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Introduction: While real-time reverse transcription PCR (RT-PCR) is the recommended laboratory method to diagnose severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection, its use in resource limited settings can be difficult to maintain due to high testing demand and shortage of reagents. The aim of this study was to evaluate the performances of Realy Tech™ and Standard Q™ in comparison to RT-PCR in a relatively low COVID-19 prevalence setting, Mali. Methods: We conducted a cross-sectional study between January and April 2021 in Bamako and Kati regions to evaluate both rapid tests during a large SARS-CoV-2 prevalence study in Mali. Results: Of the 390 samples tested, the sensitivity and specificity of Realy Tech™ and Standard Q™ were 57.1% (95%CI: 44.1-69.2), 95.8% (95%CI: 93.1-97.5); 61.9% (95%CI: 46.8-75.0), and 94.1% (95%CI: 89.5-96.8) respectively. Using RT-PCR, the global prevalence of SARS-CoV-2 was 14.4% (56/390). In both rapid antigen tests, the performance was better when used in suspected patients compared to positive patients under treatment. Moreover, higher viral loads equivalent to Ct < 25 were associated with better detection rates. Conclusion: While waiting for more complete data, these preliminary studies suggest that Realy Tech™ and Standard Q™ should not be used alone for COVID-19 diagnosis in Mali.
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Humans , Male , Female , SARS-CoV-2 , COVID-19ABSTRACT
Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become a global public health problem. The real-time reverse transcription-polymerase chain reaction (RT-PCR) is the gold standard test for the detection of SARS-CoV-2. However, the assay requires hours to get the final results. Therefore, antigen-based rapid assays are being used extensively to reduce the time. We have evaluated the performance of the antigen-based rapid test for the detection of SARS-CoV-2 virus in comparison with RT-PCR. Materials and methods: Nasopharyngeal and throat swabs were collected from 366 suspected patients of COVID-19 visiting our institute and subjected to qualitative RT-PCR and antigen-based rapid assays to detect the presence of SARS-CoV-2 virus. The sensitivity and specificity of the antigen-based assay were calculated in comparison with RT-PCR. Results: Compared with RT-PCR, sensitivity and specificity of the antigen-based rapid assay were observed to be 70.5% and 98.6%, respectively, in comparison with RT-PCR. However, the sensitivity of antigen-based rapid assay varied significantly with decreasing viral load. The sensitivity of the rapid antigen assay was equivalent to RT-PCR (23/23, 100%) at a higher viral load (Ct value 15�). In contrast, the antigen assay could only detect 3/21 (14.28%) samples with Ct value >30. Conclusion: The antigen-based assay could assist in the rapid screening of a large population. However, the rapid antigen assay might not detect early stages of infection represented by low viral load. Therefore, the antigen-based assay could not replace RT-PCR testing. The study reiterates that all antigen-based negative tests should be confirmed by RT-PCR.
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Purpose: To assess the rapid antigen test (RAT) against the gold standard reverse transcription?polymerase chain reaction (RT?PCR) to screen COVID?19 infection in asymptomatic patients undergoing ophthalmic procedures. Methods: This was a retrospective hospital?based study. Point?of?care (PoC) RAT was performed using nasopharyngeal swab, while RT?PCR for SARS?CoV?2 viral RNA was performed using both nasopharyngeal and throat swabs. Results: A total of 629 patients were tested for SARS?CoV?2 by using both RAT and RT?PCR. Only one patient had tested positive for SARS?CoV?2 with both RAT and RT?PCR, while two patients had tested positive with RT?PCR after an initial negative RAT. The positivity rate for RAT was 0.15% (1/629), and that for RT?PCR was 0.47%. Percent agreement or proportion of agreement observed between the two tests was 99.68%, while Cohen’s kappa coefficient value was 0.49. The sensitivity of RAT in comparison to RT?PCR was 33.33%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 99.68%. Conclusion: The sensitivity and Cohen’s kappa coefficient in our study were low but that can be attributed to the overall low positivity rates with both RAT and RT?PCR. However, percent agreement observed between the two tests was very high. Therefore, we recommend initial screening of all the patients for COVID?19 symptoms followed by RAT before performing any ophthalmic surgical procedure to ensure the safety of the health care professionals as well as the patients.
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Background:Accurate diagnosis and widespread use of diagnostic tests with easy accessis important to contain the spread of SARS-CoV-2. A Real-time reverse transcription polymerase chain reaction (RT-PCR) has high cost and can be performed in special laboratories. There have been several easy to perform rapid antigen detection tests developed and recommended to use at point of care for timely detection of positive patients and their isolation to limit the spread of infection. The aim of the study was to compare the cost effectiveness and the role of RT-PCR and rapid antigen testing in diagnosing different suspects of COVID-19.Methods:In this cross-sectional study the data of all the suspected cases who underwent COVID-19 testing over a period of seven weeks at divisional level was used for analysis.Results:The widespread use of rapid antigen testing makes it more cost effective in detecting COVID-19 cases than the highly sensitive and specific RT-PCR testing. Conclusions:Rapid antigen tests can be used as a screening testing tool in high-risk groups to identify the infected persons quickly and for preventing the transmission of infection particularly in low resource settings.
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ABSTRACT The performance of a test can be suboptimal, but in appropriate setting such a test is still useful for clinical decision making. We investigated the role of Antigen Rapid Diagnostic Test (Ag-RDT) for clinical decision making in an Emergency Department (ED) in Curacao during peak of COVID-19 pandemic. Ag-RDT was performed in the naso- and oropharynxswabs from patients with respiratory insufficiency presented to the ED. Ag-RDT was performed in 153 patients, of which 64 (41.8%) showed positive results. Comparing Ag-RDT results with molecular tests, its sensitivity was 68.8% (95% CI 57.4 to 78.7), and specificity of 94.6% (95% CI 84.9 to 98.9). The positive and negative predictive value were 95.1% (95% CI 86.5 to 98.3) and 66.3 (95% CI 58.6 to 73.3), respectively. All patients with Ag-RDT positive test were admitted to the cohorted COVD-19 department of the hospital. By using Ag-RDT, 35.9% of rapid PCR tests (that are more costly and laborious to perform) could be avoided at cost of 5.8% patients with false positive result. In conclusion, in real practice, disease prevalence is as important as test's performance for clinical decision making. The conclusion may also be applicable for other diagnostic tests than COVID-19 diagnostic.
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BACKGROUND: The SD Bioline Strep A Ultra (SD, Yongin, Korea) is a recently developed rapid antigen detection test (RADT) for diagnosing bacterial pharyngitis caused by Group A Streptococcus, We evaluated the performance of SD Bioline Strep A Ultra, using the number of colony forming units and color intensity. METHODS: Three throat swabs each were taken from 343 children with pharyngitis who visited pediatric clinics. We evaluated the performance of SD Bioline Strep A Ultra and compared its positive rate with the number of colony forming units, using the Fisher exact test. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value (95% confidence interval) were 97.4% (94.0–99.1%), 90.8% (85.0–94.9%), 93.0% (88.5–96.1%), and 96.5% (92.0–98.9%), respectively. Positive rate significantly differed by number of colony forming units (P=0.021). ROC plot for color intensity showed 0.938 of AUC (area under curve). CONCLUSIONS: SD Bioline Strep A Ultra showed excellent performance, and its positive rate differed by the number of colony counts. This RADT could be used as a sensitive and semi-quantitative method detecting bacterial pharyngitis.
Subject(s)
Child , Humans , Area Under Curve , Methods , Pharyngitis , Pharynx , Sensitivity and Specificity , Stem Cells , StreptococcusABSTRACT
Introducción: Las faringitis producidas por el estreptococo beta hemolítico del grupo A no se pueden distinguir clínicamente de las faringitis producidas por otros gérmenes, sin embargo la utilización de los criterios de Centor y el test de detección rápida de antígeno son de gran utilidad para determinar las probabilidades que estos sean causados por el estreptococo beta hemolítico del grupo A. En este estudio se comparó la sensibilidad entre ambos métodos. Objetivos: Se realizó un estudio para determinar la sensibilidad del criterio clínico en el diagnóstico de faringitis causada por Estreptococo en comparación a la sensibilidad del test de detección rápida de antígeno. Metodología: En el Centro de Salud Bárbara, se tomaron a los pacientes pediátricos que consultaron por dolor de garganta durante dos meses. Se puntuó según la escala de Centor y se tomó una muestra para el test de detección rápida de antígeno, luego, se comparó con el cultivo de orofaringe. Resultados: Se comparó la sensibilidad de ambos parámetros. Discusión: Un puntaje ≥ 3 puntos en la escala de Centor tuvo una sensibilidad de 81.8% y especificidad de 50%. Mientras que el RADT presentó una sensibilidad del 83.3% y especificidad de 84.2%.
Introduction: Pharyngitis caused by group A beta-hemolytic streptococci cannot be distinguished clinically from pharyngitis caused by other germs, however the use of the Centor criteria and the rapid antigen detection test are very useful to determine this pathogen. These are likely to be caused by group A beta hemolytic streptococcus. In this study the sensitivity between the two methods were compared. Objectives: A study was conducted to determine the sensitivity of clinical criteria in the diagnosis of pharyngitis caused by Streptococcus in comparison to the sensitivity of the rapid antigen detection test. Methodology: In the Barbara Health Center, pediatric patients who consulted for sore throat for two months were taken. It was scored according to the Centor scale and a sample was taken for the rapid antigen detection test, later these were compared with the oropharynx culture. Results: The sensitivity of both parameters were compared. Discussion: A score ≥ 3 points on the Centor scale had a sensitivity of 81.8% and specificity of 50%. While the RADT presented a sensitivity of 83.3% and specificity of 84.2%.
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Presence of a foreign object embedded in and around a tooth is unusual. Such object may get lodged and become a source of pain and infection, causing the patient to present to the dentist. This paper present two such case reports of foreign body imbedded within or around the tooth. One of the reported cases is the first case in which staple pin is present in primary molar. Present article emphasizes upon maintenance of oral hygiene and regular dental check up can prevent such undesirable situation.
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This was a cross sectional study to estimate the prevalence of Group AStreptococcal (GAS) infection among children with acute sore throat and to compare results of Rapid antigen detection test (RADT) with throat culture. Children aged 3-15 years who presented with acute sore throat (throat pain ± redness of pharynx, palate, tonsils), whose parents were willing to participate in the study by giving a written consent were included. Two sterile throat swabs were taken by vigorously rubbing the tonsils or posterior pharyngeal wall, one for RADT (cerTEST Strep Acard test) and 2nd for bacterial culture. The samples were sent to the in-hospital NABLcertified laboratory (SRLLtd). The results of RADT were obtained within 15 minutes while the culture report was available after 72 hours. During the 7 months study period we took 90 throat samples from 86 children. Of these 26 were RADT positive and 22 were culture positive. The prevalence of GAS by RADT was 28.88% and by culture was 25.56%. The sensitivity and specificity of RADTwas 95.65% and 94.02 % respectively. Since the RADThad high sensitivity and specificity and the results were available within 15 minutes, the need for throat swab culture (with additional cost and delay in results) could be avoided. Appropriate antibiotic may be started on the basis of RADT. If RADTis negative culture should be sent.
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BACKGROUND AND OBJECTIVES: This study aims to verify the usefulness of Centor scores to diagnose the Group A Streptococcal pharyngitis. SUBJECTS AND METHOD: The subjects of this study were 379 patients who had been examined by the rapid antigen detection test (RADT) for Group A Streptococcus. We analyzed their medical records and laboratory test results retrospectively and compared the results of Centor symptom scores with those of RADT. Then we analyzed the association of RADT, the Centor score and the laboratory test results statistically. RESULTS: There were no correlation between the RADT results and fever, cough, tonsillar enlargement, nasal symptoms, myalgia or chilling (p>0.05). In the RADT positive group, there were more patients with tonsillar exudate, neck lymph node enlargement, tenderness and pharyngeal abscess formation significantly (p<0.05). The Centor score and C-reactive protein were significantly higher in the RADT positive group (p<0.05). CONCLUSION: The results of this study suggest that Centor symptom scores can be used to determine which antibiotics to use. The Centor score system can help reduce medical costs and detect the problematic Group A Streptococcal pharyngitis.
Subject(s)
Humans , Abscess , Anti-Bacterial Agents , C-Reactive Protein , Cough , Decision Making , Diagnosis , Exudates and Transudates , Fever , Lymph Nodes , Medical Records , Methods , Myalgia , Neck , Pharyngitis , Retrospective Studies , Streptococcus , Streptococcus pyogenesABSTRACT
Abstract Objective: The aim of this study was to evaluate the QuickVue® RSV Test Kit (QUIDEL Corp, CA, USA) as a screening tool for respiratory syncytial virus in children with acute respiratory disease in comparison with the indirect immunofluorescence assay as gold standard. In Brazil, rapid antigen detection tests for respiratory syncytial virus are not routinely utilized as a diagnostic tool, except for the diagnosis of dengue and influenza. Methods: The authors retrospectively analyzed 486 nasopharyngeal aspirate samples from children under age 5 with acute respiratory infection, between December 2013 and August 2014, the samples were analyzed by indirect immunofluorescence assay and QuickVue® RSV Test kit. Samples with discordant results were analyzed by real time PCR and nucleotide sequencing. Results: From 313 positive samples by immunofluorescence assays, 282 (90%) were also positive by the rapid antigen detection test, two were positive only by rapid antigen detection test, 33 were positive only by immunofluorescence assays, and 171 were positive by both methods. The 35 samples with discordant results were analyzed by real time PCR; the two samples positive only by rapid antigen detection test and the five positive only by immunofluorescence assays were also positive by real time PCR. There was no relation between the negativity by QuickVue® RSV Test and viral load or specific strain. The QuickVue® RSV Test showed sensitivity of 90%, specificity of 98.8%, predictive positive value of 99.3%, and negative predictive value of 94.6%, with accuracy of 93.2% and agreement κ index of 0.85 in comparison to immunofluorescence assay. Conclusions: This study demonstrated that the QuickVue® RSV Test Kit can be effective in early detection of Respiratory syncytial virus in nasopharyngeal aspirate and is reliable for use as a diagnostic tool in pediatrics.
Resumo Objetivo: Avaliar o teste QuickVue® RSV Test Kit (QUIDEL Corp, CA, EUA) para o diagnóstico rápido do vírus sincicial respiratório em crianças com doença respiratória aguda, comparandoo com a imunofluorescência indireta como padrão ouro. Visto que, no Brasil, testes rápidos para detecção de antígenos para vírus sincicial respiratório não são rotineiramente utilizados como ferramenta de diagnóstico, exceto para Dengue e Influenza. Métodos: Um total de 486 amostras de aspirado de nasofaringe de crianças menores de 5 anos com doença respiratória aguda, coletadas entre dezembro de 2013 e agosto de 2014, foram analisadas por imunofluorescência e pelo teste QuickVue®. Amostras com resultados discordantes entre os métodos foram submetidas a PCR em tempo real e sequenciamento. Resultados: Das 313 amostras positivas por IFI, 282 foram positivas no teste rápido (90%), 2 amostras foram positivas apenas no teste rápido (0.6%), 33 apenas na imunofluorescência (10.5%) e 171 foram negativas em ambos os métodos. As 35 amostras com resultados discordantes foram testadas por PCR em tempo real, sendo que duas que foram positivas apenas no teste rápido e 5 apenas na imunofluorescência confirmaram-se positivas. Não houve relação entre a ausência de positividade no teste QuickVue® com a carga ou com a cepa viral. O teste QuickVue® mostrou sensibilidade de 90.1%, especificidade 98.9%, valor preditivo positivo 99.3%, valor preditivo negativo de 94.6%, acurácia de 93.2% e índice de concordância de 0.85 em comparação à imunofluorescência. Conclusões: Nosso estudo demonstrou que o teste QuickVue® RSV pode ser efetivo na detecção precoce do vírus sincicial respiratório em amostras de aspirado de nasofaringe e é confiável como uma ferramenta de diagnósticos em pediatria.
Subject(s)
Humans , Male , Female , Child, Preschool , Respiratory Syncytial Viruses/immunology , Respiratory Syncytial Virus Infections/diagnosis , Reverse Transcriptase Polymerase Chain Reaction , Antigens, Viral/analysis , Reagent Kits, Diagnostic , Respiratory Syncytial Viruses/isolation & purification , Respiratory Tract Infections/virology , Brazil , Retrospective Studies , Sensitivity and Specificity , Respiratory Syncytial Virus Infections/virology , Fluorescent Antibody Technique, IndirectABSTRACT
Objective To analyze the consistency of two rapid antigen assays for the diagnosis of influenza A and B. We evaluated the clinical usefulness of silver amplification immunochromatography influenza virus detection kit.Methods Nasopharyngeal swab samples were collected from patients who were suspected of influenza at Huashan Hospital between January and February 2015. Two samples were collected from the same one patient. The samples were tested simultaneously by using IMMUNO AG Cartridge Flu AB kit (AG1) and commercial immunochromatographic assay kit, Clearview exact influenza A&B (CV). PCR method was used as reference.Results A total of 91 samples were tested, of which 7 were positive for influenza A and 53 positive for influenza B by AG1 system; 7 positive for influenza A and 50 positive for influenza B by CV system; and 8 positive for influenza A and 60 positive for influenza B by PCR. The sensitivity and specificity of the AG1 system were 87.5 % and 100 % for influenza A, and 88.3 % and 100 % for influenza B; while the CV system showed sensitivity and specficity of 87.5 % and 100 % for influenza A, 83.3 % and 100 % for influenza B. The AG1 system was 100 % consistent with the CV system in the positive rate of influenza A, and 94.3 % consistent with the CV system in the positive rate of influenza B.Conclusions The AG1 system is well consistent with the conventional immunochromatography-based diagnostic tests in diagnosis of influenza. The AG1 system is useful in earlier diagnosis of influenza due to fewer human error in result interpretation.
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BACKGROUND: Throat culture is the golden standard for diagnosis of group A streptococcal (GAS) pharyngitis. However, because it is a time-consuming procedure, antibiotics are often empirically administrated. Rapid antigen tests (RATs) can detect bacterial infections within 15 minutes, thus helping to reduce unnecessary administration of antibiotics. METHODS: In total, 108 patients, between 3 and 17 yr of age, who visited our hospital from August 2011 to July 2012, were tested for suspected acute pharyngitis with two RATs––SD Bioline Strep A (SD, Korea) and BinaxNOW Strep A (Binax, Inc., USA)––as well as throat culture. We compared the sensitivity, specificity, and consistency of the two RATs and assessed the clinical manifestations of GAS pharyngitis. RESULTS: Of the 108 patients, 15 were confirmed to have GAS pharyngitis by throat culture. The SD test showed a sensitivity of 93.3% and a specificity of 97.8%; the positive and negative predictive values were 87.5% and 98.9%, respectively. The Binax test showed a sensitivity of 86.7% and a specificity of 100%; the positive and negative predictive values were 100% and 97.9%, respectively. The Kappa values for conformity degree were high, 0.887 and 0.918 in the SD and the Binax tests, respectively (P=0.00). Clinical manifestation assessment of GAS pharyngitis indicated that scarlatiniform rash and strawberry tongue were significantly associated signs (P<0.05). CONCLUSIONS: GAS pharyngitis diagnosis based on clinical manifestations alone has practical limitations. The two RATs are useful as substitutes for throat culture and their frequent use in clinical settings is advisable.
Subject(s)
Animals , Humans , Rats , Anti-Bacterial Agents , Bacterial Infections , Diagnosis , Exanthema , Fragaria , Pharyngitis , Pharynx , Sensitivity and Specificity , Streptococcus pyogenes , TongueABSTRACT
BACKGROUND: Respiratory syncytial virus (RSV) is one of the most important causes of lower respiratory tract infection. The rapid antigen test is a simple, cheap, and quick method for RSV detection, however, it has an acknowledged low sensitivity. The aim of this study is to evaluate the diagnostic performance of the rapid antigen test by comparing it with a multiplex reverse transcription-PCR (RT-PCR). METHODS: A total of 557 nasopharyngeal aspirates or swabs that were submitted for both a rapid antigen test, Binax NOW RSV (Binax; Alere Scarborough, Inc., USA) and multiplex RT-PCR, Seeplex RV7 (Seegene Inc., Korea) were included in this study. We performed both tests according to the manufacturer's recommendations and analyzed the diagnostic performances of a rapid antigen tests based on the results of multiplex RT-PCR. RESULTS: Among the 557 specimens, the positive rates determined from the rapid antigen test and multiplex RT-PCR were 12.2% (N=68) and 25.1% (N=140), respectively. The relative sensitivity and specificity of the rapid antigen test were 46.4% and 99.3% based on the multiplex RT-PCR, respectively. Positive and negative predictive values were 95.6% and 84.7%, respectively. The diagnostic sensitivity was lower (28.6%) in children >36 months compared with children < or =36 months of age. Test sensitivity declined when RSV infection was accompanied by infection with other respiratory viruses. CONCLUSIONS: Binax NOW RSV exhibited good diagnostic performance, easy handling, and rapidity. However, it does have the possibility of false-negative results, and additional tests are needed when there is clinical suspicion of RSV infection.
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Child , Humans , Respiratory Syncytial Viruses , Respiratory Tract Infections , Sensitivity and SpecificityABSTRACT
Objective To investigate the sensitivity and specificity of colloidal gold immunochromatography assay in rapid detection of respiratory syncytial virus (RSV)antigen.Methods A total of 197 nasal-pharyngeal swabs (NPs)or nasal-pharyngeal aspirates (NPAs ) obtained from patients were tested by RSV assay kits, i. e., colloidal gold immunochromatography assay.The results determined by reverse-transcription polymerase chain reaction (RT-PCR)were taken as reference.Compared to the results of RT-PCR,the sensitivity of the kit was different when testing different types of specimens or specimensobtained from patients of different ages.Results A total of 95 (48.2%)samples were positive for RSV tested by RT-PCR.The sensitivity and specificity of colloidal gold immunochromatography assay were 34.7% and 100%, respectively compared with RT-PCR results.The positive rate of the assay was higher in testing NPAs than NPs (36.2% vs 8.6%,P < 0.01 ), which was the same in the sensitivity (22.1% vs 12.6%). The positive rate of colloidal gold year old,RT-PCR method should be used for RSV detection in clinical practice to avoid missed diagnosis.
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No abstract available.
Subject(s)
Humans , Antigens, Viral/analysis , Biomarkers/analysis , DNA, Viral/analysis , Fluorescent Antibody Technique , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/diagnosis , Pandemics , Predictive Value of Tests , Republic of Korea/epidemiology , SeasonsABSTRACT
BACKGROUND: Rapid antigen test and real-time reverse transcription PCR (rRT-PCR) are widely used for the detection of influenza A virus. In this study, we evaluated and compared the effectiveness of a rapid antigen test, currently used for detecting influenza B virus, with the effectiveness of using rRT-PCR for the same purpose. METHODS: Samples obtained from 92 patients during an outbreak of influenza B were assessed using the rapid antigen test (SD BIOLINE Influenza Ag; SD, Korea) and rRT-PCR (Anyplex FluA/B Real-time Detection; Seegene, Korea). RESULTS: The sensitivity and specificity of the rapid antigen test were 69% and 100%, respectively, in detecting influenza B when compared to rRT-PCR. Twenty-nine patients (31.5%) were positive for both rapid antigen test and rRT-PCR, while 50 (54.3%) were negative for both rapid antigen test and rRT-PCR. The overall concordance rate between rapid antigen test and rRT-PCR was 85.9%. Thirteen patients (14.1%) were positive only for rRT-PCR. CONCLUSIONS: The rapid antigen test showed high specificity and good correlation with rRT-PCR and is likely to be as useful in the detection of influenza B viruses.
Subject(s)
Humans , Influenza A virus , Influenza B virus , Influenza, Human , Polymerase Chain Reaction , Real-Time Polymerase Chain Reaction , Reverse Transcription , Sensitivity and SpecificityABSTRACT
PURPOSE: Rapid antigen test (RAT) is used to screen influenza rapidly. The clinical sensitivity of RAT was poor for 2009 H1N1 influenza. The aim of this study was to identify the correlation of time gap (TG) between fever onset and the sensitivity of RAT for 2009 H1N1 influenza. METHODS: Data were collected retrospectively during the pandemic H1N1 2009 influenza season between October 2009 and February 2010. The RAT was done by using SD Bioline influenza antigen (Standard Diagnostics Inc.) in nasopharyngeal swab. The 2009 H1N1 influenza was confirmed by real-time reverse transcriptase polymerase chain reaction (rRT-PCR). Specimens were categorized according to the TG between fever onset and performance of RAT. They were classified into 120 hours (TG6). RESULTS: The overall sensitivity of RAT was 69.9%. The TG dependent sensitivity of RAT at TG1, TG2, TG3, TG4, TG5, and TG6 was 64.3%, 73.3%, 61.1%, 88.9%, 83.3%, and 61.1% respectively. The sensitivity of RAT was the highest when the TG was 72 to 96 hours. But this result was not statistically significant. CONCLUSION: Correlation of TG between fever onset and the sensitivity of RAT for 2009 H1N1 influenza was not statistically significant. But our study suggested that 72 to 96 hours after fever onset is the most sensitive time of RAT. Timely optimal performance of the RAT could have a significant impact on improving results. Further evaluation for better sensitivity would be needed.
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Animals , Rats , Fever , Influenza, Human , Pandemics , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , SeasonsABSTRACT
PURPOSE: The aim of this study was to examine the sensitivity and specificity of the influenza rapid antigen test, in comparison with reverse transcription polymerase chain reaction (RT-PCR), according to the time of the test from symptom onset and the clinical manifestations in the patients tested for suspected infection of the influenza A (H1N1) at a second hospital. METHODS: A total of 529 pediatric patients, aged between 6 and 12 years old, who visited the emergency department from October 1, 2009 to December 31, 2009, received the influenza rapid antigen test and RT-PCR. We examined the sensitivity and specificity of the influenza rapid antigen test in comparison with RT-PCR according to the time of the test from symptom onset (72 hours) and clinical manifestations (fever, cough, rhinorrhea.nasal obstruction, sore throat, gastrointestinal symptoms, and general symptoms) in a retrospective study based on hospital charts. RESULTS: The sensitivity of the influenza rapid antigen test at elapsed times of less than 24 hours, 24 to 48 hours, and 48 to 72 hours after the onset of the symptoms was 53.9%, 61.4%, and 62.1% respectively. When the elapse time was greater than 72 hours, the sensitivity was 31.6%; thus, the sensitivity of the influenza rapid antigen test tended to decrease with elapsed time. The sensitivity of the test was 79% in patients presenting with gastrointestinal symptoms, which was the highest, but there was no statistical difference according to the clinical manifestations of the patients. CONCLUSION: Our study suggests that more accurate results might be gained when the influenza rapid antigen test is performed within 72 hours after symptom onset.
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Aged , Child , Humans , Cough , Emergencies , Influenza, Human , Pharyngitis , Polymerase Chain Reaction , Retrospective Studies , Reverse Transcription , Sensitivity and SpecificityABSTRACT
Purpose: A rapid test for influenza viruses (Binax NOW® ) was evaluated. Materials and Methods: In season-1, 35 respiratory samples were tested retrospectively; in season-2, 45 samples were tested prospectively [gold-standard: viral culture in season-1, culture+ reverse transcriptase-polymerase chain reaction (RT-PCR) in season-2]. Results: Sensitivity for Binax for influenza A was 59.3 and 0% in season-1 and -2, respectively. Sensitivity was low for influenza B (33.3% in season-1, 26.1% in season-2). Samples having low viral load were more likely to have a negative Binax test. Specificity of Binax was high (100 and 94.7% with influenza A and B, respectively). Conclusion: Sensitivity information provided in the kit insert does not always reflect post licensure performance in clinical settings.