The seroprevalence of the newly identified porcine circovirus type 4 in China investigated by an enzymed‐linked immunosorbent assay

Abstract

Porcine circovirus 4 (PCV4) is the fourth porcine circovirus newly identified in China, and it could be detected in diseased and healthy pigs. To date, the prevalence of PCV4 DNA in pig herds has been investigated in many provinces from both China and Korea, with positive rates varied from 3.28% to 25.4% in samples from different regions. However, up to now no serological data have been reported to evaluate the prevalence of PCV4 in pig herds. In this study, an indirect anti-PCV4 IgG enzyme-linked immunosorbent assay (ELISA) based on replicase protein (Rep) was developed and utilized to investigate the seroprevalence of PCV4 in pig herds of China. A total of 1790 swine serum samples from 17 provinces of China were tested including samples confirmed positive for PCV4 DNA. There was no cross-reactivity of this ELISA with PCV1, PCV2 and PCV3. PCV4 Rep antibodies have been detected in serum samples from 16 out of 17 provinces in China. The PCV4 overall seroprevalence was 43.97%, with the highest of 67.8% been detected in sows, followed by fattening and suckling pigs with positive rates of 35.0% and 14.56%, respectively, and the lowest of 12.61% been detected in nursery pigs. Moreover, from the present data, the earliest positive sample could be

Current knowledge on epidemiology and evolution of novel porcine circovirus 4

“…In a serological survey of 1790 serum samples collected from pigs in 17 provinces of China between 2008 and 2020, overall seroprevalence of PCV4 was 43.97% [ 5 ]. PCV4 Rep-specific antibodies were detected in sera from pigs of various ages, with the highest prevalence (67.8%) in sows, and the earliest evidence from a sample collected in 2008 [ 5 ].…”

“…In a serological survey of 1790 serum samples collected from pigs in 17 provinces of China between 2008 and 2020, overall seroprevalence of PCV4 was 43.97% [ 5 ]. PCV4 Rep-specific antibodies were detected in sera from pigs of various ages, with the highest prevalence (67.8%) in sows, and the earliest evidence from a sample collected in 2008 [ 5 ]. In another serological survey of 1048 pig serum samples collected from Jiangsu province of China between 2018 and 2021, 3.44% of samples had PCV4 Cap-specific antibodies [ 27 ].…”

“…PCV4, a newly emerging circovirus, was first identified in 2019 in Hunan, China, in pigs with several clinical disease syndromes, including respiratory and enteric signs as well as porcine dermatitis nephropathy syndrome (PDNS) [ 3 ]. However, in retrospective studies, PCV4 genomic DNA was detected in swine tissue samples collected in 2012 from Henan, China [ 4 ], with some serum samples collected as early as 2008 from Chinese swine positive for PCV4 antibody [ 5 ]. Therefore, there is evidence that PCV4 has been present and circulating in swine herds for more than a decade.…”

Porcine Circovirus Type 4 Strains Circulating in China Are Relatively Stable and Have Higher Homology with Mink Circovirus than Other Porcine Circovirus Types

“…The most recently reported PCV, namely, PCV4, was first identified in Chinese farmed pigs with severe clinical disease in 2019 [ 5 ]. Thereafter, several groups have conducted epidemiological investigations on PCV4 and found that PCV4 also exists widely in pigs [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Kim et al found that the positive rates of PCV4 in individual pig samples and at the farm level were 39.3% and 45.7%, respectively [ 9 ].…”

Development and application of an indirect ELISA for the detection of antibody to porcine circovirus 4 in pigs

“…Zhang, Bai, et al, 2020). Ge et al (2021) performed a serological survey on PCV4 using serum samples collected from 17 provinces of China, and the results showed that the positive rates ranged from 0% to 83.33%, which indicated the widespread of PCV4 in China. Jiangsu province is located at the Yangtze River, an important pig producing area in China.…”