Consensus recommendations on diagnostic testing for the detection of paratuberculosis in cattle in the United States

Abstract

The report provided here contains a simplified set of diagnostic testing recommendations. These recommendations were developed on the basis of research funded by the USDA-Animal and Plant Health Inspection Service-Veterinary Services through a cooperative agreement. The report is intended to provide simple, practical, cost-effective consensus testing recommendations for cattle herds that are not enrolled in the US Test-Negative Program. The information has been reviewed by paratuberculosis (Johne's disease) experts at the USDA and academic centers as well as stakeholders in various segments of the cattle industry. The recommendations were accepted by the National Johne's Working Group and Johne's Disease Committee of the US Animal Health Association during their annual meetings in October 2006. The report is intended to aid veterinarians who work with cattle producers in the United States. The recommendations are based on information available up to October 2006. There is a paucity of large-scale, high-quality studies of multiple tests conducted on samples obtained from the same cattle. It is understood that there may be special circumstances that require deviation from these recommendations. Furthermore, as new information becomes available and assays are improved and their accuracy is critically evaluated, changes to these recommendations may be necessary.

Testing new dairy cattle for disease can boost herd health, cut costs

“…Only one Johne's disease test-positive animal was found in our study, resulting in less than 1% prevalence. However, the sensitivity of tests for this disease is notoriously low (Collins et al 2006). The ELISA test on serum has a sensitivity of about 30% to 50%, which is the probability that a test is positive given that the animal is truly infected (Collins et al 2006).…”

A meta-analysis of the effect of dose and age at exposure on shedding ofMycobacterium aviumsubspeciesparatuberculosis(MAP) in experimentally infected calves and cows

“…Transmission of MAP is assumed to be primarily from infectious adults to susceptible young animals, and control of MAP within farms currently involves a twofold approach of testing and removing infected adult animals and increasing hygiene on the farm to limit contact between calves and faecal material of adult animals [12]. It is generally assumed that poor diagnostic-test sensitivity [13] leading to incomplete culling where some infectious animals remain in the herd and environmental persistence of MAP bacteria [14,15] contribute to the sustained prevalence of MAP in herds despite intervention attempts.…”

Fecal culture and two fecal-PCR methods for the diagnosis of Mycobacterium avium subsp. paratuberculosis in a seropositive herd

“…However, due to recent developments, PCR has been suggested for herd screening (Collins et al, 2006;Anonymous, 2010), and it has been recently discussed as a possible new gold standard for PTB (Stevenson, 2010a;2010b). The PCR technique is rapid and specific, and in contrast to a culture-based diagnostic, no additional tests are required to confirm the identity of the organism detected (Collins, 1996).…”

“…The limits of detection, sensitivity, and specificity vary with the targeted sequence and primer choice, the matrix tested, and the PCR format (conventional gelbased PCR, reverse transcriptase PCR, nested PCR, real-time PCR, or multiplex PCR; Möbius et al, 2008a;Bolske and Herthnek, 2010; National Advisory Committee on Microbiological Criteria for Foods, 2010;Stevenson, 2010b). Ideally, sampling all adult cattle in every herd, environmental sampling, serial testing, and the use of two to three diagnostic tests would be the recommendation for herd screening, to increase the accuracy of MAP diagnosis (Collins et al, 2006;Clark et al, 2008;Stevenson, 2010b).…”

“…These include tests to detect antibodies against MAP, detection of MAP genes, bacterial culture of fecal samples and test to detect MAP on tissue samples (Collins et al, 2006;Nielsen and Toft, 2008;Stevenson, 2010a;2010b). Sensitivity and specificity of tests for the ante-mortem diagnosis of PTB vary significantly depending on MAP infection stage and intrinsic characteristics of each test (Nielsen and Toft, 2008).…”