Detection of SARS-CoV-2 Delta Variant (B.1.617.2) in Domestic Dogs and Zoo Tigers in England and Jersey during 2021.

Reverse zoonotic transmission events of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described since the start of the pandemic, and the World Organisation for Animal Health (WOAH) designated the detection of SARS-CoV-2 in animals a reportable disease. Eighteen domestic and zoo animals in Great Britain and Jersey were tested by APHA for SARS-CoV-2 during 2020-2023. One domestic cat (Felis catus), three domestic dogs (Canis lupus familiaris), and three Amur tigers (Panthera tigris altaica) from a zoo were confirmed positive during 2020-2021 and reported to the WOAH. All seven positive animals were linked with known SARS-CoV-2 positive human contacts. Characterisation of the SARS-CoV-2 variants by genome sequencing indicated that the cat was infected with an early SARS-CoV-2 lineage. The three dogs and three tigers were infected with the SARS-CoV-2 Delta variant of concern (B.1.617.2). The role of non-human species in the onward transmission and emergence of new variants of SARS-CoV-2 remain poorly defined. Continued surveillance of SARS-CoV-2 in relevant domestic and captive animal species with high levels of human contact is important to monitor transmission at the human-animal interface and to assess their role as potential animal reservoirs.

SARS-COV-2 INFECTION AND LONGITUDINAL FECAL SCREENING IN MALAYAN TIGERS (PANTHERA TIGRIS JACKSONI), AMUR TIGERS (PANTHERA TIGRIS ALTAICA ), AND AFRICAN LIONS (PANTHERA LEO KRUGERI) AT THE BRONX ZOO, NEW YORK, USA.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged as the cause of a global pandemic in 2019-2020. In March 2020, New York City became the epicenter in the United States for the pandemic. On 27 March 2020, a Malayan tiger (Panthera tigris jacksoni) at the Bronx Zoo in New York City developed a cough and wheezing with subsequent inappetence. Over the next week, an additional Malayan tiger and two Amur tigers (Panthera tigris altaica) in the same building and three lions (Panthera leo krugeri) in a separate building also became ill. The index case was anesthetized for diagnostic workup. Physical examination and bloodwork results were unremarkable. Thoracic radiography and ultrasonography revealed a bronchial pattern with peribronchial cuffing and mild lung consolidation with alveolar-interstitial syndrome, respectively. SARS-CoV-2 RNA was identified by real-time, reverse transcriptase PCR (rRT-PCR) on oropharyngeal and nasal swabs and tracheal wash fluid. Cytologic examination of tracheal wash fluid revealed necrosis, and viral RNA was detected in necrotic cells by in situ hybridization, confirming virus-associated tissue damage. SARS-CoV-2 was isolated from the tracheal wash fluid of the index case, as well as the feces from one Amur tiger and one lion. Fecal viral RNA shedding was confirmed in all seven clinical cases and an asymptomatic Amur tiger. Respiratory signs abated within 1-5 days for most animals, although they persisted intermittently for 16 days in the index case. Fecal RNA shedding persisted for as long as 35 days beyond cessation of respiratory signs. This case series describes the clinical presentation, diagnostic evaluation, and management of tigers and lions infected with SARS-CoV-2 and describes the duration of viral RNA fecal shedding in these cases. This report documents the first known natural transmission of SARS-CoV-2 from humans to nondomestic felids.

Distemper, extinction, and vaccination of the Amur tiger.

Canine distemper virus (CDV) has recently emerged as an extinction threat for the endangered Amur tiger (Panthera tigris altaica). CDV is vaccine-preventable, and control strategies could require vaccination of domestic dogs and/or wildlife populations. However, vaccination of endangered wildlife remains controversial, which has led to a focus on interventions in domestic dogs, often assumed to be the source of infection. Effective decision making requires an understanding of the true reservoir dynamics, which poses substantial challenges in remote areas with diverse host communities. We carried out serological, demographic, and phylogenetic studies of dog and wildlife populations in the Russian Far East to show that a number of wildlife species are more important than dogs, both in maintaining CDV and as sources of infection for tigers. Critically, therefore, because CDV circulates among multiple wildlife sources, dog vaccination alone would not be effective at protecting tigers. We show, however, that low-coverage vaccination of tigers themselves is feasible and would produce substantive reductions in extinction risks. Vaccination of endangered wildlife provides a valuable component of conservation strategies for endangered species.

Evaluation of an in-house indirect enzyme-linked immunosorbent assay of feline panleukopenia VP2 subunit antigen in comparison to hemagglutination inhibition assay to monitor tiger antibody levels by Bayesian approach.

BACKGROUND: Feline panleukopenia virus (FPV) is an etiologic pathogen of feline panleukopenia that infects all members of Felidae including tigers (Panthera tigris). Vaccinations against FPV among wild felid species have long been practiced in zoos worldwide. However, few studies have assessed the tiger immune response post-vaccination due to the absence of a serological diagnostic tool. To address these limitations, this study aimed to develop an in-house indirect enzyme-linked immunosorbent assay (ELISA) for the monitoring of tiger antibody levels against the feline panleukopenia vaccine by employing the synthesized subunit capsid protein VP2. An in-house horseradish peroxidase (HRP) conjugated rabbit anti-tiger immunoglobulin G (IgG) polyclonal antibody (HRP-anti-tiger IgG) was produced in this study and employed in the assay. It was then compared to a commercial HRP-conjugated goat anti-cat IgG (HRP-anti-cat IgG). Sensitivity and specificity were evaluated using the Bayesian model with preferential conditional dependence between HRP-conjugated antibody-based ELISAs and hemagglutination-inhibition (HI) tests. RESULTS: The posterior estimates for sensitivity and specificity of two indirect ELISA HRP-conjugated antibodies were higher than those of the HI test. The sensitivity and specificity of the indirect ELISA for HRP-anti-tiger IgG and HRP-anti-cat IgG were 86.5, 57.2 and 86.7%, 64.6%, respectively, while the results of the HI test were 79.1 and 54.1%. In applications, 89.6% (198/221) and 89.1% (197/221) of the tiger serum samples were determined to be seropositive by indirect ELISA testing against HRP-anti-tiger and HRP-anti-cat, respectively. CONCLUSION: To the best of our knowledge, the specific serology assays for the detection of the tiger IgG antibody have not yet been established. The HRP-anti-tiger IgG has been produced for the purpose of developing the specific immunoassays for tigers. Remarkably, an in-house indirect ELISA based on VP2 subunit antigen has been successfully developed in this study, providing a potentially valuable serological tool for the effective detection of tiger antibodies.

Susceptibility to SARS, MERS, and COVID-19 from animal health perspective.

Viruses are having great time as they seem to have bogged humans down. Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and novel coronavirus (COVID-19) are the three major coronaviruses of present-day global human and animal health concern. COVID-19 caused by SARS-CoV-2 is identified as the newest disease, presumably of bat origin. Different theories on the evolution of viruses are in circulation, yet there is no denying the fact that the animal source is the skeleton. The whole world is witnessing the terror of the COVID-19 pandemic that is following the same path of SARS and MERS, and seems to be more severe. In addition to humans, several species of animals are reported to have been infected with these life-threatening viruses. The possible routes of transmission and their zoonotic potentialities are the subjects of intense research. This review article aims to overview the link of all these three deadly coronaviruses among animals along with their phylogenic evolution and cross-species transmission. This is essential since animals as pets or food are said to pose some risk, and their better understanding is a must in order to prepare a possible plan for future havoc in both human and animal health. Although COVID-19 is causing a human health hazard globally, its reporting in animals are limited compared to SARS and MERS. Non-human primates and carnivores are most susceptible to SARS-coronavirus and SARS-CoV-2, respectively, whereas the dromedary camel is susceptible to MERS-coronavirus. Phylogenetically, the trio viruses are reported to have originated from bats and have special capacity to undergo mutation and genomic recombination in order to infect humans through its reservoir or replication host. However, it is difficult to analyze how the genomic pattern of coronaviruses occurs. Thus, increased possibility of new virus-variants infecting humans and animals in the upcoming days seems to be the biggest challenge for the future of the world. One health approach is portrayed as our best way ahead, and understanding the animal dimension will go a long way in formulating such preparedness plans.

Construction and Immunogenicity of Virus-Like Particles of Feline Parvovirus from the Tiger.

Feline panleukopenia, caused by feline parvovirus (FPV), is a highly infectious disease characterized by leucopenia and hemorrhagic gastroenteritis that severely affects the health of large wild Felidae. In this study, tiger FPV virus-like particles (VLPs) were developed using the baculovirus expression system. The VP2 gene from an infected Siberian tiger (Panthera tigris altaica) was used as the target gene. The key amino acids of this gene were the same as those of FPV, whereas the 101st amino acid was the same as that of canine parvovirus. Indirect immunofluorescence assay (IFA) results demonstrated that the VP2 protein was successfully expressed. SDS-PAGE and Western blotting (WB) results showed that the target protein band was present at approximately 65 kDa. Electron micrograph analyses indicated that the tiger FPV VLPs were successfully assembled and were morphologically similar to natural parvovirus particles. The hemagglutination (HA) titer of the tiger FPV VLPs was as high as 1:218. The necropsy and tissue sections at the cat injection site suggested that the tiger FPV VLPs vaccine was safe. Antibody production was induced in cats after subcutaneous immunization, with a >1:210 hemagglutination inhibition (HI) titer that persisted for at least 12 months. These results demonstrate that tiger FPV VLPs might provide a vaccine to prevent FPV-associated disease in the tiger.

CARNIVORE PROTOPARVOVIRUS 1 (PARVOVIRUSES) AT THE DOMESTIC-WILD CARNIVORE INTERFACE IN INDIA.

Carnivore protoparvovirus 1 (CP1, earlier called Feline panleukopenia virus) variants such as canine parvovirus (CPV) and feline parvovirus (FPV) are significant, emerging, multihost pathogens of domestic and wild carnivores. The diversity of CP1 variants was studied between 2008 and 2014 in Wayanad, India, where flagship wildlife species such as tigers (Panthera tigris) and leopards (Panthera pardus) coexist alongside domestic carnivores, including dogs (Canis lupus familiaris) and cats (Felis catus). Using polymerase chain reaction, FPV and CPV sequences were obtained from the heart blood of a necropsied leopard individual for the first time in the world and from rectal swabs of three sympatric and clinically ill domestic dogs. CP1 amplicons were also detected in a tiger. Cross-species transmission possibilities were identified, as the closest relatives to the leopard FPV sequence were found in domestic cats from a neighboring state.

Genomic characterization of a novel astrovirus identified in Amur tigers from a zoo in China.

Astroviruses (AstVs) have a very wide range of hosts and are associated with enteric and extra-enteric disease in mammals and birds. Cross-species transmission of AstVs has been observed frequently. In the present study, the genome of a novel astrovirus from Amur tigers (Panthera tigris) from a zoo in China was characterized and was found to have the typical genomic features of other mammal AstVs. It showed the highest nucleotide sequence similarity (46.1-87.3% identity) to AstVs from cats, indicating a close phylogenetic relationship and possible cross-species transmission between them. To our knowledge, this is the first identification and characterization of AstV from tigers, and this virus is the third astrovirus identified in hosts of the family Felidae. The results of this study will be helpful for understanding the origin, genetic diversity, and cross-species transmission of AstV.

Isolation and identification of tiger parvovirus in captive siberian tigers and phylogenetic analysis of VP2 gene.

To better understand the prevalence and molecular epidemiology of parvovirus, this study reports the isolation and characterization of a tiger parvovirus (TPV) named CHJL-Siberian Tiger-01/2017 from a captive Siberian tiger in Jilin Province, China. A phylogenetic tree based on the full-length VP2 nucleotide sequence was constructed using the isolated strain in this study and 56 reference strains. The results showed that all the parvoviruses can be grouped into two large branches: the canine parvovirus (CPV) branch and the feline parvovirus (FPV) branch. FPV strains comprised TPVs, FPVs, blue fox parvoviruses (BFPVs), mink enteritis viruses (MEVs), and raccoon feline parvoviruses (RFPVs), and CPV strains comprised CPVs and raccoon dog parvoviruses (RDPVs). RFPVs are also often very closely related to those sampled from other carnivorous species, and raccoons may represent conduits for parvovirus transmission to other hosts. The results of amino acid changes in the VP2 protein of the isolated strain showed that amino acid Ile 101 was mutated to Thr (I 101T). Taken together, a field TPV strain CHJL-Siberian Tiger-01/2017 was isolated, which may be suitable for future studies on FPV infection, replication and vaccine development. This study provided new important findings about the evolution of parvovirus infection in tigers.

Outbreak and genotyping of canine distemper virus in captive Siberian tigers and red pandas.

In this study, four canine distemper virus (CDV) strains were isolated from captive Siberian tigers (Panthera tigris altaica) and red pandas (Ailurus fulgens) during two separate CDV outbreaks in a zoo in Guangdong province, China. Sequence alignment and phylogenetic analyses based on the full-length hemagglutinin (H) and fusion (F) genes showed that they were closely identical to genotype Asia-1. Prior to confirmation of CDV in Siberian tigers, to control spread of the disease, a live attenuated combination CDV vaccine was used among almost all carnivore animals except for red pandas in which another recombinant combination CDV vaccine was used. However, about two months later, CDV re-emerged and caused the death among red pandas. Based on the vaccination records, the live combination vaccine could be considered an ideal weapon against CDV in zoo carnivore animals. Although the recombinant combination CDV vaccine was safe for red pandas, its protection effectiveness remains to be further investigated. Moreover, according to the outbreak interval time and sequence characterization, we suspected that stray cats circulating in the zoo were the intermediate host, which contributed to CDV spread from stray dogs to zoo animals. This study revealed the importance of vaccination and biosecurity for zoo animals.

Molecular characterization of a feline calicivirus isolated from tiger and its pathogenesis in cats.

Feline calicivirus (FCV) is a virus that causes respiratory disease in cats. In this study, the FCV TIG-1 was isolated from Siberian tiger feces collected in 2014 in Heilongjiang Province, China. Phylogenetic analysis among TIG-1 and other FCVs showed that TIG-1 does not share the same lineage with other FCV isolates from Heilongjiang or other regions in China but is located in the same cluster with the FCV strain Urbana, which was isolated from the United States. The growth kinetics in vitro and the pathogenicity in cats between TIG-1 and the domestic cat-origin FCV strain F9 (vaccine strain) and strain 2280 were compared. We found that the growth kinetics of strains TIG-1 and 2280 were faster than that of strain F9 from 12h to 36h post-infection, indicating that strains TIG-1 and 2280 produce infectious virions and reach peak yields earlier. Challenge experiments in cats showed that TIG-1 grew faster than the other two strains in the lungs of cats and that TIG-1 is a virulent FCV with 100% morbidity and lethality. In addition, the histopathological results showed that the virulent TIG-1 strain directly led to severe lung tissue damage and indirectly led to intestinal damage. The results presented here show that a tiger-origin FCV exhibits high virulence in cats.

Canine distemper virus as a threat to wild tigers in Russia and across their range.

Canine distemper virus (CDV) has recently been identified in populations of wild tigers in Russia and India. Tiger populations are generally too small to maintain CDV for long periods, but are at risk of infections arising from more abundant susceptible hosts that constitute a reservoir of infection. Because CDV is an additive mortality factor, it could represent a significant threat to small, isolated tiger populations. In Russia, CDV was associated with the deaths of tigers in 2004 and 2010, and was coincident with a localized decline of tigers in Sikhote-Alin Biosphere Zapovednik (from 25 tigers in 2008 to 9 in 2012). Habitat continuity with surrounding areas likely played an important role in promoting an ongoing recovery. We recommend steps be taken to assess the presence and the impact of CDV in all tiger range states, but should not detract focus away from the primary threats to tigers, which include habitat loss and fragmentation, poaching and retaliatory killing. Research priorities include: (i) recognition and diagnosis of clinical cases of CDV in tigers when they occur; and (ii) collection of baseline data on the health of wild tigers. CDV infection of individual tigers need not imply a conservation threat, and modeling should complement disease surveillance and targeted research to assess the potential impact to tiger populations across the range of ecosystems, population densities and climate extremes occupied by tigers. Describing the role of domestic and wild carnivores as contributors to a local CDV reservoir is an important precursor to considering control measures.

Canine distemper virus (CDV) in another big cat: should CDV be renamed carnivore distemper virus?

One of the greatest threats to the conservation of wild cat populations may be dogs or, at least, one of their viruses. Canine distemper virus (CDV), a single-stranded RNA virus in the Paramyxoviridae family and genus Morbillivirus, infects and causes disease in a variety of species, not just canids. An outbreak of CDV in wild lions in the Serengeti, Tanzania, in 1994 was a wake-up call for conservationists, as it demonstrated that an infectious disease could swiftly impact a previously healthy felid population. To understand how this virus causes disease in noncanid hosts, researchers have focused on specific mutations in the binding site of the CDV hemagglutinin gene. Now, Seimon et al. provide information on CDV in its latest feline victim, the endangered wild Amur tiger (Panthera tigris altaica) [T. A. Seimon et al., mBio 4(4):e00410-13, 2013, doi:10.1128/mBio.00410-13]. Their findings of CDV strains infecting tigers, in combination with recent information from other felids, paints a different picture, one in which CDV strains from a variety of geographic lineages and with a variety of amino acid residues in the hemagglutinin gene binding site can infect cats and cause disease. Although CDV has been known as a multihost disease since its discovery in domestic dogs in 1905, perhaps it is time to reconsider whether these noncanid species are not just incidental or "spillover" hosts but, rather, a normal part of the complex ecology of this infectious disease.

Isolation, molecular characterization, and phylogenetic analysis of encephalomyocarditis virus from South China tigers in China.

Although encephalomyocarditis virus (EMCV) can infect many host species and cause myocarditis and sudden death in many species, little is known about EMCV infection in tigers. A virus was isolated from organs of dead South China tigers with sudden death in southern China. The production of cytopathic effect on BHK cells, and the results of PCR, electron microscopy (EM), and whole genome sequencing indicated that the pathogen was EMCV, the strain was named FJ13. Other pathogenic agents were excluded as possible pathogenic agents. Phylogenetic analyses of the whole genome, ORF (open reading frame) and CCR (capsid coding region) using the neighbour-joining method revealed that EMCV isolates cluster into two groups (group 1 and 2) with two sub-clusters within group 1 (group 1a and 1b), and FJ13 belongs to group 1a. Animal experiment showed that the isolated strain FJ13 could cause clinical symptoms and pathological changes. The results of this study indicated that FJ13 caused myocarditis of tigers and provided new epidemiologic data on EMCV in China.

Canine distemper virus: an emerging disease in wild endangered Amur tigers (Panthera tigris altaica).

UNLABELLED: Fewer than 500 Amur tigers (Panthera tigris altaica) remain in the wild. Due to low numbers and their solitary and reclusive nature, tiger sightings across their range in the Russian Far East and China are rare; sightings of sick tigers are rarer still. Serious neurologic disease observed in several wild tigers since 2001 suggested disease emergence in this endangered species. To investigate this possibility, histology, immunohistochemistry (IHC), in situ hybridization (ISH), and reverse transcription-PCR (RT-PCR) were performed on tissues from 5 affected tigers that died or were destroyed in 2001, 2004, or 2010. Our results reveal canine distemper virus (CDV) infection as the cause of neurologic disease in two tigers and definitively establish infection in a third. Nonsuppurative encephalitis with demyelination, eosinophilic nuclear viral inclusions, and positive immunolabeling for CDV by IHC and ISH were present in the two tigers with available brain tissue. CDV phosphoprotein (P) and hemagglutinin (H) gene products were obtained from brains of these two tigers by RT-PCR, and a short fragment of CDV P gene sequence was detected in lymph node tissue of a third tiger. Phylogenetically, Amur tiger CDV groups with an Arctic-like strain in Baikal seals (Phoca siberica). Our results, which include mapping the location of positive tigers and recognition of a cluster of cases in 2010, coupled with a lack of reported CDV antibodies in Amur tigers prior to 2000 suggest wide geographic distribution of CDV across the tiger range and recent emergence of CDV as a significant infectious disease threat to endangered Amur tigers in the Russian Far East. IMPORTANCE: Recognition of disease emergence in wildlife is a rare occurrence. Here, for the first time, we identify and characterize a canine distemper virus (CDV), the second most common cause of infectious disease death in domestic dogs and a viral disease of global importance in common and endangered carnivores, as the etiology of neurologic disease and fatal encephalitis in wild, endangered Amur tigers. We establish that in 2010 CDV directly or indirectly killed -1% of Amur tigers. Location of positive cases over an expansive geographic area suggests that CDV is widely distributed across the tiger range. Interspecies interactions are increasing as human populations grow and expand into wildlife habitats. Identifying animal reservoirs for CDV and identifying the CDV strains that are transmissible to and among wildlife species, including Amur tigers and sympatric critically endangered Amur leopards (Panthera pardus orientalis), is essential for guiding conservation and mitigation efforts.

An outbreak of canine distemper virus in tigers (Panthera tigris): possible transmission from wild animals to zoo animals.

Canine distemper virus (CDV), a morbillivirus that causes one of the most contagious and lethal viral diseases known in canids, has an expanding host range, including wild animals. Since December 2009, several dead or dying wild raccoon dogs (Nyctereutes procyonoides) were found in and around one safari-style zoo in Japan, and CDV was isolated from four of these animals. In the subsequent months (January to February 2010), 12 tigers (Panthera tigris) in the zoo developed respiratory and gastrointestinal diseases, and CDV RNA was detected in fecal samples of the examined tigers. In March 2010, one of the tigers developed a neurological disorder and died; CDV was isolated from the lung of this animal. Sequence analysis of the complete hemagglutinin (H) gene and the signal peptide region of the fusion (F) gene showed high homology among these isolates (99.8-100%), indicating that CDV might have been transmitted from raccoon dog to tiger. In addition, these isolates belonged to genotype Asia-1 and had lower homology (<90%) to the vaccine strain (Onderstepoort). Seropositivity of lions (Panthera leo) in the zoo and wild bears (Ursus thibetanus) captured around this area supported the theory that a CDV epidemic had occurred in many mammal species in and around the zoo. These results indicate a risk of CDV transmission among many animal species, including large felids and endangered species.