US scientists warn of high toll from Ebola as cases mount

The deadly Ebola outbreak sweeping across three countries in West Africa is likely to last 12 to 18 months more, much longer than anticipated, and could infect hundreds of thousands of people before it was brought under control, according to scientists mapping its spread for the US government, The New York Times reports.

Bryan Lewis, an epidemiologist at the Virginia Bioinformatics Institute at Virginia Tech said they hoped they were wrong.

According to the model, both the time it would take to control the epidemic and the number of cases it forecast far exceed the estimates by the World Health Organization, which said last month that it hoped to be able to control the outbreak within nine months and predicted 20,000 total cases by that time.

According to a WHO spokesman, the organisation was sticking by its estimates.

However, according to various universities, the virus' present rate of growth could easily see close to 20,000 cases in one month, not in nine.

A number of leading US epidemiologists, with long experience in tracking diseases such as influenza, had been creating computer models of the Ebola epidemic at the request of the National Institutes of Health and the Defense Department.

Meanwhile, according to the World Health Organization, Ebola virus cases in West Africa were rising faster than the ability to contain them, as experts warned that the exponential rise could become a worldwide disaster, CBC News reported.

The death toll had risen to over 2,400 people out of 4,784 cases, WHO director general Margaret Chan told reporters at the UN health agency's headquarters in Geneva on Friday, noting the figures could be an underestimate.

According to Chan, in the three hardest hit countries, Guinea, Liberia and Sierra Leone, the number of new patients was moving far faster than the capacity to manage them. She added, that there was a need to surge at least three to four times to catch up with the outbreaks.

She called for urgent international support in the form of doctors, nurses, medical supplies and aid to the worst-affected countries.

Health-care workers had been infected with Ebola while treating patients in West Africa, and the infection left almost half of the 301 health-care workers who had developed the disease  dead.

Welcoming Cuba's announcement that it would send 165 health-care workers to fight the outbreak, she added least 500 doctors from abroad are needed.

An infectious disease expert, Michael Osterholm  warned in The New York Times on Friday that  "the Ebola epidemic in West Africa has the potential to alter history as much as any plague has ever done."

Osterholm is the director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

Though Ebola is known to spread through direct contact with bodily fluids, Osterholm had raised a possibility that virologists were loath to discuss openly but considered behind closed doors - the prospect that the Ebola virus could mutate to become transmissible through the air.