scholarly journals Comparison of Chemicon SimulFluor Direct Fluorescent Antibody Staining with Cell Culture and Shell Vial Direct Immunoperoxidase Staining for Detection of Herpes Simplex Virus and with Cytospin Direct Immunofluorescence Staining for Detection of Varicella-Zoster Virus

2001 ◽  
Vol 8 (5) ◽  
pp. 909-912 ◽  
Author(s):  
Edward L. Chan ◽  
Ken Brandt ◽  
Greg B. Horsman
Keyword(s):  
Cell Culture ◽  
Predictive Value ◽  
Fluorescent Antibody ◽  
Turnaround Time ◽  
Immunofluorescence Assay ◽  
Direct Immunofluorescence ◽  
Shell Vial ◽  
Varicella Zoster ◽  
Simplex Virus ◽  
Sensitivity Specificity

ABSTRACT A new rapid direct immunofluorescence assay, the SimulFluor direct fluorescent-antibody (DFA) assay, which can simultaneously detect herpes simplex virus types 1 and 2 (HSV-1 and -2) and varicella-zoster virus (VZV), was evaluated in comparison with our current standard procedures of (i) shell vial direct immunoperoxidase (shell vial IP) staining and cell culture for detection of HSV and (ii) cytospin DFA staining for VZV detection. A total of 517 vesicular, oral, genital, and skin lesion specimens were tested by all three procedures. For HSV detection, the SimulFluor DFA assay had an overall sensitivity, specificity, positive predictive value, and negative predictive value of 80.0, 98.3, 92.3, and 95.1%, respectively, when compared to culture. Shell vial IP staining had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.6, 100, 100, and 96.9%, respectively, when compared with cell culture. The SimulFluor DFA assay, however, offers same-day, 1.5-hours results versus a 1- to 2-day wait for shell vial IP staining results and a 1- to 6-day wait for culture results for HSV. For VZV detection SimulFluor DFA staining detected 27 positive specimens as compared to 31 by our standard cytospin DFA technique—a correlation of 87.1%. A positive SimulFluor reaction for VZV is indicated by yellow-gold fluorescence compared to the bright apple-green fluorescence observed by cytospin DFA staining. There is no difference in turnaround time between the two assays. The SimulFluor DFA assay is a rapid immunofluorescence assay that can detect 80% of the HSV-positive specimens and 87% of the VZV-positive specimens with a 1.5-h turnaround time.

scholarly journals A Rapid Monoclonal Immunofluorescence Assay for Chlamydia Psittaci in Fecal Smears from Psittacine Birds

1989 ◽  
Vol 1 (2) ◽  
pp. 150-153 ◽  
Author(s):  
Leslie W. Woods ◽  
Jill F. Dotson ◽  
Anthony E. Castro
Keyword(s):  
Cell Culture ◽  
Chlamydial Infection ◽  
Fluorescent Antibody ◽  
Antibody Test ◽  
Relative Sensitivity ◽  
Immunofluorescence Assay ◽  
Chlamydia Psittaci ◽  
Direct Immunofluorescence ◽  
California Department ◽  
Direct Fluorescent Antibody

One hundred two fecal specimens from psittacine birds submitted to Veterinary Laboratory Services of the California Department of Food and Agriculture at Petaluma were screened for Chlamydia psittaci by a direct immunofluorescence assay using a fluorescein-labeled monoclonal antibody conjugate specific for Chlamydia sp. Results were compared with those obtained by isolation of Chlamydia in cultures of McCoy mouse cells. The relative specificity of the direct fluorescent antibody test on fecal smears was 98.9% and the relative sensitivity was 62.5%. The results of this study suggested that the direct fluorescent antibody test was highly specific, and it proved to be a useful same-day antemortem diagnostic test for birds with symptomatic Chlamydial infection. The use of centrifugation in the cell culture assay was found to significantly enhance the level of Chlamydial infection in cell culture.

scholarly journals Comparison of the Sensitivity and Specificity of Tzanck Smear and Immunofluorescence Assay for the Diagnosis of Cutaneous Herpes Simplex Virus and Varicella Zoster Virus Infections in a Real-life Clinical Setting

2021 ◽  
Vol 73 (5) ◽  
Author(s):  
Chayada Chaiyabutr ◽  
Nuttagarn Jantanapornchai ◽  
Chalermkwan Apinuntham ◽  
Charussri Leeyaphan ◽  
Sukhum Jiamton
Keyword(s):  
Sensitivity And Specificity ◽  
Early Onset ◽  
Real Life ◽  
Immunofluorescence Assay ◽  
Virus Infections ◽  
Detection Rates ◽  
Varicella Zoster ◽  
Diagnostic Coding ◽  
Simplex Virus ◽  
Hsv Infections

Objective: This research aim to compare (1) the sensitivities and specificities of Tzanck smears and indirect immunofluorescence assays (IFA) for cutaneous HSV and VZV infections in real-life settings; and (2) the detection rates of the tests for various patient types and lesion morphologies.Materials and Methods: This retrospective study reviewed 440 and 172 samples from patients with clinically suspicious cutaneous HSV and VZV infections, respectively. All patients underwent a Tzanck smear and IFA. The gold standard for the study was agreement of pre- and post-diagnostic coding (determined by a dermatologist) for cutaneous HSV and VZV infections.Results: For HSV infections, the respective sensitivity and specificity of Tzanck smears were 32.8% and 96.6%, whereas those for IFA were 60.7% and 100%. As to VZV infections, the sensitivity and specificity of Tzanck smears were 54.3% and 97.8%, respectively, while the corresponding IFA values were 71.7% and 100%. According to disease characteristics and lesion morphologies, the detection ability of cutaneous HSV by IFA was substantially higher than Tzanck smear especially in immunosuppressed condition.  Tzanck smears and IFA demonstrated no statistical difference for early-onset ( 3 days) VZV infections.Conclusion: Tzanck smears and IFA had higher sensitivities for detecting VZV than HSV infections. IFA testing in suspected cutaneous HSV patients with immunosuppressed conditions should be recommended. Despite the overall sensitivity and specificity of IFA being greater than those for Tzanck smears especially in HSV infections, the latter test is a comparable option for early-onset VZV infections.

scholarly journals Evaluation of GeneXpert MTB/RIF for detecting Mycobacterium tuberculosis in a hospital in China

2017 ◽  
Vol 45 (2) ◽  
pp. 816-822 ◽  
Author(s):  
Tingyu Tang ◽  
Fang Liu ◽  
Xiaoling Lu ◽  
Qingdong Huang
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Predictive Value ◽  
Rate Sensitivity ◽  
Turnaround Time ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Significant Difference ◽  
Kappa Value ◽  
Positive Rate ◽  
Sensitivity Specificity

Objective To evaluate the performance of GeneXpert MTB/RIF in diagnosing pulmonary tuberculosis (TB) in China. Methods This cross-sectional study included sputum specimens of 240 suspected TB cases. Specimens were examined by light microscopy for the presence of acid-fast bacilli, which were cultured by the BACTEC MGIT 960 (M960) system and detected by the GeneXpert MTB/RIF assay. The positive rate, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and average turnaround time of methods were evaluated. Results The positive rate was 36.6% (87/238) for the GeneXpert MTB/RIF assay and 34.0% (81/238) by M960 culture, with no significant difference between methods (χ2 = 0.33, p > 0.05). According to culture results, sensitivity of the GeneXpert MTB/RIF assay was 84.0% (68/81), specificity was 87.8% (129/147), the PPV was 78.2% (68/87), and the NPV was 87.2% (129/148). The agreement for results between Gene Xpert MTB/RIF and the M960 system was 82.8% and the Kappa value was 0.73. Conclusion The GeneXpert MTB/RIF assay is a simple, rapid, and accurate test for detecting Mycobacterium tuberculosis in sputum specimens.

scholarly journals Prospective study with rapid and low cost serodiagnostic assay for rickettsial infections in children of Vijayapura district, Northern Karnataka, India

2018 ◽  
Vol 5 (4) ◽  
pp. 1244 ◽  
Author(s):  
Trimal Kulkarni ◽  
Govind Benakatti ◽  
Laxman Bidari
Keyword(s):  
Prospective Study ◽  
Clinical Features ◽  
Predictive Value ◽  
Low Cost ◽  
Immunofluorescence Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rickettsial Infections ◽  
Significant Difference ◽  
Diagnostic Difficulties ◽  
Sensitivity Specificity

Background: Rickettsial infections do exist in study area posing diagnostic difficulties. The study is aimed to compare performance of serological assays for rapid and low-cost diagnosis for rickettsial infections in northern Karnataka, India.Methods: Prospective study was done on 40 children upto 12 years old, hospitalized during 1-year period with fever and presence of one or more of the clinical features of rickettsial infections. Clinical and biochemical findings and serological assays such as indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay-IgM (ELISA-IgM) and Weil-Felix were used to diagnose the disease. Statistical analysis was used to compare the results. Performance characteristics such as sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated using MedCalc for Windows.Results: All 40 patients met the inclusion criteria (23 males and 17 females). Mortality was 2%. Predominant age group was 1-3 years (57.50%). Fever, rashes and hepatosplenomegaly was in all 40 patients (100%); whereas other clinical features showed mixed results. Biochemical findings: anemia in 90%, thrombocytopenia in 45% and elevated transaminases 57.50% and 55%. The ELI-SA-IgM assay showed a sensitivity of 95.00%, a specificity of 95.24% and 95.12% accuracy.  The Weil-Felix assay showed a sensitivity of 77.50%, a specificity of 81.63% and 79.78% accu-racy. ELISA-IgM test showed only 5% (p=0.5555) and Weil-Felix test showed 12.50% (p=0.3816) non-significant difference when both compared with IFA test. Whereas ELISA-IgM showed 17.50% more significant (p=0.0239) when compared with Weil-Felix.Conclusions: ELISA-IgM may serve as rapid and low cost serodiagnostic assay over IFA for rickettsial infections.

scholarly journals Diagnostic Indexes of a Rapid IgG/IgM Combined Antibody Test for SARS-CoV-2

2020 ◽  
Author(s):  
Liu Ying ◽  
Liu Yue-ping ◽  
Diao Bo ◽  
Ren Feifei ◽  
Wang Yue ◽  
...  
Keyword(s):  
Predictive Value ◽  
Antibody Test ◽  
Turnaround Time ◽  
Ease Of Use ◽  
Sample Collection ◽  
Rt Pcr ◽  
Illness Onset ◽  
Test Kit ◽  
Combined Test ◽  
Sensitivity Specificity

[Abstract]ObjectiveCoronavirus disease 2019 (COVID-19) has become pandemic in the world. The need for IgG-IgM combined antibody test is booming, but data on diagnostic indexes evaluation was inadequate. The aim of this study was to evaluate diagnostic indexes of a rapid IgG-IgM combined antibody test for SARS-CoV-2.MethodsA total of 179 patients were enrolled. Serum were collected for IgG-IgM combined antibody test and corresponding nasal and pharyngeal swab specimens were collected for SARS-CoV-2 RT-PCR. According to SARS-CoV-2 RT-PCR results, patients under study were categorized as PCR positive group in 90 patients and PCR negative group in 89 patients.Results1. Of the 90 PCR positive samples, 77 were tested positive by SARS-CoV-2 IgG-IgM test kit, yielding a sensitivity of 85.6%. Meanwhile, of the 89 PCR negative sample, 8 samples were detected positive, resulting in a specificity of 91%. Positive predictive value, negative predictive value and accuracy of this test kit was 95.1%, 82.7%, and 88.3%, respectively. Kappa efficiency between IgG/IgM test kit and RT-PCR were 0.75. 2. Accuracy in mild/common and severe/critical subgroup were 73.9% and 97.7%, respectively. Accuracy in clinical confirmed, suspected cases and other disease subgroups were 70%, 60%, and 100%, respectively. 3. Patients were further divided into ‘0 - 7’, ‘8 - 15’ and ‘>= 16’ groups according to the time from illness onset to sample collection. Sensitivity, specificity and accuracy in these three groups were 18.8%, 77.8% and 40%; 100%, 50% and 87.5%; 100%, 64.3%, and 93.9, respectively.ConclusionThe sensitivity and specificity of this ease-of-use IgG/IgM combined test kit were adequate, plus short turnaround time, no specific requirements for additional equipment or skilled technicians, all of these collectively contributed to its competence for mass testing. At the current stage, it cannot take the place of SARA-CoV-2 nucleic acid RT-PCR, but can be served as a complementary option for RT-PCR. The combination of RT-PCR and IgG-IgM combined test kit could provide further insight into SARS-CoV-2 infection diagnosis.

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