An Ebola suspect being examined in Guinea

West Africa’s Ebola outbreak no longer constitutes a threat to international public health, the World Health Organization (WHO) said on Tuesday, declaring an end to a nearly 20-month emergency that has killed about 11,300 people.

Dr. Margaret Chan, the WHO director-general, accepted the recommendations of a committee of independent experts who also called for lifting any travel and trade restrictions affecting Guinea, Liberia and Sierra Leone.

“The Ebola outbreak in West Africa is no longer a Public Health Emergency of International Concern (PHEIC),” Chan told a news briefing at WHO headquarters in Geneva.

“However a high level of vigilance and response capacity must be maintained to ensure the ability of the countries to prevent Ebola infections and to rapidly detect and respond to flare-ups in the future,” she said.

Margaret Chan

Ebola, a haemorrhagic fever, has killed about 11,300 people in the three countries since emerging undetected in late 2013 in the forest of Guinea. It caused global alarm in mid-2014 – and heavy criticism of WHO, the U.N. health agency – as governments and aid agencies rushed to help contain the epidemic.

All original chains of virus transmission have now ended, although new clusters of infections continue to occur due to reintroductions of the virus, the WHO said in a statement.

A new chain in Guinea has infected eight people including seven who have died, WHO officials said.

Liberia closed its border with Guinea a week ago as a precaution against Ebola following five deaths at the time from the virus in Guinea.

“What is happening in Guinea is a cluster related to (virus) reintroduction in population, one of risk that has to be managed as the outbreak is brought to its complete conclusion,” said WHO expert Dr. Bruce Aylward.

Professor Robert Steffen, Vice Chair of WHO’s Emergency Committee, took a long view. “We know that little clusters will continue to flare up; that will be normal life just as in previous decades there have been now and then an outbreak of Ebola in various parts of sub-Saharan Africa.”

The virus is known to persist in the semen of some male survivors for a long time, requiring further study into vaccination, WHO said. “In terms of persistence we now have a couple of men where (the) virus has been persisting for over a year, 15 months,” Aylward said.

About 1,000 WHO experts are still deployed in the three countries to help detect any emerging cases, he said. “The plan is to maintain that as much as possible through 2016 and into 2017.”