A cross-sectional serosurvey of SARS-CoV-2 and co-infections in stray cats from the second wave to the sixth wave of COVID-19 outbreaks in Spain

A cross-sectional serosurvey of SARS-CoV-2 and co-infections in stray cats from the second wave to the sixth wave of COVID-19 outbreaks in Spain Sergio Villanueva-Saz 1 2 3, Mariví Martínez 4 5, Jacobo Giner 4 5, Ana González 4 6, Ana Pilar Tobajas 7 8, María Dolores Pérez 7 8, Erandi Lira-Navarrete 9, Andrés Manuel González-Ramírez 9, Javier Macías-León 9, Maite Verde 4 7 6, Andrés Yzuel 4, Ramón Hurtado-Guerrero 9 10 11 12 13, Maykel Arias 14 15, Llipsy Santiago 14 15, Jordi Aguiló-Gisbert 16, Héctor Ruíz 5, Delia Lacasta 5 7, Diana Marteles 4, Antonio Fernández 17 18 19 Vet Res Commun. 2023 Jun;47(2):615-629. doi: 10.1007/s11259-022-10016-7. Epub 2022 Oct 14.

Severe Acute Respiratory Syndrome Coronavirus 2 is the causative agent of Coronavirus Disease 2019 in humans. Among domestic animals, cats are more susceptible to SARS-CoV-2 than dogs. The detection of anti-SARS-CoV-2 antibodies in seemingly healthy cats and/or infected cats which are in close contact with infected humans has been described. The presence of animals that tested positive by serology or molecular techniques could represent a potential transmission pathway of SARS-CoV-2 that can spill over into urban wildlife. This study analyses the seroprevalence variation of SARS-CoV-2 in stray cats from different waves of outbreaks in a geographical area where previous seroepidemiological information of SARS-CoV-2 was available and investigate if SARS-CoV-2-seropositive cats were exposed to other co-infections causing an immunosuppressive status and/or a chronic disease that could lead to a SARS-CoV-2 susceptibility. For this purpose, a total of 254 stray cats from Zaragoza (Spain) were included. This analysis was carried out by the enzyme-linked immunosorbent assay using the receptor binding domain of Spike antigen and confirmed by serum virus neutralization assay. The presence of co-infections including Toxoplasma gondii, Leishmania infantum, Dirofilaria immitis, feline calicivirus, feline herpesvirus type 1, feline leukemia virus and feline immunodeficiency virus, was evaluated using different serological methods. A seropositivity of 1.57% was observed for SARS-CoV-2 including the presence of neutralizing antibodies in three cats. None of the seropositive to SARS-CoV-2 cats were positive to feline coronavirus, however, four SARS-CoV-2-seropositive cats were also seropositive to other pathogens such as L. infantum, D. immitis and FIV (n = 1), L. infantum and D. immitis (n = 1) and L. infantum alone (n = 1).Considering other pathogens, a seroprevalence of 16.54% was detected for L. infantum, 30.31% for D. immitis, 13.78%, for T. gondii, 83.86% for feline calicivirus, 42.52% for feline herpesvirus type 1, 3.15% for FeLV and 7.87% for FIV.Our findings suggest that the epidemiological role of stray cats in SARS-CoV-2 transmission is scarce, and there is no increase in seropositivity during the different waves of COVID-19 outbreaks in this group of animals. Further epidemiological surveillances are necessary to determine the risk that other animals might possess even though stray cats do not seem to play a role in transmission.