Identifying the reservoir of the Ebola virus, a priority to prevent future epidemics

On 1 October 2019 Placide Mbala defended his doctoral thesis entitled: ‘Ebola virus at the human-wildlife interface and animal reservoir of Ebola viruses in the Democratic Republic of Congo (DRC)’, at the Faculty of Medicine of the University of Montpellier, France.

The research conducted as part of this thesis has contributed to a better understanding of where the virus circulates between Ebola Virus Disease (EVD) outbreaks in the DRC, a country where eight of the twenty-five documented Ebola epidemics in Central and West Africa have occurred. This work also focused on the search for the Ebola virus animal reservoir which, more than forty years after the virus was first identified, is still unknown. It was confirmed that non-human primates are not reservoir species, and that the role of bats in this regard requires further investigation.

During the preparation of this thesis, the DRC was hit by the emergence of three successive epidemics of Ebola Virus Disease (EVD), for which Mbala’s work played a crucial role. In particular, he identified the strain of the virus that for over a year has been causing the epidemic in the eastern part of the country. This discovery was essential for guiding health interventions, particularly to initiate immunisation activities to limit the spread of the epidemic.

At the onset of the outbreak, Mbala also contributed to the organisation of the response on the ground. “While continuing his research in a complex context, Mbala supervised the opening of diagnostic laboratories in many health centers, as well as the deployment of mobile units, and supported partners coordination,” says Martine Peeters, Virologist at the Institute for Research for Development (IRD). She co-supervised the thesis with Dr. Steve Ahuka-Mundeke, Laboratory Director at the National Institute of Biomedical Research (INRB). Following the jury’s deliberation, Mbala was admitted to the rank of Doctor of Biology and received the jury’s congratulations. “This defense is the culmination of three years of work during which Placide has never lost his optimism and modesty, and I wish him all the best,” said Martine Peeters.

'Beyond the response to the current human epidemic, improving early detection of the virus in wildlife remains a priority'

Following his thesis defence, Mbala highlighted the major challenges for the coming years:

Entirely won over by the ‘One Health’ approach, he adds, ‘strengthening epidemiological surveillance by involving both human and animal health experts will allow us to make crucial new breakthroughs’. Today Mbala is the Deputy Director of the Laboratory of Virology at INRB and is part of Professor Jean-Jacques Muyembe’s team. The latter is the Technical Secretary of the Multisectoral Committee for the Response to the Ebola Virus Disease. The INRB teams are continuing their efforts to better identify the Ebola virus reservoir by studying different species of wildlife and bushmeat specimens.

Some activities of this thesis, and in particular the collection of wildlife sampling during epidemic periods in the Democratic Republic of Congo, have benefited from the support of the European Union through the EBO-SURSY project. Indeed, one of the priorities of this project is to contribute to the emergence of high-level researchers and professionals, and to the consolidation of the scientific and research communities in West and Central Africa.

For more information on TransVIHMI Research Unit (IRD): https://transvihmi.ird.fr/
For more information on the National Institute of Biomedical Research (INRB): https://inrb.net/
For more information on the EBO-SURSY project: https://rr-africa.oie.int/en/projects/renforcement-des-capacites-et-surveillance-des-fievres-hemorragiques-virales/

Photos: ©OIE/S. Nguyen