SARS-CoV-2 has shown the world with devastating clarity the threat that undetected viruses can pose to global public health. SpillOver, a new web application developed by scientists at the University of California, Davis, and with input from experts around the world, classifies the risk of overflowing from wild animals to humans for newly discovered viruses.
SpillOver is the first open source risk assessment tool that assesses wildlife viruses to estimate their zoonotic spillover and pandemic potential. It effectively creates a watch list for newly discovered viruses to help policy makers and health scientists prioritize them for further characterization, surveillance and risk reduction interventions.
The tool is linked to a study published in the journal PNAS, in which the authors identified the most relevant viral, host and environmental risk factors for the virus spillover. The team then rated the risk of 887 wildlife viruses using data collected from a variety of sources, including viruses detected by the USAID Emerging Pandemic Threats PREDICT project, led by the UC Davis One Health Institute from 2009 to 2020.
Primates and cattle explore the surroundings of a residence in Ghana. Credit: Terra Kelly, UC Davis
Coronavirus with high rating
At the top of the list were 12 known human pathogens, which was expected and validates the utility of the tool. Interestingly, SpillOver has classified several newly discovered coronaviruses as having a higher risk of overflowing than some viruses already known to be zoonotic. This watch list includes a new coronavirus provisionally called PREDICT_CoV-35, which ranked among the top 20.
The power of the tool lies in the fact that it is open source – the more data entered, the more robust the classification. SARS CoV-2 currently ranks second among the 887 viruses analyzed, among the Lassa and Ebola viruses.
This may seem counterintuitive, the authors note, given the current global devastation of the pandemic. They explain that the tool is classifying the potential for another overflow in addition to what happened historically. In addition, important information remains unknown about SARS CoV-2 and its risk of overflowing, such as the number and extent of its host species. As scientists learn more about this virus, it is possible for SARS CoV-2 to move up to number one.
“SARS-CoV-2 is just one example of many thousands of viruses that have the potential to spread from animals to humans,” said lead author Zoë Grange, who led the development of SpillOver as a postdoctoral researcher at UC Davis One Institute of Health. “We need to not only identify, but also prioritize viral threats with the greatest risk of contamination before another devastating pandemic occurs. Our SpillOver Viral Risk Ranking tool is the starting point for building proactive solutions. “
Credit Score Virus
SpillOver was inspired by risk assessments used by banks and insurers. It creates a “credit-like” score for viruses, looking at the main risk factors and using them to prioritize the viruses that pose the greatest potential threats to human health for a watch list. Users can customize the watch list according to their own circumstances, such as the country of interest.
Previous virus classification tools were limited in the number or types of viruses analyzed, with minimal risk factors considered. SpillOver considers 32 risk factors for the virus and hosts, including the associated environment and human behavior. It also includes 25 different viral families, from coronavirus to the viral family that causes ebolaviruses.
Classify your virus
SpillOver produces a detailed risk report for each virus and its ‘Risk Comparison’ tool allows users to compare and contrast classified viruses, as well as filter viruses on a selection of key attributes, including virus species, host species and country detection.
As an open source tool, SpillOver provides a living platform for continuous overflow risk classification. Scientists can contribute data to existing viruses or assess the risk of new viruses using the ‘Classify your virus’ application.
“This tool is intended to start a global conversation that will allow us to go far beyond how we thought about virus classification in the past and allow real-time scientific collaboration to identify new threats in advance,” said corresponding author Jonna Mazet, professor the UC Davis School of Veterinary Medicine, founding director of One Health Institute and former global director of PREDICT. “SpillOver can help advance our understanding of viral health threats and allows us to act to reduce the risk of overflowing before pandemics can catch fire.”
SpillOver involves and allows scientists who are discovering viruses to collaborate in a One Health framework that focuses not only on viral characteristics, but also on all circumstances present in areas at high risk for the onset of disease. This allows the tool to be a catalyst to quickly identify and classify newly discovered viruses and their human-animal transmission interfaces.
This paradigm shift can facilitate collaboration from the start, across disciplinary and national boundaries. Identifying and classifying viruses for human health risks can help scientists identify critical control points and deal with human behaviors that put humans and animals at risk for new viral infections.
Reference: April 5, 2021, Proceedings of the National Academy of Sciences.
DOI: 10.1073 / pnas.2002324118
The study’s co-authors include hundreds of individuals who supported the PREDICT Project in their countries and local institutions, as well as global scientific leaders in viral emergencies and major collaborating institutions, including the Wildlife Conservation Society, EcoHealth Alliance, Metabiota, Smithsonian Conservation Biology Institute, Columbia UniversityInfection and Immunity Center of the.
Financial support for the study was provided by the USAID Emerging Threats Project.