PCV3-associated disease in the United States swine herd

Abstract

Porcine circovirus-associated disease encompasses multiple disease syndromes including porcine circovirus 2 systemic diseases, reproductive failure, and porcine dermatitis and nephropathy syndrome. Until recently, porcine circovirus 2 was the only species associated with the porcine circovirus-associated disease. In this report, diagnostic investigations of thirty-six field cases submitted from multiple production systems, numerous sites and varied geographic locations demonstrated porcine circovirus 3 within lesions by in situ hybridization including fetuses with myocarditis, weak-born neonatal piglets with encephalitis and myocarditis, from cases of porcine dermatitis and nephropathy syndrome, and in weaned pigs with systemic periarteritis. Porcine circovirus 3 was detected by PCR in numerous fetuses and perinatal piglets at high viral loads (trillions of genome copies per mL of tissue homogenate). Samples from all cases in this study were assayed and found negative for porcine circovirus 2 by PCR. Metagenomic sequencing was performed on a subset of reproductive cases, consisting of sixteen fetuses/fetal sample pools. PCV3 was identified in all pools and the only virus identified in fourteen pools. Based on these data, porcine circovirus 3 is considered a putative cause of reproductive failure, encephalitis and myocarditis in perinatal piglets, porcine dermatitis and nephropathy syndrome, and periarteritis in swine in the United States.

WITHDRAWN: Identification of Porcine circovirus type (PCV2) and type 3 (PCV3), Porcine 2 parvovirus (PPV) in swine by multiplex PCR test

“…Since its initial identification in the US [1], PCV3 has been subsequently, but almost simultaneously, found in vavious pig-producing countries. The 39.4% detection rate for PCV3 in our study was also comparable to other reports elsewhere, such as 44.2% in Korea [32]; 31.18% in Central China [33]; 50% in Germany [34]; 56.4%, 37.4%, 14.8% in Denmark, Italy, Spain respectively [35]; 61.1% in United States [36]; and 47.8% in Brazil [37]. It is therefore possible that this virus had already emerged and spread through the global swine population before it was discovered in the US.…”

Genotyping Porcine Circovirus 3 (PCV-3) Nowadays: Does It Make Sense?

“…Nevertheless, the virus has also been detected in healthy animals [7]. Therefore, at the present state, although there are strong suspicions of associations with reproductive disease and multisystemic inflammation [8], the causative role of PCV-3 in the observed clinical conditions has not been confidently defined [9]. In addition, the circulation of strains with different virulence has not been reported.…”

Lack of Porcine circovirus 4 Genome Detection in Pig Samples from Italy and Spain

“…Despite less stringent evidence currently being available on its pathogenic role, a strong suspicion of association with reproductive disease and multisystemic inflammation is mounting [8]. Both PCV-2 and PCV-3 are frequently detected in asymptomatic animals [3,5,9,10], testifying the multifactorial nature of the disease and the need of co-factors (environmental, managerial, co-infections and host-related ones) for overt clinical signs development [11].…”