Coronaviruses (CoVs) belonging to the
Coronaviridae family are viruses known to infect a wide range of animals and humans. In humans, CoVs are responsible for mild to severe respiratory illnesses such as the Severe Acute Respiratory Syndrome (SARS) and the Middle-East Respiratory Syndrome (MERS). The epidemic of SARS which started in 2002 in China, and spread on various other continents such as North America and Europe, reached a mortality rate of 9%
1. The other severe epidemic illness (MERS) appeared more recently in the Middle East, and like the SARS, it also spread in other countries in Africa, America and Europe with case fatality rates of 35% (reviewed by de Wit
et al.
2). Currently the world is facing an ongoing pandemic caused by a new coronavirus (SARS-CoV-2) that emerged in China in December 2019 and caused disease (COVID-19) resulting in 118 326 confirmed cases and 4292 deaths as of March 11, 2020
3. Since the emergence of these respiratory diseases, CoVs have been considered a real public health problem because of their ability to become epidemic and pandemic
4. Even though human to human transmission of SARS-CoV and MERS-CoV occurs mainly through nosocomial transmission, some human cases recorded were occasionally the results of a zoonotic transmission
5. This raised an interest in the identification of animal reservoirs. Indeed, it appears that almost each human CoV have zoonotic origins or otherwise have a close relative that circulate in wild animals (bats)
6,7,8 and domestic animals (camels and cattle)
9,10. Besides SARS-CoVs and MERS-CoVs, numerous other CoVs have been detected in bats in Africa, Asia, Europe and America and are classified into the genera
Alphacoronavirus and
Betacoronavirus11,12. For SARS-CoV-2, a recent study revealed that the whole genome sequence of SARS-CoV-2 was most closely related with a bat coronavirus detected in bats from Yunnan Province in China
13. Consequently, bats were defined as reservoirs of ancestral coronaviruses which were transmitted to humans
14,15. Other wildlife species appear to play an important role in the chain of transmission and the emergence of these viruses in humans, namely palm civets
5 and wild rodents, in which infections by an alphacoronavirus and a betacoronavirus have been recently identified
16.
Gabon, a country located in Central Africa, displays a large diversity of wildlife species. Aside from bats in which CoVs have been detected in the cave-dwelling species
Hipposideros cf.
ruber17, to our knowledge, there is no information on the carriage of other mammalian species. CoVs are prone to host switching
18 and could be a current and future threat to public health.
The aim of this study was to explore the genetic diversity and the ecology of CoVs circulating among several wild mammals in Gabon in order to determine the potential reservoir species of these viruses and the risk for zoonotic emergence, and identify the factors driving CoVs infection in bats.
