Macroepidemiological aspects of PRRSV detection by major labs in the USA over time, age group, and specimen

PLoS One. 2019 Oct 16;14(10):e0223544. doi: 10.1371/journal.pone.0223544. eCollection 2019.

Macroepidemiological aspects of porcine reproductive and respiratory syndrome virus detection by major United States veterinary diagnostic laboratories over time, age group, and specimen.

Trevisan G1, Linhares LCM1, Crim B1, Dubey P1, Schwartz KJ1, Burrough ER1, Main RG1, Sundberg P2, Thurn M3, Lages PTF3, Corzo CA3, Torrison J3, Henningson J4, Herrman E4, Hanzlicek GA4, Raghavan R4, Marthaler D4, Greseth J5, Clement T5, Christopher-Hennings J5, Linhares DCL1.

Author information

1

Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, Iowa, United States of America.

2

Swine Health Information Center, Ames, Iowa, United States of America.

3

Veterinary Population Medicine, University of Minnesota, Saint Paul, Minnesota, United States of America.

4

College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America.

5

Veterinary & Biomedical Sciences Department, South Dakota State University, Brookings, South Dakota, United States of America.

Abstract

This project investigates the macroepidemiological aspects of porcine reproductive and respiratory syndrome virus (PRRSV) RNA detection by veterinary diagnostic laboratories (VDLs) for the period 2007 through 2018. Standardized submission data and PRRSV real-time reverse-transcriptase polymerase chain reaction (RT-qPCR) test results from porcine samples were retrieved from four VDLs representing 95% of all swine samples tested in NAHLN laboratories in the US. Anonymized data were retrieved and organized at the case level using SAS (SAS® Version 9.4, SAS® Institute, Inc., Cary, NC) with the use of PROC DATA, PROC MERGE, and PROC SQL scripts. The final aggregated and anonymized dataset comprised of 547,873 unique cases was uploaded to Power Business Intelligence-Power BI® (Microsoft Corporation, Redmond, Washington) to construct dynamic charts. The number of cases tested for PRRSV doubled from 2010 to 2018, with that increase mainly driven by samples typically used for monitoring purposes rather than diagnosis of disease. Apparent seasonal trends for the frequency of PRRSV detection were consistently observed with a higher percentage of positive cases occurring during fall or winter months and lower during summer months, perhaps due to increased testing associated with well-known seasonal occurrence of swine respiratory disease. PRRSV type 2, also known as North American genotype, accounted for 94.76% of all positive cases and was distributed across the US. PRRSV type 1, also known as European genotype, was geographically restricted and accounted for 2.15% of all positive cases. Co-detection of both strains accounted for 3.09% of the positive cases. Both oral fluid and processing fluid samples, had a rapid increase in the number of submissions soon after they were described in 2008 and 2017, respectively, suggesting rapid adoption of these specimens by the US swine industry for PRRSV monitoring in swine populations. As part of this project, a bio-informatics tool defined as Swine Disease Reporting System (SDRS) was developed. This tool has real-time capability to inform the US swine industry on the macroepidemiological aspects of PRRSV detection, and is easily adaptable for other analytes relevant to the swine industry.

PMID:

 

31618236

  

DOI:

 

10.1371/journal.pone.0223544

Assessing PRRSv status in suckling pigs by sampling sows and environment.

Vet Microbiol. 2019 Oct;237:108406. doi: 10.1016/j.vetmic.2019.108406. Epub 2019 Sep 3.

Indirect assessment of porcine reproductive and respiratory syndrome virus status in pigs prior to weaning by sampling sows and the environment.

Vilalta C1, Sanhueza J2, Garrido J2, Murray D3, Morrison R2, Corzo CA2, Torremorell M2.

Author information

Abstract

There is a need to develop cost effective approaches to sample large populations in particular to determine the disease status of pigs prior to weaning. In this study we assessed the presence of the porcine reproductive and respiratory syndrome virus (PRRSV) in the environment (surfaces and air) of farrowing rooms, and udder skin of lactating sows as an indirect measure of piglet PRRSV status. Samples were collected at processing and weaning every three weeks for 23 weeks after a PRRSV outbreak was diagnosed in a swine breeding herd. PRRSV was detected at processing in udder skin wipes, environmental wipes and airborne deposited particle samples up to 14 weeks post outbreak and at weaning in udder skin wipes up to 17 weeks post outbreak. Similar sensitivities were observed for udder skin wipes (43% [95% CI: 23%-66%]) and surface wipes (57% [95% CI: 34%-77%]) when compared to serum at the litter level from piglets at processing. PRRSV was detected in the environment and the udder skin of lactating sows, which indicates that aggregate samples of the environment or lactating sows may be used to evaluate the PRRSV status of the herd in pigs prior to weaning. However, the use of environmental samples to detect PRRSV by RT-PCR should not be used as the single method to assess the PRRSV status at the litter level. Furthermore, our findings also highlight potential sources of PRRSV infection for piglets in breeding herds.

Copyright © 2019 Elsevier B.V. All rights reserved.

KEYWORDS: 

Environment; Monitoring; Nurse sow; PRRSV; Udder

PMID:

 

31585654

 

DOI:

 

10.1016/j.vetmic.2019.108406

PLoS One. 2019 Oct 9;14(10):e0223250. doi: 10.1371/journal.pone.0223250. eCollection 2019.

Unweaving tangled mortality and antibiotic consumption data to detect disease outbreaks - Peaks, growths, and foresight in swine production.

Lopes Antunes AC1, Jensen VF1, Jensen D2.

Author information

1

Division for Diagnostics & Scientific Advice-Epidemiology, National Veterinary Institute/Centre for Diagnostics-Technical University of Denmark, Lyngby, Denmark.

2

Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark.

Abstract

As our capacity to collect and store health data is increasing, a new challenge of transforming data into meaningful information for disease monitoring and surveillance has arisen. The aim of this study was to explore the potential of using livestock mortality and antibiotic consumption data as a proxy for detecting disease outbreaks at herd level. Changes in the monthly records of mortality and antibiotic consumption were monitored in Danish swine herds that became positive for porcine reproductive and respiratory syndrome (PRRS) and porcine pleuropneumonia. Laboratory serological results were used to identify herds that changed from a negative to a positive status for the diseases. A dynamic linear model with a linear growth component was used to model the data. Alarms about state changes were raised based on forecast errors, changes in the growth component, and the values of the retrospectively smoothed values of the growth component. In all cases, the alarms were defined based on credible intervals and assessed prior and after herds got a positive disease status. The number of herds with alarms based on mortality increased by 3% in the 3 months prior to laboratory confirmation of PRRS-positive herds (Se = 0.47). A 22% rise in the number of weaner herds with alarms based on the consumption of antibiotics for respiratory diseases was found 1 month prior to these herds becoming PRRS-positive (Se = 0.22). For porcine pleuropneumonia-positive herds, a 10% increase in antibiotic consumption for respiratory diseases in sow herds was seen 1 month prior to a positive result (Se = 0.5). Monitoring changes in mortality data and antibiotic consumption showed changes at herd level prior to and in the same month as confirmation from diagnostic tests. These results also show a potential value for using these data streams as part of surveillance strategies.

PMID:

 

31596880

 

DOI:

 

10.1371/journal.pone.0223250

Using commercial ELISAs to assess humoral response in sows repeatedly vaccinated with MLV PRRSV.

Vet Rec. 2019 Oct 1. pii: vetrec-2019-105432. doi: 10.1136/vr.105432. [Epub ahead of print]

Using commercial ELISAs to assess humoral response in sows repeatedly vaccinated with modified live porcine reproductive and respiratory syndrome virus.

Díaz I1, Genís-Jorquera B2, Martín-Valls GE3, Mateu E2,3.

Author information

1

IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Bellaterra, Spain ivan.diaz@irta.es.

2

IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Bellaterra, Spain.

3

Departament de Sanitat i Anatomia Animals, Facultat Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain.

Abstract

BACKGROUND: 

Sows in breeding herds are often mass vaccinated against porcine reproductive and respiratory syndrome (PRRS) every few months using modified live vaccines (MLV). Field veterinarians repeatedly report that multiple vaccinated sows test negative in ELISA. Obviously, this creates uncertainty when assessing the compliance of vaccination and the status of sows.

METHODS: 

In the present study, four commercial ELISAs were used to assess the serological PRRS status in gilts and sows of three farms that were PRRS MLV vaccinated every four months. Animals were tested before vaccination (BV) and postvaccination (PV). Total and neutralising antibodies and cell-mediated responses were also measured in animals that yielded negative results in all ELISAs.

RESULTS: 

The proportion of seronegative animals BV varied depending on the farm and the ELISA used. When samples were analysed using only one ELISA, a substantial number of negative results obtained BV remained as negative afterwards. Five animals were negative BV and PV with all the examined ELISAs. Those animals also yielded negative results in all the other immunological assays.

CONCLUSION: 

Our findings suggest that the use of ELISA for monitoring multiple PRRS MLV vaccinated sows is very limited due to the variability of the humoral responses and the moderate agreement between tests.

© British Veterinary Association 2019. No commercial re-use. See rights and permissions. Published by BMJ.

KEYWORDS: 

Diagnostics; ELISA; Porcine reproductive and respiratory syndrome (PRRS); Vaccines

PMID:

 

31575761

 

DOI:

 

10.1136/vr.105432