Modeling of alternative testing strategies to demonstrate freedom from Mycobacterium avium ssp. paratuberculosis infection in test-negative dairy herds in the Republic of Ireland

Meyer, Anne; McAloon, Conor G.; Tratalos, Jamie A.; More, Simon J.; Citer, Lorna; Graham, D. A.; Sergeant, E.

doi:10.3168/jds.2018-14883

Cited by 18 publications

(23 citation statements)

References 39 publications

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“…Using data from the Irish pilot programme (2013-2016), a stochastic simulation model was developed to examine the impact of alternative testing strategies on confidence of herd freedom, accounting for the risk attributable to stock introductions from the general population of herds. This work found that a single annual herd ELISA test (milk or serum) of cattle ≥2 or ≥ 3 years could achieve adequate confidence within a reasonable timeframe [9]. This scenario provides a more practical strategy than that used in the pilot programme in Ireland, where biannual milk testing was used.…”

Section: Assurance Testingmentioning

confidence: 80%

“…Once these objectives had been agreed, the narrative review of control programmes was adjusted to consider programmes with similar objectives, with particular consideration of control options, and of challenges and constraints to programme credibility and sustainability. Further, two modelling studies were specifically commissioned by AHI to assess testing methods used to demonstrate confidence of freedom in herds [9] and to evaluate a range of national surveillance strategies for the detection of infected herds [10]. Collectively, this information was used to inform recommendations to the JDIG on the design and structure of a credible and sustainable Irish Johne's disease control programme.…”

Section: The Approachmentioning

confidence: 99%

“…The degree of confidence in freedom is dependent on factors including the sampling strategy and interval employed, the expected true prevalence of the disease in the population sampled and diagnostic test performance (sensitivity and specificity) [19,20]. In the context of MAP, confidence of freedom is also greatly influenced by the purchasing behaviour of the herdowner prior to and in the intervening period between testing [9,21].…”

Section: Assurance Testingmentioning

confidence: 99%

“…Imperfect test specificity is also problematic and follow-up confirmatory testing of positive test results adds to the cost and complicates herd assurance determination. Despite these limitations, moderate increases in confidence of freedom can be achieved over several years of repeated herd-testing [9,21].…”

Section: Assurance Testingmentioning

confidence: 99%

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Johne’s disease in Irish dairy herds: considerations for an effective national control programme

et al. 2020

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The Irish dairy industry has established a reputation for the production of safe and healthy dairy products and is seeking to further expand its export market for high value dairy products. To support its reputation, stakeholders aim to control Johne's disease. To assist decision-makers determine the most appropriate design for an Irish programme, a narrative review of the scientific literature on the epidemiology of Johne's disease, and selected control programmes throughout the world was undertaken. Two modelling studies specifically commissioned by Animal Health Ireland to assess testing methods used to demonstrate confidence of freedom in herds and to evaluate a range of possible surveillance strategies provided additional information. The majority of control programmes tend to be voluntary, because of the unique epidemiology of Johne's disease and limited support for traditional regulatory approaches. While acknowledging that test performance and sub-clinical sero-negative shedders contributes to the spread of infection, a range of socio-political issues also exist that influence programme activities. The paper provides a rationale for the inclusion of a Veterinary Risk Assessment and Management Plan (VRAMP), including voluntary whole herd testing to identify infected herds and to support assurance-based trading through repeated rounds of negative testing, national surveillance for herd-level case-detection, and improved understanding of biosecurity management practices. Identification and promotion of drivers for industry and producer engagement in Ireland is likely to guide the future evolution of the Irish Johne's Control Programme (IJCP) and further enhance its success. The provision of training, education and extension activities may encourage farmers to adopt relevant farm management practices and help them recognize that they are ultimately responsible for their herd's health and biosecurity.

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Section: Assurance Testingmentioning

confidence: 80%

Section: The Approachmentioning

confidence: 99%

Section: Assurance Testingmentioning

confidence: 99%

Section: Assurance Testingmentioning

confidence: 99%

See 2 more Smart Citations

Johne’s disease in Irish dairy herds: considerations for an effective national control programme

et al. 2020

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“…Due to these potential differences in production systems, we must consider that the spread of MAP in a Swedish herd could be different from what this model predicts and therefore augment the uncertainty of the final model estimates. Others have also modelled the spread of MAP including a highly detailed mechanistic within-herd model ( Kirkeby et al, 2016 ) and other compartments models that include a between herd spread ( Beaunée et al, 2015 ; Magombedze et al, 2013 ) as well as scenario tree models of surveillance efficacy ( Meyer et al, 2018 ; Frössling et al, 2013 ). These models and approaches were considered for the current work but the structures could not readily be used in the SimInf model framework in order to the include within- and between-herd animal movement events as was done in the current work to precisely reflect the Swedish cattle industry.…”

Section: Discussionmentioning

confidence: 99%

Modelling spread and surveillance of Mycobacterium avium subsp. paratuberculosis in the Swedish cattle trade network

Rosendal¹,

Widgrén²,

Ståhl³

et al. 2020

Preventive Veterinary Medicine

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To monitor a state of disease freedom and to ensure a timely detection of new introductions of disease, surveillance programmes need be evaluated prior to implementation. We present a strategy to evaluate surveillance of Mycobacterium avium subsp. paratuberculosis (MAP) using simulated testing of bulk milk in an infectious disease spread model. MAP is a globally distributed, chronic infectious disease with substantial animal health impact. Designing surveillance for this disease poses specific challenges because methods for surveillance evaluation have focused on estimating surveillance system sensitivity and probability of freedom from disease and do not account for spread of disease or complex and changing population structure over long periods. The aims of the study were to 1. define a model that describes the spread of MAP within and between Swedish herds; 2. define a method for simulation of imperfect diagnostic testing in this framework; 3. to compare surveillance strategies to support surveillance design choices. The results illustrate how this approach can be used to identify differences between the probability of detecting disease in the population based on choices of the number of herds sampled and the use of risk-based or random selection of these herds. The approach was also used to assess surveillance to detect introduction of disease and to detect a very low prevalence endemic state. The use of bulk milk sampling was determined to be an effective method to detect MAP in the population with as few as 500 herds tested per year if the herd-level prevalence was 0.2 %. However, detection of point introductions in the population was unlikely in the 13-year simulation period even if as many as 2000 herds were tested per year. Interestingly, the use of a risk-based selection strategy was found to be a disadvantage to detect MAP given the modelled disease dynamics.

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The inappropriate use of formulae and references and the possible domino effect of spurious results

Gautam

Wagener

Nérette

et al. 2019

Preventive Veterinary Medicine

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Modeling of alternative testing strategies to demonstrate freedom from Mycobacterium avium ssp. paratuberculosis infection in test-negative dairy herds in the Republic of Ireland

Cited by 18 publications

References 39 publications

Johne’s disease in Irish dairy herds: considerations for an effective national control programme

Johne’s disease in Irish dairy herds: considerations for an effective national control programme

Modelling spread and surveillance of Mycobacterium avium subsp. paratuberculosis in the Swedish cattle trade network

The inappropriate use of formulae and references and the possible domino effect of spurious results

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