Hongying Li a , f , Emma Mendelsohn a , Chen Zong b , Wei Zhang c , Emily Hagan a , Ning Wang c , Shiyue Li d , Hong Yan d , Huimin Huang d , Guangjian Zhu a , Noam Ross a , Aleksei Chmura a , Philip Terry e , Mark Fielder f , Maureen Miller g , Zhengli Shi c , ∗ , Peter Daszak a , ∗∗
9 November 2019
Human interaction with animals has been implicated as a primary risk factor for several high impact zoonoses, including many bat-origin viral diseases. However the animal-to-human spillover events that lead to emerging diseases are rarely observed or clinically examined, and the link between specific interactions and spillover risk is poorly understood. To investigate this phenomenon, we conducted biological-behavioral surveillance among rural residents in Yunnan, Guangxi, and Guangdong districts of Southern China, where we have identified a number of SARS-related coronaviruses in bats. Serum samples were tested for four bat-borne coronaviruses using newly developed enzyme-linked immunosorbent assays (ELISA). Survey data were used to characterize associations between human-animal contact and bat coronavirus spillover risk. A total of 1,596 residents were enrolled in the study from 2015 to 2017. Nine participants (0.6%) tested positive for bat coronaviruses. 265 (17%) participants reported severe acute respiratory infections (SARI) and/or influenza-like illness (ILI) symptoms in the past year, which were associated with poultry, carnivore, rodent/shrew, or bat contact, with variability by family income and district of residence. This study provides serological evidence of bat coronavirus spillover in rural communities in Southern China. The low seroprevalence observed in this study suggests that bat coronavirus spillover is a rare event. Nonetheless, this study highlights associations between human-animal interaction and zoonotic spillover risk. These findings can be used to support targeted biological behavioral surveillance in high-risk geographic areas in order to reduce the risk of zoonotic disease emergence.
Evidence before this study.
Bat borne coronaviruses have caused several emerging infectious disease outbreaks of global significance, including SARS. Novel SARS-related coronaviruses have been discovered in bat populations in Southern China, some of which have the capacity to infect human cells. Human-animal interactions are thought to be critical for the emergence of bat coronaviruses, however the specific interactions linked to animal-to-human spillover remain unknown.
This study found serological evidence for bat-borne coronavirus transmission to people. Direct contact with bats was not identified as a risk factor. However, self-reported severe acute respiratory infection (SARI) and/or influenza-like illness (ILI) was linked to human interaction with other wildlife and livestock, suggesting that there may be other zoonotic exposures leading to clinical illness in these populations.
Significance of the study.
Findings from this study suggested that an integrated biological and behavioral surveillance in healthy community settings can help identify potential zoonotic disease spillover events or target surveillance to at-risk populations. This approach represents a potential early-warning system that could be used under non-outbreak conditions to identify potential zoonotic emerging diseases prior to largescale outbreaks.