Sierra Leone Might Have Beaten Ebola

Sierra Leone Ebola transmission at zero for 42 days


Health workers might have finally pushed Ebola out of Sierra Leone.

It's been more than 42 days since the last known Ebola patient in the country tested negative for the virus, according to the World Health Organization (WHO). Why is 42 days such a milestone? It's twice the incubation period for the virus. That means that Sierra Leone has gone two incubation cycles — during which anyone exposed to the virus would have begun showing symptoms — without a new case.

Considering that the West African Ebola outbreak has killed more than 11,000 people since it began in early 2014, that's huge. But it doesn't necessarily mean the virus is gone. Back in late August, a new case popped up in the country just days after its last known Ebola patient was released from the hospital.

Now, Sierra Leone will begin a 90-day "enhanced surveillance" period to make sure there are no new cases. A WHO representative for Sierra Leone, Dr. Anders Nordström, said WHO will continue to support the West African nation during this period.

“We now have a unique opportunity to support Sierra Leone to build a strong and resilient public health system ready to detect and respond to the next outbreak of disease, or any other public health threat,” Dr. Nordström said in a press release.

Ebola is an often deadly virus that causes high fever, nausea, vomiting and unexplained bleeding. The current outbreak is the largest in history but appears to be winding down in the three hardest-hit countries: Guinea, Liberia and Sierra Leone. Guinea has had seven confirmed cases in the last 21 days, according to Nov. 4 WHO data. Liberia has seen no new cases in the past 21 days.