An emerging Ebola outbreak in Guinea may have been sparked by a survivor of the historic West African outbreak of 2013-2016. That means the virus would have had to incubate in the index case, without replicating enough to cause acute disease, for at least five years. There are more questions than answers at this point, but the genetic match with the virus that killed 11,000 people in Western Africa in the previous outbreak appears beyond doubt to researchers.

“This [genetic] pattern shows clearly that the new outbreak is the result of the resurgence of a strain that previously circulated in the West African outbreak from 2013-2016,” researchers reported.1 “The unexpectedly short branch leading to the 2021 Guinean Ebola virus genomes suggests a marked substitution rate slowdown, which might be due to latency in a survivor.”

It previously was known that the Ebola virus can try to escape the immune system by hiding in the eyes and testes, sensitive areas that the body is reluctant to attack. The surprising element here is that the virus was transmitted after such a prolonged period and the possibility that sexual transmission may have occurred.

“The human origin of the current Ebola outbreak and the associated shift in our perception of [virus] emergence call for careful attention to survivors,” the authors concluded. “The possibility of resurgence of Ebola, up to five years or more after [infection], opens new challenges for survivors, their families, and their communities but also for the health system that has to create ways to work with communities, known and unknown survivors, without creating further stigmatization.”

As of March 6, 2021, Guinea has had 18 cases of Ebola, with nine deaths and two recoveries. Five healthcare workers are among the confirmed cases. In an unrelated outbreak in Congo, there were 11 cases with four deaths and two recoveries. Two healthcare workers are among the confirmed cases.2

With two outbreaks ongoing as this report was filed, the Centers for Disease Control and Prevention (CDC) is advising healthcare personnel to be aware of the African outbreaks and ask incoming patients about international travel.

“[S]hare this information with all personnel who might conduct screening and triage activities or be responsible for initial clinical management of patients, including emergency medical services, outpatient, and emergency department personnel,” the CDC advised.3

In addition, the CDC continues to recommend screening and triaging everyone entering the facility for signs and symptoms of COVID-19. With Ebola now added to this, the CDC recommends posting “contact information for infection control personnel and the local public health jurisdiction for reporting of communicable diseases, including Ebola, in easily visible locations.”


  1. Keita AK, Düx A, Diallo H, et al. Resurgence of Ebola virus in Guinea after 5 years calls for careful attention to survivors without creating further stigmatization.
  2. APO Group Africa Newsroom. Africa Union Member States reporting Ebola virus disease update. March 6, 2021.
  3. Google Groups. CDC infection prevention and control guidance for identifying and managing patients with possible and confirmed Ebola virus disease. March 2, 2021.