Serological evidence of SARS‐CoV‐2 and co‐infections in stray cats in Spain

Abstract

A new coronavirus known as SARS‐CoV‐2 emerged in Wuhan in 2019 and spread rapidly to the rest of the world causing the pandemic disease named coronavirus disease of 2019 (COVID‐19). Little information is known about the impact this virus can cause upon domestic and stray animals. The potential impact of SARS‐CoV‐2 has become of great interest in cats due to transmission among domestic cats and the severe phenotypes described recently in a domestic cat. In this context, there is a public health warning that needs to be investigated in relation with the epidemiological role of this virus in stray cats. Consequently, in order to know the impact of the possible transmission chain, blood samples were obtained from 114 stray cats in the city of Zaragoza (Spain) and tested for SARS‐CoV‐2 and other selected pathogens susceptible to immunosuppression including Toxoplasma gondii, Leishmania infantum, feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) from January to October 2020. Four cats (3.51%), based on enzyme‐linked immunosorbent assay (ELISA) using the receptor binding domain (RBD) of Spike antigen, were seroreactive to SARS‐CoV‐2. T. gondii, L. infantum, FeLV and FIV seroprevalence was 12.28%, 16.67%, 4.39% and 19.30%, respectively. Among seropositive cats to SARS‐CoV‐2, three cats were also seropositive to other pathogens including antibodies detected against T. gondii and FIV (n = 1); T. gondii (n = 1); and FIV and L. infantum (n = 1). The subjects giving positive for SARS‐CoV‐2 were captured in urban areas of the city in different months: January 2020 (2/4), February 2020 (1/4) and July 2020 (1/4). This study revealed, for the first time, the exposure of stray cats to SARS‐CoV‐2 in Spain and the existence of concomitant infections with other pathogens including T. gondii, L. infantum and FIV, suggesting that immunosuppressed animals might be especially susceptible to SARS‐CoV‐2 infection.

SARS-CoV-2 neutralising antibodies in Dogs and Cats in the United Kingdom

“…Experimental infections have shown that cats and, to a lesser extent, dogs are susceptible to SARS-CoV-2 and that cats can transmit the virus to other cats [18][19][20]. Infections in companion animals appear to have occurred as a result of human-toanimal transmission; however, the reported transmission of SARS-CoV-2 from farmed mink to in-contact humans, cats and dogs [21,22] and the detection of the virus in stray dogs and cats [23,24], suggest it is important to continue surveillance in companion animals. Here we conducted a survey of SARS-CoV-2 neutralising antibodies in cats and dogs attending UK veterinary practices.…”

Absence of SARS-CoV-2 Antibodies in Natural Environment Exposure in Sheep in Close Contact with Humans

“…Moreover, SARS-CoV-2 titration and micro-neutralization assays are labor-intensive and expensive, requiring trained personnel with specific laboratory requirements such as culture areas and biosafety cabinets. ELISA techniques are widely used in this type of seroepidemiological survey performed in animals to detect the presence of anti-SARS-CoV-2 antibodies [2,3,14,24].…”

“…An in-house indirect ELISA was established for the detection of IgG specific for RBD of the spike protein [2,3]. Ninety-six-well plates were coated overnight, at 4 • C with 100 ng RBD protein in phosphate-buffered saline (PBS).…”

“…Animal infection associated with SARS-CoV-2 has been described in both natural conditions and experimental infections, including dogs, ferrets, cats, lions and minks, among others [1]. Moreover, exposure to SARS-CoV-2 in the absence of clinical signs has been recently described in Spain in stray cats [2] and household ferrets [3].…”

Seroepidemiology of Toxoplasma gondii in wild ruminants in Spain

“…Unfortunately, there is almost no information on T. gondii in felids in BR1 (Sobrino et al, 2007), and no large-scale studies have been carried out to assess T. gondii distribution in these species in this area of the country. Because most of the sampling sites of the present study were located far from urban areas, feral and wild felines that (Sparkes et al, 2013)] has been shown to be high in mainland Spain, ranging between 12.3% and 52% (Millán et al, 2009;Villanueva-Saz et al, 2021). Although some studies have shown that seroprevalence to T. gondii in the endangered Iberian lynx (Lynx pardinus) is high in Spain, ranging between 44.0% and 81.5% (Roelke et al, 2008;Sobrino et al, 2007), its spatial distribution in south and central Spain could not have affected the high seroprevalence observed in wild ruminants in northern Spain.…”