For the first time in the United States, the transmission of COVID-19 from parent to pet is genetically documented in a study by the Translational Genomics Research Institute (TGen), a subsidiary of City of Hope.
The published results of the current study appear in Health. This is one of five nationwide pilot studies examining COVID in animals. The TGen study, however, is the only one to include genomic sequencing of the virus from animal and human samples. This level of testing results from TGen’s overall efforts to monitor the virus and its potentially more dangerous variants by sequencing as many positive human samples of the virus as possible.
In the Arizona case study, the pet owner, cat and dog were all infected with the same strain of coronavirus: B.1.575, an early and commonplace version of SARS-CoV-2, the virus that causes COVID. There are fewer than 25 documented cases of Arizonans infected with this strain, according to information from the COVID variant tracking dashboard that TGen manages for the CDC and ADHS. To date, more than 46,000 positive samples of Arizonans with COVID have been sequenced.
“This case study was the first example we had of the project that demonstrated the likelihood of transmission of the virus from an animal owner to pets in the house,” said lead author Hayley Yaglom.
The researchers deduced that the virus had spread from the animal’s parent to the dog or cat, or both. The animals were confined to an apartment and therefore had little or no opportunity to be exposed to the virus, so it was very unlikely that the animals infected their owner. Additionally, in each case examined in the study, it was the parent of the pet who presented COVID first. Globally, there are no documented cases of transmission of COVID from a pet to its parent.
Researchers were unable to say whether the dog or cat was infected first, or whether one infected the other, although that is a possibility. This particular dog and cat were friends who had close contact with each other, the researchers said.
Including this case study, the Arizona researchers tested 61 pets, 39 dogs and 22 cats, living in 24 households. There have been 14 positive cases of COVID in pets among six of the households.
“This is a great example of using genomics to gain insight into pathogens,” said David Engelthaler of TGen.
“This study shows that we can not only use genomics to help track COVID variants around the world, but we can also use this technology to track exact transmissions, and in this case transmission from pet owners to animals.”
