Detection of SADS-CoV, PDCoV, TGEV and PEDV in field samples
To determine the prevalence of swine enteropathogenic CoVs in pig farms, a total of 300 serum samples were collected from commercial growing pigs on different farms with reported diarrhea outbreaks from eleven provinces in China from July 1 to September 30, 2020, and all serum samples were tested for presence of anti-SADS-CoV, PDCoV, TGEV and PEDV IgG antibodies using the ELISA kits. As shown in Fig 7, 81.7% (245/300) of the pig serum samples were positive for anti-SADS-CoV IgG antibodies and the IgG positive for TGEV, PDCoV and PEDV were 54% (162/300), 65.3% (196/300), 6% (18/300), respectively. In addition, of 300 pig serum samples examined, 4 (1.3%) were positive for both SADS-CoV and PEDV, 59 (19.7%) were positive for both SADS-CoV and PDCoV, 53 (17.7%) were positive for both SADS-CoV and TGEV. Of note, 11 (3.7%) were positive for SADS-CoV, PEDV, PDCoV and TGEV, indicating that swine enteropathogenic CoVs coinfections exist in pig farms.