Sensitivity of Sniffer Dogs for a Diagnosis of Parkinson's Disease: A Diagnostic Accuracy Study.

BACKGROUND: The diagnostic criteria for Parkinson's disease (PD) remain complex, which is especially problematic for nonmovement disorder experts. A test is required to establish a diagnosis of PD with improved accuracy and reproducibility. OBJECTIVE: The study aimed to investigate the sensitivity and specificity of tests using sniffer dogs to diagnose PD. METHODS: A prospective, diagnostic case-control study was conducted in four tertiary medical centers in China to evaluate the accuracy of sniffer dogs to distinguish between 109 clinically established medicated patients with PD, 654 subjects without PD, 37 drug-naïve patients with PD, and 185 non-PD controls. The primary outcomes were sensitivity and specificity of sniffer dog's identification. RESULTS: In the study with patients who were medicated, when two or all three sniffer dogs yielded positive detection results in a sample tested, the index test sensitivity, specificity, and positive and negative likelihood ratios were 91% (95% CI: 84%-96%), 95% (95% CI: 93%-97%), and 19.16 (95% CI: 13.52-27.16) and 0.10 (95% CI: 0.05-0.17), respectively. The corresponding sensitivity, specificity, and positive and negative likelihood ratios in patients who were drug-naïve were 89% (95% CI: 75%-96%), 86% (95% CI: 81%-91%), and 6.6 (95% CI: 4.51-9.66) and 0.13 (95% CI: 0.05-0.32), respectively. CONCLUSIONS: Tests using sniffer dogs may be a useful, noninvasive, fast, and cost-effective method to identify patients with PD in community screening and health prevention checkups as well as in neurological practice. © 2022 International Parkinson and Movement Disorder Society.

[Development and application of TaqMan MGB probe fluorescence quantitative PCR method for rapid detection of Clostridium piliforme].

OBJECTIVE: To develop a TaqMan MGB probe-based, sensitive and specific fluorescence quantitative PCR assay method for rapid detection of Clostridium piliforme. METHODS: Primers and probes specific to 16S rRNA gene of Clostridium piliforme were designed. A TaqMan MGB probe-based, fluorescence quantitative PCR method was established. Specificity, sensitivity and stability of the method were assessed, followed by real-time quantitative PCR assay to detect Clostridium piliforme on 1156 clinical specimens during 2008-2011 and compared with conventional PCR assay. RESULTS: The specificity of TaqMan MGB probe-based fluorescence quantitative PCR was high and did not show cross-reactivity with Helicobacter hepaticus, Helicobacter pylori, Campylobacter jejuni, Pasteurella pneumotropica, Escherichia coli or Pseudomonas aeruginosa. The detection limit was 2.2 copies/µl. The correlation coefficient and slope value of standard curve were 0.999 and -3.204, respectively and the efficiency of TaqMan MGB-based probe fluorescence quantitative PCR assay was 100%. When the TaqMan MGB-based probe fluorescence quantitative PCR assay was preformed to detect Clostridium piliforme on 1156 clinical specimens, a total of 101 specimens showed positive on Clostridium piliforme. However, only 44 specimens showed positive when conventional PCR was used. The real-time quantitative PCR for Clostridium piliforme could be completed within 2 hours. CONCLUSION: The TaqMan MGB-based probe fluorescence quantitative PCR assay method was a reliable, specific, sensitive and useful tool for rapid detection of Clostridium piliforme.