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Clilverd H, Li Y, Martín-Valls G, Aguirre L, Martín M, Cortey M, Mateu E. Selection of viral variants with enhanced transmission and reduced neutralization susceptibility alongside lateral introductions may explain the persistence of porcine reproductive and respiratory syndrome virus in vaccinated breeding herds. Virus Evol 2024; 10:veae041. [PMID: 38817667 PMCID: PMC11137674 DOI: 10.1093/ve/veae041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/13/2024] [Accepted: 05/14/2024] [Indexed: 06/01/2024] Open
Abstract
This study investigates the long-term evolutionary dynamics of porcine reproductive and respiratory syndrome virus (PRRSV-1) in an endemically infected and vaccinated pig herd. Over a one year and a half period, piglets from seven farrowing batches in a 300-sow PRRSV-vaccinated farm were monitored from birth to nine weeks of age by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Eighty-five PRRSV-positive samples were subjected to whole genome sequencing (Illumina Miseq), and 251 samples to open reading frame 5 (ORF5) sequencing. Farm-specific PRRSV variants' impact on anti-PRRSV antibodies was evaluated using enzyme-linked immunosorbent and neutralizing antibody assays. The replication kinetics and cytokine inhibition capabilities (IFN-α and TNF-α) of these variants were assessed in porcine alveolar macrophages. The study revealed fluctuating PRRSV-1 incidences in farrowing units and nurseries, attributed to two key evolutionary events: an escape variant emergence and a lateral introduction of a new strain. Initially, strain 1 variant α was swiftly replaced within weeks by variant 1β (99.5 per cent genomic similarity), with twenty-five amino acid mutations, primarily in nsp1α, GP2, GP3, and GP5, including an additional glycosylation site and a deletion downstream the neutralization epitope of GP5. This shift to 1β correlated with increased incidence in nurseries and higher viral loads, with sera from 1α-exposed animals showing reduced neutralization against 1β. Consistently for in vitro assays, variant 1β demonstrated enhanced replication in porcine alveolar macrophages but no difference regarding IFN-α or TNF-α responses. Later, a new strain (strain 2, 83.3 per cent similarity to strain 1) emerged and led to incidence resurgence because of the low cross reactivity with the previous antibodies. The study highlights PRRSV's rapid adaptability and challenges in controlling its spread, underscoring the necessity for more effective vaccines and eradication approaches.
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Affiliation(s)
- Hepzibar Clilverd
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Yanli Li
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Gerard Martín-Valls
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Laia Aguirre
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Marga Martín
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Martí Cortey
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
| | - Enric Mateu
- Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Cerdanyola del Vallès 08193, Spain
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Martin-Valls GE, Li Y, Clilverd H, Soto J, Cortey M, Mateu E. Levels of neutralizing antibodies against resident farm strain or vaccine strain are not indicators of protection against PRRSV-1 vertical transmission under farm conditions. BMC Vet Res 2023; 19:217. [PMID: 37858141 PMCID: PMC10588270 DOI: 10.1186/s12917-023-03785-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Vertical transmission is key for the maintenance of porcine reproductive and respiratory syndrome virus (PRRSV) infection. In vaccinated farms, vertical transmission can still occur despite sows having some level of immunity because of repeated vaccination or contact with the wild-type virus. The present study aimed to correlate the age of sows and the amplitude of neutralizing antibodies (Nab) (heterologous neutralization) with PRRSV-1 vertical transmission (VT). For this purpose, umbilical cords of 1,554 newborns (corresponding to 250 litters) were tested for PRRSV by RT-PCR in two PRRSV-unstable vaccinated farms. In parallel, the sows were bled after farrowing and the levels of antibodies were determined by ELISA and by the viral neutralization test against the vaccine virus, the virus circulating in the farm, and other unrelated contemporary PRRSV-1 strains. The relationship between the parity and the probability of delivering infected piglets and the presence of broadly Nabs examined. RESULTS The proportion of VT events in the two examined farms ranged from 18.9% to 23.0%. Young sows (parity 1-2) were 1.7 times more likely to have VT than older sows (p < 0.05). Despite higher ELISA S/P antibody ratios in younger sows (p < 0.05), NAb against the resident farm strain were at a similar level between sows delivering infected and healthy piglets regardless of age, mostly with low titers (2-3 log2). The titers of NAb against the vaccine virus were also low, and no correlations with VT were observed. When a panel of another 4 strains (1 isolated in the 1990s, and 3 contemporary strains) were used for the neutralization test, most sow sera were not capable of neutralizing the contemporary strains. CONCLUSIONS Titers of NAb could not be correlated with the occurrence of PRRSV VT. The amplitude of NAb present in most vaccinated sows is limited with a considerable proportion unresponsive regarding NAb production.
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Affiliation(s)
- Gerard Eduard Martin-Valls
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Travessera dels Turons S/N, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Yanli Li
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Travessera dels Turons S/N, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Hepzibar Clilverd
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Travessera dels Turons S/N, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Jordi Soto
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Travessera dels Turons S/N, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Martí Cortey
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Travessera dels Turons S/N, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain
| | - Enric Mateu
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, Travessera dels Turons S/N, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain.
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Lebret A, Normand V, Berton P, Nicolazo T, Teixeira Costa C, Chevance C, Brissonnier M, Boulbria G. Alternative Samples for Porcine Reproductive and Respiratory Syndrome Surveillance in an Endemic PRRSV-1-Infected Breeding Herd: A Descriptive Study. Vet Sci 2023; 10:558. [PMID: 37756080 PMCID: PMC10537479 DOI: 10.3390/vetsci10090558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/28/2023] [Accepted: 09/01/2023] [Indexed: 09/28/2023] Open
Abstract
Knowing porcine reproductive and respiratory syndrome (PRRS) status is essential for designing herd management protocols. For this, weaning-age pigs are a key subpopulation. Recently, different alternatives to blood sampling have been introduced because they are easier, welfare-friendly and cost-saving tools. Moreover, most of them allow the testing of more animals and seem to be more sensitive in low-prevalence scenarios. However, these studies were implemented mainly in PRRSV-2-infected herds. The first objective of our study was to compare the rate of detection of PRRSV-1 by RT-qPCR in individual serum samples, family oral fluid samples (FOF) and udder wipes (UW) collected the day before weaning. The second objective was to evaluate the suitability of pooling. The study was performed on a 210-sow farrow-to-finish farm which was PRRSV-1 infected and unstable. A total of 119 litters were sampled. The rate of detection of PRRSV-1 in blood samples, FOF and UW was 10.9%, 7.6% and 0.8%, respectively. The agreement between sera and FOF was almost perfect even if the detection capacity of sera was numerically superior to FOF. The Ct values of positive sera were statistically lower than those of FOF. Two modalities of pooling (1:3 and 1:5) were tested for sera and FOF. For sera, both modalities did not impact the PRRSV-1 status either at the litter level or at the batch one. On the other hand, whatever the modality (pooled by 3 or 5), most of the pools of FOF gave negative results, misclassifying many litters and batches.
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Affiliation(s)
- Arnaud Lebret
- Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- Rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Valérie Normand
- Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- Rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Pauline Berton
- Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Théo Nicolazo
- Rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | | | - Céline Chevance
- Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- Rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Mathieu Brissonnier
- Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Gwenaël Boulbria
- Porc.Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- Rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
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Machado IF, Magalhães ES, Poeta Silva APS, Moraes DCA, Cezar G, Mil-Homens MP, Osemeke OH, Paiva R, Moura CAA, Gauger P, Trevisan G, Silva GS, Linhares DCL. Porcine reproductive and respiratory syndrome virus RNA detection in tongue tips from dead animals. Front Vet Sci 2022; 9:993442. [PMID: 36213411 PMCID: PMC9533096 DOI: 10.3389/fvets.2022.993442] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/18/2022] [Indexed: 11/13/2022] Open
Abstract
The control of porcine reproductive and respiratory syndrome virus (PRRSV) hinges on monitoring and surveillance. The objective of this study was to assess PRRSV RNA detection by RT-PCR in tongue tips from dead suckling piglets compared to serum samples, processing fluids, and family oral fluids. Tongue tips and serum samples were collected from three PRRSV-positive breeding herd farms (farms A, B, and C) of three different age groups: newborns (<24 h), processing (2 to 7 days of age), and weaning (18 to 22 days of age). Additionally, processing fluids and family oral fluids were collected from 2–7 days of age and weaning age, respectively. In farms A and B, PRRSV RNA was detected in tongue tips from all age groups (100 and 95%, respectively). In addition, PRRSV RNA was detected in pooled serum samples (42 and 27%), processing fluids (100 and 50%), and family oral fluids (11 and 22%). Interestingly, the average Ct value from tongue tips was numerically lower than the average Ct value from serum samples in the newborn age. In farm C, PRRSV RNA was only detected in serum samples (60%) and family oral fluids (43%), both from the weaning age. Further, no PRRSV RNA was detected in tongue tips when pooled serum samples from the same age group tested PRRSV RNA-negative. Taken together, these results demonstrate the potential value of tongue tips for PRRSV monitoring and surveillance.
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Affiliation(s)
- Isadora F. Machado
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Edison S. Magalhães
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Ana Paula S. Poeta Silva
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Daniel C. A. Moraes
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Guilherme Cezar
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Mafalda P. Mil-Homens
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Onyekachukwu H. Osemeke
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Rodrigo Paiva
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | | | - Phillip Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Giovani Trevisan
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Gustavo S. Silva
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Daniel C. L. Linhares
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
- *Correspondence: Daniel C. L. Linhares
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Martín‐Valls GE, Mortensen P, Clilvert H, Li Y, Cortey M, Sno M, Barna T, Terré M, Guerra N, Mateu E. The use of a whole inactivated PRRS virus vaccine administered in sows and impact on maternally derived immunity and timing of PRRS virus infection in piglets. Vet Rec Open 2022; 9:e34. [PMID: 35414939 PMCID: PMC8982505 DOI: 10.1002/vro2.34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 02/18/2022] [Accepted: 03/04/2022] [Indexed: 11/21/2022] Open
Abstract
Background Porcine reproductive and respiratory syndrome virus (PRRSV) vaccination is usually based on administering periodically PRRS modified live virus (MLV) in sows throughout their life. Using this schedule, transfer of maternally derived antibodies to the offspring is limited. The aim of the present study was to test the concept of priming with an MLV and boosting with a commercial inactivated virus vaccine in sows to reduce PRRSV incidence and improve productivity. Methods On two farms, all the sows were vaccinated with a MLV vaccine at week 8 of gestation. Then two groups were designated, one group was re‐vaccinated in the third week prior to farrowing and using a commercial inactivated vaccine (the PG group). The second group was the control group (C). Assays for PRRSV infection and productive parameters were evaluated. Results For both farms, the incidence of PRRSV was lower at 6 weeks of age in PG than in C (p < 0.05). At weaning the proportion of PRRSV seropositive piglets was higher for PG as well (p < 0.05). The litters from C sows from both farms showed a higher pre‐weaning mortality (odds ratio, C vs. PG = 1.18 ± 0.09; p < 0.05). Conclusions Administration of the vaccine in sows before farrowing was safe and associated with reduced incidence of PRRSV in piglets up to 6 weeks of age.
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Affiliation(s)
- Gerard Eduard Martín‐Valls
- Departament de Sanitat i Anatomia Animals Facultat de Veterinària Travessera dels Turons s/n Universitat Autònoma de Barcelona Barcelona Spain
| | | | - Hepzibar Clilvert
- Departament de Sanitat i Anatomia Animals Facultat de Veterinària Travessera dels Turons s/n Universitat Autònoma de Barcelona Barcelona Spain
| | - Yanli Li
- Departament de Sanitat i Anatomia Animals Facultat de Veterinària Travessera dels Turons s/n Universitat Autònoma de Barcelona Barcelona Spain
| | - Martí Cortey
- Departament de Sanitat i Anatomia Animals Facultat de Veterinària Travessera dels Turons s/n Universitat Autònoma de Barcelona Barcelona Spain
| | - Melanie Sno
- Ceva Animal Health Ceva Phylaxia Veterinary Biologicals Co. Ltd., Budapest Hungary
| | - Timea Barna
- Ceva Animal Health Ceva Phylaxia Veterinary Biologicals Co. Ltd., Budapest Hungary
| | - Marisa Terré
- Cooperativa d'Artesa de Segre Artesa de Segre Lleida Spain
| | | | - Enric Mateu
- Departament de Sanitat i Anatomia Animals Facultat de Veterinària Travessera dels Turons s/n Universitat Autònoma de Barcelona Barcelona Spain
- C ReSA‐IRTA‐UAB Campus UAB Cerdanyola del Vallès Barcelona Spain
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6
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Ryu J, Kang GJ, Kim O, Park JY, Shin HJ. Transplacental Transmission of Porcine Epidemic Diarrhea Virus. Front Vet Sci 2022; 8:802816. [PMID: 35372525 PMCID: PMC8964783 DOI: 10.3389/fvets.2021.802816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/31/2021] [Indexed: 12/04/2022] Open
Abstract
Because the porcine epidemic diarrhea virus (PEDV) is a critical pathogen resulting in rapid spreading and high mortality rates in piglets, understanding of the transmission route of PEDV is required for its controlling. Until now, it is well known that PEDV transmission routes are various, such as fecal–oral route, contaminated feed, farmworkers, and transport vehicles. However, unlike several swine-infected viruses, there were no reports of vertical transmission with PEDV. In our study, we confirmed possible vertical transmission of PEDV. We confirmed PEDV in piglet testicles and umbilical cords from PEDV-positive sow. These findings are direct evidence that PEDV is transmitted vertically through placenta. This is the first report on transplacental transmission of PEDV and will be very important information for controlling PED.
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Affiliation(s)
- Jihoon Ryu
- Research Institute of Veterinary Medicine, Daejeon, South Korea
| | - Gi-Jong Kang
- Laboratory of Infectious Disease, College of Veterinary Medicine, Chungnam National University, Daejeon, South Korea
| | - Onnuri Kim
- Laboratory of Infectious Disease, College of Veterinary Medicine, Chungnam National University, Daejeon, South Korea
| | - Jae-Yeon Park
- Laboratory of Infectious Disease, College of Veterinary Medicine, Chungnam National University, Daejeon, South Korea
| | - Hyun-Jin Shin
- Research Institute of Veterinary Medicine, Daejeon, South Korea
- Laboratory of Infectious Disease, College of Veterinary Medicine, Chungnam National University, Daejeon, South Korea
- *Correspondence: Hyun-Jin Shin
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López-Lorenzo G, López-Novo C, Prieto A, Díaz P, Panadero R, Rodríguez-Vega V, Morrondo P, Fernández G, Díaz-Cao JM. Monitoring of porcine circovirus type 2 infection through air and surface samples in vaccinated and unvaccinated fattening farms. Transbound Emerg Dis 2021; 69:1108-1117. [PMID: 33711193 DOI: 10.1111/tbed.14069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/25/2021] [Accepted: 03/10/2021] [Indexed: 11/30/2022]
Abstract
Air and surfaces of swine farms are the two alternative samples to obtain information about the health status of the herd. The aim of this study was to assess air and surface sampling for the detection of porcine circovirus type 2 (PCV2) in vaccinated and unvaccinated fattening farms, studying the relationship between the viral load in these samples with the viremia at herd level. Three swine fattening batches (one unvaccinated; two vaccinated) were monitored at 10, 12, 14, 16 and 18 weeks old; at each stage, blood, air and different surfaces were sampled and analysed by qPCR. In all herds, PCV2 was detected in all types of samples. Whenever viremia was detected, PCV2 was also detected in air and surface samples, even in those cases with a low estimated prevalence (1.6%); moreover, in two out of the three herds, PCV2 was detected in air and surface samples earlier than in the blood of the sampled population. In addition, a good correlation between the viremia of pig population and the PCV2 load in air and surface samples was found in both cases (τ = 0.672 and 0.746, respectively; p <0.05). These results show that air and surface samples could be useful tools to monitor PCV2 infection, being suitable for detecting the virus in cases of low prevalence and even before pigs develop viremia; therefore, these sampling techniques would speed up the implementation of the required measures to prevent productive and economic losses due to PCV2 infection.
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Affiliation(s)
- Gonzalo López-Lorenzo
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | - Cynthia López-Novo
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | - Alberto Prieto
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | - Pablo Díaz
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | - Rosario Panadero
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | | | - Patrocinio Morrondo
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | - Gonzalo Fernández
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
| | - José Manuel Díaz-Cao
- Department of Animal Pathology (INVESAGA Group), Universidade de Santiago de Compostela, Lugo, Spain
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Lebret A, Berton P, Normand V, Messager I, Robert N, Bouchet F, Brissonnier M, Boulbria G. PRRSV detection by qPCR in processing fluids and serum samples collected in a positive stable breeding herd following mass vaccination of sows with a modified live vaccine. Porcine Health Manag 2021; 7:6. [PMID: 33397484 PMCID: PMC7783972 DOI: 10.1186/s40813-020-00186-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/14/2020] [Indexed: 02/06/2023] Open
Abstract
In the last two decades, in France, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) stabilization protocols have been implemented using mass vaccination with a modified live vaccine (MLV), herd closure and biosecurity measures. Efficient surveillance for PRRSV is essential for generating evidence of absence of viral replication and transmission in pigs. The use of processing fluid (PF) was first described in 2018 in the United States and was demonstrated to provide a higher herd-level sensitivity compared with blood samples (BS) for PRRSV monitoring. In the meantime, data on vertical transmission of MLV viruses are rare even as it is a major concern. Therefore, veterinarians usually wait for several weeks after a sow mass vaccination before starting a stability monitoring. This clinical study was conducted in a PRRSV-stable commercial 1000-sow breed-to-wean farm. This farm suffered from a PRRS outbreak in January 2018. After implementing a stabilisation protocol, this farm was controlled as stable for more than 9 months before the beginning of the study. PF and BS at weaning were collected in four consecutive batches born after a booster sow mass MLV vaccination. We failed to detect PRRSV by qPCR on PF and BS collected in a positive-stable breeding herd after vaccination with ReproCyc® PRRS EU (Boehringer Ingelheim, Ingelheim, Germany).
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Affiliation(s)
- A. Lebret
- Porc. Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - P. Berton
- Porc. Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - V. Normand
- Porc. Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - I. Messager
- Boehringer Ingelheim Animal Health France, Swine Bussiness Unit, 16, rue Louis Pasteur, 44119 Treillères, France
| | - N. Robert
- Boehringer Ingelheim Animal Health France, Swine Bussiness Unit, 16, rue Louis Pasteur, 44119 Treillères, France
| | - F. Bouchet
- Porc. Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - M. Brissonnier
- Porc. Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - G. Boulbria
- Porc. Spective Swine Vet Practice, ZA de Gohélève, 56920 Noyal-Pontivy, France
- rezoolution Pig Consulting Services, ZA de Gohélève, 56920 Noyal-Pontivy, France
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Vilalta C, Sanhueza J, Alvarez J, Murray D, Torremorell M, Corzo C, Morrison R. Use of processing fluids and serum samples to characterize porcine reproductive and respiratory syndrome virus dynamics in 3 day-old pigs. Vet Microbiol 2018; 225:149-156. [PMID: 30293648 DOI: 10.1016/j.vetmic.2018.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/12/2018] [Accepted: 09/13/2018] [Indexed: 12/12/2022]
Abstract
Collection of serum samples of pigs at weaning to monitor for porcine reproductive and respiratory syndrome virus (PRRSV) has become a common practice to determine PRRSV herd infection status. Diagnostic sensitivity of this practice is low in herds undergoing PRRSV elimination once prevalence of infection is near zero. Thus, the goal of this study was to characterize the dynamics of PRRSV infection in 3 day-old pigs overtime using serum and serosanguineous fluids obtained as part of castration and tail docking practices (processing fluids (PF)). Secondary goal was to estimate sensitivity and specificity of PF in the 3 day old population. A 6000 breed-to-wean sow herd was monitored every three weeks for 23 weeks after a PRRSV outbreak by collecting both PF and individual serum samples from all pigs in the selected litters. Out of the 77 litters tested, 23 (29.8%) were identified as positive using the PF and the serum samples, with a Cohen's kappa statistic of 0.81 (95% CI: 0.59-1) between the results obtained in each sample type. The sensitivity and specificity of the PF relative to the results in serum was 87% (95% CI: 66%-97%) and 94% (95% CI: 85%-99%) respectively. The percentage of PRRSV positive litters decreased over time and litters from gilts were more likely to test positive than those from older sows. Overall, the study demonstrates that PF can be a convenient and reliable specimen to monitor PRRSV infection in breeding herds.
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Affiliation(s)
- Carles Vilalta
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave., St Paul, MN 55108, United States.
| | - Juan Sanhueza
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave., St Paul, MN 55108, United States
| | - Julio Alvarez
- VISAVET Health Surveillance Center, Universidad Complutense, Avda Puerta de Hierro S/N, Madrid, 28040, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, Avda Puerta de Hierro S/N, Madrid, 28040, Spain
| | - Deb Murray
- New Fashion Pork, Jackson, MN, United States
| | - Montserrat Torremorell
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave., St Paul, MN 55108, United States
| | - Cesar Corzo
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave., St Paul, MN 55108, United States
| | - Robert Morrison
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave., St Paul, MN 55108, United States
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