The utility of rapid Group A streptococcus molecular testing compared with throat culture for the diagnosis of Group A streptococcal pharyngitis in a high-incidence rheumatic fever population.

Author(s):  
Amanda Taylor ◽  
Susan Morpeth ◽  
Rachel Webb ◽  
Susan Taylor

Background: Group A Streptococcus (GAS) causes significant morbidity and mortality in New Zealand and is responsible for invasive disease and immune sequelae including acute Rheumatic Fever (ARF). Early treatment of GAS pharyngitis reduces the risk of ARF. In settings with a high-burden of GAS disease, a rapid GAS pharyngitis diagnostic test with a strong negative predictive value is needed to enable prompt and accurate treatment. Methods: This prospective study compares the Xpert® Xpress Strep A molecular test (Cepheid) to throat culture and a second molecular method, the BioGX Group A Streptococcus -OSR for BD MAX TM for the diagnosis of GAS pharyngitis. Throat swabs were collected from the emergency department and wards of Middlemore Hospital, New Zealand. The BioGX Group A Streptococcus - OSR for BD MAX TM , contributes to the composite gold-standard: throat culture or both molecular methods positive. Basic demographic, clinical and laboratory data was collected. Results: 205/214 swabs were suitable for analysis. 28/205 (13.7%) were GAS culture positive, 45/205 (22%) Xpert® Xpress Strep A positive and 38/205 (18.5%) BioGX positive. Compared to culture, the sensitivity, specificity, positive and negative predictive values of the Xpert® Xpress Strep A molecular test were 100%, 90.4%, 62.2% and 100%, respectively. Compared to the composite gold-standard, the sensitivity, specificity, PPV and NPV and were 100%, 95.8%, 84.4% and 100% respectively. 17 samples were Xpert® Xpress positive but culture-negative; 6 of these 17 swabs represent true positives with evidence of recent GAS infection. Ten samples were culture negative but both Xpert® Xpress and BioGX positive. Conclusion: The Xpert® Xpress Strep A molecular test is highly sensitive with a strong negative predictive value and rapid turnaround time. It can be safely introduced as a first line test for throat swabs in a high-incidence ARF population.

2015 ◽  
Vol 54 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Arlo Upton ◽  
Liselle Bissessor ◽  
Elizabeth Farrell ◽  
Stanford T. Shulman ◽  
Xiaotian Zheng ◽  
...  

Group A streptococcal (GAS) pharyngitis is a particularly important condition in areas of New Zealand where the incidence of acute rheumatic fever remains unacceptably high. Prompt diagnosis and treatment of GAS pharyngitis are cornerstones of the Rheumatic Fever Prevention Programme, but these are hindered by the turnaround time of culture. Tests with excellent performance and rapid turnaround times are needed. For this study, throat swabs (Copan ESwabs) were collected from schoolchildren self-identifying with a sore throat. Samples were tested by routine culture and theillumigeneGAS assay using loop-mediated isothermal amplification. Discrepant results were resolved by retesting of the same specimen by an alternative molecular assay. Seven hundred fifty-seven throat swab specimens were tested by both methods. The performance characteristics of theillumigeneassay using culture on blood agar as the “gold standard” and following discrepancy analysis were as follows: sensitivity, 82% and 87%, respectively; specificity, 93% and 98%, respectively; positive predictive value, 61% and 88%, respectively; and negative predictive value, 97% and 97%, respectively. In our unique setting of a school-based throat swabbing program, theillumigeneassay did not perform quite as well as described in previous reports. Despite this, its improved sensitivity and rapid turnaround time compared with those of culture are appealing.


2019 ◽  
Vol 28 (4) ◽  
pp. 338-44
Author(s):  
Ariani Dewi Widodo ◽  
Muzal Kadim ◽  
Ina Susianti Timan ◽  
Nuraini Irma Susanti ◽  
Fatima Safira Alatas ◽  
...  

BACKGROUND Lipid malabsorption causes many health problems, for example stunting, a major worldwide issue. There has not been any assessment on the effectivity of lipid microscopic test in diagnosing lipid malabsorption. This research was aimed to study the effectivity of lipid microscopic test in detecting lipid malabsorption in children. METHODS This was a cross-sectional diagnostic study that evaluated the effectivity of lipid microscopic test using Sudan III against steatocrit test as the gold standard in diagnosing lipid malabsorption. The study was done in 68 children aged 6–60 months in Cipto Mangunkusumo Hospital, Jakarta. Results of lipid microscopic test were compared with that of steatocrit test among children with lipid malabsorption and normal children. The primary endpoints of this study are the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS A total of 68 children consisting of 41 boys and 27 girls were included, with a median age of 14.3 months. The most frequently found stool consistency was mushy (50%). The most common result of microscopic test, found in 42% of subjects, was positive 1. Sensitivity, specificity, PPV, and NPV of lipid microscopic test were 49.15%, 66.67%, 90.63%, and 16.67%, respectively. CONCLUSIONS Lipid microscopic test has a moderate sensitivity in diagnosing fat malabsorption and needs to be complemented with other methods such as steatocrit.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Felix Wuennemann ◽  
Laurent Kintzelé ◽  
Felix Zeifang ◽  
Michael W. Maier ◽  
Iris Burkholder ◽  
...  

Abstract Background Superior labral anterior to posterior (SLAP) lesions remain a clinical and diagnostic challenge in routine (non-arthrographic) MR examinations of the shoulder. This study prospectively evaluated the ability of 3D-Multi-Echo-Data-Image-Combination (MEDIC) compared to that of routine high resolution 2D-proton-density weighted fat-saturated (PD fs) sequence using 3 T-MRI to detect SLAP lesions using arthroscopy as gold standard. Methods Seventeen consecutive patients (mean age, 51.6 ± 14.8 years, 11 males) with shoulder pain underwent 3 T MRI including 3D-MEDIC and 2D-PD fs followed by arthroscopy. The presence or absence of SLAP lesions was evaluated using both sequences by two independent raters with 4 and 14 years of experience in musculoskeletal MRI, respectively. During arthroscopy, SLAP lesions were classified according to Snyder’s criteria by two certified orthopedic shoulder surgeons. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 3D-MEDIC and 2D-PD fs for detection of SLAP lesions were calculated with reference to arthroscopy as a gold standard. Interreader agreement and sequence correlation were analyzed using Cohen’s kappa coefficient. Figure 1 demonstrates the excellent visibility of a proven SLAP lesion using the 3D-MEDIC and Fig. 2 demonstrates a false-positive case. Results Arthroscopy revealed SLAP lesions in 11/17 patients. Using 3D-MEDIC, SLAP lesions were diagnosed in 14/17 patients by reader 1 and in 13/17 patients by reader 2. Using 2D-PD fs, SLAP lesions were diagnosed in 11/17 patients by reader 1 and 12/17 patients for reader 2. Sensitivity, specificity, PPV, and NPV of 3D-MEDIC were 100.0, 50.0, 78.6, and 100.0% for reader 1; and 100.0, 66.7, 84.6, and 100% for reader 2, respectively. Sensitivity, specificity, PPV, and NPV of 2D-PD fs were 90.9, 83.3, 90.9, and 83.3% for reader 1 and 100.0, 83.3, 91.7, and 100.0% for reader 2. The combination of 2D-PD fs and 3D-MEDIC increased specificity from 50.0 to 83.3% for reader 1 and from 66.7 to 100.0% for reader 2. Interreader agreement was almost perfect with a Cohen’s kappa of 0.82 for 3D-MEDIC and 0.87 for PD fs. Conclusions With its high sensitivity and NPV, 3D-MEDIC is a valuable tool for the evaluation of SLAP lesions. As the combination with routine 2D-PD fs further increases specificity, we recommend incorporation of 3D-MEDIC as an additional sequence in conventional shoulder protocols in patients with non-specific shoulder pain.


1987 ◽  
Vol 7 (2) ◽  
pp. 111-122 ◽  
Author(s):  
Mary C. Law ◽  
Helene J. Polatajko

This article describes a model for the evaluation of diagnostic tests used in occupational therapy. In this model, new diagnostic tests are compared to valid tests (“gold standard”), and their sensitivity, specificity, predictive value, and agreement are calculated. The use of this method is illustrated with data from the Southern California Postrotary Nystagmus Test and the Stille-Werner Rotation Chair.


2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 821-821
Author(s):  
Sienna Durbin ◽  
Meghan Mooradian ◽  
Leyre Zubiri ◽  
Ian Matthew Allen ◽  
Florian Fintelmann ◽  
...  

821 Background: CPI therapy has expanded rapidly in recent years and represents a major advancement in the treatment of many cancers, including hepatocellular carcinoma, gastric cancer, and colon cancer. However, these therapies are associated with significant toxicities. CPI colitis is one of the most common toxicities and can be fatal, especially when not diagnosed and treated promptly. The current gold standard for diagnosis is endoscopy with biopsy, an invasive procedure that is resource- and time-intensive. CT has emerged as a possible alternative. The primary objective of this study is to identify the diagnostic performance of CT in the evaluation of CPI colitis. Methods: With IRB approval, we conducted a retrospective cohort study of patients who received CPI therapy between 2009-2019 across a single healthcare system. Patients were included if they underwent both abdominal CT and upper/lower endoscopy with biopsy within 72 hours of each other. We reviewed the electronic medical record to identify possible cases of colitis based on either CT or pathology. All cases were labeled as either true positive or false positive based on pathology. We examined clinical characteristics, including CTCAE grade and treatment received. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT for diagnosing CPI colitis when compared to the gold standard of tissue diagnosis. Results: Of the 4,474 patients screened, 141 met inclusion criteria. Average age was 63 years (23 – 91); 43% were male. Most common tumor types were melanoma (36%) and NSCLC (20%). Seventy-four percent of patients were treated with anti-PD-1/PD-L1 monotherapy. Forty percent had signs of colitis on CT scan and 59% had biopsy-proven CPI colitis. Sensitivity and specificity of CT were 51% and 74%, respectively. PPV of CT was 74% and NPV was 51%. Of those with confirmed CPI colitis, 78% had symptoms that were classified as grade 3 or above. Seventy-three percent received IV steroids and 38% received infliximab. Conclusions: CT demonstrates moderate specificity and PPV and remains an important diagnostic test but does not replace endoscopy/biopsy in the evaluation of CPI colitis.


2016 ◽  
Vol 60 (3) ◽  
pp. 205-210 ◽  
Author(s):  
Shweta Chaudhary ◽  
Yanjun Hou ◽  
Rulong Shen ◽  
Shveta Hooda ◽  
Zaibo Li

Objective: The Afirma gene expression classifier (GEC) is a molecular test to further classify indeterminate fine-needle aspiration (FNA) as benign or suspicious for malignancy. Study Design: A total of 158 FNAs with Bethesda category III/IV cytology were sent for an Afirma GEC test. We correlated the Afirma GEC results with surgical outcome and also compared the data after Afirma's implementation with the data before. Results: Among the 158 FNAs, the Afirma result was benign in 63 (40%), suspicious in 85 (54%) and unsatisfactory in 10 (6%). In total, 73 (86%) suspicious Afirma cases had surgery and 28 (38%) showed carcinoma. In contrast, only 8 (13%) benign Afirma cases had surgery and all of them were benign. The sensitivity, specificity, negative predictive value and positive predictive value (PPV) of Afirma were 100, 15, 100 and 38%, respectively. The PPV was 20% in cases with follicular lesion of undetermined significance, but was 50% in cases suspicious for follicular neoplasm (SFN). The surgical excisional rate was significantly decreased in SFN cases after the Afirma test. Conclusions: The Afirma GEC is useful for further risk stratifying SFN cases.


2021 ◽  
Author(s):  
Bindiya Gupta ◽  
Rashmi Shreya ◽  
Shalini Rajaram ◽  
Anshuja Singla ◽  
Sandhya Jain ◽  
...  

Abstract Purpose: Standardization of colposcopic evaluation is important as it is observer dependent.The aim of the study was to compare the strength of association of colposcopic findings by International Federation of Colposcopy and Cervical Pathology (IFCPC) nomenclature and Swede score. Methods: In the prospective study, 150 women aged 30 to 60 years with abnormal screening results underwent colposcopy, the findings were evaluated using both IFCPC and Swede score and biopsy was taken from abnormal areas. Performances by both the methods were calculated taking biopsy as gold standard. Results: Nineteen ≥ CIN2 lesions were detected. The sensitivity, specificity, positive predictive value and negative predictive value for detecting ≥ CIN2 lesion by IFCPC scoring was 63.6%, 96.0%, 78.7%, 91.9%. Using Swede score, sensitivity, specificity, positive predictive value and negative predictive value at cut off of 8 were 42.4, 95%, 96.6% and 81.8% while at cut-off of 5, these were 96%, 88.3%,76.7% and 93.6%. The agreement between IFCPC major lesion and Swede score ≥ 8 for ≥ CIN2 was 0.626 (p<0.01). Conclusion: Swede score is an easier and more objective method for colposcopic evaluation and a score >8 can be applied to the screen and treat programme.


2019 ◽  
Vol 6 (6) ◽  
pp. 2593
Author(s):  
Nayantara R. Gandra ◽  
Kalavathy Jasmine Masillamoni

Background: Even though there are many programs run by Government to tackle the problem of malnutrition in India, problem of malnutrition is still there. Malnutrition leads to infections and even can lead to death of child in severe cases. The mortality rate is very high compared to other countries. The objective of the study to study validity of age independent various nutritional status indices in comparison to gold standard of weight for ageMethods: Present study was institution based cross sectional study carried out at SDA high school, from January 2019 to July 2019 among 58 school children aged 34-92 months of age. Anthropometric measurements like weight, height, head circumference, chest circumference, mid arm circumference were recorded as per the standard guidelines. Weight for height, weight of age, Kanawati Index, Jeliffe’s ratio, Rao index, and Dugdales index was calculated. Gold standard used was weight for age. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for these indices.Results: Majority of the children belonged to 48-60 months and 61-72 months i.e. 29.3% each. Males were more than females. Prevalence of malnutrition was 60.3%, 48.3%, 51.7%, 91.4%, and 56.8% based on weight for age, Kanawati index, Rao index, Jeliffe’s ratio and Dugdale’s index respectively. Dugdale’s index was found to have high sensitivity (85.7%) and specificity (86.9%) compared to all other indices.Conclusions: Among age independent indices of nutritional status available, Dugdales index can be used as it has been found that it has remarkably higher sensitivity and specificity compared to other age independent indices of nutritional status.


2019 ◽  
Vol 55 (1) ◽  
pp. 48
Author(s):  
Reza Gunadi Ranuh ◽  
Alpha Fardah Athiyyah ◽  
Deanty Ayu PA ◽  
Andy Darma ◽  
Dadik Rahardjo ◽  
...  

In developing countries, Norovirus is the second-leading cause of acute diarrhea, after rotavirus. The approved gold standard method for diagnosis of norovirus infection is RT-PCR. The rapid immunochromatographic test is a novel and expedient method for diagnosing norovirus that is relatively affordable. However, the use of the rapid immunochromatographic test remains controversial because of its accuracy. This study aimed to explore whether the rapid immunochromatographic test could be used for diagnosing norovirus-related diarrhea in children. Rapid immunochromatographic test (QuickNaviTM-Norovirus2) and RT-PCR on stool samples was used to diagnose norovirus. Stool samples were obtained from pediatric patients aged between 1 and 60 months who had diarrhea and were admitted to the pediatric ward at Dr. Soetomo General Hospital Surabaya, between April 2013 and March 2014. Ninety-four subjects provided stool samples that were tested using QuickNaviTM-Noro2 and RT-PCR. Using the test, 64 samples tested positive for norovirus and 30 tested negatives. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the rapid immunochromatographic test were consecutively 90.3%, 42.9%, 43.8%, 90%, and 58.5%. RT-PCR was used to test all samples to assess the accuracy, which showed that one from 31 samples contained the GI strain (1.1%), while 30 samples (32%) contained the GII strain. This study definitively establishes that the rapid immunochromatography test is not sufficiently accurate for use as a screening or diagnostic tool in norovirus-related diarrhea cases in children.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Salama Bin Hendi ◽  
Zainab A. Malik ◽  
Amar Hassan Khamis ◽  
Fadil Y. A. Al-Najjar

Abstract Background Diagnosis of Group A Streptococcus (GAS) pharyngitis in children is hindered by variable sensitivity of clinical criteria and rapid Strep A tests (SAT), resulting in reliance on throat cultures as the gold standard for diagnosis. Delays while awaiting culture reports result in unnecessary antibiotic prescriptions among children, contributing to the spread of antimicrobial resistance (AMR). Methods Diagnostic accuracy study of an automated SAT (A-SAT) in children up to 16 years of age presenting to an emergency room with signs and symptoms of pharyngitis between March and June 2019. Paired throat swabs for A-SAT and culture were collected. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for A-SAT were calculated. Results Two hundred and ninety-one children were included in this study. 168 (57.7%) were boys and the mean age was 4.2 years. A-SAT was positive in 94 (32.3%) and throat culture was positive in 90 (30.9%) children. A-SAT and throat culture results showed a high level of consistency in our cohort. Only 6 (2%) children had inconsistent results, demonstrating that the A-SAT has a high sensitivity (98.9%), specificity (97.5%), PPV (94.7%) and NPV (99.5%) for the diagnosis of GAS pharyngitis in children. Only 92 (32%) children were prescribed antibiotics while the vast majority (68%) were not. Conclusions A-SAT is a quick and reliable test with diagnostic accuracy comparable to throat culture. Its widespread clinical use can help limit antibiotic prescriptions to children presenting with pharyngitis, thus limiting the spread of AMR.


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