With increasing demand for large numbers of testing during the coronavirus disease 2019 pandemic, alternative protocols were developed with shortened turn-around time. We evaluated the performance of such a protocol wherein 1138 consecutive clinic attendees were enrolled; 584 and 554 respectively from two independent study sites in the cities of Pune and Kolkata. Paired nasopharyngeal and oropharyngeal swabs were tested by using both reference and index methods in a blinded fashion. Prior to conducting real-time polymerase chain reaction, swabs collected in viral transport medium (VTM) were processed for RNA extraction (reference method) and swabs collected in a dry tube without VTM were incubated in Tris–EDTA–proteinase K buffer for 30 min and heat-inactivated at 98 °C for 6 min (index method). Overall sensitivity and specificity of the index method were 78.9% (95% confidence interval (CI) 71–86) and 99% (95% CI 98–99.6), respectively. Agreement between the index and reference method was 96.8% (k = 0.83, s.e. = 0.03). The reference method exhibited an enhanced detection of viral genes (E, N and RNA-dependent RNA polymerase) with lower Ct values compared to the index method. The index method can be used for detecting severe acute respiratory syndrome corona virus-2 infection with an appropriately chosen primer–probe set and heat treatment approach in pressing time; low sensitivity constrains its potential wider use.

Avian tuberculosis is a chronic infectious disease caused by M. avium including four subspecies Mycobacterium avium subspecies avium; M. avium hominissuis; M. avium paratuberculosis; M. avium silvaticum. This disease is characterised by the formation of granulomatous lesions in viscera, a progressive weight loss and death. It can be transmitted to healthy birds in the flock, and occasionally to human beings. It is important to diagnose avian tuberculosis in order to prevent the spread of infection and epidemiology. This paper reviews the available techniques for the diagnosis of avian tuberculosis along with their pros and cons. The main problem in diagnosis is poor availability of samples due to infrequent shedding in faeces, pattern and colour of feathers, wattle and comb and lack of specific signs and symptoms. Any single technique is not effective in diagnosing the disease due to the lack of required sensitivity and specificity. Application of two or more techniques is not a feasible option in developing countries due to financial constraints. In the short term, more research is needed to develop multidisciplinary approaches which can help fully understand the aetiology and epidemiology of disease.

Expansion of sandflies and increasing pet travel have raised concerns about canine leishmaniasis (CanL) spread to new areas of Europe. This study aimed to estimate the probability of CanL introduction and persistence following movements of infected dogs. Stochastic modelling was used to estimate the probabilities of (1) CanL infection during travels or imports of infected dogs (Pinf and PinfCA, respectively), (2) CanL persistence in a dog network with sandflies after introduction of an infected dog (Pper), and (3) persistence in a CanL-free region (Pper region) for N dogs moving between endemic and free regions. Different mitigation measures (MMs) were assessed. Pinf [7·8%, 95% predictive interval (PI) 2·6–16·4] and Pper (72·0%, 95% PI 67·8–76·0) were reduced by use of repellent, vaccine, prophylactic medication, and insecticide, in decreasing order of effectiveness. Testing and exclusion of positive dogs was most effective in reducing Pper region for a small N. The spread of CanL to CanL-free areas with sandflies is thus likely, but can be reduced by MMs.

Both zygosity and chorionicity provide important information in twin research. The East Flanders Prospective Twin Survey (EFPTS) determines zygosity and chorionicity at birth and therefore provides a gold standard for the testing of diagnostic parameters that can be used to determine chorionicity. The aim of the present study was to investigate whether birthweight discordancy can be used as an indicator of chorionicity. The study sample consisted of 4,060 live-born twin pairs from the EFPTS. We studied MZ twins, using univariate and multivariate logistic regression analyses to calculate odds ratios (OR) and 95% confidence intervals (CI) of being MC in relation to discordancy level. Diagnostic parameters, including sensitivity and specificity, were calculated. A two-fold cross-validation was carried out and a bootstrap distribution with 10,000 samples was created to estimate the standard deviations. For discordancy levels of below 10%, 10–15%, 15–20%, 20–25% and above 25%, the ORs (95% CI) were 1.16 (0.91–1.47), 1.38 (1.05–1.80), 2.13 (1.51–3.01), 2.73 (1.73–4.29) and 2.81 (2.81–4.35) respectively. There were no gender differences. Sensitivity was 42.2% (SD 5.6%), specificity was 72.8% (SD 6.3%), positive predictive value was 72.8% (1.5%) and the negative predictive value was 39.2% (0.7%). In conclusion, although a higher discordancy level resulted in higher ORs of being an MC twin, birthweight discordancy level can only be used to some weak extent as a proxy for chorionicity, highlighting the need to assess and record chorionicity data in obstetrical units.

The diagnosis of functional temporo-mandibular and cervical problems depends to a great extent on subjective information provided by patients. As a result, it is difficult to arrive at a substantiated assessment of the prevalence of these disorders. Based on the data reported from large-scale epidemiological studies, it appears that nearly 50 % of the populations of developed countries have symptoms of musculo-skeletal problems. The over-abundance of diagnostic tests suggested for assessing this problem adds confusion to this murky area. The purpose of this article is to precisely evaluate the pertinence of the various tests used to establish a clinical diagnosis.

Estimation of prevalence of disease, including construction of confidence intervals, is essential in surveys for screening as well as in monitoring disease status. In most analyses of survey data it is implicitly assumed that the diagnostic test has a sensitivity and specificity of 100%. However, this assumption is invalid in most cases. Furthermore, asymptotic methods using the normal distribution as an approximation of the true sampling distribution may not preserve the desired nominal confidence level. Here we proposed exact two-sided confidence intervals for the prevalence of disease, taking into account sensitivity and specificity of the diagnostic test. We illustrated the advantage of the methods with results of an extensive simulation study and real-life examples.

Our aim was further to clarify the diagnostic usefulness of N-terminal pro-B-type natriuretic peptide for detecting ventricular dysfunction in children, and its correlation with myocardial performance index and New York University Pediatric Heart Failure Index score. We also hypothesized that the level of this natriuretic peptide in the serum could predict the severity of diastolic abnormalities in children with cardiac failure. We enrolled 99 patients, aged from 3 months to 16 years, who had been referred for echocardiography to evaluate ventricular function. Echocardiographic evidence of left ventricular systolic and diastolic dysfunction was found in 20 and 42 patients, respectively. We classified these patients as having impaired relaxation, seen in 12 patients, pseudonormal patterns seen in 19 patients, and restrictive-like patterns of filling seen in 11 patients. The mean of the log-transformed values for N-terminal pro-B-type natriuretic peptide increased significantly according to the severity of diastolic dysfunction (p = 0.003, p = 0.022, p < 0.0001). A value of 178 pg/ml had a sensitivity of 88% and specificity of 81% for detecting abnormal diastolic function (p < 0.0001). Furthermore, the log-transformed values correlated with myocardial performance index (p < 0.0001) in a positive manner, and the levels increased significantly according to New York University Pediatric Heart Failure Index score, showing a linear correlation with a robust r value for regression (r = 0.89, p < 0.0001). Our findings suggest that higher levels of the peptide, having a good correlation with New York University Pediatric Heart Failure Index score and myocardial performance index, might be a suitable marker to rule out ventricular diastolic dysfunction in children.

Background: Previous studies have found the Mini-mental State Examination (MMSE) predictive of capacity to consent to power of attorney and to enter into residential care. We aimed to assess the utility of the MMSE in predicting capacity to consent to research in elderly U.K. care home residents, to determine the optimal cut-point score, and to ascertain which items of the MMSE most predicted capacity.

Methods: Care home residents (n = 227) who had been recruited into a randomized controlled trial and assessed for capacity to consent were subsequently administered the MMSE and a measure of depression. A receiver operator characteristic (ROC) curve was generated and the maximal MMSE cut-point that best predicted capacity status determined. Multiple regression analyses were conducted to assess the effect of other variables on capacity status.

Results: The area under the ROC curve was 0.86 (p < 0.001, 95% CI 0.80–0.91). The optimal cut-point was 13/14, which provided a positive predictive value of 0.84 (0.79–0.89) and negative predictive value of 0.69 (0.62–0.75). The odds ratio of a MMSE score ≥14 predicting having capacity was 11.95 (6.03–23.94). Depression reduced the odds of having capacity (OR 0.32, 0.17–0.62, p = 0.001). All individual items of the MMSE apart from following a written command (“close your eyes”) had odds ratios significantly associated with capacity status. The item most associated with capacity status was being able to verbally repeat a sentence (“no ifs, ands, or buts”) correctly (OR 5.6, 95% CI 3.0–10.5).

Conclusions: The MMSE is predictive of capacity to consent to research and may have a role in guiding researchers in this domain. It should not, however, be used in lieu of a formal capacity assessment as even the optimal cut-point of 13/14 mislabeled 24% of capable subjects as lacking capacity, and 21% of incapable subjects as having capacity.

The wheat curl mite (WCM), Aceria tosichella Keifer, is an eriophyoid pest of cereals, and the vector responsible for transmitting wheat streak mosaic virus. Several authors have suggested cryptic species of this mite identified through morphological variation, but this has never been conclusively demonstrated. Here, we use the mitochondrial 16S rRNA gene and two nuclear markers (internal transcribed spacer 1 and adenine nucleotide translocase) to show that WCM from Australia consists of at least two separate lineages that may represent putative species. In our study, both WCM variants were widespread and the only eriophyoids found on wheat varieties. The WCM variants were also found on alternate host plants, including some plants not known to host WCM. These results have implications for the control of this pest within Australian cereal crops.

Objectives: The evaluation of the diagnostic value of endoscopic procedures usually lacks a gold standard when performed in cross-sectional studies. The objective is to demonstrate an easily applicable method to assess the possible range of sensitivity, specificity, and predictive values of endoscopic procedures in the absence of a gold standard method.

Methods: Data from a study of 328 endoscopies comparing two different methods to diagnose superficial bladder cancer were used as a numerical example. Both endoscopic procedures were performed in the same patients in one session. Under the assumption of a systematic misclassification process, a model to correct sensitivity estimates is developed.

Results: The lowest possible sensitivity estimate for a new fluorescence endoscopy technique (FE) was 78%, the maximum 97.5%. Depending on realistic assumptions made upon the misclassification, a reasonable estimate for sensitivity was 93.4% (95% confidence interval [CI]: 90%–97.3%) for the FE technique. The sensitivity of the traditional white-light endoscopy method ranged from 47.2% to 53%, with a reasonable estimate of 46.7% (95% CI: 39.4%–54.3%).

Conclusions: This method to determine the theoretically possible range of sensitivity estimates in endoscopic procedures is helpful in cross-sectional studies with a missing gold standard method. It is easily applicable for a variety of endoscopic procedures, including upper and lower gastro-intestinal tract, urogenital tract, or diagnostic laparoscopic surgery.

Little is known about the value patients, physicians, and payers place on intangible attributes of care. Differences in valuations among these groups and misperceptions of value of intangible attributes to other groups can contribute to conflicts about treatment recommendations or coverage decisions. We surveyed patients, physicians, and managed care executives to assess their willingness to pay (WTP) for diagnostic certainty for peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). To determine if patients, physicians, and payers accurately perceive each other's valuations of diagnostic certainty, participants were also asked to estimate the WTP of each of the other types of respondents. Patients were most likely, and executives least likely, to value diagnostic certainty. For PUD, 84% of patients, 61% of physicians, and 43% of executives expressed a positive WTP. Median WTP was low for all three groups ($1–9 for patients and physicians; $0 for payers). Physicians and executives both correctly predicted patient WTP. For GERD, 87% of patients, 52% of physicians, and 29% of executives expressed a positive WTP. Executives underestimated patient WTP. For both diseases, physicians' WTP was overestimated by patients and underestimated by executives. The inconsistency in the value that patients, physicians, and managed care executives place on diagnostic certainty indicates the potential for conflict over practice guidelines or access to services. WTP surveys can provide information to aid in anticipating and addressing areas of disagreement.