What we (do not) know about mammal coronavirus and general virus? Using bibliometric information to identify neglected taxonomic groups and potential viral reservoirs of zoonotic importance

The COVID-19 pandemic is currently advancing in the world and has killed more people than other recent coronavirus outbreaks like SARS and MERS together. Coronaviruses known to infect humans were all associated to mammal sources, with different species acting as both natural and/or intermediate hosts of these viruses. Although the zoonotic origin of human coronaviruses is well accepted, a great number of mammal species were not yet investigated as their potential to carry these viruses. This work aimed to provide an overview of the current state of scientific knowledge about what are the mammal groups well known to be associated to coronaviruses and other viruses and what are the most neglected groups in these studies. Here we analyze the production of scientific publications about these and other viruses in association with the 29 taxonomic orders of the Mammalia class. Our results highlighted that most of these taxonomic orders have been little studied or completely unexplored in researches with this focus, with only six orders accumulating more than 99% of the articles on coronaviruses in mammals. Ten mammal groups were not found in any scientific publication in association with coronaviruses, with four of them not found even in works mentioning any type of viruses. These results reinforce the importance of identify all the natural and intermediate hosts for viruses to improve monitoring of potential zoonosis and reduce the chances of new disease outbreaks.