Program Sponsored by: Ecohealth Alliance


New online ‘SpillOver’ tool ranks zoonotic spillover risk of known and novel viruses

Infectious disease scientists have developed a new web application, aptly named ‘SpillOver‘, that ranks the risk of wildlife-to-human (zoonotic) spillover for known and newly discovered viruses.

This open-source tool created by researchers from the University of California, Davis and other members of the USAID PREDICT consortium (including EcoHealth Alliance), assigns each virus a ‘Risk Score’ based on 32 host, environmental, and virus risk factors associated with viral spillover (such as virus species, transmission dynamics, host species, land use in host ecosystem, and others). Viruses with larger scores receive a higher rank or ‘Risk Position’ (i.e. closer to 1).

Scientists estimate that there are roughly 1.67 million undiscovered viruses that infect mammals and birds, and that 631,000 to 827,000 of these viruses have zoonotic potential (Carroll et al. 2018). The SpillOver tool will help researchers and policymakers prioritize viral threats that pose the greatest risk to human populations (a critical service given the limited time, effort, and funding that exist to predict and prevent spillover events around the world). As researchers discover new viruses and learn more about their viral, host, and environmental attributes, this information can be added to the SpillOver platform and used to update the list of top viral threats.

The ‘Bats & Coronaviruses‘ project led by the Western Asia Bat Research Network (WAB-Net) seeks to characterize the diversity of bat-borne coronaviruses (CoVs) throughout Western Asia. Eventually, findings from this project can be entered into the SpillOver platform to determine the relative spillover risk for various CoVs found in the region. Interestingly, the SpillOver tool considers two bat-associated CoVs (Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2)) to be among the 12 viruses with the highest spillover potential.

The SpillOver tool, like the WAB-Net, fosters a proactive approach to disease prevention in an effort to build a safer world without pandemics.

Link to EcoHealth Alliance press release

Link to ‘SpillOver’ online tool

Link to full-text paper describing ‘SpillOver’ tool