Abstract
Background and Objectives: Besides highly susceptible farmed minks, the highest number of independent SARS-CoV-2 spillovers is reported in cats and dogs. In addition, some virus variants acquired mutations altering host tropism. We thus assessed the prevalence of SARS-CoV-2 infections in companion animals in Luxembourg and aimed at identifying the factors promoting inter-species transmission to assist authorities in their containment efforts in light of SARS-CoV-2 evolution and variant replacements.
Material and Methods: A total of 220 cats and 264 dogs were recruited in veterinary clinics between October 2020 and April 2021 coinciding with the 3rd (driven by B.1 strains) and 4th (Alpha B.1.1.7 and Beta B.1.351) SARS-CoV-2 waves. Among those, 24.4% of animals were recruited in households with history of SARS-CoV-2 in humans. Serum samples were tested for the presence of anti-SARS-CoV-2 antibodies by a surrogate neutralization assay. Respiratory swabs, rectal swabs and stool samples were tested for the presence of viral RNA by RT-qPCR and positives were sequenced with the Artic protocol on a MinION flow cell. A second cohort of diagnostic leftover samples was collected between April 2020 and March 2022. The cohort included 918 cat and 1572 dog sera tested by
a multiplexed surrogate neutralization assay harbouring recombinant spike proteins from several variants.
Results: In the first cohort, 4/711 samples tested positive by RT-qPCR. All positive animals originated from SARS-CoV-2 affected households. Variants B.1.221, .1.177, B.1 as well as Beta B.1.351 were identified, corresponding to the variants concomitantly circulating in the human population. Prevalence of neutralizing antibodies (NAbs) reached 28.2% (cats: 25.5%; dogs: 30.4%) in SARSCoV-2 affected households. In these households, we did not identify any factors contributing to an increased risk of transmission, likely due to already intensive contacts. In the second cohort, 4.2% of cats and 3.0% of dogs had NAbs. The majority of animal sera had the highest NAb titers against the ancestral B.1 strain (55%), followed by Delta B.1.617.2 (16%), Alpha B.1.1.7 (14%), Omicron B.1.1.529-BA.1 (6%) and Gamma P.1 (4%). Rolling 3-months seroprevalence rates tended to increase over time, likely resulting from increasing opportunities for exposure to the virus and/or lasting presence of NAbs after infection.
Conclusion: Seroprevalence rates were not consistent with increasing transmission rates of variants of concerns to companion animals or sustained animal-to-animal transmission. This study nevertheless highlighted the high frequency of cross-species transmission events in SARS-CoV-2 affected households, regardless of the variants at play. Clear recommendations to affected owners for minimizing transmission to domestic animals are thus warranted.
Material and Methods: A total of 220 cats and 264 dogs were recruited in veterinary clinics between October 2020 and April 2021 coinciding with the 3rd (driven by B.1 strains) and 4th (Alpha B.1.1.7 and Beta B.1.351) SARS-CoV-2 waves. Among those, 24.4% of animals were recruited in households with history of SARS-CoV-2 in humans. Serum samples were tested for the presence of anti-SARS-CoV-2 antibodies by a surrogate neutralization assay. Respiratory swabs, rectal swabs and stool samples were tested for the presence of viral RNA by RT-qPCR and positives were sequenced with the Artic protocol on a MinION flow cell. A second cohort of diagnostic leftover samples was collected between April 2020 and March 2022. The cohort included 918 cat and 1572 dog sera tested by
a multiplexed surrogate neutralization assay harbouring recombinant spike proteins from several variants.
Results: In the first cohort, 4/711 samples tested positive by RT-qPCR. All positive animals originated from SARS-CoV-2 affected households. Variants B.1.221, .1.177, B.1 as well as Beta B.1.351 were identified, corresponding to the variants concomitantly circulating in the human population. Prevalence of neutralizing antibodies (NAbs) reached 28.2% (cats: 25.5%; dogs: 30.4%) in SARSCoV-2 affected households. In these households, we did not identify any factors contributing to an increased risk of transmission, likely due to already intensive contacts. In the second cohort, 4.2% of cats and 3.0% of dogs had NAbs. The majority of animal sera had the highest NAb titers against the ancestral B.1 strain (55%), followed by Delta B.1.617.2 (16%), Alpha B.1.1.7 (14%), Omicron B.1.1.529-BA.1 (6%) and Gamma P.1 (4%). Rolling 3-months seroprevalence rates tended to increase over time, likely resulting from increasing opportunities for exposure to the virus and/or lasting presence of NAbs after infection.
Conclusion: Seroprevalence rates were not consistent with increasing transmission rates of variants of concerns to companion animals or sustained animal-to-animal transmission. This study nevertheless highlighted the high frequency of cross-species transmission events in SARS-CoV-2 affected households, regardless of the variants at play. Clear recommendations to affected owners for minimizing transmission to domestic animals are thus warranted.
Original language | English |
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Pages | 40 |
Number of pages | 1 |
Publication status | Published - 27 Sept 2024 |
Event | 16th EPIZONE Annual Meeting: Viruses, vectors and wildlife - Uppsala, Sweden Duration: 25 Sept 2024 → 27 Sept 2024 |
Conference
Conference | 16th EPIZONE Annual Meeting |
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Country/Territory | Sweden |
City | Uppsala |
Period | 25/09/24 → 27/09/24 |