Geneva: The World Health Organization says the Ebola outbreak in West Africa eventually could exceed 20,000 cases, more than 6 times as many as doctors know about now.
A new plan to stop Ebola by the UN health agency also assumes that in many hard-hit areas, the actual number of cases may be two to four times higher than is currently reported.
The agency on Thursday published new figures saying that 1,552 people have died from the killer virus from among the 3,069 cases reported so far in Liberia, Sierra Leone, Guinea and Nigeria. At least 40 percent of the cases have been in just the last three weeks, the UN health agency said, adding that "the outbreak continues to accelerate."
Nigerian authorities, meanwhile, said a man who contracted Ebola after coming into contact with a traveller from Liberia evaded surveillance and infected a doctor in southern Nigeria who later died.
The announcement of a sixth death in Nigeria marked the first fatality outside the commercial capital of Lagos, where a Liberian-American man Patrick Sawyer arrived in late July and later died of Ebola. On Wednesday, Nigerian authorities had said they not yet eliminated the disease from Africa's most populous nation but that it was being contained.
The Nigerian patient had come into contact with Sawyer but later left for the southern oil hub of Port Harcourt.
"After four days, following a manhunt for him, he returned to Lagos by which time he was found to be without symptoms," Health Minister Onyebuchi Chukwu told reporters. "This case would have been of no further interest since he had completed the 21 days of surveillance without any other issue but for the fact that the doctor who treated him died."
The doctor's wife is also in isolation now after she starting showing symptoms of Ebola, he added. Morticians who embalmed the doctor are part of a group of 70 people now under surveillance in Port Harcourt.
