The Finding of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) in a Wild Eurasian River Otter (Lutra lutra) Highlights the Need for Viral Surveillance in Wild Mustelids

Abstract

Animals have been involved in the three known outbreaks of severe respiratory syndromes due to coronaviruses (years 2005, 2012, and 2019). The pandemic nature of the SARS-CoV-2 outbreak increases the likelihood of infection from humans of susceptible animal species that, thus, could become secondary viral hosts and even disease reservoirs. We present evidence of spillover infection of wild mustelids by reporting the presence of SARS-CoV-2 in a Eurasian river otter found near a water reservoir in the Valencian Community (Spain). We detected the virus using two different commercial RTqPCR assays on RNA extracted from the nasopharynx (swabbing) and from lung tissue and mediastinal lymph node homogenates. The corresponding samples from two additional otters from distant sites tested negative in identical assays. The diagnosis in the positive otter was confirmed by two-tube RT-PCR assay in which RNA was first retrotranscribed, and then specific regions of the spike (S), nucleocapsid (N), and ORF10 genes were separately amplified from the produced cDNA, followed by electrophoretic visualization and Sanger sequencing. The sequences of the amplified products revealed some non-synonymous changes in the N and ORF10 partial sequences, relative to the consensus sequence. These changes, identified already in human patient samples, point to human origin of the virus, although their specific combination was unique. These findings, together with our previous report of SARS-CoV-2 infection of feral American mink, highlight the need for SARS-CoV-2 surveillance of wild or feral mustelids to evaluate the risk that these animals could become SARS-CoV-2 reservoirs.

Molecular characteristics, immune evasion, and impact of SARS-CoV-2 variants

“…7 384 , 385 ). Currently, animals including the Feline family (Cat, 386 – 389 Lion, Tiger, 390 Snow leopard, 391 Fishing, cat, 392 Lynx), Dog, 358 , 393 – 395 Mink, 111 , 389 Otter, 396 Ferret, 394 , 397 , 398 Gorilla, Deer, 399 – 402 Binturong, Coatimundi, Hippo, 403 and Hamster 404 , 405 were reported with positive cases of SARS-CoV-2 infection. These results suggested the existence of a human-to-animal transmission pathway.…”

No Evidence of SARS-CoV-2 Infection in Wild Mink (Mustela lutreola and Neogale vison) from Northern Spain during the First Two Years of Pandemic

“…Human-to-animal transmission events during the COVID-19 pandemic have been documented in several countries, including Hong Kong, Belgium, the United States, Netherlands, Denmark, Spain, Germany, and France, among others [ 1 , 2 ]. Furthermore, several animal species have proven to be susceptible to SARS-CoV-2 infection, both naturally and experimentally [ 2 , 3 ], including mustelids such as farmed American mink ( Neogale vison ) [ 4 , 5 ], mink and ferret under experimental conditions [ 6 , 7 , 8 , 9 , 10 ], household and kept ferrets [ 11 , 12 ], captive Asian small-clawed otters [ 13 ], wild Eurasian river otter ( Lutra lutra ) [ 14 ] and feral American mink [ 15 , 16 ]. In this sense, the virus spreads efficiently in farmed American mink.…”

“…Reports of SARS-CoV-2 infection and COVID-19 symptoms in wildlife and domestic animals across the globe is well documented [ 24 , 25 , 26 ]. Among wildlife, American mink [ 27 ] and Eurasian river otter [ 14 ] are the only free-living animals that have been reported to be infected with SARS-CoV-2 in Spain. Although there is no evidence that SARS-CoV-2 is circulating or has been established in wild animal populations, the possibility of such a scenario cannot be ruled out [ 27 ].…”

An Updated Review on SARS-CoV-2 Infection in Animals

“…This vaccine is designed for carnivores [ 30 ]. Surveillance of SARS-CoV-2 in wild animals has been conducted in Europe and America [ 21 , 22 , 23 , 24 , 31 ], and the control of SARS-CoV-2 infection in wild animals is quite challenging. A possible approach for controlling SARS-CoV-2 in wildlife is the application of an oral vaccine to them, which is similar to the strategy used to control rabies in wildlife.…”

“…Other pet animals, including domestic ferrets and hamsters, also tested positive in Slovenia in November 2020 and in China in January 2022, respectively [ 19 , 20 ]. Other than domestic, captive, and farmed animals, SARS-CoV-2 in wild animals including deer, feral minks, feral cats, and wild otters were reported in the USA, Spain, the Netherlands, and Spain, respectively [ 21 , 22 , 23 , 24 ] ( Figure 1 ). Since the first detection in these animals in different countries, SARS-CoV-2 has been detected in gorillas in the Netherlands, tigers and lions in European countries, cougars in the USA and Argentina, a domestic ferret in the USA, dogs and cats in many countries, and deer in Canada ( Figure 2 ).…”