Risk factors associated with Johne's disease test status in dairy herds in Ireland

Barrett, Damien; Mee, John F.; Mullowney, Peter C.; Good, Margaret; McGrath, Guy; Clegg, Tracy A.; More, Simon J.

doi:10.1136/vr.c6866

Cited by 18 publications

(18 citation statements)

References 8 publications

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“…This last finding seems surprising because MAP can be present in colostrum when colostrum is acquired from MAP-positive cows. However, in the study conducted by Barrett et al (2011), colostrum from off-farm sources seemed to be a protective factor, possibly because it had been acquired from MAP-negative animals. The association of paratuberculosis with larger herds could be due to depopulation and restocking practices, particularly after removal of animals for disease control purposes (Mee and Richardson, 2008).…”

Section: Map Survival and Disease Risk Factorsmentioning

confidence: 70%

“…A study conducted in Ireland found risk factors such as feeding waste milk to calves, large herds, absence of individual calving pens, and herd depopulations due to notifiable diseases to be significantly associated with paratuberculosis in cattle (Mee and Richardson, 2008). Another Irish study found cattle importation, herd size, and herd depopulation as significant risk factors for paratuberculosis, whereas obtaining colostrum from off-farm sources seemed to be a protective factor in this particular study (Barrett et al, 2011). This last finding seems surprising because MAP can be present in colostrum when colostrum is acquired from MAP-positive cows.…”

Section: Map Survival and Disease Risk Factorsmentioning

confidence: 78%

“…In a study conducted by Good et al (2009), most of the positive animals identified (75%) were 4 yr of age and over. Herd size has been identified as a significant factor for the spread and prevalence of paratuberculosis (Ott et al, 1999;Caldow et al, 2001;Muskens et al, 2003;Groenendaal, 2005;Sayers and Cook, 2009;Barrett et al, 2011). Cattle residing in larger herds (>100 animals) and in herds where new animals have been acquired are at higher risk and more likely to test positive to paratuberculosis (Wells and Wagner, 2000;Hirst et al, 2004;Mee and Richardson, 2008).…”

Section: Map Survival and Disease Risk Factorsmentioning

confidence: 93%

“…Fecal PCR may also be used as a confirmatory test (Clark et al, 2008). Individual fecal culture of MAP is considered the reference test (Barrett et al, 2011). The apparent prevalence of MAP will partly depend on the diagnostic test used.…”

Section: Disease Detection and Prevalencementioning

confidence: 99%

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Invited review: The economic impact and control of paratuberculosis in cattle

Garcia

Shalloo

2015

Journal of Dairy Science

189

124

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Paratuberculosis (also called Johne's disease) is a chronic disease caused by Mycobacterium avium ssp. paratuberculosis (MAP) that affects ruminants and other animals. The epidemiology of paratuberculosis is complex and the clinical manifestations and economic impact of the disease in cattle can be variable depending on factors such as herd management, age, infection dose, and disease prevalence, among others. Additionally, considerable challenges are faced in the control of paratuberculosis in cattle, such as the lack of accurate and reliable diagnostic tests. Nevertheless, efforts are directed toward the control of this disease because it can cause substantial economic losses to the cattle industry mainly due to increased premature culling, replacement costs, decreased milk yield, reduced feed conversion efficiency, fertility problems, reduced slaughter values, and increased susceptibility to other diseases or conditions. The variability and uncertainty surrounding the estimations of paratuberculosis prevalence and impact influence the design, implementation, and efficiency of control programs in diverse areas of the world. This review covers important aspects of the economic impact and control of paratuberculosis, including challenges related to disease detection, estimations of the prevalence and economic effects of the disease, and the implementation of control programs. The control of paratuberculosis can improve animal health and welfare, increase productivity, reduce potential market problems, and increase overall business profitability. The benefits that can derive from the control of paratuberculosis need to be communicated to all industry stakeholders to promote the implementation of control programs. Moreover, if the suspected link between Johne's disease in ruminants and Crohn's disease in humans was established, significant economic losses could be expected, particularly for the dairy industry, making the control of this disease a priority across dairy industries internationally.

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Section: Map Survival and Disease Risk Factorsmentioning

confidence: 70%

Section: Map Survival and Disease Risk Factorsmentioning

confidence: 78%

Section: Map Survival and Disease Risk Factorsmentioning

confidence: 93%

Section: Disease Detection and Prevalencementioning

confidence: 99%

See 2 more Smart Citations

Invited review: The economic impact and control of paratuberculosis in cattle

Garcia

Shalloo

2015

Journal of Dairy Science

189

124

View full text Add to dashboard Cite

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“…The current study sought to provide robust evidence to support the use of cost-effective testing strategies in infected herds, informed by test methods, herd sizes, and costs that are relevant to the Irish industry. The current study is also informed by available knowledge about withinherd prevalence (low in many infected herds; Good et al, 2009) and time since herds were first infected (often relatively recently, within the last 15 yr, based on work by Barrett et al, 2011). The key findings should be of wider relevance and interest.…”

Section: Discussionmentioning

confidence: 94%

Evaluation of testing strategies to identify infected animals at a single round of testing within dairy herds known to be infected with Mycobacterium avium ssp. paratuberculosis

Cameron

Strain

et al. 2015

Journal of Dairy Science

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As part of a broader control strategy within herds known to be infected with Mycobacterium avium ssp. paratuberculosis (MAP), individual animal testing is generally conducted to identify infected animals for action, usually culling. Opportunities are now available to quantitatively compare different testing strategies (combinations of tests) in known infected herds. This study evaluates the effectiveness, cost, and cost-effectiveness of different testing strategies to identify infected animals at a single round of testing within dairy herds known to be MAP infected. A model was developed, taking account of both within-herd infection dynamics and test performance, to simulate the use of different tests at a single round of testing in a known infected herd. Model inputs included the number of animals at different stages of infection, the sensitivity and specificity of each test, and the costs of testing and culling. Testing strategies included either milk or serum ELISA alone or with fecal culture in series. Model outputs included effectiveness (detection fraction, the proportion of truly infected animals in the herd that are successfully detected by the testing strategy), cost, and cost-effectiveness (testing cost per true positive detected, total cost per true positive detected). Several assumptions were made: MAP was introduced with a single animal and no management interventions were implemented to limit within-herd transmission of MAP before this test. In medium herds, between 7 and 26% of infected animals are detected at a single round of testing, the former using the milk ELISA and fecal culture in series 5 yr after MAP introduction and the latter using fecal culture alone 15 yr after MAP introduction. The combined costs of testing and culling at a single round of testing increases with time since introduction of MAP infection, with culling costs being much greater than testing costs. The cost-effectiveness of testing varied by testing strategy. It was also greater at 5 yr, compared with 10 or 15 yr, since MAP introduction, highlighting the importance of early detection. Future work is needed to evaluate these testing strategies in subsequent rounds of testing as well as accounting for different herd dynamics and different levels of herd biocontainment.

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