Targeting Surveillance for Zoonotic Virus Discovery

Jordan Levinson¹, Tiffany L. Bogich¹, Kevin J. Olival, Jonathan H. Epstein, Christine K. Johnson, William Karesh, and Peter Daszak

Author affiliations: EcoHealth Alliance, New York, New York, USA (J. Levinson, T.L. Bogich, K.J. Olival, J.H. Epstein, W. Karesh, P. Daszak); National Institutes of Health, Bethesda, Maryland, USA (T.L. Bogich); Princeton University, Princeton, New Jersey, USA (T.L. Bogich); School of Veterinary Medicine, University of California, Davis, California, USA (C.K. Johnson)

Abstract

We analyzed a database of mammal–virus associations to ask whether surveillance targeting diseased animals is the best strategy to identify potentially zoonotic pathogens. Although a mixed healthy and diseased animal surveillance strategy is generally best, surveillance of apparently healthy animals would likely maximize zoonotic virus discovery potential for bats and rodents.

Nearly two thirds of emerging infectious diseases that affect humans are zoonotic, and three fourths of these originate in wildlife, making surveillance of wildlife for novel pathogens part of a logical strategy to prevent the future emergence of zoonoses (1–4). Wildlife are thought to harbor a high diversity of unknown pathogens, but global characterization of this diversity would be costly and logistically challenging (5). Given limited resources for pandemic prevention, there is public health benefit in focusing pathogen discovery on those species most likely to harbor novel zoonoses (3,4).
One strategy to maximize the likelihood of discovering novel pathogens is surveillance of animal die-offs, outbreaks in wildlife, or diseased wildlife. We analyzed a database of known zoonotic viruses in mammal hosts to answer the driving question of whether we should stratify surveillance strategies (i.e., conduct surveillance of visibly diseased vs. apparently healthy animals) by wildlife host groups to best detect novel pathogens with zoonotic potential. In answering this question, we can better determine how host and virus taxonomy might influence our decisions about applying limited surveillance resources to a growing global health problem.