Two years after the Ebola outbreak began in Guinea and traveled around the world killing more than 11,300, the country was declared free of the virus on Tuesday.
Guinea's 42-day countdown, which is two times the incubation period of Ebola, began on Nov. 16 when a 3-month-old baby named Nubia who was born with the disease and was the country's last remaining patient cleared the virus. Sierra Leone was declared free of the virus on Nov. 7, and Liberia, the third West African country where the epidemic was centered, is on track to be Ebola-free on Jan. 14.
"This is the first time that all three countries - Guinea, Liberia and Sierra Leone - have stopped the original chains of transmission that were responsible for starting this devastating outbreak two years ago," WHO regional director for Africa, Matshidiso Moeti, said in a statement.
The pronouncement marks a key victory in the fight against the deadly infectious disease, but public health experts say it's too soon to let our guard down. Guinea's neighbor Liberia has been twice declared to be Ebola-free only to report that it had reappeared. And as the scientific community's understanding of Ebola has grown during the crisis, we have learned that it is more tenacious than we once thought - with its ability to disappear from our blood while still lurking in other places, such as the eye and semen, where it can come back and cause havoc again.
In the most high-profile cases, an American doctor and British nurse who were thought to have made a full recovery were both found to still carry the virus. Thousands of other survivors have reported other symptoms of lingering "post-Ebola syndrome" that include everything from migraine headaches to blindness.
The initial rapid and almost unchecked spread of the virus also taught us how vulnerable our public health systems are and how much work needs to be done before we can mount a robust response to whatever virus comes next. In a 28-page report in July, an independent panel of experts criticized the World Health Organization's handling of the Ebola crisis, blaming politics and bureaucracy for the mismanaged response.
"There seems to have been a hope that the crisis could be managed by good diplomacy rather than by scaling up emergency action," they wrote.
Health officials say they are prepared for the possible re-emergence of the virus in the coming months in isolated cases or even in clusters. "The coming months will be absolutely critical," warned Bruce Aylward, special representative of the director-general for the Ebola response at WHO. "This is the period when the countries need to be sure that they are fully prepared to prevent, detect and respond to any new cases."