COVID-19 and One Health: Potential role of human and animals in SARS-CoV-2 life cycle

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) in humans has zoonotic tendencies, which can potentially provoke cross-species transmission, including human-to-animal and animal-to-human infection. Consequently, the objective was to analyze the scientific evidence regarding SARS-CoV-2 animal infections from potential human transmission. A systematic review was executed following the PRISMA guidelines, in the PubMed/MEDLINE, Google Scholar and LILACS, using the descriptors combined in the following way: ((“SARS-CoV-2” OR “COVID-19” OR “2019-nCoV”) AND (animals OR zoonosis)). The results contemplated the viral susceptibility of about thirty animal species when induced naturally and/or experimentally. The mink & hamster species demonstrated ostensible animal-to-human transmission. Overall, there have been more reports of human contamination by other species than human retransmission from the pathogen. The natural infection of the virus was discovered in domestic dogs & cats, wild cats, deer, minks, rabbits and hamsters. Several animals, including the African green monkeys and rabbits, manifested high levels of viremia, respiratory secretions and fecal excretions of infectious virus conducive to environmental/aerosol transmission. It is still inadequately documented the intrinsic role of such processes, such as the animals' involvement in viral mutations, the emergence of new variants/lineages and the role of the animal host species. Accordingly, this research model type, natural and experimental analysis on varying animal species, corroborates the link between the two aforementioned forms of transmission. Epidemiological surveillance through extensive sequencing of the viral genomes of infected animals and humans can reveal the SARS-CoV-2 transmission routes and anticipate appropriate prophylactic strategies.