The last known chains of transmission in the Ebola virus in West Africa have been stamped out, but “more flare-ups” are expected, the World Health Organization (WHO) said on Thursday, calling for continued strong surveillance.
The announcement by the U.N. health agency came 42 days, or two 21-day incubuation cyles of the virus, after the last confirmed patient in Liberia tested negative twice for the deadly disease that has killed more than 11,300 in two years.
Guinea, Liberia and Sierra Leone “remain at high risk of additional small outbreaks of Ebola,” it said.
Liberia had previously declared itself virus-free in May and September of 2015 but each time a fresh cluster of cases appeared.
“We are now at a critical period in the Ebola epidemic as we move from managing cases and patients to managing the residual risk of new infections,” says Bruce Aylward, WHO’s Special Representative for the Ebola Response.