No detection of SARS-CoV-2 in animals exposed to infected keepers: results of a COVID-19 surveillance program

Host susceptibilities and entry processes of SARS-CoV-2 Omicron variants using pseudotyped viruses carrying spike protein

The zoonotic potential has been well studied for SARS-CoV-2 and its earlier variants, but the information for Omicron variants and SARS-CoV is lacking. In this study, we generated lentivirus-based pseudoviruses carrying spike protein (S) of SARS-CoV-2, parental and Omicron variants including BA.1.1, BA.4/5, XBB.1 and JN.1 to assess the entry into cells expressing human or animal ACE2 including dogs, cats and white-tailed deer. Using these pseudoviruses, along with pseudoviruses carrying S of MERS-CoV and SARS-CoV, we assessed the protease processing of these various S through western blotting, entry/inhibition assays, and fusion assays. The results showed that overall, pseudotyped viruses carrying each S of SARS-CoV-2 Omicron strains efficiently entered cells expressing human or animal ACE2 comparably (BA.1.1 and JN.1) or better (BA.4/5 and XBB.1) than those with parental strain. In addition, the entries of pseudotyped viruses carrying S of SARS-CoV were also efficient the cells expressing human or animal ACE2. The presence of TMPRSS2 significantly increased the entry of all tested pseudoviruses including those with S of MERS-CoV, SARS-CoV and SARS-CoV-2, with BA.1.1, JN1, and XBB.1 Omicron having the largest fold increase. When cathepsin inhibitors were examined to assess their inhibitory effects on entry of parental and Omicron variants, they were significantly less effective in the entry of Omicron variants compared to parent strain, suggesting Omicron strains do not depend on the endosomal route compared to parental strain.

Cattle, sheep, and goat humoral immune responses against SARS-CoV-2

Following the emergence of SARS-CoV-2 in late 2019, several species of domestic and wild animals have been found to be susceptible to SARS-CoV-2 infection through experimental inoculation and animal surveillance activities. Detection of SARS-CoV-2 specific antibodies in animals is an important surveillance tool since viral shedding in animals can only be detected for a short period of time. In this study, convenience serum samples were collected from 691 cattle, 698 sheep, and 707 goats from several regions in the United States, between 2019 and 2022. The samples were evaluated for the presence of SARS-CoV-2 specific antibodies using two commercial enzyme-linked immunosorbent assays (ELISA); one based on the inhibition of the SARS-CoV-2 receptor-binding domain (sVNT) and the other based on the nucleocapsid protein (N-ELISA) of SARS-CoV-2. Positive samples from the sVNT were additionally evaluated using a conventional virus neutralization test (VNT) employing the Wuhan-like SARS-CoV-2 USA/WA1/2020 isolate. Our results indicate that ∼1 % (6/691) of cattle, ∼2 % (13/698) of sheep, and ∼2.5 % (18/707) of goat serum samples were positive when using the sVNT, whereas ∼4 % of cattle (25/691) and sheep (27/698), and 2.5 % (18/707) of goat serum samples tested positive with the N-ELISA. None of the sVNT positive cattle, sheep, or goat serum samples had detectable neutralizing antibody activity (<1:8) against the SARS-CoV-2 USA/WA1/2020 isolate by the VNT. Our results indicate low seropositivity in cattle, sheep, and goats in the U.S., indicating the importance to continue monitoring for SARS-CoV-2 prevalence in animal species that are in close contact with humans.

Droplet Digital RT-PCR (dd RT-PCR) Detection of SARS-CoV-2 in Honey Bees and Honey Collected in Apiaries across the Campania Region

Coronaviruses (CoVs), a subfamily of Orthocoronavirinae, are viruses that sometimes present a zoonotic character. Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for the recent outbreak of COVID-19, which, since its outbreak in 2019, has caused about 774,593,066 confirmed cases and 7,028,881 deaths. Aereosols are the main route of transmission among people; however, viral droplets can contaminate surfaces and fomites as well as particulate matter (PM) in suspensions of natural and human origin. Honey bees are well known bioindicators of the presence of pollutants and PMs in the environment as they can collect a great variety of substances during their foraging activities. The aim of this study was to evaluate the possible role of honey bees as bioindicators of the prevalence SARS-CoV-2. In this regard, 91 samples of honey bees and 6 of honey were collected from different apiaries of Campania region (Southern Italy) in four time periods from September 2020 to June 2022 and were analyzed with Droplet Digital RT-PCR for SARS-CoV-2 target genes Orf1b and N. The screening revealed the presence of SARS-CoV-2 in 12/91 in honey bee samples and in 2/6 honey samples. These results suggest that honey bees could also be used as indicators of outbreaks of airborne pathogens such as SARS-CoV-2.

Transmission of severe acute respiratory syndrome coronavirus 2 from humans to animals: is there a risk of novel reservoirs?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a zoonotic virus able to infect humans and multiple nonhuman animal species. Most natural infections in companion, captive zoo, livestock, and wildlife species have been related to a reverse transmission, raising concern about potential generation of animal reservoirs due to human-animal interactions. To date, American mink and white-tailed deer are the only species that led to extensive intraspecies transmission of SARS-CoV-2 after reverse zoonosis, leading to an efficient spread of the virus and subsequent animal-to-human transmission. Viral host adaptations increase the probability of new SARS-CoV-2 variants' emergence that could cause a major global health impact. Therefore, applying the One Health approach is crucial to prevent and overcome future threats for human, animal, and environmental fields.

First serological evidence of SARS-CoV-2 natural infection in small ruminants : Brief report

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) emerged in late December 2019 and spread worldwide, quickly becoming a pandemic. This zoonotic coronavirus shows a broad host range, including wildlife and domestic animals. Small ruminants are shown to be susceptible to SARS-CoV-2 but, to date, no natural infection has been reported. Herein, we performed a survey for SARS-CoV-2 among sheep and goats in the Campania region of Italy using an indirect multispecies ELISA. Next, positive sera were submitted to virus serum neutralization for the quantification of specific neutralizing antibodies. Out of 612 sheep and goats, 23 were found ELISA positive (3.75%) and 1 of them showed 1:20 neutralizing antibodies titer. No significant difference was found between the two species, as well as between male and female, geographical location and age. Our findings demonstrate that natural infection can occur in flocks in a field situation. Moreover, low susceptibility to SARS-CoV-2 is reported for sheep and goats, nevertheless, the continuous mutations of this virus open new scenarios on viral host range and tropism, highlighting the importance of investigating animal species that could represent ongoing or future possible hosts.

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.

Equine Coronaviruses

Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In equids, equine coronavirus has been associated with diarrhea in foals and lethargy, fever, anorexia, and occasional gastrointestinal signs in adult horses. Although horses seem to be susceptible to the human severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) based on the high homology to the ACE-2 receptor, they seem to be incidental hosts because of occasional SARS-CoV-2 spillover from humans. However, until more clinical and seroepidemiological data are available, it remains important to monitor equids for possible transmission from humans with clinical or asymptomatic COVID-19.

SARS coronavirus 2-reactive antibodies in bovine colostrum

Objective

To determine if bovine colostrum and sera have antibodies that react with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Animals

Dairy and beef cattle from North America and Europe, sampled before and after the SARS-CoV-2 pandemic.

Procedures

Indirect ELISAs using whole bovine coronavirus (BCoV) and SARS-CoV-2; whole SARS-CoV-2 Spike 1, Spike 2, and nucleocapsid proteins; and SARS-CoV-2-specific nucleocapsid peptide as antigens. Virus neutralization assay for BCoV. Surrogate virus neutralization assay for SARS-CoV-2.

Results

Antibodies reactive to BCoV were highly prevalent in samples collected from cattle before and after the SARS-CoV-2 pandemic. Antibodies reactive with SARS-CoV-2 were present in the same samples, and apparently increased in prevalence after the SARS-CoV-2 pandemic. These antibodies had variable reactivity with the spike and nucleocapsid proteins of SARS-CoV-2 but were apparently not specific for SARS-CoV-2.

Conclusions

Bovine coronavirus continues to be endemic in cattle populations, as indicated by the high prevalence of antibodies to the virus in colostrum and serum samples. Also, the prevalent antibodies to SARS-CoV-2 in bovine samples, before and after the pandemic, are likely the result of responses to epitopes on the spike and nucleocapsid proteins that are shared between the 2 betacoronaviruses. Cross-reactive antibodies in bovine colostrum could be examined for prophylactic or therapeutic effects on SARS-CoV-2 infections in humans.

EFSA Panel on Animal Health and Welfare (AHAW), Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin‐Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ, Padalino B, Pasquali P, Roberts HC, Spoolder H, Velarde A, Viltrop A, Winckler C, Adlhoch C, Aznar I, Baldinelli F, Boklund A, Broglia A, Gerhards N, Mur L, Nannapaneni P, Ståhl K. SARS-CoV-2 in animals: susceptibility of animal species, risk for animal and public health, monitoring, prevention and control

The epidemiological situation of SARS-CoV-2 in humans and animals is continually evolving. To date, animal species known to transmit SARS-CoV-2 are American mink, raccoon dog, cat, ferret, hamster, house mouse, Egyptian fruit bat, deer mouse and white-tailed deer. Among farmed animals, American mink have the highest likelihood to become infected from humans or animals and further transmit SARS-CoV-2. In the EU, 44 outbreaks were reported in 2021 in mink farms in seven MSs, while only six in 2022 in two MSs, thus representing a decreasing trend. The introduction of SARS-CoV-2 into mink farms is usually via infected humans; this can be controlled by systematically testing people entering farms and adequate biosecurity. The current most appropriate monitoring approach for mink is the outbreak confirmation based on suspicion, testing dead or clinically sick animals in case of increased mortality or positive farm personnel and the genomic surveillance of virus variants. The genomic analysis of SARS-CoV-2 showed mink-specific clusters with a potential to spill back into the human population. Among companion animals, cats, ferrets and hamsters are those at highest risk of SARS-CoV-2 infection, which most likely originates from an infected human, and which has no or very low impact on virus circulation in the human population. Among wild animals (including zoo animals), mostly carnivores, great apes and white-tailed deer have been reported to be naturally infected by SARS-CoV-2. In the EU, no cases of infected wildlife have been reported so far. Proper disposal of human waste is advised to reduce the risks of spill-over of SARS-CoV-2 to wildlife. Furthermore, contact with wildlife, especially if sick or dead, should be minimised. No specific monitoring for wildlife is recommended apart from testing hunter-harvested animals with clinical signs or found-dead. Bats should be monitored as a natural host of many coronaviruses.

Surveillance and Molecular Characterization of SARS-CoV-2 Infection in Non-Human Hosts in Gujarat, India

Since December 2019, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been spreading worldwide, triggering one of the most challenging pandemics in the human population. In light of the reporting of this virus in domestic and wild animals from several parts of the world, a systematic surveillance study was conceptualized to detect SARS-CoV-2 among species of veterinary importance. Nasal and/or rectal samples of 413 animals (dogs n= 195, cattle n = 64, horses n = 42, goats n = 41, buffaloes n = 39, sheep n = 19, cats n = 6, camels n = 6, and a monkey n = 1) were collected from different places in the Gujarat state of India. RNA was extracted from the samples and subjected to RT-qPCR-based quantification of the target sequences in viral nucleoprotein (N), spike (S), and ORF1ab genes. A total of 95 (23.79%) animals were found positive, comprised of n = 67 (34.35%) dogs, n= 15 (23.43%) cattle, and n = 13 (33.33%) buffaloes. Whole SARS-CoV-2 genome sequencing was done from one sample (ID-A4N, from a dog), where 32 mutations, including 29 single-nucleotide variations (SNV) and 2 deletions, were detected. Among them, nine mutations were located in the receptor binding domain of the spike (S) protein. The consequent changes in the amino acid sequence revealed T19R, G142D, E156-, F157-, A222V, L452R, T478K, D614G, and P681R mutations in the S protein and D63G, R203M, and D377Y in the N protein. The lineage assigned to this SARS-CoV-2 sequence is B.1.617.2. Thus, the present study highlights the transmission of SARS-CoV-2 infection from human to animals and suggests being watchful for zoonosis.

Antibodies against SARS-CoV-2 Suggestive of Single Events of Spillover to Cattle, Germany

Human infection with SARS-CoV-2 poses a risk for transmission to animals. To characterize the risk for cattle, we serologically investigated 1,000 samples collected from cattle in Germany in late 2021. Eleven antibody-positive samples indicated that cattle may be occasionally infected by contact with SARS-CoV-2–positive keepers, but we found no indication of further spread.

First Description of Serological Evidence for SARS-CoV-2 in Lactating Cows

Simple Summary

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is the agent of the disease that has caused a global pandemic, known as coronavirus disease 2019 (COVID-19). Coronaviruses (CoVs) may emerge from wildlife hosts and infect humans and animals. Up to now, natural infection with SARS-CoV-2 has been reported in several animals, but it has not been found in farm animals, such as buffaloes, goats, sheep, horses, rabbits, hens, pigs, or cows, despite contact with their SARS-CoV-2-positive human breeders. Furthermore, a low susceptibility to SARS-CoV-2 has been detected in experimentally infected cattle with SARS-CoV-2. The unknown zoonotic potential of this virus is a cause of concern for pet owners and farmers. The limited data on cattle suggest that cattle show low susceptibility to SARS-CoV-2 and probably do not function as reservoirs. However, in areas with large cattle populations and a high prevalence of SARS-CoV-2 infection in humans, close contact between livestock and farmworkers may cause reverse zoonotic infections in cattle, as has already been described for highly sensitive animal species, such as minks, cats, and dogs. Thus, studying the zoonotic characteristics of SARS-CoV-2 could help in the development of a strategy for virus detection and the control of viral dissemination.

Abstract

Following the COVID-19 epidemic outbreak in Ariano Irpino, Campania region (Italy), we tested lactating cows for the presence of SARS-CoV-2 on a cattle farm at which, prior to the investigation, 13 of the 20 farmworkers showed COVID-19-like symptoms, and one of them died. Twenty-four lactating cows were sampled to detect SARS-CoV-2. All nasal and rectal swabs and milk samples were negative for SARS-CoV-2 RNA. Of the 24 collected serum samples, 11 showed antibodies against SARS-CoV-2 nucleocapsid protein, 14 showed antibodies against SARS-CoV-2 spike protein, and 13 developed neutralising antibodies for SARS-COV-2; all samples were negative for Bovine Coronavirus (BCoV), another betacoronavirus. To our knowledge, this is the first report of natural serological evidence of SARS-CoV-2 infection in lactating cows. We hypothesise that this may be a case of reverse zoonosis. However, the role of cattle in SARS-CoV-2 infection and transmission seems to be negligible.

SARS-CoV-2 Seroconversion in an Adult Horse with Direct Contact to a COVID-19 Individual

The authors report on a possible direct exposure to SARS-CoV-2 from a COVID-19-positive individual to an adult horse. The individual, diagnosed with COVID-19 (Delta B.1.617.2), had daily contact to her two horses prior to and during the development of clinical disease. None of the two horses developed abnormal clinical signs or had detectable SARS-CoV-2 in blood, nasal secretion, or feces via RT-qPCR. However, one of the two horses showed close temporal seroconversion to SARS-CoV-2 using a protein-based ELISA and the plaque reduction neutralization test. The results suggest that horses can become silently infected with SARS-CoV-2 following close contact with humans infected with SARS-CoV-2. As a precautionary measure, humans infected with SARS-CoV-2 should avoid close contact with equids and other companion animals during the time of their illness to prevent viral transmission.

Investigation of the Role of Healthy and Sick Equids in the COVID-19 Pandemic through Serological and Molecular Testing

Simple Summary

The objective of the present study was to determine if horses are susceptible to SARS-CoV-2. Nasal swabs from 667 equids with acute onset of fever and respiratory signs were tested by qPCR for SARS-CoV-2. Further, 633 serum samples collected from a cohort of 587 healthy racing Thoroughbreds with possible exposure to humans with SARS-CoV-2 infection were tested for antibodies to SARS-CoV-2 using an ELISA targeting the receptor-binding domain of the spike protein. All 667 horses with fever and respiratory signs tested qPCR-negative for SARS-CoV-2. A total of 35/587 (5.9%) Thoroughbred racing horses had detectable IgG antibodies to SARS-CoV-2. While horses appear to be susceptible to SARS-CoV-2 when in close contact with humans with SARS-CoV-2 infection, clinical disease was not observed in the study horses. Experimental challenge studies using pure inocula are needed in order to study the clinical, hematological, molecular, and serological features of adult horses infected with SARS-CoV-2.

Abstract

More and more studies are reporting on the natural transmission of SARS-CoV-2 between humans with COVID-19 and their companion animals (dogs and cats). While horses are apparently susceptible to SARS-CoV-2 infection based on the homology between the human and the equine ACE-2 receptor, no clinical or subclinical infection has yet been reported in the equine species. To investigate the possible clinical role of SARS-CoV-2 in equids, nasal secretions from 667 horses with acute onset of fever and respiratory signs were tested for the presence of SARS-CoV-2 by qPCR. The samples were collected from January to December of 2020 and submitted to a commercial molecular diagnostic laboratory for the detection of common respiratory pathogens (equine influenza virus, equine herpesvirus-1/-4, equine rhinitis A and B virus, Streptococcus equi subspecies equi). An additional 633 serum samples were tested for antibodies to SARS-CoV-2 using an ELISA targeting the receptor-binding domain of the spike protein. The serum samples were collected from a cohort of 587 healthy racing Thoroughbreds in California after track personnel tested qPCR-positive for SARS-CoV-2. While 241/667 (36%) equids with fever and respiratory signs tested qPCR-positive for at least one of the common respiratory pathogens, not a single horse tested qPCR-positive for SARS-CoV-2. Amongst the racing Thoroughbreds, 35/587 (5.9%) horses had detectable antibodies to SARS-CoV-2. Similar to dogs and cats, horses do not seem to develop clinical SARS-CoV-2 infection. However, horses can act as incidental hosts and experience silent infection following spillover from humans with COVID-19. SARS-CoV-2-infected humans should avoid close contact with equids during the time of their illness.