Viruses in bats and potential spillover to animals and humans

Abstract

In the last two decades, several high impact zoonotic disease outbreaks have been linked to bat-borne viruses. These include SARS coronavirus, Hendra virus and Nipah virus. In addition, it has been suspected that ebolaviruses and MERS coronavirus are also linked to bats. It is being increasingly accepted that bats are potential reservoirs of a large number of known and unknown viruses, many of which could spillover into animal and human populations. However, our knowledge into basic bat biology and immunology is very limited and we have little understanding of major factors contributing to the risk of bat virus spillover events. Here we provide a brief review of the latest findings in bat viruses and their potential risk of crossspecies transmission.

Human-animal interactions and bat coronavirus spillover potential among rural residents in Southern China

“…Bats (order Chiroptera) are reservoirs of a large number of zoonotic viruses, including coronaviruses (CoVs) that have caused disease outbreaks in human and livestock populations [5][6][7][8][9][10][11][12][13]: Severe Acute Respiratory Syndrome coronavirus (SARS-CoV), the causative agent of the SARS outbreak affecting 32 countries in 2002-3, infecting 8,096 people and causing 774 deaths [14]; Middle East Respiratory Syndrome coronavirus (MERS-CoV), which has caused 823 deaths from 2,374 human cases in 27 countries by the end of February 2019, and is thought to have originally spilled over from bats into camels, in which is it now endemic [15][16][17][18]; and Severe acute diarrhea syndrome coronavirus (SADS-CoV) which emerged in the pig population of Southern China and caused the deaths of more than 20,000 piglets in 2017 and 2018 [5].…”

“…A large diversity of coronaviruses, including SARS-related Coronaviruses (SARSr-CoVs), has been discovered in bats, and phylogenetic and pathogenesis studies of these suggest a high capacity for transmission across species barriers [9,11,13,[18][19][20][21][22]. However, few studies have analyzed bat-to-human spillover events in non-outbreak conditions, likely due to the rarity of these events and difficulties in identifying at-risk populations or target geographies.…”

A strategy to prevent future epidemics similar to the 2019-nCoV outbreak

“…Here, we propose three key steps to helping reduce the risk of a future epidemic similar to that caused by the novel coronavirus 2019-nCoV: 1) Surveillance of wildlife for high-risk pathogens Over the past 10 years collaborating with scientists in China, we collected samples from over 10,000 bats and~2000 other mammals across South China and discovered 52 novel SARSr-CoVs, 122 other β-CoVs, more than 350 novel α-CoVs (including the new Swine Acute Diarrheal Syndrome Coronavirus SADS-CoV), and a new "lineage E" β-CoV clade [11,12]. We found SARS-related CoVs that can bind to human cells, and that cause SARS-like disease in humanized mouse models that was not prevented with a vaccine candidate against SARS-CoV, and were not treatable with almost all of the monoclonal therapies being developed for SARS [8,[13][14][15][16]. Finally, we showed serological evidence that people living at the wildlife-human interface in rural China were being exposed to SARSrelated coronaviruses, perhaps even the same virus as nCoV-2019, between the emergence of SARS and the current outbreak [17,18].…”

A qualitative study of zoonotic risk factors among rural communities in southern China

“…the potential to spill over into the human population. 20,[32][33][34][35] In addition, rural residents may face a higher risk because of their limited access to quality healthcare facilities for proper diagnosis and treatment compared with urban residents. 36 Enforcement of current wildlife protection policy and continued community infrastructure development appears to significantly reduce high-risk contact between humans, wildlife and livestock.…”