Saturday, December 2, 2017

Efficacy and safety of simultaneous vaccination with two MLV vaccines against PRRS types 1 and 2.

2017 Nov 27. pii: S0264-410X(17)31643-2. doi: 10.1016/j.vaccine.2017.11.059. [Epub ahead of print]

Efficacy and safety of simultaneous vaccination with two modified live virus vaccines against porcine reproductive and respiratory syndrome virus types 1 and 2 in pigs.

Kristensen CS1, Kvisgaard LK2, Pawlowski M3, Holmgaard Carlsen S3, Hjulsager CK4, Heegaard PMH5, Bøtner A6, Stadejek T7, Haugegaard S8, Larsen LE9.

Author information

1: Danish Pig Research Centre, Danish Agriculture & Food Council, Kjellerup, Denmark. Electronic address: csk@seges.dk.
2: Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark. Electronic address: liki@vet.dtu.dk.
3: Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.
4: Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark. Electronic address: ckhj@vet.dtu.dk.
5: Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark. Electronic address: pmhh@vet.dtu.dk.
6: Technical University of Denmark, National Veterinary Institute, Lindholm, Denmark. Electronic address: aneb@vet.dtu.dk.
7: Warsaw University of Life Sciences, Faculty of Veterinary Medicine, Warsaw, Poland. Electronic address: tomasz.stadejek@outlook.com.
8: Danish Pig Research Centre, Danish Agriculture & Food Council, Kjellerup, Denmark. Electronic address: svh@seges.dk.
9: Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark. Electronic address: lael@vet.dtu.dk.

Abstract

The objective of the study was to compare responses of pigs vaccinated with a PRRS MLV vaccine against PRRSV-1 or PRRSV-2 with the responses of pigs vaccinated simultaneously with both vaccines. Furthermore, the efficacy of the two PRRSV MLV vaccination strategies was assessed following challenge. The experimental design included four groups of 4-weeks old SPF-pigs. On day 0 (DPV0), groups 1-3 (N=18 per group) were vaccinated with modified live virus vaccines (MLV) containing PRRSV-1 virus (VAC-T1), PRRSV-2 virus (VAC-T2) or both (VAC-T1T2). One group was left unvaccinated (N=12). On DPV 62, the pigs from groups 1-4 were mingled in new groups and challenged (DPC 0) with PRRSV-1, subtype 1, PRRSV-1, subtype 2 or PRRSV-2. On DPC 13/14 all pigs were necropsied. Samples were collected after vaccination and challenge. PRRSV was detected in all vaccinated pigs and the majority of the pigs were positive until DPV 28, but few of the pigs were still viremic 62 days after vaccination. Virus was detected in nasal swabs until DPV 7-14. No overt clinical signs were observed after challenge. PRRSV-2 vaccination resulted in a clear reduction in viral load in serum after PRRSV-2 challenge, whereas there was limited effect on the viral load in serum following challenge with the PRRSV-1 strains. Vaccination against PRRSV-1 had less impact on viremia following challenge. The protective effects of simultaneous vaccination with PRRSV Type 1 and 2 MLV vaccines and single PRRS MLV vaccination were comparable. None of the vaccines decreased the viral load in the lungs at necropsy. In conclusion, simultaneous vaccination with MLV vaccines containing PRRSV-1 and PRRSV-2 elicited responses comparable to single vaccination and the commercial PRRSV vaccines protected only partially against challenge with heterologous strains. Thus, simultaneous administration of the two vaccines is an option in herds with both PRRSV types.

KEYWORDS:

PRRSV; Porcine reproductive and respiratory syndrome virus; Swine; Vaccination

PMID:: 29191738
DOI:: 10.1016/j.vaccine.2017.11.059

Monday, October 30, 2017

Monitoring swine production data to detect PRRS outbreaks

Monitoring breeding herd production data to detect PRRSV outbreaks

https://doi.org/10.1016/j.prevetmed.2017.10.012

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Abstract

Porcine reproductive and respiratory syndrome virus (PRRSv) causes substantial economic impact due to significant losses in productivity. Thus, measuring changes in farm productivity before and after PRRS infection enables quantifying the production and economic impact of outbreaks. This study assessed the application of exponentially weighted moving average (EWMA), a statistical process control method, on selected production data (number of abortions, pre-weaning mortality rate and prenatal losses) to supplement PRRS surveillance programs by detecting significant deviations on productivity in a production system with 55,000 sows in 14 breed-to-wean herds in Minnesota, U.S.A. Weekly data from diagnostic monitoring program (available through the Morrison’s Swine Health Monitoring Project) implemented on the same herds was used as reference for PRRS status. The time-to-detect, percentage of early detection of PRRSv-associated productivity deviations, and relative sensitivity and specificity of the production data monitoring system were determined relative to the MSHMP. The time-to-detect deviations on productivity associated with PRRS outbreaks using the EWMA method was −4 to −1 weeks (interquartile range) for the number of abortions, 0–0 for preweaning mortality and −1 to 3 weeks for prenatal losses compared to the date it was reported in the MSHMP database. Overall, the models had high relative sensitivity (range 85.7–100%) and specificity (range 98.5%–99.6%) when comparing to the changes in PRRS status reported in the MSHMP database. In summary, the use of systematic data monitoring showed a high concordance compared to the MSHMP-reported outbreaks indicating that on-farm staff and veterinary oversight were efficient to detect PRRSv, but can be more efficient if they were monitoring closely the frequency of abortions. The systematic monitoring of production indicators using EWMA offers opportunity to standardize and semi-automate the detection of deviations on productivity associated with PRRS infection, offering opportunity to early detect outbreaks and/or to quantify the production losses attributed to PRRS infection.

Keywords

Monitoring;
EWMA;
SPC;
Productivity;
Disease detection;
Production data;
PRRSv

Thursday, October 19, 2017

Knockout of maternal CD163 protect fetuses from PRRSv infection

2017 Oct 17;7(1):13371. doi: 10.1038/s41598-017-13794-2.

Knockout of maternal CD163 protects fetuses from infection with porcine reproductive and respiratory syndrome virus (PRRSV).

Prather RS1, Wells KD1, Whitworth KM1, Kerrigan MA2, Samuel MS1, Mileham A3, Popescu LN2, Rowland RRR4.

Author information

1: Division of Animal Science, College of Food Agriculture and Natural Resources, University of Missouri, Columbia, MO, 65211, USA.
2: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, 66506, USA.
3: Genus, plc, DeForest, Wisconsin, USA.
4: Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, 66506, USA. browland@vet.k-state.edu.

Abstract

After infection of the porcine dam at about 90 days of gestation, porcine reproductive and respiratory syndrome virus (PRRSV) crosses the placenta and begins to infect fetuses. Outcomes of include abortion, fetal death and respiratory disease in newborn piglets. CD163 is the receptor for the virus. In this study, CD163-positive fetuses, recovered between 109 days of gestation or 20 days after maternal infection, were completely protected from PRRSV in dams possessing a complete knockout of the CD163 receptor. The results demonstrate a practical means to eliminate PRRSV-associated reproductive disease, a major source of economic hardship to agriculture.

PMID:: 29042674
DOI:: 10.1038/s41598-017-13794-2

Wednesday, October 18, 2017

Body temperature and motion: evaluation of an online monitoring system in pigs challenged with PRRSv.

2017 Sep 28;114:482-488. doi: 10.1016/j.rvsc.2017.09.021. [Epub ahead of print]

Body temperature and motion: Evaluation of an online monitoring system in pigs challenged with Porcine Reproductive & Respiratory Syndrome Virus.

Süli T1, Halas M2, Benyeda Z2, Boda R2, Belák S3, Martínez-Avilés M4, Fernández-Carrión E4, Sánchez-Vizcaíno JM4.

Author information

1: Prophyl Animal Health Ltd, Dózsa György u 18, 7700 Mohács, Hungary. Electronic address: tsuli@prophyl.hu.
2: Prophyl Animal Health Ltd, Dózsa György u 18, 7700 Mohács, Hungary.
3: Swedish University of Agricultural Sciences (SLU), Department of Biomedical Sciences and Veterinary Public Health (BVF), Almas Allé 8, Uppsala, Sweden.
4: Visavet Centre and Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Av. Séneca 2, 28040 Madrid, Spain.

Abstract

Highly contagious and emerging diseases cause significant losses in the pig producing industry worldwide. Rapid and exact acquisition of real-time data, like body temperature and animal movement from the production facilities would enable early disease detection and facilitate adequate response. In this study, carried out within the European Union research project RAPIDIA FIELD, we tested an online monitoring system on pigs experimentally infected with the East European subtype 3 Porcine Reproductive & Respiratory Syndrome Virus (PRRSV) strain Lena. We linked data from different body temperature measurement methods and the real-time movement of the pigs. The results showed a negative correlation between body temperature and movement of the animals. The correlation was similar with both body temperature obtaining methods, rectal and thermal sensing microchip, suggesting some advantages of body temperature measurement with transponders compared with invasive and laborious rectal measuring. We also found a significant difference between motion values before and after the challenge with a virulent PRRSV strain. The decrease in motion values was noticeable before any clinical sign was recorded. Based on our results the online monitoring system could represent a practical tool in registering early warning signs of health status alterations, both in experimental and commercial production settings.

KEYWORDS:

Body temperature; Early detection; Motion; Porcine Reproductive & Respiratory Syndrome virus

PMID:: 28985615
DOI:: 10.1016/j.rvsc.2017.09.021

Monday, September 11, 2017

Effect of PRRS MLV vaccine on sow reproductive performance

2017 Sep;208:47-52. doi: 10.1016/j.vetmic.2017.07.016. Epub 2017 Jul 17.

Evaluation of the effect of a porcine reproductive and respiratory syndrome (PRRS) modified-live virus vaccine on sow reproductive performance in endemic PRRS farms.

Jeong J1, Kim S1, Park KH1, Kang I1, Park SJ1, Park C1, Chae C2.

Author information

1: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
2: Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea. Electronic address: swine@snu.ac.kr.

Abstract

The efficacy of a porcine reproductive and respiratory syndrome (PRRS) modified-live virus vaccine in reproductive performance was evaluated under field conditions. Three PRRS endemic farms were selected based on their history of PRRS-associated reproductive failures. On each farm, a total of 40 sows were randomly allocated to either vaccinated (n=20) or unvaccinated (n=20) groups. Sows were vaccinated six weeks prior to breeding. Clinical data showed a significant improvement in reproductive performance in vaccinated sows. Sows in the vaccinated groups had a significantly (P<0.05) reduced number of stillborn piglets in all 3 farms. Sows in the vaccinated groups also had a significantly (P<0.05) higher number of live-born piglets in one of the farms. Sows in the vaccinated groups had a significantly (P<0.05) higher number of weaned piglets in two of the farms. Premature farrowing, one of the late gestation symptoms of PRRS, was also reduced due to vaccination as suggested by the increase in gestation length and the reduction in the number of stillborn piglets. No adverse systemic or local side effects relative to vaccination were observed during the entire gestation. No vaccine strain was detected in the vaccinated sows from all three farms at 70 and 114days post vaccination and in live-born piglets at the time of farrowing. Vaccination of sows with this PRRS vaccine was effective in improving reproductive performance in endemic PRRS farms.

KEYWORDS:

Porcine reproductive and respiratory syndrome virus; Reproductive performance; Sow; Vaccine

PMID:: 28888648
DOI:: 10.1016/j.vetmic.2017.07.016

Thursday, August 17, 2017

Bioaerosol sampling for virus surveillance

2017 Jul 27;4:121. doi: 10.3389/fvets.2017.00121. eCollection 2017.

The Use of Bioaerosol Sampling for Airborne Virus Surveillance in Swine Production Facilities: A Mini Review.

Anderson BD1,2, Lednicky JA2, Torremorell M3, Gray GC1.

Author information

Abstract

Modern swine production facilities typically house dense populations of pigs and may harbor a variety of potentially zoonotic viruses that can pass from one pig generation to another and periodically infect human caretakers. Bioaerosol sampling is a common technique that has been used to conduct microbial risk assessments in swine production, and other similar settings, for a number of years. However, much of this work seems to have been focused on the detection of non-viral microbial agents (i.e., bacteria, fungi, endotoxins, etc.), and efforts to detect viral aerosols in pig farms seem sparse. Data generated by such studies would be particularly useful for assessments of virus transmission and ecology. Here, we summarize the results of a literature review conducted to identify published articles related to bioaerosol generation and detection within swine production facilities, with a focus on airborne viruses. We identified 73 scientific reports, published between 1991 and 2017, which were included in this review. Of these, 19 (26.7%) used sampling methodology for the detection of viruses. Our findings show that bioaerosol sampling methodologies in swine production settings have predominately focused on the detection of bacteria and fungi, with no apparent standardization between different approaches. Information, specifically regarding virus aerosol burden in swine production settings, appears to be limited. However, the number of viral aerosol studies has markedly increased in the past 5 years. With the advent of new sampling technologies and improved diagnostics, viral bioaerosol sampling could be a promising way to conduct non-invasive viral surveillance among swine farms.

KEYWORDS:

air sampling; animal production; bioaerosols; swine; viruses; zoonoses

PMID:: 28798919
PMCID:: PMC5529434
DOI:: 10.3389/fvets.2017.00121

Wednesday, July 26, 2017

Epidemiological investigations of the introduction of PRRSv in Chile, 2013- 2015

2017 Jul 25;12(7):e0181569. doi: 10.1371/journal.pone.0181569. eCollection 2017.

Epidemiological investigations of the introduction of porcine reproductive and respiratory syndrome virus in Chile, 2013-2015.

Neira V1, Brito B1, Mena J1,2, Culhane M3, Apel MI4, Max V5, Perez P5, Moreno V6, Mathieu C6, Johow M6, Badia C6, Torremorell M3, Medina R7,8, Ortega R2.

Author information

Abstract

Porcine reproductive and respiratory syndrome (PRRS) is endemic in most pork producing countries. In Chile, eradication of PRRS virus (PRRSV) was successfully achieved in 2009 as a result of the combined efforts of producers and the animal health authorities. In October 2013, after several years without detecting PRRSV under surveillance activities, suspected cases were confirmed on a commercial swine farm. Here, we describe the PRRS epidemic in Chile between October 2013 and April 2015, and we studied the origins and spread of PRRSV throughout the country using official surveillance data and Bayesian phylogenetic analysis. Our results indicate that the outbreaks were caused by a PRRSV closely related to viruses present in swine farms in North America, and different from the strain that circulated in the country before 2009. Using divergence time estimation analysis, we found that the 2013-2015 PRRSV may have been circulating in Chile for at least one month before the first detection. A single strain of PRRSV spread into a limited number of commercial and backyard swine farms. New infections in commercial systems have not been reported since October 2014, and eradication is underway by clearing the disease from the few commercial and backyard farms that remain positive. This is one of the few documented experiences of PRRSV introduction into a disease-free country.

PMID:: 28742879
DOI:: 10.1371/journal.pone.0181569

Thursday, July 20, 2017

Effect of immunologic solutions on sows and gilts on time-to-stability, and on production losses in breeding herds infected with 1-7-4 PRRS virus

2017 Sep 1;144:112-116. doi: 10.1016/j.prevetmed.2017.05.024. Epub 2017 Jun 6.

Effect of immunologic solutions on sows and gilts on time to stability, and production losses in breeding herds infected with 1-7-4 PRRSv.

Linhares DCL1, Betlach C2, Morrison RB2.

Author information

1: Iowa State University College of Veterinary Medicine, 2221 Lloyd Veterinary Medicine Center, 1600 16S Street, Ames, IA, 50010, USA. Electronic address: dcl.linhares@gmail.com.
2: University of Minnesota College of Veterinary Medicine, 385B Animal Science Veterinary Medicine Building, 1988 Fitch Avenue, St. Paul, MN, 55108, USA.

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSv) is an economically significant swine pathogen causing production losses in the global swine industry. Clinical impact depends on many factors including the virus itself. One method to sub-type PRRSv is using restriction fragment length polymorphism (RFLP). The RFLP pattern 1-7-4 emerged within the United States swine industry in 2014 and has become prevalent since then. This was a field study that prospectively followed 1-7-4-infected breeding herds (n=107) and compared time to stability (TTS), time to baseline production (TTBP) and total loss per 1000 sows between herds using modified-live virus vaccine (MLV) on sows and gilts (MLV-MLV), MLV on sows and MLV in addition to field virus exposure on gilts (MLV-MLV/FVE) or not deliberately exposing sows or gilts to PRRSv (Natural-Natural). Analyses were done in SAS 9.4 and results were adjusted by selected co-variates (duration of herd closure, number of previous PRRSv outbreaks of last 3 years, weaning frequency/week, gilt development unit location, herd size and production system). Survival analysis was conducted on TTS and TTBP and regression analysis on total loss. Herds in the Natural-Natural group achieved TTS and TTBP before other herds. Herds in the MLV-MLV/FVE had the longest TTS and TTBP. The total loss was numerically least in MLV-MLV herds (1194 pigs/1000 sows) compared to MLV/MLV-FVE (1810/1000 sows) and Natural-Natural (2671/1000 sows). This study provided additional information to assist veterinarians deciding between methods of exposure to manage PRRSv infection from breeding herds.

KEYWORDS:

Control; EWMA; Elimination; Live virus exposure; Modified-live virus vaccine; PRRSv; Pigs; Statistical process control; Whole herd exposure

PMID:: 28716191
DOI:: 10.1016/j.prevetmed.2017.05.024

Optisample - sample size calculator for active surveillance activities

2017 Jul 18;12(7):e0176863. doi: 10.1371/journal.pone.0176863. eCollection 2017.

OptisampleTM: Open web-based application to optimize sampling strategies for active surveillance activities at the herd level illustrated using Porcine Respiratory Reproductive Syndrome (PRRS).

Alba A1, Morrison RE1, Cheeran A1, Rovira A2, Alvarez J1, Perez AM1.

Author information

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSv) infection causes a devastating economic impact to the swine industry. Active surveillance is routinely conducted in many swine herds to demonstrate freedom from PRRSv infection. The design of efficient active surveillance sampling schemes is challenging because optimum surveillance strategies may differ depending on infection status, herd structure, management, or resources for conducting sampling. Here, we present an open web-based application, named 'OptisampleTM', designed to optimize herd sampling strategies to substantiate freedom of infection considering also costs of testing. In addition to herd size, expected prevalence, test sensitivity, and desired level of confidence, the model takes into account the presumed risk of pathogen introduction between samples, the structure of the herd, and the process to select the samples over time. We illustrate the functionality and capacity of 'OptisampleTM' through its application to active surveillance of PRRSv in hypothetical swine herds under disparate epidemiological situations. Diverse sampling schemes were simulated and compared for each herd to identify effective strategies at low costs. The model results show that to demonstrate freedom from disease, it is important to consider both the epidemiological situation of the herd and the sample selected. The approach illustrated here for PRRSv may be easily extended to other animal disease surveillance systems using the web-based application available at http://stemma.ahc.umn.edu/optisample.

PMID:: 28719658
DOI:: 10.1371/journal.pone.0176863

Friday, July 14, 2017

Quantitative tools to access epidemiology of PRRS using Morrison's SHMP data

2017 Jun 27;4:94. doi: 10.3389/fvets.2017.00094. eCollection 2017.

A Review of Quantitative Tools Used to Assess the Epidemiology of Porcine Reproductive and Respiratory Syndrome in U.S. Swine Farms Using Dr. Morrison's Swine Health Monitoring Program Data.

Vilalta C1, Arruda AG1,2, Tousignant SJP3,4, Valdes-Donoso P1,5, Muellner P6, Muellner U6, Alkhamis MA1,7, Morrison RB1, Perez AM1.

Author information

Abstract

Porcine reproductive and respiratory syndrome (PRRS) causes far-reaching financial losses to infected countries and regions, including the U.S. The Dr. Morrison's Swine Health Monitoring Program (MSHMP) is a voluntary initiative in which producers and veterinarians share sow farm PRRS status weekly to contribute to the understanding, in quantitative terms, of PRRS epidemiological dynamics and, ultimately, to support its control in the U.S. Here, we offer a review of a variety of analytic tools that were applied to MSHMP data to assess disease dynamics in quantitative terms to support the decision-making process for veterinarians and producers. Use of those methods has helped the U.S. swine industry to quantify the cyclical patterns of PRRS, to describe the impact that emerging pathogens has had on that pattern, to identify the nature and extent at which environmental factors (e.g., precipitation or land cover) influence PRRS risk, to identify PRRS virus emerging strains, and to assess the influence that voluntary reporting has on disease control. Results from the numerous studies reviewed here provide important insights into PRRS epidemiology that help to create the foundations for a near real-time prediction of disease risk, and, ultimately, will contribute to support the prevention and control of, arguably, one of the most devastating diseases affecting the North American swine industry. The review also demonstrates how different approaches to analyze and visualize the data may help to add value to the routine collection of surveillance data and support infectious animal disease control.

KEYWORDS:

Swine Health Monitoring Project; data sharing; epidemiology; porcine reproductive and respiratory syndrome; spatiotemporal analysis

PMID:: 28702459
PMCID:: PMC5484771
DOI:: 10.3389/fvets.2017.00094

Monday, June 12, 2017

PRRSV and HEV in UK Pigs at the Time of Slaughter

2017 Jun 9;9(6). pii: E110. doi: 10.3390/v9060110.

UK Pigs at the Time of Slaughter: Investigation into the Correlation of Infection with PRRSV and HEV.

Frossard JP1, Grierson S2, Cheney T3, Steinbach F4, Choudhury B5, Williamson S6.

Author information

1: Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey KT15 3NB, UK. jean-pierre.frossard@apha.gsi.gov.uk.
2: Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey KT15 3NB, UK. Sylvia.Grierson@apha.gsi.gov.uk.
3: Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey KT15 3NB, UK. tcheney87@hotmail.com.
4: Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey KT15 3NB, UK. Falko.Steinbach@apha.gsi.gov.uk.
5: Animal and Plant Health Agency, Woodham Lane, New Haw, Surrey KT15 3NB, UK. Bhudipa.Choudhury@apha.gsi.gov.uk.
6: Surveillance Intelligence Unit, Animal and Plant Health Agency, Rougham Hill, Bury St Edmunds, Suffolk IP33 2RX, UK. Susanna.Williamson@apha.gsi.gov.uk.

Abstract

Hepatitis E virus (HEV) and porcine reproductive and respiratory syndrome virus (PRRSV) and are both globally prevalent in the pig population. While HEV does not cause clinical disease in pigs, its zoonotic potential has raised concerns in the food safety sector. PRRS has become endemic in the United Kingdom (UK) since its introduction in 1991, and continues to cause considerable economic losses to the swine industry. A better understanding of the current prevalence and diversity of PRRSV and HEV in the UK, and their potential association, is needed to assess risks and target control measures appropriately. This study used plasma, tonsil, and cecal content samples previously collected from pigs in 14 abattoirs in England and Northern Ireland to study the prevalence of several pathogens including PRRSV and HEV. The diversity of PRRSV strains detected in these samples was analyzed by sequencing open reading frame 5 (ORF5), revealing no substantial difference in PRRSV strains from these clinically unaffected pigs relative to those from clinical cases of disease in the UK. Despite the potential immuno-modulatory effect of PRRSV infection, previously demonstrated to affect Salmonellaand HEV shedding profiles, no significant association was found between positive PRRSV status and positive HEV status.

KEYWORDS:

HEV; PRRSV; co-infections; evolution and molecular epidemiology; porcine viruses

PMID:: 28598352
DOI:: 10.3390/v9060110

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Saturday, December 2, 2017

Efficacy and safety of simultaneous vaccination with two modified live virus vaccines against porcine reproductive and respiratory syndrome virus types 1 and 2 in pigs.

Abstract

KEYWORDS:

Monday, October 30, 2017

Monitoring breeding herd production data to detect PRRSV outbreaks

Abstract

Keywords

Thursday, October 19, 2017

Knockout of maternal CD163 protects fetuses from infection with porcine reproductive and respiratory syndrome virus (PRRSV).

Abstract

Wednesday, October 18, 2017

Body temperature and motion: Evaluation of an online monitoring system in pigs challenged with Porcine Reproductive & Respiratory Syndrome Virus.

Abstract

KEYWORDS:

Monday, September 11, 2017

Evaluation of the effect of a porcine reproductive and respiratory syndrome (PRRS) modified-live virus vaccine on sow reproductive performance in endemic PRRS farms.

Abstract

KEYWORDS:

Thursday, August 17, 2017

The Use of Bioaerosol Sampling for Airborne Virus Surveillance in Swine Production Facilities: A Mini Review.

Abstract

KEYWORDS:

Wednesday, July 26, 2017

Epidemiological investigations of the introduction of porcine reproductive and respiratory syndrome virus in Chile, 2013-2015.

Abstract

Thursday, July 20, 2017

Effect of immunologic solutions on sows and gilts on time to stability, and production losses in breeding herds infected with 1-7-4 PRRSv.

Abstract

KEYWORDS:

OptisampleTM: Open web-based application to optimize sampling strategies for active surveillance activities at the herd level illustrated using Porcine Respiratory Reproductive Syndrome (PRRS).

Abstract

Friday, July 14, 2017

A Review of Quantitative Tools Used to Assess the Epidemiology of Porcine Reproductive and Respiratory Syndrome in U.S. Swine Farms Using Dr. Morrison's Swine Health Monitoring Program Data.

Abstract

KEYWORDS:

Monday, June 12, 2017

UK Pigs at the Time of Slaughter: Investigation into the Correlation of Infection with PRRSV and HEV.

Abstract

KEYWORDS:

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