Surveillance of SARS-CoV-2 in Pets of Harris County, Texas, Revealed More Common Pet Infections in Households With Human COVID-19 Cases

Abstract

Local health departments can play a critical role in zoonoses surveillance at the human–domestic animal interface, especially when existing public health services and close relationships with community groups can be leveraged. Investigators at Harris County Veterinary Public Health employed a community-based surveillance tool for identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in dogs and cats in June-–December 2021. Diagnosis was made using both RT-qPCR testing of oral and nasal swabs and plaque reduction neutralization testing of serum samples. Recruitment for this free companion animal surveillance program occurred through the following two streams: case-based and event-based. The case-based stream recruited companion animals of confirmed human COVID-19 cases through the Harris County Public Health case investigations platform and used the information from epidemiological investigations of the owners to conduct further investigations of their pet(s). The event-based stream recruited companion animals participating in free or low-cost spay/neuter events at Harris County Pets Resource Center (HCPRC). A total of 97 animals were tested, with the case-based and event-based streams accounting for 36 and 61, respectively. A total of 13 animals (13.4%) tested seropositive including one that also had positive RT-qPCR swabs. Of the positives, 11 (84.6%) were associated with a confirmed human case of SARS-CoV-2 living in the same household including one household with four out of the seven animals positive for SARS-CoV-2 neutralizing antibodies. These two surveillance methods employed at the local level emphasize the importance of the One Health approach and provide a model for future zoonoses surveillance systems.