COVID-19—Zoonosis or Emerging Infectious Disease?

Abstract

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.

The Epidemiological Characteristics of the COVID-19 Pandemic in Europe: Focus on Italy

“…The role of an intermediate animal in the spread of SARS-CoV-2 is widely discussed and the infection has been defined as a zoonosis [ 23 ]. Although the initial stages of the pandemic were traced back to a Wuhan wet market and several tests carried out on the cages and on the surfaces of the market benches were SARS-CoV-2 positive, no tests carried out on animals were positive [ 24 ]. Nevertheless, SARS-CoV-2 transmission between different animal species is considered a possible event.…”

Ten considerations for conservation policy makers for the post-COVID-19 transition

“…Moreover, it is well known that anthropogenic stress (e.g., arising from disturbance or climate change) on ecosystems and wildlife can promote disease outbreaks (Keesing et al, 2010), while loss of biodiversity can itself increase rates of infectious disease (Wood et al, 2014). Efforts to minimize human disturbance in ecosystems while protecting and restoring biodiversity may limit the ability of zoonotic diseases (such as COVID-19; see Haider et al, 2020 for an acknowledgement that it may be premature to call it a zoonotic disease given that there is still uncertainty regarding source) to spill over from wildlife to humans through a buffering effect (Johnson and Thieltges 2010;Schmeller et al, 2020). Such investments in biodiversity benefit human well-being both in the short and long term (Cunningham et al, 2017).…”

A Journal of the COVID-19 (Plague) Year

“…It is argued that this virus may be an example of Zoonosis, which is defined as any infection that is transmissible from a vertebrate animal to humans (World Health Organization, 2020 ). While it is not entirely clear that our current pandemic is a result of zoonosis (Haider et al, 2020 ), it is well known that urbanization and deforestation has increased the threat of zoonotic disease transmission for which we may have no understanding or treatment. Rescue medical ethics does not concern itself with how the disease came to be and what can be done to prevent this kind of disease or the healthcare ethics that might address the health threats of industrialized farming and crowded urban environments.…”