Investigating the Circulation of Ebola Viruses in Bats during the Ebola Virus Disease Outbreaks in the Equateur and North Kivu Provinces of the Democratic Republic of Congo from 2018

Audrey Lacroix,Steve Ahuka Mundeke,Martine Peeters,Guillaume Thaurignac,Nicole Vidal,Laetitia Serrano,Jean-Jacques Muyembe Tamfum,Ahidjo Ayouba,Jacques Likofata,Guy Lempu,Daniel Mukadi Bamuleka,Placide Mbala Kingebeni,Amandine Esteban,Eric Delaporte,Simon Pierre Ndimbo Kumugo,Christelle Butel

doi:10.3390/pathogens10050557

Abstract

With 12 of the 31 outbreaks, the Democratic Republic of Congo (DRC) is highly affected by Ebolavirus disease (EVD). To better understand the role of bats in the ecology of Ebola viruses, we conducted surveys in bats during two recent EVD outbreaks and in two areas with previous outbreaks. Dried blood spots were tested for antibodies to ebolaviruses and oral and rectal swabs were screened for the presence of filovirus using a broadly reactive semi-nested RT-PCR. Between 2018 and 2020, 892 (88.6%) frugivorous and 115 (11.4%) insectivorous bats were collected. Overall, 11/925 (1.2%) to 100/925 (10.8%) bats showed antibodies to at least one Ebolavirus antigen depending on the positivity criteria. Antibodies were detected in fruit bats from the four sites and from species previously documented to harbor Ebola antibodies or RNA. We tested for the first time a large number of bats during ongoing EVD outbreaks in DRC, but no viral RNA was detected in the 676 sampled bats. Our study illustrates the difficulty to document the role of bats as a source of Ebolaviruses as they might clear quickly the virus. Given the increasing frequency of EVD outbreaks, more studies on the animal reservoir are urgently needed.

Highlights

Since the first recognized Ebolavirus disease (EVD) outbreak in humans in 1976 in the Democratic Republic of Congo (DRC), a total of 31 outbreaks have been recognized in Africa [1,2,3]
In order to increase the chances to detect viral RNA and Ebola antibodies, we investigated the presence of RNA from filoviruses and Ebola antibodies in bats from DRC collected during the EVD outbreaks in the Equateur and North Kivu provinces and in other areas that have already experienced outbreaks
In order to increase our chances to identify viral RNA in bats, we focused our efforts on studying bats as early as possible during outbreaks and tested samples from 741 bats collected during two recent EVD outbreaks and 266 from two regions that have already experienced EVD outbreaks in DRC

Summary

Introduction

Since the first recognized Ebolavirus disease (EVD) outbreak in humans in 1976 in the Democratic Republic of Congo (DRC), a total of 31 outbreaks have been recognized in Africa [1,2,3]. The majority remained limited in the number of infected individuals and in the geographic spread, but the outbreaks in West Africa (December 2013 to March 2016) and in Eastern DRC (August 2018 to June 2020) clearly showed that they can become epidemic and infect thousands of individuals over large geographic areas [4]. DRC is one of the most affected countries. The largest EVD outbreak occurred in the eastern provinces of North Kivu and Ituri over almost two years (July 2018–June 2020). It infected 3470 people and 2299 (66.2%) patients died [6,7]. On the 7th February 2021, a new resurgence has been declared in North Kivu, involving 11 cases to date [3,8]

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Conclusion