scholarly journals Poor Performance of the Chlamydia Rapid Test Device for the Detection of Asymptomatic Infections in South African Men: A Pilot Study

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
N. S. Abbai-Shaik ◽  
T. Reddy ◽  
S. Govender ◽  
G. Ramjee

Background. To the best of our knowledge, there have been no published reports on the diagnostic performance of the Chlamydia Rapid Test (CRT) Device for male urine samples. We evaluated the performance of the CRT Device when compared with that of the BD ProbeTec ET PCR Assay in a population of asymptomatic men. Methods. The study enrolled 100 men between June and July 2015. From each consenting male, 20–30 mL of urine was collected. Sensitivity and specificity of the rapid test compared to PCR were calculated. All analysis was performed in STATA version 13. Results. All men had valid rapid and PCR test results. The test showed a low sensitivity against PCR (20%) (95% CI 3.7–6.2%); however, an excellent specificity was observed (100%) (one sided 97.5% CI: 96.0–100). Conclusions. This test was not found to be suitable as a screening tool for genital Chlamydia infections in men. Our findings emphasize the need for more sensitive POC tests to be developed since the current approach for the management of STIs in Africa is confounded by poor sensitivity and specificity resulting in many infected individuals not being treated.

2011 ◽  
Vol 5 (03) ◽  
pp. 204-208 ◽  
Author(s):  
Eliningaya John Kweka ◽  
Asanterabi Lowassa ◽  
Shandala Msangi ◽  
Epiphania E Kimaro ◽  
Ester E Lyatuu ◽  
...  

Introduction: Several rapid diagnostic tools for malaria are currently available in local markets. However, diagnostic accuracy varies widely. The present study was conducted to evaluate a cheaply and easily available rapid diagnostic malaria test (ParaHIT-f) in rural Tanzania. Methodology: Participants presenting with fever at health centers in the Kilimanjaro and Manyara regions were eligible. Parasitological thin and thick smears were examined from finger-prick blood samples and compared to ParaHIT-f test results. Sensitivity, specificity and predictive values were calculated using microscopic parasitological examination as the gold standard. Results: In total, 236/743 (31.8%) individuals had a positive malaria microscopy, and 25/715 (3.4%) were positive in the rapid diagnostic test. The sensitivity of ParaHIT-f was 10.7% (95% CI, 6.7-14.7) and specificity was 100% (95% CI, 97.4-102), with positive and negative predictive values (PPV and NPV) of 100% (95% CI, 99.1-100.2) and 70.9% (95% CI, 66.9-74.9) respectively. Sensitivity of ParaHIT-f increased with increasing P. falciparum density (P > 0.003) from 5.8% (95% CI, 0-12.9) at < 100 parasites/μl to 20.5% (95% CI, 13.5-27) at ≥ 100 parasites/μl. Conclusions: Sensitivity of the ParaHIT-f rapid test was very low in this setting, therefore concomitant use of rapid diagnostic tests and microscopy is recommended. In the case of positive test results, confirmation by parasitological techniques is not necessary. Further monitoring of ParaHIT-f in various epidemiological settings in Tanzania is warranted. 


2020 ◽  
Vol 33 (1) ◽  
pp. 73-79
Author(s):  
Pablo Parodi ◽  
Luis G. Corbellini ◽  
Vanessa B. Leotti ◽  
Rodolfo Rivero ◽  
Cecilia Miraballes ◽  
...  

Detection of bovine Babesia spp. and Anaplasma marginale is based on the reading of Giemsa-stained blood or organ smears, which can have low sensitivity. Our aim was to improve the detection of bovine Babesia spp. and A. marginale by validating a multiplex PCR (mPCR). We used 466 samples of blood and/or organs of animals with signs and presumptive autopsy findings of babesiosis or anaplasmosis. The primers in our mPCR amplified the rap-1a gene region of Babesia bovis and B. bigemina, and the msp-5 region of A. marginale. We used a Bayesian model with a non-informative priori distribution for the prevalence estimate and informative priori distribution for estimation of sensitivity and specificity. The sensitivity and specificity for smear detection of Babesia spp. were 68.6% and 99.1%, and for A. marginale 85.6% and 98.8%, respectively. Sensitivity and specificity for mPCR detection for Babesia spp. were 94.2% and 97.1%, and for A. marginale 95.2% and 92.7%, respectively. Our mPCR had good accuracy in detecting Babesia spp. and A. marginale, and would be a reliable test for veterinarians to choose the correct treatment for each agent.


2019 ◽  
Vol 43 ◽  
pp. 1
Author(s):  
María Isabel Jercic ◽  
Graciela Santillan ◽  
Susana Elola ◽  
William Quispe Paredes ◽  
Lidia B Conza Blanco ◽  
...  

Objective. To compare the performance of polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) tests for diagnosing Echinococcus granulosus in dog feces among national reference laboratories in Argentina, Chile, Peru, and Uruguay. Methods. National laboratories affiliated with the Ministry of Health/Agriculture of each country exchanged panels of 10 positive/negative samples obtained from their regular national surveillance programs in November 2015 – November 2016. All laboratories applied PCR; two also applied ELISA techniques. Sensitivity and specificity were determined for each laboratory and concordance of results among the laboratories was evaluated by Cohen Kappa coefficient. Results. Poor concordance (3 of 10 paired comparisons had values of Kappa > 0.4), low sensitivity and specificity across all laboratories, and poor performance of both techniques in detecting E. granulosus in canine feces was demonstrated in this study. An ex-post comparison of the laboratories’ test protocols showed substantial heterogeneity that could partially explain poor concordance of results. Conclusion. The results underscore the heterogeneity of canine echinococcosis diagnosis across the region and indicate possible sources of variability. Efforts to standardize canine echinococcosis testing must be included in the plan of action for the Regional Initiative for the Control of Cystic Echinococcosis. Future comparisons with fecal samples of known parasite load are needed.


2020 ◽  
Vol 20 ◽  
Author(s):  
Si Yu ◽  
Menglin Huang ◽  
Jingyu Wang ◽  
Yongchang Zheng ◽  
Haifeng Xu

: Widely exploration of noninvasive tumor/cancer biomarkers has shed light on clinical diagnosis. However, many under-investigated biomarkers showed limited application potency due to low sensitivity and specificity, while extracellular vehicles (EVs) were gradually recognized as promising candidates. EVs are small vesicles transporting bioactive cargos between cells in multiple physiological processes and also in tumor/cancer pathogenesis. This review aimed to offer recent studies of EVs on structure, classification, physiological functions, as well as changes in tumor initiation and progression. Furthermore, we focused on advances of EVs and/or EV-related substances in cancer diagnosis, and summarized ongoing studies of promising candidates for future investigations.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Sungwoo Choi ◽  
Hyo Jeong Choi ◽  
Ho Jung Kim

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test ( p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high ( p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) ( p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered ( p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.


2020 ◽  
Vol 9 (9) ◽  
pp. 2917
Author(s):  
Thomas Ackmann ◽  
Burkhard Möllenbeck ◽  
Georg Gosheger ◽  
Jan Schwarze ◽  
Tom Schmidt-Braekling ◽  
...  

Introduction: D-dimer is a diagnostic criterion for periprosthetic joint infection (PJI) of the Musculoskeletal Infection Society (MSIS) in 2018. The aim of this study was to evaluate the serum D-dimer values in comparison to C-reactive protein (CRP) and interleukin-6 (IL-6) for the diagnosis of PJI. Materials and Methods: We included 119 patients (50 women, 69 men; 71 knees, 48 hips) undergoing revision arthroplasty with preoperative assessment of CRP, IL-6, and serum D-dimer. Cases were classified as infected or aseptic based on the MSIS criteria of 2018. Receiver operating curves and Youden’s index were used to define an ideal cut-off value and sensitivity and specificity for the individual parameters, and respective combinations were calculated using cross-tables. Results: The median D-dimer level (2320 vs. 1105 ng/mL; p < 0.001), the median CRP level (4.0 vs. 0.5 mg/dL; p < 0.001), and the median IL-6 level (21.0 vs. 5.0 pg/mL; p < 0.001) were significantly higher in the group of PJI compared to the group with aseptic failure. The calculated optimal cut-off values were 2750 ng/mL (AUC 0.767) for D-dimer, 1.2 mg/dL (AUC 0.914) for CRP, and 10.0 pg/mL (AUC 0.849) for IL-6. D-dimer showed a sensitivity of 38% and specificity of 94%, whereas the CRP and IL-6 had sensitivities of 88% and 76%, and specificities of 87% and 92%, respectively. Conclusion: In comparison with CRP and IL-6, serum D-dimer showed low sensitivity and specificity in our cohort. While CRP and IL-6 combination had the highest sensitivity, a combination of Il-6 and D-dimer or CRP and IL-6 had the highest specificity.


2015 ◽  
Vol 53 (12) ◽  
pp. 3935-3937 ◽  
Author(s):  
Daniel Golparian ◽  
Stina Boräng ◽  
Martin Sundqvist ◽  
Magnus Unemo

The new BD Max GC real-time PCR assay showed high clinical and analytical sensitivity and specificity. It can be an effective and accurate supplementary test for the BD ProbeTec GC Qx amplified DNA assay, which had suboptimal specificity, and might also be used for initial detection ofNeisseria gonorrhoeae.


2012 ◽  
Vol 19 (8) ◽  
pp. 1193-1198 ◽  
Author(s):  
Vijai Pal ◽  
Subodh Kumar ◽  
Praveen Malik ◽  
Ganga Prasad Rai

ABSTRACTGlanders is a contagious disease caused by the Gram-negative bacillusBurkholderia mallei. The number of equine glanders outbreaks has increased steadily during the last decade. The disease must be reported to the Office International des Epizooties, Paris, France. Glanders serodiagnosis is hampered by the considerable number of false positives and negatives of the internationally prescribed tests. The major problem leading to the low sensitivity and specificity of the complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e., crude preparations of whole cells. False-positive results obtained from other diagnostic tests utilizing crude antigens lead to financial losses to animal owners, and false-negative results can turn a risk into a possible threat. In this study, we report on the identification of diagnostic targets using bioinformatics tools for serodiagnosis of glanders. The identified gene sequences were cloned and expressed as recombinant proteins. The purified recombinant proteins ofB. malleiwere used in an indirect ELISA format for serodiagnosis of glanders. Two recombinant proteins, 0375H and 0375TH, exhibited 100% sensitivity and specificity for glanders diagnosis. The proteins also did not cross-react with sera from patients with the closely related disease melioidosis. The results of this investigation highlight the potential of recombinant 0375H and 0375TH proteins in specific and sensitive diagnosis of glanders.


2021 ◽  
pp. 109566
Author(s):  
Xi He ◽  
Derong Zhou ◽  
Yanwu Sun ◽  
Yuan Zhang ◽  
Xiaogang Zhang ◽  
...  

2021 ◽  
pp. 109352662199148
Author(s):  
M. Cristina Pacheco ◽  
Nicole Green ◽  
Jane Dickerson ◽  
Dale Lee

Objectives The goal of our study was to determine whether visual assessment of the esophagus and stomach could predict abnormal histology and determine the frequency of interventions based on biopsies in patients undergoing endoscopy for elevated tissue transglutaminase immunoglobulin A antibody (TTG). Methods Pathology records were searched for patients with biopsy performed for elevated TTG. Pathology report, endoscopy report, and follow-up were obtained and slides from the duodenum reviewed. Pathology was considered gold standard for sensitivity and specificity calculations. Results 240 patients were included. 215 patients had esophageal biopsies performed. Esophageal endoscopic visual assessment had sensitivity of 47% and specificity of 93% for abnormal histology. 16(7%) patients had therapy or referral related to results and, of these, 6(38%) had visually normal endoscopy. 237 biopsies were performed of stomach. Gastric endoscopic visual assessment had a sensitivity and specificity of 20% and 87%. 24(10%) patients had therapy based on findings and, of these, 12 (50%) had visually normal endoscopy. Conclusions Endoscopic assessment of esophagus and stomach has low sensitivity and high specificity for pathologic abnormalities when indication for endoscopy is elevated TTG. When endoscopy is visually normal clinical interventions based on biopsy are rare, and foregoing biopsy may be considered.


Sign in / Sign up

Export Citation Format

Share Document