Publications by authors named "Jordan L Mitchell"

4 Publications

  • Page 1 of 1

Diagnostic accuracy of the interferon-gamma release assay (IGRA) for cases of feline mycobacteriosis.

Prev Vet Med 2021 Aug 8;193:105409. Epub 2021 Jun 8.

The Royal (Dick) School of Veterinary Studies and The Roslin Institute, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, United Kingdom.

The aim of this study was to evaluate the sensitivity and specificity of the interferon-gamma release assay (IGRA) for diagnosing infections with members of the Mycobacterium (M.) tuberculosis-complex (MTBC) and non-tuberculous mycobacteria (NTM) in domestic cats, and to generate defined feline-specific cut-off values using receiver operating characteristic (ROC) curve analysis to improve test performance. Records of 594 cats that had been tested by IGRA were explored to identify individuals that had a culture and/or polymerase chain reaction (PCR)-confirmed case of mycobacterial disease, and those that had a final diagnosis of non-mycobacterial disease. A total of 117 cats - 80 with mycobacterial disease and 37 diagnosed with a condition other than mycobacteriosis - were identified for further detailed analysis. This population was used to estimate test sensitivity and specificity, as well as likelihood ratios for the IGRA to correctly identify a cat with or without mycobacterial disease. Agreement between IGRA results and culture/PCR using current and proposed new cut-off values was also determined. ROC analysis of defined confirmed infected and non-mycobacterial disease control cats allowed an adjustment of current test cut-offs that increased the overall test sensitivity for MTBC infections from 83.1 % (95 % confidence interval [CI]: 71.5-90.5 %) to 90.2 % (95 % CI: 80.2-95.4%), and M. bovis infection from 43 % (95 % CI: 28.2-60.7%) to 68 % (95 % CI: 51.4-82.1%) while maintaining high test specificity (100 % in both cases). Overall agreement between IGRA results and culture/PCR, while recognising that neither culture nor PCR tests have perfect sensitivity, improved from weak (κ = 0.57) to moderate (κ = 0.71) using new proposed IGRA test cut-off values. Application of these results, based upon the statistical analysis of accumulated test data, can improve the diagnostic performance of the feline IGRA, particularly for identifying infections with M. bovis, without compromising specificity.
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http://dx.doi.org/10.1016/j.prevetmed.2021.105409DOI Listing
August 2021

Serial Interferon-Gamma Release Assay (IGRA) Testing to Monitor Treatment Responses in Cases of Feline Mycobacteriosis.

Pathogens 2021 May 26;10(6). Epub 2021 May 26.

The Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Campus, University of Edinburgh, Midlothian EH25 9RG, UK.

The interferon-gamma release assay (IGRA) is used to diagnose cases of feline mycobacteriosis, but the use of serial testing to monitor treatment responses has not been evaluated in this species. From a population of cats that underwent IGRA testing for diagnostic investigation, individuals were identified with a pre- and end-of-treatment IGRA that passed control thresholds. The number of cats which reverted to negative at the end-of-treatment IGRA, changes in paired antigen-specific optical density (OD) values and differences in the pre-treatment antigen-specific OD values for those which underwent reversion were compared. Factors to explain reversion or recurrence of disease post-treatment were explored. Four of 18 cats (22%) reverted to negativity at the point of clinical resolution ( = 0.33), there was no difference in paired antigen-specific OD values ( ≥ 0.12), and cats that reverted did not have a lower baseline OD value ( = 0.63). No statistically significant factors were identified to predict reversion ( ≥ 0.08). Remaining positive at the end of treatment IGRA was not associated with recurrence of disease post-treatment ( = 0.34). Overall, these data suggest there is limited value in the use of the IGRA to monitor treatment responses in cats.
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http://dx.doi.org/10.3390/pathogens10060657DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8226617PMC
May 2021

Systemic Infection in Two Related Cats.

Pathogens 2020 Nov 18;9(11). Epub 2020 Nov 18.

The Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Campus, University of Edinburgh, Midlothian EH25 9RG, UK.

Mycobacterial infections are a major concern in veterinary medicine because of the difficulty achieving an etiological diagnosis, the challenges and concerns of treatment, and the potential zoonotic risk. , a slow-growing non-tuberculous mycobacteria, causes disease in both humans and animals. While infections have been well described in humans, where it may be misdiagnosed as tuberculosis, there are fewer reports in animals. Only four cases have been reported in the domestic cat. This case report describes systemic infection in two sibling indoor-only cats that presented two and half years apart with cutaneous disease that was found to be associated with osteolytic and pulmonary pathology. Infection with was confirmed in both cats by polymerase chain reaction on fine-needle aspirate of a lumbosacral soft tissue mass in one cat and on a tissue punch biopsy of a skin lesion in the other; interferon-gamma release assay inferred -complex and -complex infection in the two cats, respectively. Both patients made a full recovery following antimicrobial therapy with rifampicin, azithromycin, and pradofloxacin (plus N-acetyl cysteine in cat 2). This report highlights successful treatment of systemic mycobacteriosis in the cat and the challenge of accurately diagnosing this infection.
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http://dx.doi.org/10.3390/pathogens9110959DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698836PMC
November 2020

Ocular Tuberculosis: More than 'Of Mice and Men'.

Ocul Immunol Inflamm 2020 Sep 18:1-5. Epub 2020 Sep 18.

Royal (Dick) School of Veterinary Studies and the Roslin Institute, The University of Edinburgh, Midlothian, UK.

Tuberculosis (TB), caused by infection with members of the -complex, is one of the oldest known infectious disease entities, resulting in the death of millions of humans each year. It also results in a substantial degree of morbidity and mortality in animal species. Extrapulmonary TB is well recognized in humans, and the eye is one site that can be affected. Studies seeking to understand ocular TB have often relied on animal models; however, these have their limitations and may not truly reflect what happens in humans. We wish to raise awareness among ophthalmologists and vision scientists of naturally occurring cases of ocular TB in animals, namely cattle and domestic cats, and the possibilities of gaining further understanding of this presentation of TB by adopting a collaborative approach. This will hopefully improve outcomes for both human and animal patients.
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http://dx.doi.org/10.1080/09273948.2020.1797116DOI Listing
September 2020
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