Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods

Porcine reproductive and respiratory syndrome virus (PRRSV) remains a significant challenge to the swine industry, resulting in substantial productivity and, consequently, economic losses. This study aimed to quantify the impact of PRRSV outbreaks in sow farms on nursery mortality using causal infer...

Full description

Saved in:
Bibliographic Details
Main Authors: E. S. Magalhães, D. Zhang, C. A. A. Moura, Annette O’Connor, C. Wang, D. J. Holtkamp, G. S. Silva, D. C. L. Linhares
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-04-01
Series:Frontiers in Veterinary Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fvets.2025.1545034/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850174006852845568
author E. S. Magalhães
D. Zhang
C. A. A. Moura
Annette O’Connor
C. Wang
C. Wang
D. J. Holtkamp
G. S. Silva
D. C. L. Linhares
author_facet E. S. Magalhães
D. Zhang
C. A. A. Moura
Annette O’Connor
C. Wang
C. Wang
D. J. Holtkamp
G. S. Silva
D. C. L. Linhares
author_sort E. S. Magalhães
collection DOAJ
description Porcine reproductive and respiratory syndrome virus (PRRSV) remains a significant challenge to the swine industry, resulting in substantial productivity and, consequently, economic losses. This study aimed to quantify the impact of PRRSV outbreaks in sow farms on nursery mortality using causal inference methods. The study design followed a retrospective observational approach, where PRRSV epidemic status in source sow farms was the exposure, and nursery mortality (percentage of dead pigs in the first 60 days post-weaning) was the outcome. Causal inference techniques were employed to estimate the effect of the exposure (PRRSV epidemic status) on the outcome (nursery mortality). Data from a Midwestern US swine production system comprising 2,592 lots of pigs, representing approximately 5 million pigs marketed between January 2021 and December 2022, were analyzed. A causal diagram was constructed to visualize the relationship between PRRSV epidemic exposure and nursery mortality, while controlling for potential confounding factors including season, average parity at farrow, and sow farm Mycoplasma hyopneumoniae status. Four analytical approaches were employed: univariate and multivariable regression models, propensity score matching, and a doubly robust method. The results indicated that PRRSV epidemic lots had higher nursery mortality compared to non-epidemic lots, regardless of the modeling approach used. The doubly robust method provided the most accurate estimates, offering lower mortality differences and narrower confidence intervals. This study demonstrated the application of causal inference methods on swine data to measure the impact of PRRSV on swine nursery mortality, which is an approach commonly used in other epidemiology areas but not well explored in veterinary epidemiology. The findings highlight the importance of employing causal inference models in veterinary epidemiology to improve the accuracy of disease impact assessments in field conditions, with potential applications in studying other pathogens or disease-related factors in livestock production.
format Article
id doaj-art-750aeb1d2f2b498ca34f3ed5b2d490c9
institution OA Journals
issn 2297-1769
language English
publishDate 2025-04-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Veterinary Science
spelling doaj-art-750aeb1d2f2b498ca34f3ed5b2d490c92025-08-20T02:19:44ZengFrontiers Media S.A.Frontiers in Veterinary Science2297-17692025-04-011210.3389/fvets.2025.15450341545034Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methodsE. S. Magalhães0D. Zhang1C. A. A. Moura2Annette O’Connor3C. Wang4C. Wang5D. J. Holtkamp6G. S. Silva7D. C. L. Linhares8Department of Animal Science, Iowa State University, Ames, IA, United StatesDepartment of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, United StatesIowa Select Farms, Iowa Falls, IA, United StatesDepartment of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United StatesDepartment of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, United StatesDepartment of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United StatesDepartment of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United StatesDepartment of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United StatesDepartment of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United StatesPorcine reproductive and respiratory syndrome virus (PRRSV) remains a significant challenge to the swine industry, resulting in substantial productivity and, consequently, economic losses. This study aimed to quantify the impact of PRRSV outbreaks in sow farms on nursery mortality using causal inference methods. The study design followed a retrospective observational approach, where PRRSV epidemic status in source sow farms was the exposure, and nursery mortality (percentage of dead pigs in the first 60 days post-weaning) was the outcome. Causal inference techniques were employed to estimate the effect of the exposure (PRRSV epidemic status) on the outcome (nursery mortality). Data from a Midwestern US swine production system comprising 2,592 lots of pigs, representing approximately 5 million pigs marketed between January 2021 and December 2022, were analyzed. A causal diagram was constructed to visualize the relationship between PRRSV epidemic exposure and nursery mortality, while controlling for potential confounding factors including season, average parity at farrow, and sow farm Mycoplasma hyopneumoniae status. Four analytical approaches were employed: univariate and multivariable regression models, propensity score matching, and a doubly robust method. The results indicated that PRRSV epidemic lots had higher nursery mortality compared to non-epidemic lots, regardless of the modeling approach used. The doubly robust method provided the most accurate estimates, offering lower mortality differences and narrower confidence intervals. This study demonstrated the application of causal inference methods on swine data to measure the impact of PRRSV on swine nursery mortality, which is an approach commonly used in other epidemiology areas but not well explored in veterinary epidemiology. The findings highlight the importance of employing causal inference models in veterinary epidemiology to improve the accuracy of disease impact assessments in field conditions, with potential applications in studying other pathogens or disease-related factors in livestock production.https://www.frontiersin.org/articles/10.3389/fvets.2025.1545034/fullswinebreeding herdPRRS outbreakcausal inferencenursery mortality
spellingShingle E. S. Magalhães
D. Zhang
C. A. A. Moura
Annette O’Connor
C. Wang
C. Wang
D. J. Holtkamp
G. S. Silva
D. C. L. Linhares
Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods
Frontiers in Veterinary Science
swine
breeding herd
PRRS outbreak
causal inference
nursery mortality
title Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods
title_full Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods
title_fullStr Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods
title_full_unstemmed Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods
title_short Measuring the impact of sow farm outbreaks with PRRS virus on the downstream mortality using causal inference methods
title_sort measuring the impact of sow farm outbreaks with prrs virus on the downstream mortality using causal inference methods
topic swine
breeding herd
PRRS outbreak
causal inference
nursery mortality
url https://www.frontiersin.org/articles/10.3389/fvets.2025.1545034/full
work_keys_str_mv AT esmagalhaes measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT dzhang measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT caamoura measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT annetteoconnor measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT cwang measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT cwang measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT djholtkamp measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT gssilva measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods
AT dcllinhares measuringtheimpactofsowfarmoutbreakswithprrsvirusonthedownstreammortalityusingcausalinferencemethods