Probable Transmission of SARS-CoV-2 from African Lion to Zoo Employees, Indiana, USA, 2021.

We describe animal-to-human transmission of SARS-CoV-2 in a zoo setting in Indiana, USA. A vaccinated African lion with physical limitations requiring hand feeding tested positive for SARS-CoV-2 after onset of respiratory signs. Zoo employees were screened, monitored prospectively for onset of symptoms, then rescreened as indicated; results were confirmed by using reverse transcription PCR and whole-genome virus sequencing when possible. Traceback investigation narrowed the source of infection to 1 of 6 persons. Three exposed employees subsequently had onset of symptoms, 2 with viral genomes identical to the lion's. Forward contact tracing investigation confirmed probable lion-to-human transmission. Close contact with large cats is a risk factor for bidirectional zoonotic SARS-CoV-2 transmission that should be considered when occupational health and biosecurity practices at zoos are designed and implemented. SARS-CoV-2 rapid testing and detection methods for big cats and other susceptible animals should be developed and validated to enable timely implementation of One Health investigations.

Clinical and epidemiologic features of SARS-CoV-2 in dogs and cats compiled through national surveillance in the United States.

OBJECTIVE: To characterize clinical and epidemiologic features of SARS-CoV-2 in companion animals detected through both passive and active surveillance in the US. ANIMALS: 204 companion animals (109 cats, 95 dogs) across 33 states with confirmed SARS-CoV-2 infections between March 2020 and December 2021. PROCEDURES: Public health officials, animal health officials, and academic researchers investigating zoonotic SARS-CoV-2 transmission events reported clinical, laboratory, and epidemiologic information through a standardized One Health surveillance process developed by the CDC and partners. RESULTS: Among dogs and cats identified through passive surveillance, 94% (n = 87) had reported exposure to a person with COVID-19 before infection. Clinical signs of illness were present in 74% of pets identified through passive surveillance and 27% of pets identified through active surveillance. Duration of illness in pets averaged 15 days in cats and 12 days in dogs. The average time between human and pet onset of illness was 10 days. Viral nucleic acid was first detected at 3 days after exposure in both cats and dogs. Antibodies were detected starting 5 days after exposure, and titers were highest at 9 days in cats and 14 days in dogs. CLINICAL RELEVANCE: Results of the present study supported that cats and dogs primarily become infected with SARS-CoV-2 following exposure to a person with COVID-19, most often their owners. Case investigation and surveillance that include both people and animals are necessary to understand transmission dynamics and viral evolution of zoonotic diseases like SARS-CoV-2.

Transmission of SARS-CoV-2 Delta variant (B.1.617.2) from a fully vaccinated human to a canine in Georgia, July 2021.

SARS-CoV-2 infection has been described in a wide range of species, including domestic animals such as dogs and cats. Illness in dogs is usually self-limiting, and further diagnostics may not be pursued if clinical signs resolve or they respond to empirical treatment. As new variants emerge, the clinical presentation and role in transmission may vary in animals. This report highlights different clinical presentations and immunological responses in two SARS-CoV-2 Delta-variant-positive dogs with similar exposure to the same fully vaccinated human with a SARS-CoV-2 infection and emphasizes the need for active surveillance and additional One Health research on SARS-CoV-2 variant infections in companion animals and other species.

Determining the role of natural SARS-CoV-2 infection in the death of domestic pets: 10 cases (2020-2021).

OBJECTIVE: To establish a pathoepidemiological model to evaluate the role of SARS-CoV-2 infection in the first 10 companion animals that died while infected with SARS-CoV-2 in the US. ANIMALS: 10 cats and dogs that tested positive for SARS-CoV-2 and died or were euthanized in the US between March 2020 and January 2021. PROCEDURES: A standardized algorithm was developed to direct case investigations, determine the necessity of certain diagnostic procedures, and evaluate the role, if any, that SARS-CoV-2 infection played in the animals' course of disease and death. Using clinical and diagnostic information collected by state animal health officials, state public health veterinarians, and other state and local partners, this algorithm was applied to each animal case. RESULTS: SARS-CoV-2 was an incidental finding in 8 animals, was suspected to have contributed to the severity of clinical signs leading to euthanasia in 1 dog, and was the primary reason for death for 1 cat. CONCLUSIONS AND CLINICAL RELEVANCE: This report provides the global community with a standardized process for directing case investigations, determining the necessity of certain diagnostic procedures, and determining the clinical significance of SARS-CoV-2 infections in animals with fatal outcomes and provides evidence that SARS-CoV-2 can, in rare circumstances, cause or contribute to death in pets.

First Reported Cases of SARS-CoV-2 Infection in Companion Animals - New York, March-April 2020.

On April 22, CDC and the U.S. Department of Agriculture (USDA) reported cases of two domestic cats with confirmed infection with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). These are the first reported companion animals (including pets and service animals) with SARS-CoV-2 infection in the United States, and among the first findings of SARS-CoV-2 symptomatic companion animals reported worldwide. These feline cases originated from separate households and were epidemiologically linked to suspected or confirmed human COVID-19 cases in their respective households. Notification of presumptive positive animal test results triggered a One Health* investigation by state and federal partners, who determined that no further transmission events to other animals or persons had occurred. Both cats fully recovered. Although there is currently no evidence that animals play a substantial role in spreading COVID-19, CDC advises persons with suspected or confirmed COVID-19 to restrict contact with animals during their illness and to monitor any animals with confirmed SARS-CoV-2 infection and separate them from other persons and animals at home (1).

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

Understanding the ecological and epidemiological roles of pets in the transmission of SARS-CoV-2 is critical for animal and human health, identifying household reservoirs, and predicting the potential enzootic maintenance of the virus. We conducted a longitudinal household transmission study of 76 dogs and cats living with at least one SARS-CoV-2-infected human in Texas and found that 17 pets from 25.6% of 39 households met the national case definition for SARS-CoV-2 infections in animals. This includes three out of seventeen (17.6%) cats and one out of fifty-nine (1.7%) dogs that were positive by RT-PCR and sequencing, with the virus successfully isolated from the respiratory swabs of one cat and one dog. Whole-genome sequences of SARS-CoV-2 obtained from all four PCR-positive animals were unique variants grouping with genomes circulating among people with COVID-19 in Texas. Re-sampling showed persistence of viral RNA for at least 25 d-post initial test. Additionally, seven out of sixteen (43.8%) cats and seven out of fifty-nine (11.9%) dogs harbored SARS-CoV-2 neutralizing antibodies upon initial sampling, with relatively stable or increasing titers over the 2-3 months of follow-up and no evidence of seroreversion. The majority (82.4%) of infected pets were asymptomatic. 'Reverse zoonotic' transmission of SARS-CoV-2 from infected people to animals may occur more frequently than recognized.

SARS-CoV-2 B.1.1.7 variant of concern detected in a pet dog and cat after exposure to a person with COVID-19, USA.

As part of a longitudinal household transmission study of pets living with persons with COVID-19 in Texas, two pets were confirmed to be infected with the SARS-CoV-2 B.1.1.7 variant of concern (VOC). The pets were a dog and a cat from the same household, sampled two days after their owner tested positive for COVID-19. The oral, nasal and fur swabs for both pets tested positive for SARS-CoV-2 by qRT-PCR and consensus whole-genome sequences from the dog and cat were 100% identical and matched the B.1.1.7 VOC. Virus was isolated from the cat's nasal swab. One month after initial detection of infection, the pets were re-tested twice at which time only the fur swabs (both pets) and oral swab (dog only) remained positive, and neutralizing antibodies for SARS-CoV-2 were present in both animals. Sneezing by both pets was noted by the owner in the weeks between initial and follow-up testing. This study documents the first detection of B.1.1.7. in companion animals in the United States, and the first genome recovery and isolation of B.1.1.7 variant of concern globally in any animal.

Animal Reservoirs and Hosts for Emerging Alphacoronaviruses and Betacoronaviruses.

The ongoing global pandemic caused by coronavirus disease has once again demonstrated the role of the family Coronaviridae in causing human disease outbreaks. Because severe acute respiratory syndrome coronavirus 2 was first detected in December 2019, information on its tropism, host range, and clinical manifestations in animals is limited. Given the limited information, data from other coronaviruses might be useful for informing scientific inquiry, risk assessment, and decision-making. We reviewed endemic and emerging infections of alphacoronaviruses and betacoronaviruses in wildlife, livestock, and companion animals and provide information on the receptor use, known hosts, and clinical signs associated with each host for 15 coronaviruses detected in humans and animals. This information can be used to guide implementation of a One Health approach that involves human health, animal health, environmental, and other relevant partners in developing strategies for preparedness, response, and control to current and future coronavirus disease threats.