COVID-19—Zoonosis or Emerging Infectious Disease?

Najmul Haider (The Royal Veterinary College, University of London), Peregrine Rothman-Ostrow (Global Burden of Animal Diseases, University of Liverpool), Abdinasir Yusuf Osman (The Royal Veterinary College, University of London), Liã Bárbara Arruda (University College London), Laura Macfarlane-Berry (Department of Agriculture, Water and the Environment), Linzy Elton (University College London), Margaret J. Thomason (University College London), Dorothy Yeboah-Manu (University of Ghana), Rashid Ansumana (Njala University), Nathan Kapata (Zambia National Public Health Institute), Leonard Mboera (SACIDS, Sokine University of Agriculture), Jonathan Rushton (Global Burden of Animal Diseases, University of Liverpool), Timothy D. McHugh (University College London), David L. Heymann (London School of Hygiene & Tropical Medicine), Alimuddin Zumla (University College London, National Institute of Health Research), and Richard A. Kock (The Royal Veterinary Collage, University of London) have collaborated to produce the now published article COVID-19—Zoonosis or Emerging Infectious Disease?

The World Health Organization defines a zoonosis as any infection naturally transmissible from vertebrate animals to humans. The pandemic of Coronavirus disease (COVID-19) caused by SARS-CoV-2 has been classified as a zoonotic disease, however, no animal reservoir has yet been found, so this classification is premature. We propose that COVID-19 should instead be classified an “emerging infectious disease (EID) of probable animal origin.” To explore if COVID-19 infection fits our proposed re-categorization vs. the contemporary definitions of zoonoses, we reviewed current evidence of infection origin and transmission routes of SARS-CoV-2 virus and described this in the context of known zoonoses, EIDs and “spill-over” events. Although the initial one hundred COVID-19 patients were presumably exposed to the virus at a seafood Market in China, and despite the fact that 33 of 585 swab samples collected from surfaces and cages in the market tested positive for SARS-CoV-2, no virus was isolated directly from animals and no animal reservoir was detected. Elsewhere, SARS-CoV-2 has been detected in animals including domesticated cats, dogs, and ferrets, as well as captive-managed mink, lions, tigers, deer, and mice confirming zooanthroponosis. Other than circumstantial evidence of zoonotic cases in mink farms in the Netherlands, no cases of natural transmission from wild or domesticated animals have been confirmed. More than 40 million human COVID-19 infections reported appear to be exclusively through human-human transmission. SARS-CoV-2 virus and COVID-19 do not meet the WHO definition of zoonoses. We suggest SARS-CoV-2 should be re-classified as an EID of probable animal origin.

This article is available on Frontiers (Front. Public Health, 26 November 2020)