High prevalence of SARS-CoV-2 antibodies and low prevalence of SARS-CoV-2 RNA in cats recently exposed to human cases.

BACKGROUND: The primary objective of this cross-sectional study, conducted in Québec and Bristish Columbia (Canada) between February 2021 and January 2022, was to measure the prevalence of viral RNA in oronasal and rectal swabs and serum antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) amongst cats living in households with at least one confirmed human case. Secondary objectives included a description of potential risk factors for the presence of SARS-CoV-2 antibodies and an estimation of the association between the presence of viral RNA in swabs as well as SARS-CoV-2 antibodies and clinical signs. Oronasal and rectal swabs and sera were collected from 55 cats from 40 households at most 15 days after a human case confirmation, and at up to two follow-up visits. A RT-qPCR assay and an ELISA were used to detect SARS-CoV-2 RNA in swabs and serum SARS-CoV-2 IgG antibodies, respectively. Prevalence and 95% Bayesian credibility intervals (BCI) were calculated, and associations were evaluated using prevalence ratio and 95% BCI obtained from Bayesian mixed log-binomial models. RESULTS: Nine (0.16; 95% BCI = 0.08-0.28) and 38 (0.69; 95% BCI = 0.56-0.80) cats had at least one positive RT-qPCR and at least one positive serological test result, respectively. No risk factor was associated with the prevalence of SARS-CoV-2 serum antibodies. The prevalence of clinical signs suggestive of COVID-19 in cats, mainly sneezing, was 2.12 (95% BCI = 1.03-3.98) times higher amongst cats with detectable viral RNA compared to those without. CONCLUSIONS: We showed that cats develop antibodies to SARS-CoV-2 when exposed to recent human cases, but detection of viral RNA on swabs is rare, even when sampling occurs soon after confirmation of a human case. Moreover, cats with detectable levels of virus showed clinical signs more often than cats without signs, which can be useful for the management of such cases.

Risk of transmittable blood-borne pathogens in blood units from blood donor dogs in Canada.

BACKGROUND: Canine blood donors can be infected by various vector-borne or other pathogens that could be an important cause of morbidity and death in transfusion recipients. HYPOTHESIS/OBJECTIVES: To estimate and predict positivity to transmittable blood-borne pathogens in blood units collected from blood donor dogs in Canada. ANIMALS: Six thousand one hundred and fifty blood units from 1914 active blood donors registered to the Canadian Animal Blood Bank (CABB) between March 2010 and December 2016. METHODS: A registry-based retrospective study. Blood units were screened by SNAP 4Dx/4Dx Plus and PCR panel tests. Information on blood donors and test results were extracted from multiple databases and collated. Logistic regressions were used to predict blood unit positivity. RESULTS: Of 1779 blood units, 0.56% were antibody-positive for Anaplasma phagocytophilum/platys and 0% for Ehrlichia canis/ewingii. After exclusion of antibody-positive units to Anaplasma spp., 1.1% of 6140 blood units were PCR-positive to Anaplasma phagocytophilum, Bartonella spp., Brucella canis, "Candidatus Mycoplasma haematoparvum," Mycoplasma haemocanis, or a combination of these pathogens. Babesia spp., Ehrlichia spp., and Leishmania spp. were not detected. Units from the first blood collection from a dog had higher odds of testing PCR-positive (P < .001) for at least 1 pathogen than units from subsequent collections. CONCLUSIONS AND CLINICAL IMPORTANCE: Although our study indicates a low probability of detecting blood-borne pathogen in blood units collected by this Canadian blood bank, the presence of positive units highlights the importance of the preemptive identification and screening of blood units from healthy blood donors for safe blood banking, especially in first-time donors.

Dingo Density Estimates and Movements in Equatorial Australia: Spatially Explicit Mark-Resight Models.

Australia is currently free of canine rabies. Spatio-ecological knowledge about dingoes in northern Australia is currently a gap that impedes the application of disease spread models and our understanding of the potential transmission of rabies, in the event of an incursion. We therefore conducted a one-year camera trap survey to monitor a dingo population in equatorial northern Australia. The population is contiguous with remote Indigenous communities containing free-roaming dogs, which potentially interact with dingoes. Based on the camera trap data, we derived dingo density and home range size estimates using maximum-likelihood, spatially explicit, mark-resight models, described dingo movements and evaluated spatial correlation and temporal overlap in activities between dingoes and community dogs. Dingo density estimates varied from 0.135 animals/km2 (95% CI = 0.127-0.144) during the dry season to 0.147 animals/km2 (95% CI = 0.135-0.159) during the wet season. The 95% bivariate Normal home range sizes were highly variable throughout the year (7.95-29.40 km2). Spatial use and daily activity patterns of dingoes and free-roaming community dogs, grouped over ~3 month periods, showed substantial temporal activity overlap and spatial correlation, highlighting the potential risk of disease transmission at the wild-domestic interface in an area of biosecurity risk in equatorial northern Australia. Our results have utility for improving preparedness against a potential rabies incursion.