Bat Coronaviruses in China

Abstract

During the past two decades, three zoonotic coronaviruses have been identified as the cause of large-scale disease outbreaks⁻Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and Swine Acute Diarrhea Syndrome (SADS). SARS and MERS emerged in 2003 and 2012, respectively, and caused a worldwide pandemic that claimed thousands of human lives, while SADS struck the swine industry in 2017. They have common characteristics, such as they are all highly pathogenic to humans or livestock, their agents originated from bats, and two of them originated in China. Thus, it is highly likely that future SARS- or MERS-like coronavirus outbreaks will originate from bats, and there is an increased probability that this will occur in China. Therefore, the investigation of bat coronaviruses becomes an urgent issue for the detection of early warning signs, which in turn minimizes the impact of such future outbreaks in China. The purpose of the review is to summarize the current knowledge on viral diversity, reservoir hosts, and the geographical distributions of bat coronaviruses in China, and eventually we aim to predict virus hotspots and their cross-species transmission potential.

Keywords: bat; coronavirus; cross-species; epidemiology; zoonosis.

Figure 1

Geographical distribution of bat coronaviruses (CoVs) and their corresponding bat hosts in China. Each red box represents one CoV positive sample found in that particular bat species. One dot matrix was drawn for each province where a CoV positive sample had been reported. Guangdong Province, where SARS and SADS began, is circled in red. Abbreviations of bat species and virus species are indicated.

Figure 2

Genetic diversity of bat CoV in China. Sequences of 440 bp conserved the viral polymerase (RdRp) region for each CoV species were compared to related reference sequences. Reference genomes used: BtCoV-HKU10, NC_018871.1; BtRfCoV-HuB13, NC_028814.1; BtMiCoV-1, EU420138.1; BtMiCoV-HKU8, NC_010438.1; BtRhCoV-HKU2, MF094682.1; BtHpCoV-ZJ13, NC_025217.1; MERSr-CoV, NC_038294.1; BtPiCoV-HKU5, NC_009020.1; BtTyCoV-HKU4, NC_009019.1; BtRoCoV-GCCDC1, MG762606.1; BtRoCoV-HKU9, NC_009021.1; and SARSr-CoV, NC_004718.3. Notably, samples that were positive for BtMy-Sax11, BtNy-Sc13, and BtScCoV-512 were also identified in China. These were not taken into account here as too few sequences were available.