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 Organisation (WHO) said on Thursday, calling for continued strong surveillance.
"Today the World Health Organisation declares the end of the most recent outbreak of Ebola virus disease in Liberia and says all known chains of transmission have been stopped in west Africa," the UN health agency announced on Liberian state radio.
UN chief Ban Ki-moon warned the region can expect sporadic cases in the coming year but added "we also expect the potential and frequency of those flare-ups to decrease over time."
Rick Brennan, WHO chief of emergency risk management and humanitarian response, hailed an important milestone but told reporters in Geneva that "the job is still not done", pointing out that there had already been 10 small flare-ups because of the persistence of the virus in survivors.
- No celebration -
Reaction to the announcement was muted in Monrovia, where locals have become accustomed to good news on Ebola being followed by setbacks, and there was no official programme of celebration.
"We are happy to hear that Liberia is once more Ebola-free. At least now we know that our health workers are up to the task as they are no longer giving the virus a chance to spread," said teacher Abenigo Kollie, 45.
"As educators we will continue to tell our students to remain vigilant."
Aminata Kanneh, a 32-year-old entrepreneur, told AFP people were "no longer afraid" because recent flare-ups were dealt with quickly.
"The pronouncement today is a joy but does not call for celebration because we may experience another outbreak," she said.
Liberia, the country worst hit by the outbreak with 4,800 deaths, discharged its last two patients from hospital -- the father and younger brother of a 15-year-old victim -- on December 3, 2015.
Africa's oldest republic was the last country still afflicted by the outbreak that infected almost 29,000 people and claimed 11,315 lives, according to official data.
The real toll is suspected to be much higher, with many Ebola deaths believed to have gone unreported.
After the last patient is declared in the clear, a 42-day countdown -- twice the incubation period of the virus -- begins before the country is proclaimed Ebola-free.
Ebola causes severe fever and muscle pain, weakness, vomiting and diarrhoea. In many cases it shuts down organs and causes unstoppable internal bleeding. Patients often succumb within days.
From a Guinean infant who was the first victim the epidemic quickly spread into neighbouring Liberia and Sierra Leone, notching up more deaths than all other Ebola outbreaks combined.
Liberia was first to be declared free of human-to-human Ebola transmission in May, only to see the virus resurface six weeks later.
It was officially credited with beating the epidemic for a second time in September before another small cluster of cases emerged.
- Economic ruin -
The WHO came under fire for its sluggish response to the epidemic, which local healthcare systems were woefully under equipped to handle. Over 500 healthcare workers died in three west African countries at the height of the outbreak.
Brennan acknowledged the WHO's initial inertia but said the organisation had "done a lot of soul-searching", pointing to a "major reform" it is undergoing.
While Cuba sent doctors, Western governments offered little until foreign aid workers started falling ill and returning home for treatment, sparking fears of a global pandemic.
The concerns inched higher when three cases of infections came to light outside Africa -- two in the United States and one in Spain.
The US, Britain and other countries eventually rallied to the cause, sending thousands of troops and medics to Africa in 2014 and developing a number of promising potential vaccines and treatments.
But the economic ravages of the epidemic are still being felt.
The World Bank estimates the economic damage of the outbreak, which devastated the mining, agriculture and tourism industries in Liberia, Sierra Leone and Guinea, at $2.2 billion over 2014-15.
WHO director Margaret Chan described the next three months as "the most critical," as foreign medical groups shut down operations in west Africa and national health ministries take over.
The European Union which, combined with individual contributions from its member states, mobilised almost two billion euros ($2.2 bn) for the Ebola response, said it would shift its focus from emergency to development.