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Detection Rate of Porcine Circoviruses in Different Ages and Production Herds of Intensive Pig Farms in China
by
Mingyu Fan
1,2,†,
Zhiqiang Hu
3,†,
Lujie Bian
4,
Yunzhou Wang
5,
Xiaoyang Zhang
5,
Xiaowen Li
1,4,6,* and
Xinglong Wang
1,* 1
College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China
2
Shandong Swine-Health-Station Agriculture and Animal Husbandry Technology Co., Ltd., Dezhou 253000, China
3
Key Laboratory of Animal Epidemic Disease Detection and Prevention in Panxi District, College of Animal Science, Xichang University, Xichang 615013, China
4
Shandong Engineering Research Center of Pig and Poultry Health Breeding and Important Infectious Disease Purification, Shandong New Hope Liuhe Group Co., Ltd., Qingdao 266100, China
5
Department of Veterinary Medicine, Shandong Vocational Animal Science and Veterinary College, Weifang 261061, China
6
College of Agriculture and Biology, Liaocheng University, Liaocheng 252000, China
*
Authors to whom correspondence should be addressed.
†
These authors have contributed equally to this work.
Animals 2025, 15(10), 1376; https://doi.org/10.3390/ani15101376
Submission received: 3 April 2025
/
Revised: 1 May 2025
/
Accepted: 7 May 2025
/
Published: 9 May 2025
(This article belongs to the Special Issue Pathogenesis, Immunology and Epidemiology of Veterinary Viruses)
Simple Summary
Porcine circoviruses (PCV1, PCV2, PCV3, and PCV4) are prevalent in China, with PCV2 and PCV3 being most frequently associated with clinical disease and contributing to substantial economic losses in pig farming. This study aimed to examine the infection characteristics of PCVs across different age groups in intensive pig farming operations in China. In samples of suckling pig testicular fluid, PCV3 exhibited the highest detection rate at 75.4%, followed by PCV1 at 56.9%, PCV2 at 31.1%, and PCV4 at 2.2%. At the individual level, PCV1 detection was lowest in nursery pigs. The detection rate of PCV2 was highest in fattening pigs and lowest in sows. Conversely, PCV3 infection was least prevalent in fattening pigs (8.1%) and most prevalent in sows (46.1%). PCV4 was infrequently detected across all age categories. Furthermore, the incidence of mixed infections involving the four PCV types was 12.7% in nursery pigs, 16.8% in fattening pigs, and 22.4% in sows. However, no strong correlation was identified between any two co-detected PCV types across all age groups. This study provides critical reference data for the formulation of strategies aimed at preventing PCV infections in pig farms.
Abstract
Porcine circoviruses (PCVs), encompassing porcine circovirus type 1 (PCV1), porcine circovirus type 2 (PCV2), porcine circovirus type 3 (PCV3), and porcine circovirus type 4 (PCV4), have been documented in China and represent a significant threat to the swine industry. Nevertheless, there is a paucity of data regarding the infection characteristics of PCVs across different age groups within intensive pig farming operations. In this investigation, a systematic cross-sectional methodology was employed to collect 415 testicular processing fluid samples and 1583 serum samples from 30 breeding farms and 27 fattening farms in China. All samples underwent analysis using real-time quantitative polymerase chain reaction (qPCR). Among the testicular fluid samples from suckling pigs, the detection rates for PCV1, PCV2, PCV3, and PCV4 were 56.9%, 31.1%, 75.4%, and 2.2%, respectively. The lowest mean cycle threshold (Ct) values for PCV1 and PCV3 were observed in testicular fluid as opposed to serum samples. At the individual level, the detection rate of PCV1 was significantly higher in fattening pigs (28.7%) and sows (28.7%) compared to nursery pigs (8.5%). The detection rate of PCV2 was highest in fattening pigs (43.1%) and lowest in sows (19.2%). The infection profile of PCV3 contrasted markedly with that of PCV2, exhibiting the lowest prevalence in fattening pigs (8.1%) and the highest in sows (46.1%). PCV4 was infrequently detected across all age groups, with prevalence rates ranging from 0% to 1.7%. Furthermore, the incidence of mixed infections involving the four PCV types was observed to be 12.7% in nursery pigs, 16.8% in fattening pigs, and 22.4% in sows. Notably, no strong correlation was identified between any two co-detected PCV types across all pig age categories. The findings of this study contribute valuable insights into the infection dynamics of PCVs across different pig age groups. Additionally, this research offers critical reference information for devising strategies to prevent PCV infections in intensive pig farming operations in China.
