The Cat's in the Bag: Despite Limited Cat-to-Cat Severe Acute Respiratory Syndrome Coronavirus 2 Transmission, One Health Surveillance Efforts Are Needed

Low serological rate of SARS-CoV-2 in cats from military bases in Israel

Domestic cats are susceptible to SARS-CoV-2 infection and can transmit the virus to other felines. A high number of COVID-19 human cases within the military personnel and a high density of stray cats living close to soldiers raised the need to perform active animal surveillance. We validated a novel quantitative serological microarray for use in cats, that enables simultaneous detection of IgG and IgM responses; in addition, molecular genetic SARS-CoV-2 detection was performed. Three out of 131 cats analyzed, showed IgG antibodies against SARS-CoV-2 RBD and S2P (2.3 %). None of cats were positive for SARS-CoV-2 RNA by RT-PCR. SARS-CoV-2 infection rate in soldiers ranged from 4.7 % to 16 % (average rate=8.9 %). Further investigations on a larger cohort are necessary, in the light of the emerging new viral variants in other animal species and in humans.

Does having a cat in your house increase your risk of catching COVID-19?

Due to the zoonotic origin of SARS-Coronavirus 2 (SARS-CoV-2), the potential for its transmission from humans back to animals and the possibility that it might establish ongoing infection pathways in other animal species has been discussed. Cats are highly susceptible to SARS-CoV-2 and were shown experimentally to transmit the virus to other cats. Infection of cats has been widely reported. Domestic cats in COVID-19-positive households could therefore be a part of a human to animal to human transmission pathway. Here, we report the results of a qualitative risk assessment focusing on the potential of cat to human transmission in such settings. The assessment was based on evidence available by October 2021.

After the introduction of SARS-CoV-2 to a household by a human, cats may become infected and infected cats may pose an additional infection risk for other members of the household. In order to assess this additional risk qualitatively, expert opinion was elicited within the framework of a modified Delphi procedure. The conclusion was that the additional risk of infection of an additional person in a household associated with keeping a domestic cat is very low to negligible, depending on the intensity of cat-to-human interactions. The separation of cats from humans suffering from SARS-CoV-2 infection should contribute to preventing further transmission.

Cats and SARS-CoV-2: A Scoping Review

Since the beginning of the COVID-19 pandemic, various animal species were found to be susceptible to SARS-CoV-2 infection. The close contact that exists between humans and cats warrants special attention to the role of this species. Therefore, a scoping review was performed to obtain a comprehensive overview of the existing literature, and to map key concepts, types of research, and possible gaps in the research. A systematic search of the databases PubMed, Google Scholar, and Scopus and the preprint servers medRxiv and bioRxiv was performed. After a two-step screening process, 27 peer-reviewed articles, 8 scientific communication items, and 2 unpublished pre-prints were included. The main themes discussed were susceptibility to SARS-CoV-2, induced immunity, prevalence of infection, manifestation of infection, interspecies transmission between humans and cats, and lastly, intraspecies transmission between cats. The main gaps in the research identified were a lack of large-scale studies, underrepresentation of stray, feral, and shelter cat populations, lack of investigation into cat-to-cat transmissions under non-experimental conditions, and the relation of cats to other animal species regarding SARS-CoV-2. Overall, cats seemingly play a limited role in the spread of SARS-CoV-2. While cats are susceptible to the virus and reverse zoonotic transmission from humans to cats happens regularly, there is currently no evidence of SARS-CoV-2 circulation among cats.

Assessing COVID-19 Pandemic Risk Perception and Response Preparedness in Veterinary and Animal Care Workers

Veterinary and animal care workers perform critical functions in biosecurity and public health, yet little has been done to understand the unique needs and barriers these workers face when responding during a pandemic crisis. In this article, we evaluated the perceived risks and roles of veterinary and animal care workers during the COVID-19 pandemic and explored barriers and facilitators in their readiness, ability, and willingness to respond during a pandemic. We deployed a survey targeting US veterinary medical personnel, animal shelter and control workers, zoo and wildlife workers, and other animal care workers. Data were collected on respondents' self-reported job and demographic factors, perceptions of risk and job efficacy, and readiness, ability, and willingness to respond during the pandemic. We found that leadership roles and older age had the strongest association with decreased perceived risk and improved job efficacy and confidence, and that increased reported contact level with others (both coworkers and the public) was associated with increased perceived risk. We determined that older age and serving in leadership positions were associated with improved readiness, willingness, and ability to respond. Veterinary and animal care workers' dedication to public health response, reflected in our findings, will be imperative if more zoonotic vectors of SARS-CoV-2 arise. Response preparedness in veterinary and animal care workers can be improved by targeting younger workers not in leadership roles through support programs that focus on improving job efficacy and confidence in safety protocols. These findings can be used to target intervention and training efforts to support the most vulnerable within this critical, yet often overlooked, workforce.

Epidemiological profiling of SARS-CoV-2 with focus on one-health approaches in mitigating COVID-19 pandemic

Of the 1,415 human pathogens identified, 175 are responsible for causing emerging diseases, 132 are zoonotic and majority of the diseases are categorized as emerging or re-emerging. Emerging novel Coronavirus (COVID- 19) is one of them, and it is responsible for causing social and economically critical disease in both humans and animals. This review presents the understanding of epidemiological characteristics of the COVID-19 pandemic related to host, agent, and the environment with transmission and spread of the disease for better prevention of the COVID-19. The inclination of the viruses to spillover between different species and determining the number of the reservoir of coronaviruses in an entirely new host to create infection is of emerging importance. The understanding of disease patterns will potentiate our expertise to alert how, when, and where the potential epidemic will occur. One health approach involves co-operation from all the sectors, including healthcare (medical and veterinary), environmental, pharmaceutical, educational, research, police, and administration, to combat the COVID-19 pandemic and reduce the public health threat.

Animal reservoirs of SARS-CoV-2: calculable COVID-19 risk for older adults from animal to human transmission

The current COVID-19 pandemic, caused by the highly contagious respiratory pathogen SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), has already claimed close to three million lives. SARS-CoV-2 is a zoonotic disease: it emerged from a bat reservoir and it can infect a number of agricultural and companion animal species. SARS-CoV-2 can cause respiratory and intestinal infections, and potentially systemic multi-organ disease, in both humans and animals. The risk for severe illness and death with COVID-19 significantly increases with age, with older adults at highest risk. To combat the pandemic and protect the most susceptible group of older adults, understanding the human-animal interface and its relevance to disease transmission is vitally important. Currently high infection numbers are being sustained via human-to-human transmission of SARS-CoV-2. Yet, identifying potential animal reservoirs and potential vectors of the disease will contribute to stronger risk assessment strategies. In this review, the current information about SARS-CoV-2 infection in animals and the potential spread of SARS-CoV-2 to humans through contact with domestic animals (including dogs, cats, ferrets, hamsters), agricultural animals (e.g., farmed minks), laboratory animals, wild animals (e.g., deer mice), and zoo animals (felines, non-human primates) are discussed with a special focus on reducing mortality in older adults.

SARS-CoV-2 infection in domestic and feral cats: current evidence and implications

Current evidence indicates that cats play a limited role in COVID-19 epidemiology, and pets are probably dead-end hosts of SARS-CoV-2 and pose negligible risks of transmission to humans. Still, one health concept is to be adopted widely as a component of mitigation strategies to tackle the ongoing pandemic. Therefore, in terms of the magnitude of infection and potential to transmit SARS-CoV-2 to humans, our surveillance efforts should mainly focus on mustelids (especially minks, ferrets, and others) for early detection and control of infection. This will ensure that SARS-CoV-2 will not get established in the wild animal population of these susceptible species. We agree with Dr. Passarella Teixeira on the possibility of domestic and feral cats acting as an urban reservoir, subsequently transmitting the virus to human beings. However, it is less likely that such a phenomenon will be reported even if it has occurred due to the efficient and extensive human-to-human transmission of SARS-CoV-2.

SARS-CoV-2 Infection in Dogs and Cats from Southern Germany and Northern Italy during the First Wave of the COVID-19 Pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people globally since its first detection in late 2019. Besides humans, cats and, to some extent, dogs were shown to be susceptible to SARS-CoV-2, highlighting the need for surveillance in a One Health context. Seven veterinary clinics from regions with high incidences of coronavirus disease (COVID-19) were recruited during the early pandemic (March to July 2020) for the screening of patients. A total of 2257 oropharyngeal and nasal swab specimen from 877 dogs and 260 cats (including 18 animals from COVID-19-affected households and 92 animals with signs of respiratory disease) were analyzed for the presence of SARS-CoV-2 RNA using reverse transcriptase real-time polymerase chain reaction (RT-qPCR) targeting the viral envelope (E) and RNA dependent RNA polymerase (RdRp) genes. One oropharyngeal swab from an Italian cat, living in a COVID-19-affected household in Piedmont, tested positive in RT-qPCR (1/260; 0.38%, 95% CI: 0.01-2.1%), and SARS-CoV-2 infection of the animal was serologically confirmed six months later. One oropharyngeal swab from a dog was potentially positive (1/877; 0.1%, 95% CI: 0.002-0.63%), but the result was not confirmed in a reference laboratory. Analyses of convenience sera from 118 animals identified one dog (1/94; 1.1%; 95% CI: 0.02-5.7%) from Lombardy, but no cats (0/24), as positive for anti-SARS-CoV-2 receptor binding domain (RBD) antibodies and neutralizing activity. These findings support the hypothesis that the prevalence of SARS-CoV-2 infection in pet cat and dog populations, and hence, the risk of zoonotic transmission to veterinary staff, was low during the first wave of the pandemic, even in hotspot areas.

SARS-Cov-2 Natural Infection in a Symptomatic Cat: Diagnostic, Clinical and Medical Management in a One Health Vision

Despite the reported increase in SARS-CoV-2-infected pets, the description of the clinical features from natural infection and the medical follow up in symptomatic pets is still not sufficiently documented. This study reports the case of an indoor cat that displayed respiratory signs and a gastrointestinal syndrome, following the COVID-19 diagnosis of his owners. Thoracic radiographies were suggestive of bronchial pneumonia, while blood tests were indicative of a mild inflammatory process. Nasal and oropharyngeal swabs tested positive through RT-qPCR assays targeting SARS-CoV-2 genes 14 days after his owners tested positive for the virus. Nasal swabs persisted to be RT-qPCR positive after 31 days. Serology confirmed the presence of antibodies through ELISA, electrochemiluminescence analysis and plaque reduction neutralization test, recording a high antibody titre after 31 days. The cat improved after medical treatment and clinically recovered. This study suggests that exposure to SARS-CoV-2 could lead to a natural infection with bronchial pneumonia in cats along with a possible prolonged persistence of SARS-CoV-2 RNA in the upper airways, albeit at a low level. The cat developed neutralizing antibodies, reaching a high titre after 31 days. Further descriptions of SARS-CoV-2 naturally infected pets, their medical management and diagnostic findings would be useful to enhance knowledge about COVID-19 in susceptible animals.