Using a dog's superior olfactory sensitivity to identify Clostridium difficile in stools and patients: proof of principle study.

OBJECTIVE: To investigate whether a dog's superior olfactory sensitivity can be used to detect Clostridium difficile in stool samples and hospital patients. DESIGN: Proof of principle study, using a case-control design. SETTING: Two large Dutch teaching hospitals. PARTICIPANTS: A 2 year old beagle trained to identify the smell of C difficile and tested on 300 patients (30 with C difficile infection and 270 controls). INTERVENTION: The dog was guided along the wards by its trainer, who was blinded to the participants' infection status. Each detection round concerned 10 patients (one case and nine controls). The dog was trained to sit or lie down when C difficile was detected. MAIN OUTCOME MEASURES: Sensitivity and specificity for detection of C difficile in stool samples and in patients. RESULTS: The dog's sensitivity and specificity for identifying C difficile in stool samples were both 100% (95% confidence interval 91% to 100%). During the detection rounds, the dog correctly identified 25 of the 30 cases (sensitivity 83%, 65% to 94%) and 265 of the 270 controls (specificity 98%, 95% to 99%). CONCLUSION: A trained dog was able to detect C difficile with high estimated sensitivity and specificity, both in stool samples and in hospital patients infected with C difficile.

Influence of four different PTH methods on the classification of chronic kidney disease patients according to the new KDIGO guideline.

BACKGROUND: Secondary hyperparathyroidism develops frequently with chronic kidney disease (CKD) and is associated with poor outcome. The new CKD-MBD guideline, Kidney Disease: Improving Global Outcomes (KDIGO), recommends a target range for PTH which is based on the locally used, upper reference range limit (URL). We examined the impact of the KDIGO guideline on the classification of dialysis patients in two different hospitals using 4 different intact-PTH assays. METHODS: Blood samples from 76 consecutive hemodialysis CKD patients were measured for PTH concentration. Classification of the patients was performed according to the previous KDOQI and the KDIGO guideline using the manufacturers' and laboratory determined URLs. Classification of patients based on 3 different PTH methods (Siemens ADVIA Centaur, Siemens Immulite 2000, and Beckman Coulter Unicel DxI) was compared with the classification found in another hospital using the Roche Modular E170 PTH assay. RESULTS: Depending on the PTH assay used, between 9 (12%) to 14 (18%) of the patients were classified differently in the two hospitals if the KDOQI guideline was followed. Application of the KDIGO-PTH target range resulted in a similar or decreased number of differently classified patients if the PTH concentration was measured using the Advia Centaur and Immulite assays. With the Beckman Coulter PTH assay, however, the number of differently KDIGO-classified patients increased if the manufacturers' URL (9.3 pmol/L) was used to calculate the PTH-target range. Application of the laboratory determined URL (7.0 pmol/L) improved concordance in classification, although the number of differently classified patients was still higher than with the other PTH assays. The best concordance in classification for the Beckman Coulter assay was found at a PTH value of 6.0 pmol/L. Regarding the Roche and Siemens assays, no significant difference was found in the classification using the URL either determined by the laboratory or the manufacturers. CONCLUSIONS: Compared with the KDOQI guideline, the new KDIGO guideline may increase the number of discrepancies in the classification of CKD patients if the Access Beckman Coulter PTH assay is used in conjunction with the calculated target range based on the manufacturers' URL. The best concordance in the classification for the Beckman Coulter assay was found at a PTH value below the manufacturers' and laboratory determined URL.