The new Ebola outbreak in the West African nation of Guinea is directly related to the region’s devastating epidemic between 2014 and 2016.

The African Centres for Disease Control (CDC) said on Thursday.

Gene sequencing has shown that the current outbreak is the result of a resurgence of a strain that previously circulated in West Africa, the head of the Africa CDC Ebola team, Merawi Aragaw, said during a media briefing.

“This is really a concern. It means that the virus can last longer in (Ebola) survivors than it had been presumed before,’’ Merawi said.

Scientists had previously assumed that the virus can only survive for several months inside the body of a healed Ebola patient, not for several years, Merawi said.

Further research needed to be done to clarify if the current outbreak was caused by an ongoing previously undiscovered chain of infection or rather by a persistent chronic infection, Merawi added.

More than 11,000 people were killed during the 2014-2016 Ebola outbreaks, which mostly affected the West African nations of Guinea, Liberia and Sierra Leone.

Guinean authorities announced the outbreak of a new Ebola epidemic in February, while the Democratic Republic of Congo also recently reported a new outbreak, the Central African country’s twelfth.

So far, 30 Ebola cases have been detected in  both countries, 12 in Congo and 18 in Guinea, according to the CDC.

The Ebola virus causes a fever and often leads to massive internal bleeding and fatalities.