Porcine Circovirus type 3 and type 4 infection in subsistence pigs

• Grant number: 24/23045-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Luís Guilherme de Oliveira
• Grantee: Ana Beatriz Vieira
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Porcine circoviruses (PCVs) are single-stranded DNA viruses that cause circovirus disease in pigs, affecting multiple systems and negatively impacting pig production, resulting in significant deaths and economic losses. Types 3 (PCV-3) and 4 (PCV-4) are emerging pathogens that can be found in animals in a subclinical form or associated with various clinical syndromes. This study aims to determine the occurrence of these viruses in pigs raised in subsistence systems in the State of Paraná, Brazil. Blood samples will be collected from approximately 400 animals, originating from a seroepidemiological survey for Classical Swine Fever, following actions by the Agricultural Surveillance Agency. In the laboratory, the blood will be centrifuged to obtain blood serum and will subsequently be subjected to DNA extraction using a Tris-HCL protocol. After extraction, sample pools of 10 animals each will be prepared, and then real-time polymerase chain reaction (qPCR) will be performed to detect and quantify PCV-3 and PCV-4 using primers and probes appropriate for each pathogen. In the case of positive pools, a new reaction will be performed with individual samples to detect animals positive for the pathogens. The results obtained regarding the quantification of pathogens by the qPCR technique will be subjected to the normality test with the Shapiro-Wilk test. If the data are normally distributed, analysis of variance (ANOVA) will be performed. In addition, an epidemiological questionnaire will be administered, with dichotomous answers of "yes" or "no" to the producers; and the location of geographic coordinates will be noted for the investigation of risk factors. The results aim to identify the presence and prevalence of viruses, providing information to understand their distribution, pathogenesis and support control and prevention strategies.