World Health Organization declares Liberia Ebola-free

Liberia is now free of Ebola after going 42 days — twice the maximum incubation period for the deadly disease — without any new cases, the World Health Organization (WHO) announced on Saturday. The virus killed more than 4,700 people in the West African nation during a year-long epidemic.

While celebrating the milestone, President Ellen Johnson Sirleaf on Saturday said the damage wrought by the worst Ebola outbreak in history was "a scar on the conscience of the world."

For some survivors, she said, "the pain and grief will take a generation to heal."

However, the medical aid group Doctors Without Borders (known by its French acronym MSF) urged vigilance until the disease is also extinguished in neighboring Guinea and Sierra Leone. New cases were reported this week in both countries, and for that reason, officials said they are cautious about openly celebrating the end of Ebola in Liberia. The continued presence of the disease in the region means just one sick patient slipping over the border into Liberia could spark a resurgence of cases.

"We can't take our foot off the gas until all three countries record 42 days with no cases," Mariateresa Cacciapuoti, MSF's head of mission in Liberia, said in a statement.

She urged Liberia to step up cross-border surveillance to prevent Ebola slipping back into the country.

A total of 11,005 people have died from Ebola in the three West African neighbors since the outbreak began in December 2013, according to the WHO.

However, Sirleaf said she was confident her country was now prepared "to deal quickly with any new cases should they emerge."

On Saturday Sirleaf, accompanied by U.S. Ambassador Deborah Malac, toured health centers in Monrovia, embracing and taking group photos with doctors and nurses. Nearly 200 health workers died fighting Ebola in Liberia.

In a statement on Saturday, Sirleaf lamented the damage done to her country, which was only about a decade removed from a devastating civil conflict when the outbreak struck.

"Young Liberians who only months before strode confidently to school with dreams of a future as an engineer, a teacher or a doctor — all of which Liberia desperately needs — had their lives mercilessly cut short," she said.

The international response to the Ebola outbreak has been roundly criticized as too slow and ineffective. While praising the role international partners played in getting Liberia to zero cases, Sirleaf said the fight "got off to slow start."

"Therefore, let today's announcement be a call to arms that we will build a better world for those Ebola could not reach," she said. "It is the least the memories of our dearly departed deserve."

The U.N. Special Envoy on Ebola, David Nabarro, said this week that Liberian authorities had pledged to maintain heightened surveillance for at least a year after being declared Ebola-free.

Nabarro suggested that, even though fewer than 20 new cases were reported in Guinea and Sierra Leone last week, it could take months to get to zero.

International Medical Corps (IMC), an aid group that ran two Ebola clinics in Liberia, appealed for international support in rebuilding the health care system there in the wake of the virus.

"Now is the time to build on the momentum we have generated to strengthen the Liberian health system," Anouk Boschma, IMC's acting country director in Liberia, said in a statement.

Wire services