Evidence of SARS-CoV-2 infection and co-infections in stray cats in Brazil.

The zoonotic virus SARS-CoV-2, which causes severe acute respiratory syndrome in humans (COVID-19), has been identified in cats. Notably, most positive cases were in cats that had close contact with infected humans, suggesting a role for humans in animal transmission routes. Previous studies have suggested that animals with immune depletion are more susceptible to SARS-CoV-2 infection. To date, there is limited evidence of SARS-CoV-2 infections in stray and free-range cats affected by other pathogens. In this study, we investigated infections caused by SARS-CoV-2, Leishmania spp., Toxoplasma gondii, Mycoplasma spp., Bartonella spp., Feline leukemia virus (FeLV), and Feline immunodeficiency virus (FIV) in stray cats from an urban park in Brazil during the COVID-19 pandemic. From February to September 2021, 78 mixed-breed cats were tested for SARS-CoV-2 and hemopathogens using molecular analysis at Américo Renné Giannetti Municipal Park, Belo Horizonte, Minas Gerais, Brazil. An enzyme-linked immunosorbent assay (ELISA) was used to detect IgG in T. gondii. None of the animals in this study showed any clinical signs of infections. The SARS-CoV-2 virus RNA was detected in 7.7 % of cats, and a whole virus genome sequence analysis revealed the SARS-CoV-2 Delta lineage (B.1.617.2). Phylogenetic analysis showed that SARS-CoV-2 isolated from cats was grouped into the sublineage AY.99.2, which matches the epidemiological scenario of COVID-19 in the urban area of our study. Leishmania infantum was detected and sequenced in 9 % of cats. The seroprevalence of T. gondii was 23.1 %. Hemotropic Mycoplasma spp. was detected in 7.7 % of the cats, with Mycoplasma haemofelis and Candidatus Mycoplasma haemominutum being the most common. Bartonella henselae and Bartonella clarridgeiae were detected in 38.5 % of the cats, FeLV was detected in 17,9 %, and none of the cats studied tested positive for FIV. This study reports, for the first time, the SARS-CoV-2 infection with whole-genome sequencing in stray cats in southeastern Brazil and co-infection with other pathogens, including Bartonella spp. and Feline leukemia virus. Our study observed no correlation between SARS-CoV-2 and the other detected pathogens. Our results emphasize the importance of monitoring SARS-CoV-2 in stray cats to characterize their epidemiological role in SARS-CoV-2 infection and reinforce the importance of zoonotic disease surveillance.

Molecular detection and characterization of SARS-CoV-2 in cats and dogs of positive owners during the first COVID-19 wave in Brazil.

Despite previous reports of SARS-CoV-2 infection in dogs and cats worldwide, the type of swab sample used for its detection through RT-qPCR needs to be better compared and described. Accordingly, as part of a multicenter study in Brazil, the aim of the present study was to assess which rectal or oropharyngeal swabs would be more appropriate for detecting SARS-CoV-2 in cats and dogs, through viral load comparison. Pets of owners diagnosed with COVID-19 in the last 7 days were eligible. A total of 148 animals from four of the five Brazilian geographical regions were analyzed, among which 10/48 cats (20.83%) and 11/100 dogs (11.00%) were positive. The results suggested that oropharyngeal swabs should be considered for SARS-CoV-2 detection, particularly in cats, due to the higher cDNA viral load. Also, the genomic results showed similarities between SARS-CoV-2 animal variants and human variants that were circulating at the time of sampling, thus corroborating the existence of zooanthroponotic transmission. In conclusion, the present study highlighted the importance of SARS-CoV-2 monitoring among cats and dogs, as virus modification may indicate the possibility of mutations in animals and spillover back to owners. Thus, positive individuals should always self-isolate from their pets during COVID-19, to prevent trans-species transmission and mutation.

Molecular detection and characterization of Hepatozoon canis in stray dogs from Cuba.

Canine hepatozoonosis caused by Hepatozoon canis is a worldwide distributed tick-borne disease of domestic and wild canids that is transmitted by ingestion of Rhipicephalus sanguineus sensu lato (s.l.) ticks. The present study was aimed to determine the prevalence of Hepatozoon infections in 80 stray dogs from Havana Province in Cuba, and to confirm the species identity and phylogenetic relationships of the causative agent. Samples were screened by microscopical examination of thin blood smears for the presence of Hepatozoon spp. gamonts and by genus-specific SYBR green-based real-time PCR assay targeting the 18S rRNA gene. Direct microscopy examination revealed Hepatozoon gamonts in the peripheral blood of 8 dogs (10.0%; 95% CI: 4.80-18.0%), while 38 animals (47.5%; 95% CI: 36.8-58.4%) were PCR-positive, including all microscopically positive dogs. Hence, the agreement between the two detection methods was 'poor' (κ = 0.20). Hematological parameters did not differ significantly between PCR-positive and PCR-negative dogs (p > 0.05). The DNA sequences of the 18S rRNA gene of the Hepatozoon spp. from Cuban dogs showed a nucleotide identity >99% with those of 18S rRNA sequences of Hepatozoon canis isolates from Czech Republic, Brazil and Spain. Phylogenetic analysis revealed that obtained sequences clustered within the Hepatozoon canis clade, different from the Hepatozoon felis or Hepatozoon americanum clades. The present study represents the first molecular characterization of Hepatozoon canis in stray dogs within Cuba.