۱٫ Introduction

۲٫ Materials and methods

۳٫ Results

۴٫ Discussion

Acknowledgements

References

Abstract

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.

Introduction

In the highly biodiverse southern region of China, interactions among humans, wildlife, and livestock are likely to be common, and are hypothesized to be a risk factor in the emergence of zoonotic infectious diseases [1–۳]. Human-animal interactions may pose a particular public health threat in rural communities where frequent contact with animals occurs and where disease prevention measures are likely less well-developed [4]. Although human-animal interactions are thought to be associated with zoonotic disease emergence, few studies have addressed the nature of specific interactions that occur between animals (particularly wild animals) and humans that lead to pathogen spillover.

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 [5–۱۳]: 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 [15–۱۸]; 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].