SARS-CoV-2 surveillance in a veterinary health system provides insight into transmission risks.

OBJECTIVE: To investigate the prevalence and seropositivity of SARS-CoV-2 in companion and exotic animals in a veterinary healthcare system. SAMPLE: A total of 341 animals were sampled by a combination of oral and nasal swabs. Serum from whole blood was collected from a subset of animals (86 canines, 25 felines, and 6 exotic animals). METHODS: After informed owner consent, convenience samples from client-owned animals and the pets of students and staff members associated with Colorado State University's Veterinary Health System were collected between May 2021 and September 2022. Study samples were collected by trained veterinarians, Veterinary Health System staff, and veterinary students. RESULTS: SARS-CoV-2 RNA was detected by reverse transcription PCR in 1.6% (95% CI, 0.5% to 4.6%) of domestic canines and 1.1% (95% CI, 0.2% to 6.1%) of domestic felines. No RNA was detected in any of the exotic animal species tested (n = 66). Plaque reduction neutralization tests indicated that 12.8% (95% CI, 7.3% to 21.5%) of canines and 12.0% (95% CI, 4.2% to 30.0%) of felines had neutralizing antibodies against SARS-CoV-2. CLINICAL RELEVANCE: This study provides insight regarding SARS-CoV-2 spillover in domestic companion and exotic animals and contributes to our understanding of transmission risk in the veterinary setting.

Comprehensive Immune Profiling Reveals CD56+ Monocytes and CD31+ Endothelial Cells Are Increased in Severe COVID-19 Disease.

Immune response dysregulation plays a key role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis. In this study, we evaluated immune and endothelial blood cell profiles of patients with coronavirus disease 2019 (COVID-19) to determine critical differences between those with mild, moderate, or severe COVID-19 using spectral flow cytometry. We examined a suite of immune phenotypes, including monocytes, T cells, NK cells, B cells, endothelial cells, and neutrophils, alongside surface and intracellular markers of activation. Our results showed progressive lymphopenia and depletion of T cell subsets (CD3+, CD4+, and CD8+) in patients with severe disease and a significant increase in the CD56+CD14+Ki67+IFN-γ+ monocyte population in patients with moderate and severe COVID-19 that has not been previously described. Enhanced circulating endothelial cells (CD45-CD31+CD34+CD146+), circulating endothelial progenitors (CD45-CD31+CD34+/-CD146-), and neutrophils (CD11b+CD66b+) were coevaluated for COVID-19 severity. Spearman correlation analysis demonstrated the synergism among age, obesity, and hypertension with upregulated CD56+ monocytes, endothelial cells, and decreased T cells that lead to severe outcomes of SARS-CoV-2 infection. Circulating monocytes and endothelial cells may represent important cellular markers for monitoring postacute sequelae and impacts of SARS-CoV-2 infection during convalescence and for their role in immune host defense in high-risk adults after vaccination.