39 research outputs found

    Diagnostic accuracy of two DNA‐based molecular assays for detection of porcine circovirus 3 in swine population using Bayesian latent class analysis

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    Molecular‐based tools sometimes are the only laboratory techniques available to detect a recently discovered agent, and their validation without the existence of previously described ‘gold standard’ methods poses a challenge for the diagnosticians. A good example within this scenario is the recently described porcine circovirus 3 (PCV‐3) in the swine population worldwide, from which only few PCR methods have been described. Therefore, the primary objective of this study was to estimate the diagnostic accuracy of a direct PCR (dPCR) and a real‐time qPCR (qPCR) for detection of PCV‐3 in Italian swine population. Bayesian latent class analysis approach was used to rigorously assess their features and applicability in routine diagnostic activity. Data on dPCR and qPCR were available from 116 domestic pigs, which were randomly selected from 55 farms located at different regions in Northern Italy. The sensitivity (Se) estimates of dPCR (94%; posterior credible interval (PCI%) 84–100) and qPCR (96%; PCI% 90–100) were high and similar. The estimated specificity (Sp) of both dPCR and qPCR assays was around 97%. dPCR and qPCR assays showed a high and comparable Se and Sp estimates for the detection of PCV‐3 in Italian swine population.info:eu-repo/semantics/acceptedVersio

    Bayesian estimation of qPCR and bacterial culture accuracy for detection of bovine coagulase-negative staphylococci from milk and teat apex at different test cut-off points

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    Aim:To primarily estimate the sensitivity (Se) and specificity (Sp) of thecommercially available Mastit4 quantitative PCR (qPCR) assay and bacterialculture (BC) for diagnosis of intramammary infections (IMI) and teat apexcolonization (TAC) with coagulase-negative staphylococci (CNS) at differentcut-offs for qPCR cycle threshold values using Bayesian latent class analysis. Asecondary objective was to evaluate two cut-offs of BC for diagnosis of IMIand TAC with CNS.Methods and Results:We randomly selected 13–20 cows with subclinicalmastitis from eight dairy herds. Teat skin samples and aseptically collectedforemilk samples were collected from the right hindquarters (n=149) for BCand qPCR analysis. The Se of qPCR was always higher than BCSein diagnosis ofIMI, however; the Sp of BC was higher than qPCRSp.BCSeand BCSpshowed nosubstantial difference between the tested BC cut-offs. In contrast to IMI,estimates of BC and qPCR in diagnosing TAC were different. BCSewas higherthan qPCRSeat all tested cut-offs, however; qPCRSpwas higher than BCSp.Conclusion:The overall performance of qPCR is higher than BC in thediagnosis of IMI; however, the performance of BC is better than qPCR indiagnosis of TAC. The qPCR and BC are valid diagnostics for bovine IMI withCNS. However, for TAC, both techniques require further investigation toreduce the uncertainty of the true status of the quarter and teat skin.Significance and Impact of the Study:We reported, for the first time, thediagnostic performance of new mastitis technology (Mastit4 PCR) and culturefor detection of CNS in milk and nonmilk samples in dairy herds withautomatic milking systems. Our findings will improve the interpretation of thetest results of culture and qPCR assay and subsequently, will strengthen thecontrol of IMI with CNS in dairy cows.info:eu-repo/semantics/acceptedVersio

    Incidence of Interval Colorectal Cancer Among Inflammatory Bowel Disease Patients Undergoing Regular Colonoscopic Surveillance

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    Surveillance is recommended for patients with long-term inflammatory bowel disease because they have an increased risk of colorectal cancer (CRC). To study the effectiveness of surveillance, we determined the incidence of CRC after negative findings from surveillance colonoscopies (interval CRC). Methods: We collected data from 1273 patients with ulcerative colitis or Crohn's disease, enrolled in a surveillance program at 7 hospitals in The Netherlands, who underwent 4327 surveillance colonoscopies from January 1, 2000, through January 1, 2014. Patients were followed up from their first surveillance colonoscopy until the last surveillance colonoscopy, colectomy, or CRC. Factors that might have contributed to the occurrence of CRC were categorized as inadequate procedures (ie, inadequate bowel preparation), inadequate surveillance (CRC occurring outside the appropriate surveillance interval), or inadequate management of dysplasia (CRC diagnosed in the same colonic segment as a previous diagnosis of dysplasia). The remaining CRC cases were classified as true interval CRCs. Results: CRC was diagnosed in 17 patients (1.3%), with an incidence of 2.5 per 1000 years of follow-up evaluation. Factors that might account for the occurrence of CRC were identified in 12 patients (70%). These were inadequate colonoscopies in 4 patients (24%), inadequate surveillance intervals in 9 patients (53%), and inadequate management of dysplasia in 2 patients (12%). The remaining 5 cases of CRC (30%) were classified as true interval CRCs. Conclusions: In a retrospective analysis of patients with inflammatory bowel disease participating in a surveillance program, the incidence of CRC was only 1%, which supports the implementation of longer surveillance intervals. However, the fact that 30% of CRC cases were interval cancers indicates the need for variable surveillance intervals based on risk factors for CRC

    High Risk of Advanced Colorectal Neoplasia in Patients With Primary Sclerosing Cholangitis Associated With Inflammatory Bowel Disease

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    Background & Aims: Patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC, termed PSC-IBD) are at increased risk for colorectal cancer, but their risk following a diagnosis of low-grade dysplasia (LGD) is not well described. We aimed to determine the rate of advanced colorectal neoplasia (aCRN), defined as high-grade dysplasia and/or colorectal cancer, following a diagnosis of indefinite dysplasia or LGD in this population. Methods: We performed a retrospective, longitudinal study of 1911 patients with colonic IBD (293 with PSC and 1618 without PSC) who underwent more than 2 surveillance colonoscopies from 2000 through 2015 in The Netherlands or the United States (9265 patient-years of follow-up evaluation). We collected data on clinical and demographic features of patients, as well as data from each surveillance colonoscopy and histologic report. For each surveillance colonoscopy, the severity of active inflammation was documented. The primary outcome was a diagnosis of aCRN during follow-up evaluation. We also investigated factors associated with aCRN in patients with or without a prior diagnosis of indefinite dysplasia or LGD. Results: Patients with PSC-IBD had a 2-fold higher risk of developing aCRN than patients with non-PSC IBD. Mean inflammation scores did not differ significantly between patients with PSC-IBD (0.55) vs patients with non-PSC IBD (0.56) (P =.89), nor did proportions of patients with LGD (21% of patients with PSC-IBD vs 18% of patients with non-PSC IBD) differ significantly (P =.37). However, the rate of aCRN following a diagnosis of LGD was significantly higher in patients with PSC-IBD (8.4 per 100 patient-years) than patients with non-PSC IBD (3.0 per 100 patient-years; P =.01). PSC (adjusted hazard ratio [aHR], 2.01; 95% CI, 1.09–3.71), increasing age (aHR 1.03; 95% CI, 1.01–1.05), and active inflammation (aHR, 2.39; 95% CI, 1.63–3.49) were independent risk factors for aCRN. Dysplasia was more often endoscopically invisible in patients with PSC-IBD than in patients with non-PSC IBD. Conclusions: In a longitudinal study of almost 2000 patients with colonic IBD, PSC remained a strong independent risk factor for aCRN. Once LGD is detected, aCRN develops at a higher rate in patients with PSC and is more often endoscopically invisible than in patients with only IBD. Our findings support recommendations for careful annual colonoscopic surveillance for patients with IBD and PSC, and consideration of colectomy once LGD is detected

    Self-reported Disability in Patients with Inflammatory Bowel Disease Largely Determined by Disease Activity and Illness Perceptions

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    BACKGROUND: The inflammatory bowel disease (IBD) disability index has been introduced to measure patients' physical, psychological, familial, social limitations associated with IBD. We assessed factors related to self-reported disability and the relationship between disability and health care costs. METHODS: A large cohort of patients with Crohn's and ulcerative colitis (UC) was prospectively followed for 2 years by 3 web-based questionnaires. At 2 years, patients completed the IBD index, with lower score indicating more disability. Linear regression was used to examine the impact of demographics, clinical illness perceptions on self-reported disability. Trends in direct health costs across the disability severity groups minimal, mild, moderate, and were tested. RESULTS: A total of 554 patients with CD and 424 patients completed the IBD disability index (response rate, 45%). Both clinical characteristics and illness perceptions significantly contributed to self-reported disability (45%-47%, P = 0.000 and 8%-12%, P = 0.000, respectively). Patients with CD scored lower on the self-reported IBD index than patients with UC (0.255 versus 3.890, P < 0.000), indicating disability in patients with CD. Factors independently associated with self-reported disability rates were increased disease activity, illness (higher number of symptoms attributed to IBD), and stronger emotional Disease duration and disease phenotype were not associated with self- disability. Direct health care costs increased with the worsening of self-reported disability (P = 0.000). CONCLUSIONS: More disability was by patients with CD than by UC. Self-reported disability in IBD was determined by clinical disease activity and illness perceptions but not disease duration or disease phenotype
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