Lippke Ricardo T, De Conti Elisa R, Hernig Luciana F, Teixeira Angélica P, de Quadros Fernando A, Fiúza Aparecida T, Pereira Juliana B, Ulguim Rafael da Rosa, Barcellos David E S N, Takeuti Karine Ludwig
Boehringer-Ingelheim Animal Health do Brasil, São Paulo, Brazil.
Setor de Suínos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Front Vet Sci. 2024 Apr 8;11:1368644. doi: 10.3389/fvets.2024.1368644. eCollection 2024.
Porcine circovirus type 2 (PCV-2) is the agent of one of the most important diseases in the swine industry. Although it has been controlled through vaccination, viremic piglets at birth may represent a risk by reducing vaccination efficacy. Since there are few reports on the viremic status of pre-suckling piglets regarding PCV-2 infection, we assessed the PCV-2 frequency in sows housed in 18 breeding farms with no history of clinical PCVAD in Brazil, using placental umbilical cord serum (PUCS). The selection criteria were: breeding farms with more than 1,000 sows; sows not vaccinated for PCV-2 at least for 2 years prior to the study; farms with no history of PCV-2 clinical disease in the last 12 months; and production systems with a maximum of two sites. Blood from the umbilical cords in sow placenta or directly from piglet's immediately after birth was collected from 30 litters on each farm for PCR. In addition, blood from 538 sows was collected for PCV-2 antibody detection. A total of 17.29% of the PUCS tested positive. The PCV-2 DNA was detected in PUCS from 94.4% of all farms. A total of 94.8% of the sows was positive for PCV-2 antibodies. However, seronegative sows were detected in 44.4% of farms. All 18 farms had at least 46.9% seropositive dams. A higher percentage of seronegative sows was observed for farms with more than 10% of PCV-2-positive litters compared to those with ≤10% of PCV-2 positive litters (8.9 +/-1.7% vs. 1.5 +/- 0.7%, < 0.01, respectively).
猪圆环病毒2型（PCV - 2）是养猪业中最重要疾病之一的病原体。尽管通过疫苗接种已对其进行控制，但出生时处于病毒血症状态的仔猪可能会因降低疫苗接种效果而带来风险。由于关于哺乳前仔猪PCV - 2感染的病毒血症状况的报道较少，我们使用胎盘脐带血清（PUCS）评估了巴西18个无临床PCVAD病史的种猪场中母猪的PCV - 2感染频率。选择标准为：种猪场母猪数量超过1000头；在研究前至少2年未接种PCV - 2疫苗的母猪；过去12个月内无PCV - 2临床疾病病史的猪场；以及最多两个场地的生产系统。从每个猪场的30窝仔猪中采集母猪胎盘脐带血或仔猪出生后立即采集的血样用于PCR检测。此外，采集538头母猪的血样用于PCV - 2抗体检测。共17.29%的PUCS检测呈阳性。在所有猪场中，94.4%的PUCS检测到PCV - 2 DNA。共94.8%的母猪PCV - 2抗体呈阳性。然而，在44.4%的猪场中检测到血清阴性母猪。所有18个猪场中至少有46.9%的母畜血清呈阳性。与PCV - 2阳性仔猪比例≤10%的猪场相比，PCV - 2阳性仔猪比例超过10%的猪场中血清阴性母猪的比例更高（分别为8.9±1.7%和1.5±0.7%，P＜0.01）。
