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

Objective To characterize clinical and epidemiologic features of SARS-CoV-2 in companion animals detected through both passive and active surveillance in the U.S. 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 epidemiological information through a standardized One Health surveillance process developed by 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 post exposure in both cats and dogs. Antibodies were detected starting 5 days post exposure and titers were highest at 9 days in cats and 14 days in dogs. Conclusions and Clinical Relevance Our data support 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 includes both people and animals is necessary to understand transmission dynamics and viral evolution of zoonotic diseases like SARS-CoV-2.

No Evidence of SARS-CoV-2 Among Flies or Cockroaches in COVID-19 Positive Households (preprint)

Background:The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a pandemic of coronavirus disease (COVID-19), which continues to cause infections and mortality worldwide. SARS-CoV-2 is transmitted primarily via the respiratory route and has experimentally been found to be stable on surfaces for multiple days. Flies (Diptera) and other arthropods mechanically transmit several pathogens, including turkey coronavirus. A previous experimental study demonstrated house flies, Musca domestica, can mechanically transmit SARS-CoV-2, but the ability of flies in general to acquire and deposit this virus in natural settings has not been explored. The purpose of this study was to explore the possibility of mechanical transmission of SARS-CoV-2 by peridomestic insects and their potential as a xenosurveillance tool for detection of the virus.Methods:In order to optimize chances of viral detection, flies were trapped in homes where at least one confirmed human COVID-19 case(s) resided. Sticky and liquid baited fly traps were deployed inside and outside of the homes of SARS-CoV-2 human cases in Brazos, Bell, and Montgomery Counties, from June to September 2020. Flies from sticky traps were identified, pooled by taxa, homogenized, and tested for the presence of SARS-CoV-2 RNA using qRT-PCR. Liquid traps were drained, and the collected fluid similarly tested after RNA concentration. Experimental viral detection pipeline and viral inactivation were confirmed in a Biosafety Level 3 lab.  As part of a separate ongoing study, companion animals in the home were sampled and tested for SARS-CoV-2 on the same day of insect trap deployment.Results:We processed the contents of 133 insect traps from 44 homes, which contained over 1,345 individual insects of 11 different Diptera families and Blattodea.These individuals were grouped into 243 pools, and all tested negative for SARS-CoV-2 RNA.  Dead flies exposed to SARS-CoV-2 in a BSL3 lab were processed using the same methods and viral RNA was detected by RT-PCR. Fourteen traps in seven homes were deployed on the day that cat or dog samples tested positive for SARS-CoV-2 RNA by nasal, oral, body, or rectal samples.Conclusions:This study presents evidence that biting and non-biting flies are not likely to contribute to mechanical transmission of SARS-CoV-2 or be useful in xenosurveillance for SARS-CoV-2.

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 (preprint)

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.