Animal Reservoirs and Hosts for Emerging Alphacoronaviruses and Betacoronaviruses

Abstract

C oronaviruses are a family of RNA viruses whose large genomes, propensity for mutation, and frequent recombination events have resulted in a diversity of strains and species that are capable of rapid adaptation to new hosts and ecologic environments (1). This viral plasticity has garnered widespread concern because of zoonotic potential and the consequences of new emergence events in both human and animal populations. The emergence of a new strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease (COVID-19) has once again demonstrated the role of the family Coronaviridae in causing human disease outbreaks. SARS-CoV-2, a novel betacoronavirus, was identifi ed in human patients from Wuhan, China, during December 2019 and has resulted in a global pandemic, an unprecedented public health emergency, and untold economic and societal repercussions worldwide. Similar to the 2002-2003 severe acute respiratory syndrome (SARS) epidemic, a live animal market where hundreds of animal species were sold is suspected to be associated with the emergence or early spread of COVID-19 in humans (2). Although COVID-19 is novel in the breadth of the human outbreak, several pathogenic alphacoronaviruses and betacoronaviruses have shown similar patterns of emergence. As early as the 1930s, coronaviruses pathogenic to livestock, companion animals, and laboratory animals were identifi ed (3). During the 1960s, 2 human coronaviruses, HCoV-229E and HCoV-OC43, were detected in patients who had common colds (4,5). Although it is speculated that HCoV-OC43 might also have emerged through a global pandemic in the late 1800s (6), the 2002-2003 SARS outbreak is the fi rst known global epidemic caused by a coronavirus. The SARS epidemic triggered research within this viral family (3). This research led to detection of 2 new human coronaviruses, HCoV-NL63 and HCoV-HKU1 (7,8). HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1 are now accepted as globally endemic common cold species that are typically associated with mild-to-moderate respiratory illness. In 2012, the most deadly human coronavirus to date was detected in the Arabian Peninsula: Middle East respiratory syndrome coronavirus (MERS-CoV) (9). A cumulative body of research on these and other coronaviruses has shown that most alphacoronaviruses and betacoronaviruses infecting humans have come from animal hosts and that both historic patterns and coronavirus biology establish an urgent ongoing threat to human and animal health (10).

SARS-CoV-2 Infections and Viral Isolations among Serially Tested Cats and Dogs in Households with Infected Owners in Texas, USA

“…However, the virus may have emerged in the human population by way of a yet unidentified intermediate host [ 1 ]. As the pandemic continues, studies have established that several mammalian groups, including primates, felids, mustelids, and some species of rodent, lagomorph, and bat, are susceptible to natural or experimental infection [ 2 ]. Across the globe, there are two common groups where suspected human-to-animal transmission events have been repeatedly detected: farmed mink and companion animals.…”

Serological Detection of SARS-CoV-2 Antibodies in Naturally-Infected Mink and Other Experimentally-Infected Animals

“…Indeed, detection of SARS-CoV-2 RNA in the lymph nodes of two feral mink in eastern Spain has recently been reported [ 5 ]. Of additional concern is the potential for recombination events between SARS-CoV-2 and other coronaviruses in the animal host, as has been observed for other coronaviruses [ 6 , 7 , 8 , 9 ]. Additionally, since its emergence, there have been several reported infections (both natural or experimental) of different animal species with SARS-CoV-2 including dogs, cats, cattle, ferrets, captive gorillas, lions, tigers, pumas, snow leopards, racoon-dogs, bats, white-tailed deer and minks [ 2 , 10 ].…”

SARS-CoV-2 Portrayed against HIV: Contrary Viral Strategies in Similar Disguise

“…Since HIV-1, the major driver of the HIV pandemic, originated from great apes such as chimpanzee and gorilla, the initial reservoir and the pathology is mostly restricted to/specific for hominids. In contrast, the reservoir of betacoronaviruses such as severe acute respiratory syndrome coronavirus 1 and 2 (SARS-CoV-1 and SARS-CoV-2) and Middle East respiratory syndrome coronavirus (MERS-CoV) is substantially broader and includes bats, cats, dogs, pangolins, minks, ferrets, and even camelids in the case of MERS-CoV [ 109 , 110 , 111 , 112 ]. Compared to HIV, coronavirus cross-species transmission events between humans and animals are believed to occur more frequently and back and forth, leading to potentially more diffuse epidemic dynamics that might be harder to control.…”