Frequency of PCV-2 viremia in nursery piglets from a Spanish swine integration system in 2020 and 2022 considering PRRSV infection status

Mònica Sagrera; Laura Garza-Moreno; Marina Sibila; Salvador Oliver-Ferrando; Sonia Cárceles; Carlos Casanovas; Patricia Prieto; Alberto García-Flores; David Espigares; Joaquim Segalés

doi:10.1186/s40813-024-00354-0

Frequency of PCV-2 viremia in nursery piglets from a Spanish swine integration system in 2020 and 2022 considering PRRSV infection status

Porcine Health Manag. 2024 Jan 16;10(1):4. doi: 10.1186/s40813-024-00354-0.

Authors

Mònica Sagrera^#^{1

2

3}, Laura Garza-Moreno^#³, Marina Sibila^{1

2

4}, Salvador Oliver-Ferrando³, Sonia Cárceles³, Carlos Casanovas³, Patricia Prieto⁵, Alberto García-Flores⁵, David Espigares³, Joaquim Segalés^{6

7

8}

Affiliations

¹ IRTA. Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de La UAB, 08193, Bellaterra, Cerdanyola del Vallès, Spain.
² Unitat Mixta d'Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), Campus de la Universitat Autònoma de Barcelona (UAB), 08193, Bellaterra, Barcelona, Spain.
³ Ceva Salud Animal, Avenida Diagonal, 609-615, 08028, Barcelona, Spain.
⁴ WOAH Collaborating Center for Research and Control of Emerging and Re-Emerging Pig Diseases (IRTA-CReSA), 08193, Bellaterra, Barcelona, Spain.
⁵ Inga Food S.A., Ronda de Poniente, 9, 28760, Tres Cantos, Madrid, Spain.
⁶ Unitat Mixta d'Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), Campus de la Universitat Autònoma de Barcelona (UAB), 08193, Bellaterra, Barcelona, Spain. Joaquim.segales@irta.cat.
⁷ WOAH Collaborating Center for Research and Control of Emerging and Re-Emerging Pig Diseases (IRTA-CReSA), 08193, Bellaterra, Barcelona, Spain. Joaquim.segales@irta.cat.
⁸ Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, UAB, 08193, Bellaterra, Barcelona, Spain. Joaquim.segales@irta.cat.

^# Contributed equally.

Abstract

Background: Porcine circovirus 2 (PCV-2) poses a significant economic threat for the swine industry, causing a range of diseases collectively referred to as porcine circovirus diseases (PCVDs). Despite PCV-2 vaccine effectiveness, the need for monitoring infectious pressure remains. PCV-2 coinfection with other pathogens like porcine reproductive and respiratory syndrome virus (PRRSV) can exacerbate disease severity and lead to PCV-2-systemic disease cases. Monitoring both PRRSV and PCV-2 in co-infected farms is crucial for an effective management and vaccination programs. The present cross-sectional study aimed to determine PCV-2 antibody levels in piglets at weaning and PCV-2 and PRRSV viremia in pooled serum samples at weaning (vaccination age) and at 6 and 9 weeks of age from a Spanish swine integration system in 2020 (48 farms) and in 2022 (28 out of the 48 analysed previously).

Results: The frequency of PCV-2 detection in pools of piglet sera was 2.1% (2020) and 7.1% (2022) at vaccination age but increased at the end of the nursery period (10.4% in 2020 and 39.3% in 2022) in both years. Co-infections between PCV-2 and PRRSV were detected in a significant proportion of PRRSV positive farms (15% in 2020, and 60% in 2022). PCV-2 antibody levels (ELISA S/P ratios) at weaning were lower in PCV-2 qPCR positive farms at different sampling time-points (0.361 in 2020 and 0.378 in 2022) compared to PCV-2 qPCR negative ones (0.587 in 2020 and 0.541 in 2022). The 28 farms tested both years were classified in four different epidemiological scenarios depending on their PCV-2 virological status. Those PCV-2 qPCR negative farms in 2020 that turned to be positive in 2022 had a statistically significant increase of PRRSV RT-qPCR detection and a PCV-2 antibody levels reduction, facts that were not observed in the rest of the scenarios.

Conclusion: This epidemiological study in farms from the same integration system determined the occurrence, in 2020 and in 2022, of PCV-2 and PRRSV infections in piglets during the nursery period by using pooled serum samples.

Keywords: Detection frequency; Porcine circovirus 2 (PCV-2); Porcine reproductive and respiratory syndrome virus (PRRSV); Spain; Viremia.