Pub Date : 2026-02-07DOI: 10.1016/j.prevetmed.2026.106791
Charlott Olofsson, Aliaksandr Hubin, Hilde Vinje, Amira Rachah, Olav Reksen, Camilla Kielland, Ingrid Toftaker
The large amount of data collected through automatic milking systems (AMS) may be used for early detection of intramammary infections and become instrumental for monitoring udder health in dairy herds. Machine learning (ML) techniques can aid in improving diagnostic test properties of current indicators of subclinical mastitis (SCM). In this study, we present novel customized ML models for predicting SCM from AMS data. We show how results from several diagnostic tests can be incorporated into ML model training by explicitly accounting for their sensitivity and specificity. The underlying infection status was modeled as a latent variable derived from bacteriological culture (BC) and polymerase chain reaction (PCR) results on milk samples. Model performance was evaluated using a customized log-likelihood (CLL) function, addressing uncertainty in prediction target, and compared with traditional metrics using simulated data. Our study demonstrates that incorporating prior knowledge of sensitivity and specificity of the tests directly into the likelihood function during model training enables reliable ML even in scenarios with an imperfect target variable. The customized models achieved the highest CLL scores on real data and demonstrated significantly better calibration on simulated data. At the same time, all models showed similarly near-perfect area under the curve (AUC) on simulated data. Further validation across herds is needed, but our approach shows promise for robust SCM prediction from AMS data using ML. The framework is applicable to other scenarios in veterinary epidemiology with imperfectly measured outcomes.
{"title":"Machine learning for detection of subclinical mastitis: A Bayesian approach incorporating diagnostic test properties.","authors":"Charlott Olofsson, Aliaksandr Hubin, Hilde Vinje, Amira Rachah, Olav Reksen, Camilla Kielland, Ingrid Toftaker","doi":"10.1016/j.prevetmed.2026.106791","DOIUrl":"https://doi.org/10.1016/j.prevetmed.2026.106791","url":null,"abstract":"<p><p>The large amount of data collected through automatic milking systems (AMS) may be used for early detection of intramammary infections and become instrumental for monitoring udder health in dairy herds. Machine learning (ML) techniques can aid in improving diagnostic test properties of current indicators of subclinical mastitis (SCM). In this study, we present novel customized ML models for predicting SCM from AMS data. We show how results from several diagnostic tests can be incorporated into ML model training by explicitly accounting for their sensitivity and specificity. The underlying infection status was modeled as a latent variable derived from bacteriological culture (BC) and polymerase chain reaction (PCR) results on milk samples. Model performance was evaluated using a customized log-likelihood (CLL) function, addressing uncertainty in prediction target, and compared with traditional metrics using simulated data. Our study demonstrates that incorporating prior knowledge of sensitivity and specificity of the tests directly into the likelihood function during model training enables reliable ML even in scenarios with an imperfect target variable. The customized models achieved the highest CLL scores on real data and demonstrated significantly better calibration on simulated data. At the same time, all models showed similarly near-perfect area under the curve (AUC) on simulated data. Further validation across herds is needed, but our approach shows promise for robust SCM prediction from AMS data using ML. The framework is applicable to other scenarios in veterinary epidemiology with imperfectly measured outcomes.</p>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"249 ","pages":"106791"},"PeriodicalIF":2.4,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146157986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-06DOI: 10.1016/j.prevetmed.2026.106806
Dana C Pittman Ratterree, Robert Ohsfeldt, Sapna Chitlapilly Dass, Martial L Ndeffo-Mbah
Swine influenza virus A (SIV-A) is endemic in hog farms globally, causing significant economic losses to the swine industry. While vaccination is a recommended control strategy, its economic value in specific production phases remains under-evaluated. This study investigated the economic viability of SIV-A vaccination in a U.S. wean-to-finish commercial farm using a stochastic epidemic model. A cost-benefit analysis was performed to estimate the Benefit-Cost Ratio (BCR), Net Present Value (NPV), and Return on Investment (ROI) of swine vaccination. In the absence of vaccination, the model predicted a high within-farm attack rate of approximately 82.5 % (95 % Confidence Interval (CI): 81 % - 0.84 %). Economic analysis showed that the profitability of SIV-A vaccination was highly dependent on vaccine efficacy. Vaccine efficacy below 70 % was shown to be not economically viable, yielding negative NPV and BCR below 1. Conversely, vaccination with ≥ 80 % efficacy was profitable, with BCRs ranging from 1.54 (95 % CI: 1.538, 1.54) to 4.09 (95 % CI: 4.082, 4.092) and net profits varying from US$0.90 ( 95 % CI: US$0.79, US$1.02) per pig up to US$3.41 (95 %CI: US$3.40, US$3.41) per pig. Vaccination against SIV-A in wean-to-finish settings was shown to be an economically favorable intervention when the vaccine is highly efficacious against the circulating SIV-A subtype. Sensitivity analysis indicated that vaccine efficacy, the cost of vaccination, and influenza-induced mortality rates were the most critical drivers determining the economic success of the program.
{"title":"Cost-benefit analysis of swine influenza a vaccination in wean-to-finish production setting in the United States.","authors":"Dana C Pittman Ratterree, Robert Ohsfeldt, Sapna Chitlapilly Dass, Martial L Ndeffo-Mbah","doi":"10.1016/j.prevetmed.2026.106806","DOIUrl":"https://doi.org/10.1016/j.prevetmed.2026.106806","url":null,"abstract":"<p><p>Swine influenza virus A (SIV-A) is endemic in hog farms globally, causing significant economic losses to the swine industry. While vaccination is a recommended control strategy, its economic value in specific production phases remains under-evaluated. This study investigated the economic viability of SIV-A vaccination in a U.S. wean-to-finish commercial farm using a stochastic epidemic model. A cost-benefit analysis was performed to estimate the Benefit-Cost Ratio (BCR), Net Present Value (NPV), and Return on Investment (ROI) of swine vaccination. In the absence of vaccination, the model predicted a high within-farm attack rate of approximately 82.5 % (95 % Confidence Interval (CI): 81 % - 0.84 %). Economic analysis showed that the profitability of SIV-A vaccination was highly dependent on vaccine efficacy. Vaccine efficacy below 70 % was shown to be not economically viable, yielding negative NPV and BCR below 1. Conversely, vaccination with ≥ 80 % efficacy was profitable, with BCRs ranging from 1.54 (95 % CI: 1.538, 1.54) to 4.09 (95 % CI: 4.082, 4.092) and net profits varying from US$0.90 ( 95 % CI: US$0.79, US$1.02) per pig up to US$3.41 (95 %CI: US$3.40, US$3.41) per pig. Vaccination against SIV-A in wean-to-finish settings was shown to be an economically favorable intervention when the vaccine is highly efficacious against the circulating SIV-A subtype. Sensitivity analysis indicated that vaccine efficacy, the cost of vaccination, and influenza-induced mortality rates were the most critical drivers determining the economic success of the program.</p>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"249 ","pages":"106806"},"PeriodicalIF":2.4,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146157954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-04DOI: 10.1016/j.prevetmed.2026.106789
Eric Kazadi-Kawaya, Blaise Mbiala Vodiasilua, Didier Mwanangombe Makopa, Christian Bakebidio Kanda, Gilby Situtala Benina, Serge Lwange Mufolo, Prisca Kabangu Nsimba, Christian Maheshe Murhula, Madimba-Kapanga
The Democratic Republic of the Congo (DRC) has set out a plan to eliminate dog-transmitted human rabies by 2033. The 50 million US dollar plan, 65 % of which is allocated to free vaccinations, has been difficult to fund. A study in three DRC sites (Mont-Ngafula in Kinshasa and Matadi and Muanda in Kongo-Central) aimed to explore an affordable, cost-effective local routine vaccination system. A survey was conducted in dog-owning households at each site regarding socioeconomic status, awareness of rabies and the characteristics and vaccination status of dogs. Then veterinary service accessibility, affordability and resources were assessed. Finally, a pilot of a routine vaccination service was implemented. Using R software, a logistic regression was performed to explore factors influencing rabies vaccination. Factors influencing vaccination included socio-economic status, dog characteristics, and the affordability of vaccinations. The cost of vaccinations (25-30 USD in Mont-Ngafula, 10-15 USD in Matadi, 7 USD in Muanda) was two to three times more expensive than owners considered affordable (7-9 USD, 1-5 USD, 2-6 USD). Geographical distribution of providers was poor and resources to vaccinate dogs routinely were inadequate. A pilot programme supplied vaccines and accessories to public veterinary services, expanding their geographic coverage by setting up temporary vaccination points and charging affordable costs (4 USD in Matadi and Muanda, and 5 USD in Mont-Ngafula). This increased adherence among dog owners, though the response varied between sites. The study offers useful insights into the key considerations for successfully implementing a cost-effective and affordable routine vaccination service at local level.
{"title":"Lessons learned from a pilot dog rabies vaccination model in Kinshasa and Kongo-Central, Democratic Republic of the Congo.","authors":"Eric Kazadi-Kawaya, Blaise Mbiala Vodiasilua, Didier Mwanangombe Makopa, Christian Bakebidio Kanda, Gilby Situtala Benina, Serge Lwange Mufolo, Prisca Kabangu Nsimba, Christian Maheshe Murhula, Madimba-Kapanga","doi":"10.1016/j.prevetmed.2026.106789","DOIUrl":"https://doi.org/10.1016/j.prevetmed.2026.106789","url":null,"abstract":"<p><p>The Democratic Republic of the Congo (DRC) has set out a plan to eliminate dog-transmitted human rabies by 2033. The 50 million US dollar plan, 65 % of which is allocated to free vaccinations, has been difficult to fund. A study in three DRC sites (Mont-Ngafula in Kinshasa and Matadi and Muanda in Kongo-Central) aimed to explore an affordable, cost-effective local routine vaccination system. A survey was conducted in dog-owning households at each site regarding socioeconomic status, awareness of rabies and the characteristics and vaccination status of dogs. Then veterinary service accessibility, affordability and resources were assessed. Finally, a pilot of a routine vaccination service was implemented. Using R software, a logistic regression was performed to explore factors influencing rabies vaccination. Factors influencing vaccination included socio-economic status, dog characteristics, and the affordability of vaccinations. The cost of vaccinations (25-30 USD in Mont-Ngafula, 10-15 USD in Matadi, 7 USD in Muanda) was two to three times more expensive than owners considered affordable (7-9 USD, 1-5 USD, 2-6 USD). Geographical distribution of providers was poor and resources to vaccinate dogs routinely were inadequate. A pilot programme supplied vaccines and accessories to public veterinary services, expanding their geographic coverage by setting up temporary vaccination points and charging affordable costs (4 USD in Matadi and Muanda, and 5 USD in Mont-Ngafula). This increased adherence among dog owners, though the response varied between sites. The study offers useful insights into the key considerations for successfully implementing a cost-effective and affordable routine vaccination service at local level.</p>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"249 ","pages":"106789"},"PeriodicalIF":2.4,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146137518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-31DOI: 10.1016/j.prevetmed.2026.106790
Simon Bourassi, Emily John, J Trenton McClure, Emilia Bourassi, Greg Keefe, Shawn Mckenna, John VanLeeuwen, Henrik Stryhn
Bovine leukemia virus (BLV) causes enzootic bovine leukosis and can lead to significant economic losses in dairy herds. Accurate estimation of within-herd prevalence is an essential step for effective continuous surveillance and control. The objectives of this study were: (1) to build a statistical model predicting within-herd BLV prevalence using Bulk Tank Milk (BTM) ELISA antibody titers, (2) to assess the temporal stability of this model over three years, and (3) to explore the relationship between mean individual cow antibody titers and BTM results. A convenience sample of 30 dairy herds in the Canadian Maritimes was studied. Three years of bi-monthly BTM samples were collected to measure the BTM ELISA antibody titers. Individual ELISA testing of cows contributing to BTM was performed annually for three years, permitting estimation of the true within-herd prevalence. Among the 30 herds, 1453 cows tested BLV-positive in Year 1, 899 in Year 2, and 760 in Year 3. Mean within-herd prevalence were 42 % (SD 24 %), 31 % (SD 20 %), and 29 % (SD 20 %) in Year 1, 2, and 3, respectively. Seven univariable linear regression models for true within-herd prevalence were built, with predictors consisting of single BTM results or averages from two or three rounds of BTM results in proximity to the time of individual ELISA testing. The model using the average of two BTM samples collected two months apart as a predictor prevalence in the herd was selected as the best model based on the highest R² = 0.91 and Predictive R² = 0.90. Model predictions showed strong agreement with observed within-herd prevalence in subsequent years (concordance correlation coefficients 0.94-0.98), indicating temporal stability. Mean individual cow antibody titers were strongly correlated with BTM antibody levels (r = 0.95). This study presents a practical, stable, and cost-effective approach to estimate and monitor BLV within-herd prevalence using BTM ELISA testing. The model can support surveillance programs and help guide herd-level BLV management decisions over time.
{"title":"Stability and validation of a bulk tank milk-based model to estimate within-herd bovine leukemia virus prevalence in dairy herds.","authors":"Simon Bourassi, Emily John, J Trenton McClure, Emilia Bourassi, Greg Keefe, Shawn Mckenna, John VanLeeuwen, Henrik Stryhn","doi":"10.1016/j.prevetmed.2026.106790","DOIUrl":"https://doi.org/10.1016/j.prevetmed.2026.106790","url":null,"abstract":"<p><p>Bovine leukemia virus (BLV) causes enzootic bovine leukosis and can lead to significant economic losses in dairy herds. Accurate estimation of within-herd prevalence is an essential step for effective continuous surveillance and control. The objectives of this study were: (1) to build a statistical model predicting within-herd BLV prevalence using Bulk Tank Milk (BTM) ELISA antibody titers, (2) to assess the temporal stability of this model over three years, and (3) to explore the relationship between mean individual cow antibody titers and BTM results. A convenience sample of 30 dairy herds in the Canadian Maritimes was studied. Three years of bi-monthly BTM samples were collected to measure the BTM ELISA antibody titers. Individual ELISA testing of cows contributing to BTM was performed annually for three years, permitting estimation of the true within-herd prevalence. Among the 30 herds, 1453 cows tested BLV-positive in Year 1, 899 in Year 2, and 760 in Year 3. Mean within-herd prevalence were 42 % (SD 24 %), 31 % (SD 20 %), and 29 % (SD 20 %) in Year 1, 2, and 3, respectively. Seven univariable linear regression models for true within-herd prevalence were built, with predictors consisting of single BTM results or averages from two or three rounds of BTM results in proximity to the time of individual ELISA testing. The model using the average of two BTM samples collected two months apart as a predictor prevalence in the herd was selected as the best model based on the highest R² = 0.91 and Predictive R² = 0.90. Model predictions showed strong agreement with observed within-herd prevalence in subsequent years (concordance correlation coefficients 0.94-0.98), indicating temporal stability. Mean individual cow antibody titers were strongly correlated with BTM antibody levels (r = 0.95). This study presents a practical, stable, and cost-effective approach to estimate and monitor BLV within-herd prevalence using BTM ELISA testing. The model can support surveillance programs and help guide herd-level BLV management decisions over time.</p>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"249 ","pages":"106790"},"PeriodicalIF":2.4,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146119752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-29DOI: 10.1016/j.prevetmed.2026.106793
Sen Wang , Yue Wang , Yaling Cao , Quanzhen Cai , Jing Li , Yumei Liu
The occurrence of zoonotic diseases on livestock farms, especially infectious diseases such as echinococcosis, poses a severe threat to surrounding ecosystems and the health of nearby residents. It is crucial to take proper measures to increase farmers' knowledge, awareness and practices regarding zoonoses. Cognitive interventions are widely used in the control of epidemics. Using Chinese livestock farming as a case study, this study examined the effect of cognitive intervention (i.e., training and dissemination) on farmers’ pro-environmental behaviors, with the key dependent variable including both zoonosis-prevention behaviors (e.g., dog deworming and lamb vaccination) and daily management behaviors (e.g., household waste and sewage handling). Based on survey data collected from 496 livestock farmers over four years in Qinghai province, China, the study employed a two-way fixed-effects regression model to explore both the direct and indirect effects of zoonotic cognitive intervention on farmers' pro-environmental behaviors, and also explored the mediating effects of zoonotic knowledge and perceptions of environment. The findings reveal that: (1) Zoonotic cognitive interventions significantly improved farmers' behaviors in preventing and controlling zoonotic diseases. (2) The interventions generated positive indirect effects on other pro-environmental behaviors, particularly proper disposal of livestock waste and household garbage. (3) Increased knowledge on zoonosis, as well as pollution awareness were key mechanisms linking interventions to behavioral changes, and (4) the effects were heterogeneously stronger among less-educated farmers and in regions with lower epidemic prevalence and stricter ecological protection policies. These results highlight the policy relevance of incorporating cognitive interventions into rural public health and environmental management programs, providing new evidence to support sustainable livestock farming and inform integrated strategies for health and agricultural policy.
{"title":"Direct and indirect effects of zoonosis intervention on pro-environmental behaviors among livestock farmers","authors":"Sen Wang , Yue Wang , Yaling Cao , Quanzhen Cai , Jing Li , Yumei Liu","doi":"10.1016/j.prevetmed.2026.106793","DOIUrl":"10.1016/j.prevetmed.2026.106793","url":null,"abstract":"<div><div>The occurrence of zoonotic diseases on livestock farms, especially infectious diseases such as echinococcosis, poses a severe threat to surrounding ecosystems and the health of nearby residents. It is crucial to take proper measures to increase farmers' knowledge, awareness and practices regarding zoonoses. Cognitive interventions are widely used in the control of epidemics. Using Chinese livestock farming as a case study, this study examined the effect of cognitive intervention (i.e., training and dissemination) on farmers’ pro-environmental behaviors, with the key dependent variable including both zoonosis-prevention behaviors (e.g., dog deworming and lamb vaccination) and daily management behaviors (e.g., household waste and sewage handling). Based on survey data collected from 496 livestock farmers over four years in Qinghai province, China, the study employed a two-way fixed-effects regression model to explore both the direct and indirect effects of zoonotic cognitive intervention on farmers' pro-environmental behaviors, and also explored the mediating effects of zoonotic knowledge and perceptions of environment. The findings reveal that: (1) Zoonotic cognitive interventions significantly improved farmers' behaviors in preventing and controlling zoonotic diseases. (2) The interventions generated positive indirect effects on other pro-environmental behaviors, particularly proper disposal of livestock waste and household garbage. (3) Increased knowledge on zoonosis, as well as pollution awareness were key mechanisms linking interventions to behavioral changes, and (4) the effects were heterogeneously stronger among less-educated farmers and in regions with lower epidemic prevalence and stricter ecological protection policies. These results highlight the policy relevance of incorporating cognitive interventions into rural public health and environmental management programs, providing new evidence to support sustainable livestock farming and inform integrated strategies for health and agricultural policy.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"249 ","pages":"Article 106793"},"PeriodicalIF":2.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Effective Salmonella control in pigs requires understanding how the pathogen is introduced and spreads on farms. This study aimed to identify potential sources of Salmonella infection in pigs using both epidemiological and microbiological methods. A cross-sectional study was conducted on 148 fattening pig farms in the Netherlands. Porcine fecal samples were collected and tested for the presence of Salmonella, and a questionnaire on farm characteristics was completed. Risk factors significantly associated with Salmonella presence at farm-level were identified through logistic regression analysis. For source attribution based on microbial subtyping, serotyped Salmonella isolates obtained from the Dutch national laboratory surveillance system (2016–2023) were used. Pig isolates (n = 494) were attributed to nine putative sources (n = 4171 isolates) using the modified Dutch (mDM) and modified Hald (mHM) models.
A farm-level prevalence of 9.5 % (14/148; 95 % CI 5.3–15.4 %) was found. Cleaning the pens between batches (odds ratio [OR] 0.139, 95 % CI 0.030–0.625) and moving piglets at a later age to the fattening unit (in weeks, OR 0.538, 95 % CI 0.290–0.998) were significantly associated with reduced odds of Salmonella presence, whereas the presence of cattle on the farm increased the odds (OR 4.860, 95 % CI 1.346–17.544). Both mDM and mHM attributed most pig isolates to other pigs (mDM: 43.0 %; mHM: 72.6 %), followed by cattle (mDM: 22.6 %; mHM: 11.0 %) and broilers (mDM: 9.2 %; mHM: 5.0 %), as sources.
This study indicates pig-to-pig transmission as the main source of Salmonella in pigs and suggests that cattle may significantly contribute to Salmonella introduction into pig herds on multi-species farms.
有效控制猪的沙门氏菌需要了解病原体是如何在农场引入和传播的。本研究旨在利用流行病学和微生物学方法确定猪沙门氏菌感染的潜在来源。对荷兰148个育肥猪场进行了横断面研究。收集猪粪便样本，检测是否存在沙门氏菌，并完成农场特征问卷调查。通过logistic回归分析，确定了与沙门氏菌在农场水平存在显著相关的危险因素。对于基于微生物亚型的来源归属，使用了从荷兰国家实验室监测系统（2016-2023）获得的血清型沙门氏菌分离株。猪分离株（n = 494）采用改进的Dutch （mDM）和改进的Hald （mHM）模型归因于9个假定来源（n = 4171株）。农场水平的患病率为9.5 %（14/148;95 % CI 5.3-15.4 %）。清理批次之间的猪圈（比值比[OR] 0.139, 95 % CI 0.030-0.625）和将仔猪移至育猪场（以周为单位，比值比[OR] 0.538, 95 % CI 0.290-0.998）与沙门氏菌存在的几率降低显著相关，而在猪场饲养牛则增加了沙门氏菌存在的几率（比值比[OR] 4.860, 95 % CI 1.346-17.544）。mDM和mHM都将大多数猪分离株归因于其他猪（mDM: 43.0 %;mHM: 72.6 %），其次是牛（mDM: 22.6 %;mHM: 11.0 %）和肉鸡（mDM: 9.2 %;mHM: 5.0 %）。该研究表明，猪与猪之间的传播是猪中沙门氏菌的主要来源，并表明在多物种农场中，牛可能对沙门氏菌传入猪群有重要贡献。
{"title":"Sources of Salmonella infection in pigs in the Netherlands: Epidemiological risk factors and subtyping-based source attribution","authors":"Hester Bloem , Indra Bergval , Tryntsje Cuperus , Maren Lanzl , Greetje Castelijn , Ben Wit , Marieke Opsteegh , Lapo Mughini-Gras","doi":"10.1016/j.prevetmed.2026.106792","DOIUrl":"10.1016/j.prevetmed.2026.106792","url":null,"abstract":"<div><div>Effective <em>Salmonella</em> control in pigs requires understanding how the pathogen is introduced and spreads on farms. This study aimed to identify potential sources of <em>Salmonella</em> infection in pigs using both epidemiological and microbiological methods. A cross-sectional study was conducted on 148 fattening pig farms in the Netherlands. Porcine fecal samples were collected and tested for the presence of <em>Salmonella</em>, and a questionnaire on farm characteristics was completed. Risk factors significantly associated with <em>Salmonella</em> presence at farm-level were identified through logistic regression analysis. For source attribution based on microbial subtyping, serotyped <em>Salmonella</em> isolates obtained from the Dutch national laboratory surveillance system (2016–2023) were used. Pig isolates (<em>n</em> = 494) were attributed to nine putative sources (<em>n</em> = 4171 isolates) using the modified Dutch (mDM) and modified Hald (mHM) models.</div><div>A farm-level prevalence of 9.5 % (14/148; 95 % CI 5.3–15.4 %) was found. Cleaning the pens between batches (odds ratio [OR] 0.139, 95 % CI 0.030–0.625) and moving piglets at a later age to the fattening unit (in weeks, OR 0.538, 95 % CI 0.290–0.998) were significantly associated with reduced odds of <em>Salmonella</em> presence, whereas the presence of cattle on the farm increased the odds (OR 4.860, 95 % CI 1.346–17.544). Both mDM and mHM attributed most pig isolates to other pigs (mDM: 43.0 %; mHM: 72.6 %), followed by cattle (mDM: 22.6 %; mHM: 11.0 %) and broilers (mDM: 9.2 %; mHM: 5.0 %), as sources.</div><div>This study indicates pig-to-pig transmission as the main source of <em>Salmonella</em> in pigs and suggests that cattle may significantly contribute to <em>Salmonella</em> introduction into pig herds on multi-species farms.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"249 ","pages":"Article 106792"},"PeriodicalIF":2.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146070869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-15DOI: 10.1016/j.prevetmed.2026.106786
Eva Lena Estensmo , Silje Granstad , Kim B. Stevens , Sokratis Ptochos , Marianne Økland , Mona Nordmark , Siri Kulberg Sjurseth , Sigrid Gossé , Magne Hansen , Adrian L. Smith , Damer P. Blake , Camilla Sekse , Øivind Øines
Norway discontinued the prophylactic use of coccidiostats in broiler production in 2016, and all broilers are now raised without the routine use of coccidiostats. As an alternative strategy to control coccidiosis, all broiler flocks in Norway are now routinely vaccinated at hatch with vaccines based on live attenuated Eimeria oocysts. In this study, we investigated the population dynamics and interactions of Eimeria spp. and Clostridium perfringens in Norwegian broiler flocks vaccinated against coccidiosis in field settings. We also explored how this may be influenced by farm management practices. Fresh pooled fecal samples were collected as part of a longitudinal time-series and through a case-control design from commercial broiler flocks diagnosed with coccidiosis, necrotic enteritis (NE) or both. Samples were analyzed using conventional and molecular methods targeting the relevant pathogens. Management data were analyzed using multivariable logistic regression models to identify factors associated with coccidiosis and NE. The occurrence of Eimeria oocysts showed varying dynamics over time across individual flocks and companies, and Eimeria species composition largely reflected the content of the vaccine used. Higher numbers of E. maxima and lower overall management scores were identified as risk factors associated with NE. Coccidiosis appeared to be well controlled under the current production practices, whereas NE seems to increase after the abolishment of coccidiostats. This may be related to the indirect effects of coccidiostats on Clostridium spp. and is a consequence that should be carefully monitored in any circumstance where there is a move towards the use of anticoccidial vaccines in broiler production.
{"title":"A new era of coccidiosis control: Eimeria and Clostridium perfringens dynamics in vaccinated broiler flocks after the ionophore phase-out in Norway","authors":"Eva Lena Estensmo , Silje Granstad , Kim B. Stevens , Sokratis Ptochos , Marianne Økland , Mona Nordmark , Siri Kulberg Sjurseth , Sigrid Gossé , Magne Hansen , Adrian L. Smith , Damer P. Blake , Camilla Sekse , Øivind Øines","doi":"10.1016/j.prevetmed.2026.106786","DOIUrl":"10.1016/j.prevetmed.2026.106786","url":null,"abstract":"<div><div>Norway discontinued the prophylactic use of coccidiostats in broiler production in 2016, and all broilers are now raised without the routine use of coccidiostats. As an alternative strategy to control coccidiosis, all broiler flocks in Norway are now routinely vaccinated at hatch with vaccines based on live attenuated <em>Eimeria</em> oocysts. In this study, we investigated the population dynamics and interactions of <em>Eimeria</em> spp. and <em>Clostridium perfringens</em> in Norwegian broiler flocks vaccinated against coccidiosis in field settings. We also explored how this may be influenced by farm management practices. Fresh pooled fecal samples were collected as part of a longitudinal time-series and through a case-control design from commercial broiler flocks diagnosed with coccidiosis, necrotic enteritis (NE) or both. Samples were analyzed using conventional and molecular methods targeting the relevant pathogens. Management data were analyzed using multivariable logistic regression models to identify factors associated with coccidiosis and NE. The occurrence of <em>Eimeria</em> oocysts showed varying dynamics over time across individual flocks and companies, and <em>Eimeria</em> species composition largely reflected the content of the vaccine used. Higher numbers of <em>E. maxima</em> and lower overall management scores were identified as risk factors associated with NE. Coccidiosis appeared to be well controlled under the current production practices, whereas NE seems to increase after the abolishment of coccidiostats. This may be related to the indirect effects of coccidiostats on <em>Clostridium</em> spp. and is a consequence that should be carefully monitored in any circumstance where there is a move towards the use of anticoccidial vaccines in broiler production.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"248 ","pages":"Article 106786"},"PeriodicalIF":2.4,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146012155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-15DOI: 10.1016/j.prevetmed.2026.106785
Jaden M. Carlson , T. Brendan Murphy , Luke O’Grady , Jonas Brock , Maria P. Guelbenzu-Gonzalo , David A. Graham , Guy McGrath , Jamie A. Tratalos , Rafael de Andrade Moral , Niamh Mimnagh , Niamh L. Field , John F. Mee , Damien J. Barrett , Elizabeth A. Lane , Conor G. McAloon
Syndromic surveillance, which monitors clinical or production data as potential indicators of disease, can complement existing diagnostic testing strategies for a more comprehensive surveillance system. Consistently recorded mortality data with established identification and traceability routes across cattle sectors could be useful indicators to monitor in a syndromic surveillance system. Ireland is progressing toward the eradication of bovine viral diarrhoea (BVD) virus following a programme initiated in 2013 to identify and remove calves that test positive for BVD. As the country prepares for BVD-free status under the EU Animal Health Law, stakeholders must consider strategies to detect possible re-emergence. Historical data from the eradication programme provides a unique opportunity to evaluate mortality-based syndromic surveillance for this purpose. This study aimed to develop a syndromic surveillance model based on calf mortality data and evaluate its use for early detection of BVD re-emergence in Ireland. For years 2014 through 2023, mixed-effects Cox proportional hazards models were built using calf mortality up to 100 days of age. Herd-level frailty estimates were extracted from these models for each year, which were then clustered to identify subgroups of herds with distinct temporal patterns in herd-level mortality hazard. Four separate thresholds were used to flag herds with increased calf mortality hazard. Overall, these flags demonstrated high specificity (86–92 %) but low sensitivity (11–22 %) for herd-level BVD status, suggesting that this approach alone would not reliably detect BVD re-emergence. Nonetheless, this method could support Ireland’s ability to achieve and sustain BVD-free status while providing valuable insights for similar surveillance efforts more broadly. This methodology is adaptable to other species, diseases, and syndromes, making it a versatile tool for animal health surveillance.
{"title":"Using herd frailty estimates from survival models in a mortality-based syndromic surveillance system","authors":"Jaden M. Carlson , T. Brendan Murphy , Luke O’Grady , Jonas Brock , Maria P. Guelbenzu-Gonzalo , David A. Graham , Guy McGrath , Jamie A. Tratalos , Rafael de Andrade Moral , Niamh Mimnagh , Niamh L. Field , John F. Mee , Damien J. Barrett , Elizabeth A. Lane , Conor G. McAloon","doi":"10.1016/j.prevetmed.2026.106785","DOIUrl":"10.1016/j.prevetmed.2026.106785","url":null,"abstract":"<div><div>Syndromic surveillance, which monitors clinical or production data as potential indicators of disease, can complement existing diagnostic testing strategies for a more comprehensive surveillance system. Consistently recorded mortality data with established identification and traceability routes across cattle sectors could be useful indicators to monitor in a syndromic surveillance system. Ireland is progressing toward the eradication of bovine viral diarrhoea (BVD) virus following a programme initiated in 2013 to identify and remove calves that test positive for BVD. As the country prepares for BVD-free status under the EU Animal Health Law, stakeholders must consider strategies to detect possible re-emergence. Historical data from the eradication programme provides a unique opportunity to evaluate mortality-based syndromic surveillance for this purpose. This study aimed to develop a syndromic surveillance model based on calf mortality data and evaluate its use for early detection of BVD re-emergence in Ireland. For years 2014 through 2023, mixed-effects Cox proportional hazards models were built using calf mortality up to 100 days of age. Herd-level frailty estimates were extracted from these models for each year, which were then clustered to identify subgroups of herds with distinct temporal patterns in herd-level mortality hazard. Four separate thresholds were used to flag herds with increased calf mortality hazard. Overall, these flags demonstrated high specificity (86–92 %) but low sensitivity (11–22 %) for herd-level BVD status, suggesting that this approach alone would not reliably detect BVD re-emergence. Nonetheless, this method could support Ireland’s ability to achieve and sustain BVD-free status while providing valuable insights for similar surveillance efforts more broadly. This methodology is adaptable to other species, diseases, and syndromes, making it a versatile tool for animal health surveillance.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"248 ","pages":"Article 106785"},"PeriodicalIF":2.4,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146019401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The most effective proactive measures to combat the African swine fever virus (ASFV) and mitigate the financial losses associated with its spread to pig farms is to minimise its transmission within the wild boar population. The aim of the study was to compare traditional human ground search with alternative methods using specially trained detection dogs, hunting dogs and drones in locating and removing wild boar carcasses as the main source of ASFV infection. Most of wild boar carcasses 397 out of 400 (99.2 %) were found by the trained search dogs, while other 3 were located using hunting dogs. Also, the efficiency of carcass retrieval with hunting dogs was much lower than with trained dogs with 0.002 versus 2.08 ASFV RT-PCR positive WB carcasses found per search. Searches with drones, humans or mixed method were found unsuccessful. The search efficiency using dogs trained for this purpose was on average more than two and a half times higher than the values determined by the EFSA ASF exit strategy developed using the wild boar approach. The carcass retrieval by search dogs was associated with ASF seasonality in wild boar in the central Europe, however, was not affected by the harsher conditions of winter months. This is particularly important due to the ASFV ability to survive in low temperatures. The study revealed also local variation in the sampling efforts which could have affected effectivity of ASF passive surveillance. To our knowledge, the presented research is the first attempt to evaluate the use of dogs to locate wild boar carcasses as a key element of passive surveillance in ASF control.
{"title":"Use of dogs trained to search for wild boar carcasses in passive surveillance as the most effective tool to control the spread of African swine fever in Poland","authors":"Mateusz Kruszyński , Magdalena Larska , Beata Banaszak , Jadwiga Świlak , Patryk Tarka , Zygmunt Pejsak , Małgorzata Juszkiewicz , Grzegorz Woźniakowski","doi":"10.1016/j.prevetmed.2026.106784","DOIUrl":"10.1016/j.prevetmed.2026.106784","url":null,"abstract":"<div><div>The most effective proactive measures to combat the African swine fever virus (ASFV) and mitigate the financial losses associated with its spread to pig farms is to minimise its transmission within the wild boar population. The aim of the study was to compare traditional human ground search with alternative methods using specially trained detection dogs, hunting dogs and drones in locating and removing wild boar carcasses as the main source of ASFV infection. Most of wild boar carcasses 397 out of 400 (99.2 %) were found by the trained search dogs, while other 3 were located using hunting dogs. Also, the efficiency of carcass retrieval with hunting dogs was much lower than with trained dogs with 0.002 versus 2.08 ASFV RT-PCR positive WB carcasses found per search. Searches with drones, humans or mixed method were found unsuccessful. The search efficiency using dogs trained for this purpose was on average more than two and a half times higher than the values determined by the EFSA ASF exit strategy developed using the wild boar approach. The carcass retrieval by search dogs was associated with ASF seasonality in wild boar in the central Europe, however, was not affected by the harsher conditions of winter months. This is particularly important due to the ASFV ability to survive in low temperatures. The study revealed also local variation in the sampling efforts which could have affected effectivity of ASF passive surveillance. To our knowledge, the presented research is the first attempt to evaluate the use of dogs to locate wild boar carcasses as a key element of passive surveillance in ASF control.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"248 ","pages":"Article 106784"},"PeriodicalIF":2.4,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146012171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.prevetmed.2026.106783
P.J. Atkinson , C. Quimby , A. Datt , T.D. Nielsen , C.G.B. Caraguel
Our prospective cross-sectional survey of dogs from Western Fiji aimed to evaluate the fitness of common diagnostic test modalities to rule-in Dirofilaria immitis infection in patients with suggestive clinical history or signs. In the absence of a perfect reference standard, we used latent class modelling to evaluate the relative diagnostic accuracy of two point-of-care (POC) detection modalities – the modified Knott’s test (MKT) to detect circulating microfilaria and four antigen lateral flow immunoassays (LFI): Anigen Rapid Canine HW Ag Test® (Bionote Co.), SNAP® Heartworm RT Test (IDEXX Laboratories), trūRapid Heartworm (Heska), WITNESS Dirofilaria® (Zoetis Inc.). The tests’ fitness for ruling-in infection were compared using the likelihood ratios of a positive result (LR+). The performances of the MKT and the Anigen Rapid LFI to rule-in infection on fresh blood of clinically suspected dogs were moderate to strong (LR+=13.4, 95 %PCI: 6.7–114.6; LR+=20.2, 95 %PCI: 5.4–138.2; respectively) but not consistently different from each other. The Anigen Rapid, SNAP and truRapid tests consistently provided the strongest evidence to rule-in infection. The LR+ of the WITNESS test was approximately twelve times, nine times and two times lower than the SNAP, truRapid and Anigen Rapid LFIs respectively (Bayesian p-value 0.002, 0.004 and 0.02 respectively). Overall, a positive result from MKT or LFIs is suitable to rule-in infection in dogs raising clinical suspicion and would increase the post-test probability of infection similarly. If veterinarians are choosing between LFIs, they should favour either Anigen Rapid, SNAP and truRapid over WITNESS.
{"title":"Relative accuracy of point-of-care tests to rule-in heartworm infection in clinically suspected dogs using Bayesian latent class modelling","authors":"P.J. Atkinson , C. Quimby , A. Datt , T.D. Nielsen , C.G.B. Caraguel","doi":"10.1016/j.prevetmed.2026.106783","DOIUrl":"10.1016/j.prevetmed.2026.106783","url":null,"abstract":"<div><div>Our prospective cross-sectional survey of dogs from Western Fiji aimed to evaluate the fitness of common diagnostic test modalities to rule-in <em>Dirofilaria immitis</em> infection in patients with suggestive clinical history or signs. In the absence of a perfect reference standard, we used latent class modelling to evaluate the relative diagnostic accuracy of two point-of-care (POC) detection modalities – the modified Knott’s test (MKT) to detect circulating microfilaria and four antigen lateral flow immunoassays (LFI): Anigen Rapid Canine HW Ag Test® (Bionote Co.), SNAP® Heartworm RT Test (IDEXX Laboratories), trūRapid Heartworm (Heska), WITNESS Dirofilaria® (Zoetis Inc.). The tests’ fitness for ruling-in infection were compared using the likelihood ratios of a positive result (LR<sup>+</sup>). The performances of the MKT and the Anigen Rapid LFI to rule-in infection on fresh blood of clinically suspected dogs were moderate to strong (LR<sup>+</sup>=13.4, 95 %PCI: 6.7–114.6; LR<sup>+</sup>=20.2, 95 %PCI: 5.4–138.2; respectively) but not consistently different from each other. The Anigen Rapid, SNAP and truRapid tests consistently provided the strongest evidence to rule-in infection. The LR<sup>+</sup> of the WITNESS test was approximately twelve times, nine times and two times lower than the SNAP, truRapid and Anigen Rapid LFIs respectively (Bayesian p-value 0.002, 0.004 and 0.02 respectively). Overall, a positive result from MKT or LFIs is suitable to rule-in infection in dogs raising clinical suspicion and would increase the post-test probability of infection similarly. If veterinarians are choosing between LFIs, they should favour either Anigen Rapid, SNAP and truRapid over WITNESS.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"248 ","pages":"Article 106783"},"PeriodicalIF":2.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号