Seroprevalence of anti-SARS-CoV-2 antibodies in household domestic ferrets (Mustela putorius furo) in Spain, 2019–2023

Abstract

SARS-CoV-2 is the causal agent of Coronavirus Disease 2019 (COVID-19) in humans that emerged in late 2019. This virus is able to infect humans and different animal species. Among pets, cats and ferrets are more susceptible to be infected by the SARS-CoV-2. Epidemiological studies are an important tool to provide information under natural conditions of exposure to SARS-CoV-2 virus. In comparison to cats, limited epidemiological studies have been performed in domestic ferrets (Mustela putorius furo) reporting the presence of antibodies in this species. This study analysed the presence of anti-SARS-CoV-2 antibodies in 432 cliend-owned ferrets from different geographical areas of Spain during the different waves of COVID-19 outbreaks from December 2019 to May 2023 (42 months). For this purpose, anti-SARS-CoV-2 antibodies were detected by an enzyme-linked immunosorbent method (ELISA) using the receptor binding domain (RBD) of Spike antigen and confirmed by serum virus neutralization assay. Eighteen of the 432 ferrets included were seroreactive by the in-house ELISA (4.17%, 95% Confidence Interval (CI): 2.65–6.49). In this sense, the wave of COVID-19 with the higher number of seropositive ferrets occurred during the seventh wave when the different Omicron subvariants were the dominant virus variants. Our results suggest that the risk of SARS-CoV-2 transmission in domestic ferrets in natural conditions is low. Further research is need to evaluate the potential risk of transmission of SARS-CoV-2 from human to pets.

Molecular and Serological Studies on Potential SARS-CoV-2 Infection among 43 Lemurs under Human Care—Evidence for Past Infection in at Least One Individual

“…The fact that only one animal was seropositive could raise doubts about the origin of the RBD used in the ELISA, which comes from the ancestral variant (Wuhan), not being the most prevalent variant during the study period. However, the application of this same technique in ferrets during the same study period (with Omicron being the most prevalent) and the detection of several seropositive cases confirm that, in this instance, it did not interfere with the results [ 24 ]. Furthermore, it is crucial to emphasize the absence of available information regarding the pattern of anti-SARS-CoV-2 antibodies and cross-reactivity across different SARS-CoV-2 virus variants in the majority of wildlife species.…”

“…To the best of our knowledge, the present study represents the first report of a thorough study of captive lemur populations concerning SARS-CoV-2 infection, conducted on two distinct species of lemurs, ring-tailed lemur ( L. catta ) and black-and-white ruffed lemurs ( V. variegata ), kept in proper care in a highly visited zoological institution. Moreover, this investigation has introduced serological diagnostic methodologies [ 24 , 25 ] into these specific lemur species, filling a void in which there was only one report of serological study in a single wild ruffed lemur as a part of a serological survey of many different types of animals [ 22 ].…”

“…An indirect enzyme-linked immunosorbent assay (ELISA) that detects IgG recognizing the receptor-binding domain (RBD) of the spike protein (S) of SARS-CoV-2 virus (ancestral SARS-CoV-2 strain, Wuhan strain) in multiple animal species was used as previously described [ 24 , 25 ]. Unfortunately, despite the prevailing presence of the SARS-CoV-2 Omicron variant (B.1.1.529) during our study period, this specific variant was not accessible in our laboratory for analysis.…”

“…Unfortunately, despite the prevailing presence of the SARS-CoV-2 Omicron variant (B.1.1.529) during our study period, this specific variant was not accessible in our laboratory for analysis. However, this limitation did not hinder the detection of seropositive ferrets using the same technique within the study period in a previous work [ 24 ]. The sera under study were used at 1:100 dilution, utilizing for detection Pierce recombinant protein A/G conjugated to horseradish peroxidase (ref.…”

“…32490 from Thermo Fisher Scientific, Waltham, MA, USA) diluted 1:100,000, with colorimetric detection of the peroxidase activity at 492 nm on a Multiskan ELISA reader (Labsystems, Midland, ON, Canada) using ortho-phenylene-diamine as a peroxidase substrate. Each 96-well plate included a positive control, consisting of sera from previously identified seropositive ferret [ 24 ] and cat [ 25 ], as well as serum from a healthy, non-infected lemur obtained before the COVID-19 pandemic as a negative control.…”