantine when he fell ill."

The US on Tuesday warned its citizens against travel to Kenya due to "health risks."

In Nigeria, the patient arrived on an international flight from Uganda and was admitted to a private hospital, "where she received care for several days before the diagnosis was confirmed," Nigerian Health Minister Muhammad Ali Pate said in a statement.

"She is currently in isolation and receiving medical care," he said.

"Contact tracing has commenced with 44 close contacts identified presently," the statement added, "with public health teams identifying and monitoring people who may have been exposed, including healthcare workers, patients, caregivers and travel contacts."

Late Tuesday, the Ugandan Health Ministry said there were "no confirmed active Ebola cases" in the country, and that "travel through Uganda does not establish that infection occurred here."

It is the west African country's first registered Ebola case since 2014.