key: cord-0929112-se8g79j2 authors: Dong, Nan; Fang, Liurong; Zeng, Songlin; Sun, Qianqian; Chen, Huanchun; Xiao, Shaobo title: Porcine Deltacoronavirus in Mainland China date: 2015-12-03 journal: Emerg Infect Dis DOI: 10.3201/eid2112.150283 sha: 0c4bfbf56443b6d80e018f40564789037ce69418 doc_id: 929112 cord_uid: se8g79j2 nan 110 (51.2%) were positive for PEDV, and 5 (2.3%) were positive for TGEV. Of the 14 PDCoV-positive samples, 7 (50%) were also positive for PEDV; 2 of the 215 samples were co-infected with PEDV, TGEV, and PDCoV (online Technical Appendix Table 1 ). Previous studies have shown that prevalence of PDCoV in the midwestern United States in 2014 was high (30%) and that PDCoV co-infections with other pathogens (such as PEDV and rotavirus) are more common (78% of PDCoV infections) (4) . At the same time in mainland China, the rate of PDCoV positivity was lower (7.27%), whereas that of PEDV was higher (52.73%), suggesting that PEDV remains the main causative agent of piglet diarrhea diseases in mainland China. Similarly, in South Korea in 2014, only 2 PDCoV-positive samples were detected in 113 samples of diarrhea from pigs (6) . We also examined the collection dates and geographic locations of the PDCoV-positive samples and found that PD-CoV was detected in pigs in Hubei (8/124), Jiangsu (4/81), and Anhui (2/6) Provinces. However, all samples from pigs in Guangxi Province were negative for PDCoV. All PDCoVpositive samples from Hubei and Jiangsu Provinces had been collected in 2014, whereas the 2 PDCoV-positive samples from Anhui Province had been collected in 2004. Among the PDCoV-positive samples, we selected 3 for complete genome sequencing with 16 pairs of overlapping primers, as described previously (2) Figure) . Although all reported PDCoV strains from China shared high similarity with each other, a phylogenetic tree based on all available complete PDCoV genome sequences showed that these PDCoV strains clearly cluster in different clades (Figure) . As an emerging virus, PDCoV has been poorly understood. Our data suggest that PDCoV has existed in mainland China for at least 11 years. Although the rate of PDCoV infection detected in mainland China in this study was relatively low, the results may not accurately reflect the prevalence of PDCoV in mainland China because the tested samples were collected from only 4 provinces. Extensive surveillance is required to define the epidemiology and evolution of PDCoV in mainland China. Recent confirmation that PDCoV is enteropathogenic in gnotobiotic pigs (9) highlights the need for effective vaccines against this emerging virus. Discovery of seven novel mammalian and avian coronaviruses in the genus Deltacoronavirus supports bat coronaviruses as the gene source of Alphacoronavirus and Betacoronavirus and avian coronaviruses as the gene source of Gammacoronavirus and Deltacoronavirus Detection and genetic characterization of deltacoronavirus in pigs Porcine coronavirus HKU15 detected in 9 US states Rapid detection, complete genome sequencing, and phylogenetic analysis of porcine deltacoronavirus Full-length genome sequence of porcine deltacoronavirus strain USA/IA/2014/8734 Complete genome characterization of Korean porcine deltacoronavirus strain KOR/KNU14-04/2014 Outbreak of porcine epidemic diarrhea in suckling piglets Complete genome sequence of porcine epidemic diarrhea virus strain AJ1102 isolated from a suckling piglet with acute diarrhea in China Pathogenicity of 2 porcine deltacoronavirus strains in gnotobiotic pigs