Evaluation of the CervidTB STAT-PAK for the Detection of Mycobacterium bovis Infection in Wild Deer in Great Britain

Abstract

Deer are acknowledged as hosts of Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), and determining the prevalence of infection in deer species is one of the key steps in understanding the epidemiological role played by cervids in the transmission and maintenance of bTB in the United Kingdom. This study evaluated a rapid lateral-flow test for the detection of bTB in samples from wild deer species in the United Kingdom. Fallow deer (Dama dama), roe deer (Capreolus capreolus), and red deer (Cervus elaphus) from areas in Wales, the Cotswolds, and southwestern England were necropsied for a bTB survey. Serum samples from individual deer were tested with the CervidTB STAT-PAK, and the results were evaluated against the culture of M. bovis from tissues (n ‫؍‬ 432). Sensitivity and specificity were 85.7% (95% confidence interval [CI], 42.1 to 99.6%) and 94.8% (95% CI, 92.3 to 96.7%), respectively, with an odds ratio of 109.9 (95% CI, 12.7 to 953.6%) for a positive STAT-PAK result among culture-positive deer. The low prevalence of infection (3.8%, n ‫؍‬ 860) affected the confidence of the sensitivity estimate of the test, but all culture-positive fallow deer (n ‫؍‬ 6) were detected by the test. In addition, antibodies to M. bovis could be detected in poor-quality serum samples. The results suggest that the CervidTB STAT-PAK could be deployed as a field test for further evaluation.In the United Kingdom, the involvement of wildlife species in the disease dynamics of bovine tuberculosis (bTB) has fueled research into their potential role in the maintenance and transmission of the disease. Badgers (Meles meles) are thought to be the main wildlife reservoir of bTB, but the presence of Mycobacterium bovis in United Kingdom deer species (1, 4) and the risk of spillover posed by deer in other countries (7,18) have driven the need to evaluate the risk posed to cattle by the spillover of M. bovis from cervids in the United Kingdom.A semiquantitative risk assessment indicated that fallow deer (Dama dama dama) in particular posed a relatively high, though localized, risk of transmission to cattle in areas with a high incidence of bTB (5). However, model predictions were constrained by the lack of adequate data on the abundance and distribution of the six United Kingdom deer species and the prevalence and distribution of M. bovis infection in these species. To address this issue, the Department for the Environment, Food and Rural Affairs (DEFRA) commissioned additional surveys of M. bovis in deer (6).Obtaining statistically robust prevalence estimates from large wildlife populations poses a number of challenges, particularly when the prevalence of infection is low. In New Zealand, for example, control policies aimed at both domestic (cattle and deer) and wildlife (possums) species have reduced the herd prevalence of bTB in cattle and deer from 2.4% in 1993 to 0.35% in 2004 (21), but the assays used for whole-herd diagnostic testing include an antibody enzyme-linked immunosorbent assay and a lymphocyte transformat...

Sensitivity, Specificity, and Confounding Factors of Novel Serological Tests Used for the Rapid Diagnosis of Bovine Tuberculosis in Farmed Red Deer ( Cervus elaphus )

“…In the absence of apparent confounding factors, the test specificities were higher than those in the current studies, ranging from 94.8 to 98.9% (3,9,14). There may be differences in sensitivity between species of deer due to different affinities of test reagents with antibodies from these deer, especially between Old World Cervus sp.…”

“…The proportion of false positives is likely to increase with the decreasing prevalence of M. bovis-infected deer herds in various parts of the world, as improved strategies to control TB in these animals are implemented. Hence, the development of novel tests with enhanced specificity is imperative for more accurate detection of bovine TB in deer.The CervidTB STAT-PAK lateral-flow test (Chembio Diagnostic Systems, Inc., Medford, NY) has been evaluated using a number of different species of free-ranging wild deer (3,9,14). Although the test showed a high sensitivity for detecting M. bovis infection, it is not clear whether the test specificity is affected when testing sera from M. avium subsp.…”

“…The CervidTB STAT-PAK lateral-flow test (Chembio Diagnostic Systems, Inc., Medford, NY) has been evaluated using a number of different species of free-ranging wild deer (3,9,14). Although the test showed a high sensitivity for detecting M. bovis infection, it is not clear whether the test specificity is affected when testing sera from M. avium subsp.…”

Review of the Diagnosis of Tuberculosis in Non-Bovid Wildlife Species Using Immunological Methods - An Update of Published Work Since 2009

“…The new serological tests (RT and DPP) have also been evaluated in a number of studies with deer and found to perform well. The sensitivity and specificity of the RT for three common species of deer in the UK were 85.7% and 94.8%, respectively (Gowtage‐Sequeira et al., ), comparing well to an evaluation of the same test in fallow deer in Spain and the United States (Jaroso et al., ; Waters et al., ) and white‐tailed deer ( Odocoileus virginianus ) and elk in the United States (Lyashchenko et al., ; Waters et al., ). Similarly, the more recent DPP test gave a sensitivity of 79% and 91% in elk and fallow deer, respectively, at specificities approaching 100% (Waters et al., ).…”

Applying the One Health Concept to Mycobacterial Research – Overcoming Parochialism

“…Mycobacterium bovis is also a well‐documented zoonotic agent, is highly virulent in both animals and humans and has a worldwide distribution. It principally affects the family Bovidae including buffaloes, bison, antelopes, goats and sheep but can also cause disease in other mammals such as pigs, horses, camels and wildlife as well as pet animals like dogs and cats (Thoen et al., ; Melinda et al., ; Rodwell et al., ; Drewe et al., ; Gowtage‐Sequeira et al., ; Shrikrishna et al., ; Chambers et al., ; Park et al., ; Lyashchenko et al., ; Greene, ; Olivier et al., ). In the United Kingdom, M. bovis is endemic in the wild badger population with spillover into farm animals, especially cow herds.…”