Discovery of coronavirus infections in white-tailed deer can help predict or prevent the emergence of novel variants.

Photo: Adobe Stock

Photo: Adobe Stock


Can we prevent potential spillback of SARS-CoV-2 from wild animals to humans?

  • The global spread of SARS-CoV-2 (the virus that causes COVID-19 in humans) poses risks for spillover transmission to nonhuman hosts, which could in turn act as reservoirs for the virus, and potentially "spillback" to human hosts.


A team of researchers reported the first direct evidence of SARS-CoV-2 virus in any free-living species when they discovered that more than 80 percent of the white-tailed deer sampled in different parts of Iowa between December 2020 and January 2021 tested positive for the virus.

  • The team examined nearly 300 samples collected as a part of a routine health surveillance program in Iowa, finding several different SARS-CoV-2 lineages circulating within geographically confined herds. This research suggested the occurrence of multiple independent spillover events from humans to deer, followed by local deer-to-deer transmission.


This discovery highlights the urgent need to support and sustain a robust and proactive "one health" approach that includes surveillance programs to monitor the spread of SARS-CoV-2 within deer and other susceptible wildlife species in the battle against the long-term persistence and evolution of this coronavirus.

  • A better understanding of the ecology, molecular evolution, and spread of SARS-CoV-2 will help scientists and public health officials to predict and even prevent the emergence of future infectious diseases with pandemic and spillover potential.

Research Credit


Participating Departments


  • Iowa Department of Natural Resources (DNR)
  • Penn State Eberly College of Sciences
  • Iowa State University
  • Penn State College of Engineering
  • University of Cambridge
  • Weill Cornell Medical College
  • Argonne National Laboratory
  • Houston Methodist Research Institute
  • Houston Methodist Hospital

Competitive Funding

  • US Fish and Wildlife Service (Wildlife and Sport Fish Restoration Program)
  • Penn State Huck Institutes of the Life Sciences
  • Iowa DNR (Fish and Game Protection Fund)
  • Houston Methodist Academic Institute (Infectious Diseases Fund)
  • National Institutes of Health
  • NSF (Ecology and Evolution of Infectious Diseases Program)

Federal and State Appropriations

  • USDA NIFA Hatch Project PEN04748, Accession #1023391

Emerging Discoveries

Published Research

Multiple spillovers from humans and onward transmission of SARS-CoV-2 in white-tailed deer.

Office for Research and Graduate Education


217 Agricultural Administration Building
University Park, PA 16802-2600

Office for Research and Graduate Education


217 Agricultural Administration Building
University Park, PA 16802-2600