Piginveszt Ltd., Tótkomlós, Hungary.
National PRRS Eradication Committee, Budapest, Hungary.
Acta Vet Scand. 2022 May 7;64(1):12. doi: 10.1186/s13028-022-00630-5.
Porcine reproductive and respiratory syndrome virus (PRRSV) causes severe economic losses worldwide and only four countries in Europe are free from PRRSV. Complete depopulation-repopulation is the safest and fastest, but also the most expensive method for eradicating PRRSV from a population. Another possible way to eliminate an endemic PRRSV infection is to replace the infected breeding stock by gilts reared isolated and protected from PRRSV on an infected farm. With this method it is possible to maintain continuous production on the farm. The authors report the first successful elimination of PRRSV in a Hungarian large-scale pig farm by using an inactivated vaccine and performing segregated rearing of the offspring.
The study was performed on a PRRSV infected farm (Farm A) with 1475 sows. The clinical signs of reproductive failure had been eliminated previously by using an inactivated vaccine (Progressis, Ceva). At the beginning of the elimination programme, gilts intended for breeding were vaccinated at 60 and 90-100 days of age. After that, gilts selected for breeding were vaccinated at 6 months of age, on the 60-70th day of pregnancy and at weaning. Approximately 1200 piglets from vaccinated sows were transported at 7 weeks of age to a closed, empty farm (Farm B) after being tested negative for PRRSV by a polymerase chain reaction (PCR) method, and then were reared here until 14 weeks of age. At this age, all pigs were tested by PRRS ELISA. Seronegative gilts (n = 901) were subsequently transported from Farm B to a third, closed and empty farm (Farm C), and (having reached the breeding age) they were inseminated here after a second negative serological test (ELISA). At the same time, Farm A was depopulated, cleaned and disinfected. All pregnant gilts were transported from Farm C to Farm A after being re-tested negative for antibodies against PRRSV. Follow-up serology tests were performed after farrowing and results yielded only seronegative animals. Based on the subsequent negative test results, the herd was declared PRRSV free by the competent authority.
The presented farm was the first during the National PRRS Eradication Programme of Hungary to eradicate PRRSV successfully by vaccinating the sows with an inactivated vaccine and performing segregated rearing of the offspring. Production was almost continuous during the whole process of population replacement.
猪繁殖与呼吸综合征病毒（PRRSV）在全球范围内造成严重的经济损失，仅有 4 个欧洲国家没有 PRRSV。完全清群-重新引种是最安全、最快的根除 PRRSV 的方法，但也是最昂贵的方法。另一种可能根除地方性 PRRSV 感染的方法是用在受感染的农场中单独隔离和保护的后备母猪替换受感染的繁殖母猪。使用这种方法，可以在农场中维持连续生产。作者报告了首例通过使用灭活疫苗并对后代进行隔离饲养，在匈牙利的一个大型养猪场成功根除 PRRSV。
该研究在一个感染 PRRSV 的农场（A 场）进行，该农场有 1475 头母猪。以前通过使用灭活疫苗（Progressis，Ceva）消除了繁殖失败的临床症状。在根除计划开始时，后备母猪在 60 日龄和 90-100 日龄时接种疫苗。此后，选择用于繁殖的后备母猪在 6 月龄、妊娠第 60-70 天和断奶时接种疫苗。大约 1200 头来自接种母猪的仔猪在 7 周龄时通过聚合酶链反应（PCR）方法检测 PRRSV 为阴性后被运送到一个封闭的空农场（B 场），然后在这里饲养至 14 周龄。此时，所有猪都通过 PRRS ELISA 进行检测。随后，从 B 场将 901 头血清阴性后备母猪运往第三个封闭的空农场（C 场），并在第二次血清学检测（ELISA）阴性后在这里配种。与此同时，A 场被清空、清洁和消毒。所有妊娠后备母猪在重新检测到 PRRSV 抗体阴性后从 C 场运至 A 场。产仔后进行了后续血清学检测，结果仅为血清阴性动物。根据随后的阴性检测结果，该养殖场经主管部门宣布根除 PRRSV。
该农场是匈牙利国家 PRRS 根除计划中首例通过给母猪接种灭活疫苗并对后代进行隔离饲养成功根除 PRRSV 的农场。在整个种群替换过程中，生产几乎连续进行。
