Resurgence of Ebola virus in 2021 in Guinea suggests a new paradigm for outbreaks

Abstract

Seven years after the declaration of the first epidemic of Ebola virus disease in Guinea, the country faced a new outbreak-between 14 February and 19 June 2021-near the epicentre of the previous epidemic 1,2 . Here we use next-generation sequencing to generate complete or near-complete genomes of Zaire ebolavirus from samples obtained from 12 different patients. These genomes form a well-supported phylogenetic cluster with genomes from the previous outbreak, which indicates that the new outbreak was not the result of a new spillover event from an animal reservoir. The 2021 lineage shows considerably lower divergence than would be expected during sustained human-to-human transmission, which suggests a persistent infection with reduced replication or a period of latency. The resurgence of Zaire ebolavirus from humans five years after the end of the previous outbreak of Ebola virus disease reinforces the need for long-term medical and social care for patients who survive the disease, to reduce the risk of re-emergence and to prevent further stigmatization.At least 30 outbreaks of Ebola virus disease (EVD) have been identified since the late 1970s, the most severe of which affected Guinea, Sierra Leone and Liberia from December 2013 to June 2016 1,2 . Guinea experienced a new outbreak of EVD in 2021, which started in Gouéké-a town about 200 km away from the epicentre of the 2013-2016 outbreak. The probable index case was a 51-year-old nurse, an assistant of the hospital midwife in Gouéké. On 21 January 2021, she was admitted to hospital in Gouéké suffering from headache, asthenia, nausea, anorexia, vertigo and abdominal pain. She was diagnosed with malaria and salmonellosis and was released two days later. Feeling ill again once at home, she attended a private clinic in Nzérékoré (40 km away) and visited a traditional healer, but died three days later. In the week after her death, her husband-as well as other family members who attended her funeral-fell ill, and four of them died. They were reported as the first suspect cases by the national epidemic alert system on 11 February. On 12 February, blood was taken from two suspect cases admitted to

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Dynamics of Antibodies to Ebolaviruses in an Eidolon helvum Bat Colony in Cameroon

“…The majority of EVD outbreaks occurred in remote areas and remained geographically restricted, but the recent outbreaks in West Africa (December 2013 to March 2016) and in Eastern DRC (August 2018 to June 2020) clearly showed that thousands of individuals can be infected over large geographic areas [ 3 ]. From these larger epidemics, it is evident that certain EVD outbreaks can be linked to individuals who recovered from the disease, even after more than five years [ 4 , 5 ].…”

Estimation of Ebola's spillover infection exposure in Sierra Leone based on sociodemographic and economic factors

“…The frequency of subsequent EVD outbreaks -approximately every other year since 1976-as October 1, 2021 1/24 well as their locations -overwhelmingly in the sub-Saharian region-reveals the dimension of a problem that is endemic to the African continent. New evidence hints at the possibility of latency as one of the mechanisms to explain this endemism [7]. As a matter of fact, at the time of preparation of this manuscript there were ongoing outbreaks in Guinea and in the Democratic Republic of Congo.…”