Rapid detection of S. pyogenes and S. pneumoniae in pleural fluid for diagnosis of parapneumonic empyema.

The aim of this study was to assess the reliability of rapid antigen detection tests (RADT) for Streptococcus pyogenes (GAS) and Streptococcus pneumoniae on pleural fluid samples for diagnosis of parapneumonic effusion/empyema (PPE) and their potential for improving pathogen identification rates. Sixty-three pleural samples were included from 54 patients on which GAS and S. pneumoniae RADT (BinaxNOW), culture, 16S rRNA PCR, and S. pneumoniae-specific PCR were performed. GAS RADT showed a sensitivity of 95.2% and a specificity of 100%. Pneumococcal RADT showed a sensitivity of 100% and specificity of 88.6%. Both RADT increased the pathogen identification rate in PPE compared to culture.

Use of point-of-care tests in pharyngotonsillitis - a registry-based study in primary health care.

BACKGROUND: Point-of-care (POC) tests, including C-reactive protein (CRP) tests and rapid antigen detection tests (RADT) for group A streptococci (GAS), are widely used in Swedish primary health care (PHC). This study quantifies their use in pharyngotonsillitis and explore their association with antibiotic prescribing. MATERIAL AND METHODS: Retrospective data from 2012-2016 in Region Kronoberg, Sweden, included all PHC visits with a pharyngotonsillitis diagnosis. Patient characteristics, test usage and antibiotic prescriptions were linked by visit date and personal identification number. Descriptive statistics were used for POC test analysis. Logistic regression assessed the association between CRP levels and antibiotic prescribing. RESULTS: Of 24,237 visits, 68% included RADT and 36% included a CRP test, with 89% of CRP tests performed alongside RADT. CRP testing was more frequent in patients with negative (56%) than positive RADTs (42%) (p < .001). Overall, 66% of RADTs were positive. Median CRP levels were 23 mg/l for positive RADT and 31 mg/l for negative RADT (p < .001). Antibiotics were prescribed for 95% of positive RADTs and 43% of negative RADTs (p < .001). In patients with negative RADTs, CRP testing was associated with higher antibiotic prescribing (57%) compared to no CRP testing (26%) (p < .001). Among these patients, CRP levels were associated with prescribing (aOR 1.032; 95% CI 1.029-1.035; p < .001), with 50% of prescriptions occuring at CRP levels ≤ 20 mg/l. CONCLUSION: The use of RADTs and the proportion of positive test were higher than expected, indicating inappropriate use and diagnostic bias. CRP testing, contrary to guidelines, was common and associated with increased antibiotic prescribing.

The evaluation results of proposed antigen rapid diagnostic tests for COVID-19: some possible factors might influence.

PURPOSE: In addition to existing gold standard qRT-PCR methods, there is a need to develop reliable rapid tests for infection control with early notification of COVID-19 cases to enable effective outbreak management. We evaluated the validity of the three Ag-RDT kits proposed by some companies in different countries by using qRT-PCR and analyzed its results. METHODS: Each of the three Ag-RDT kits (namely A, B, and C) was tested with 90 samples, consisting of samples with Ct ≤ 25, samples with Ct > 25, and negative SARS-CoV-2 PCR samples. RESULTS: This study showed that for samples with Ct > 25, all the three kits could not detect SARS-CoV-2 Ag (0% sensitivity) but showed 100% specificity. Meanwhile, for samples with Ct ≤ 25, kit C was the best (76.7% sensitivity and 100% specificity). The PPV of the three kits was 100%, but their NPV ranged 63-84.8%. Kit C showed the best accuracy (89.9%). Some factors might influence the results of evaluation, such as variation of virus proteins and transportation-storage of the kits. CONCLUSION: The overall specificity of the three kits for all samples was high; however, all of them have not met the minimum performance requirements of ≥ 80% sensitivity for samples with Ct ≤ 25. The validation test is much necessary to be carried out by the authority in national health care to ensure the feasibility of the kit for point-of-care testing (POCT) of COVID-19. Some factors that might influence should be anticipated to increase their sensitivities and specificities.

Agreement between rapid antigen detection test and culture for group A streptococcus in patients recently treated for pharyngotonsillitis - a prospective observational study in primary care.

OBJECTIVE: The aim was to compare rapid antigen detection test (RADT) and throat culture for group A streptococci (GAS) among patients recently treated with penicillin V for GAS pharyngotonsillitis. DESIGN AND SETTING: The study was a secondary analysis within a randomized controlled trial comparing 5 versus 10 days of penicillin V for GAS pharyngotonsillitis. Patients were recruited at 17 primary health care centres in Sweden. SUBJECTS: We included 316 patients ≥ 6 years of age, having 3-4 Centor criteria, a positive RADT and a positive throat culture for GAS at inclusion, and also having a RADT and throat culture for GAS taken at a follow-up visit within 21 days. MAIN OUTCOME MEASURES: RADT and conventional throat culture for GAS. RESULTS: This prospective study showed 91% agreement between RADT and culture at follow-up within 21 days. Only 3/316 participants had negative RADT with a positive throat culture for GAS at follow-up, and 27/316 patients with positive RADT had a negative culture for GAS. Log rank test did not reveal any difference in the decline over time of positive tests between RADT and throat culture (p = 0.24). Agreement between RADT and throat culture for GAS at the follow-up was not associated with treatment duration, number of days from inclusion until follow-up, throat symptoms at follow-up, gender, or age. CONCLUSION: RADT and culture for GAS agreed to a high extent also after recent penicillin V treatment. RADT for GAS means a low risk for missing the presence of GAS.KEY POINTSTesting for group A streptococci (GAS) before antibiotic treatment can reduce antibiotic prescription for pharyngotonsillitis. It has been proposed that rapid antigen detection tests (RADT) for group A streptococci after recent penicillin V treatment may be falsely positive due to possible persisting antigens from non-viable bacteria.The decline of the presence of GAS was similar between RADT and conventional throat culture in patients who had recently completed penicillin V treatment for GAS pharyngotonsillitisRADT for GAS is useful in identifying the presence of GAS after recent penicillin V treatment.

Performance of 20 rapid antigen detection tests to detect SARS-CoV-2 B.1.617.2 (Delta) and B.1.1.529 (Omicron) variants using a clinical specimen panel from January 2022, Berlin, Germany.

BackgroundThere are conflicting reports on the performance of rapid antigen detection tests (RDT) in the detection of the SARS-CoV-2 Omicron (B.1.1.529) variant; however, these tests continue to be used frequently to detect potentially contagious individuals with high viral loads.AimThe aim of this study was to investigate comparative detection of the Delta (B.1.617.2) and Omicron variants by using a selection of 20 RDT and a limited panel of pooled combined oro- and nasopharyngeal clinical Delta and Omicron specimens.MethodsWe tested 20 CE-marked RDT for their performance to detect SARS-CoV-2 Delta and Omicron by using a panel of pooled clinical specimens collected in January 2022 in Berlin, Germany.ResultsWe observed equivalent detection performance for Delta and Omicron for most RDT, and sensitivity was widely in line with our previous pre-Delta/Omicron evaluation. Some variation for individual RDT was observed either for Delta vs Omicron detection, or when compared with the previous evaluation, which may be explained both by different panel sizes resulting in different data robustness and potential limitation of batch-to-batch consistency. Additional experiments with three RDT using non-pooled routine clinical samples confirmed comparable performance to detect Delta vs Omicron. Overall, RDT that were previously positively evaluated retained good performance also for Delta and Omicron variants.ConclusionOur findings suggest that currently available RDT are sufficient for the detection of SARS-CoV-2 Delta and Omicron variants.

Head-to-head comparison of the accuracy of saliva and nasal rapid antigen SARS-CoV-2 self-testing: cross-sectional study.

BACKGROUND: The diagnostic accuracy of unsupervised self-testing with rapid antigen diagnostic tests (Ag-RDTs) is mostly unknown. We studied the diagnostic accuracy of a self-performed SARS-CoV-2 saliva and nasal Ag-RDT in the general population. METHODS: This large cross-sectional study consecutively included unselected individuals aged ≥ 16 years presenting for SARS-CoV-2 testing at three public health service test sites. Participants underwent molecular test sampling and received two self-tests (the Hangzhou AllTest Biotech saliva self-test and the SD Biosensor nasal self-test by Roche Diagnostics) to perform themselves at home. Diagnostic accuracy of both self-tests was assessed with molecular testing as reference. RESULTS: Out of 2819 participants, 6.5% had a positive molecular test. Overall sensitivities were 46.7% (39.3-54.2%) for the saliva Ag-RDT and 68.9% (61.6-75.6%) for the nasal Ag-RDT. With a viral load cut-off (≥ 5.2 log10 SARS-CoV-2 E-gene copies/mL) as a proxy of infectiousness, these sensitivities increased to 54.9% (46.4-63.3%) and 83.9% (76.9-89.5%), respectively. For the nasal Ag-RDT, sensitivities were 78.5% (71.1-84.8%) and 22.6% (9.6-41.1%) in those symptomatic and asymptomatic at the time of sampling, which increased to 90.4% (83.8-94.9%) and 38.9% (17.3-64.3%) after applying the viral load cut-off. In those with and without prior SARS-CoV-2 infection, sensitivities were 36.8% (16.3-61.6%) and 72.7% (65.1-79.4%). Specificities were > 99% and > 99%, positive predictive values > 70% and > 90%, and negative predictive values > 95% and > 95%, for the saliva and nasal Ag-RDT, respectively, in most analyses. Most participants considered the self-performing and result interpretation (very) easy for both self-tests. CONCLUSIONS: The Hangzhou AllTest Biotech saliva self Ag-RDT is not reliable for SARS-CoV-2 detection, overall, and in all studied subgroups. The SD Biosensor nasal self Ag-RDT had high sensitivity in individuals with symptoms and in those without prior SARS-CoV-2 infection but low sensitivity in asymptomatic individuals and those with a prior SARS-CoV-2 infection which warrants further investigation.

Development of a risk assessment profile tool to determine appropriate use of SARS-CoV-2 rapid antigen detection tests for different activities and events in Ireland, since October 2021.

We describe the development of a risk assessment profile tool that incorporates data from multiple domains to help determine activities and events where rapid antigen detection tests (Ag-RDT) could be used to screen asymptomatic individuals to identify infectious cases as an additional mitigation measure to reduce transmission of SARS-CoV-2. The tool aims to stratify, in real time, the overall risk of SARS-CoV-2 transmission associated with common activities and events, and this can be matched to an appropriate Ag-RDT testing protocol.

Performance and user-friendliness of the rapid antigen detection tests QuickVue Dipstick Strep A test and DIAQUICK Strep A Blue Dipstick for pharyngotonsillitis caused by Streptococcus pyogenes in primary health care.

Sensitivity and specificity of rapid antigen detection tests (RADTs) for detection of group A hemolytic streptococcus (GAS) vary. The purpose is to present the first SKUP (Scandinavian evaluation of laboratory equipment for point of care testing) evaluations concerning the assessment of the diagnostic performance and user-friendliness of two RADTs for detection of GAS when used under real-life conditions in primary health care. Throat samples were collected in duplicates at primary health care centers (PHCCs) from patients with symptoms of pharyngitis. The performance of QuickVue Dipstick Strep A test (307 samples) and DIAQUICK Strep A Blue Dipstick (348 samples) was evaluated using culture results at a clinical microbiology laboratory as comparison. The user-friendliness was evaluated using a questionnaire. The diagnostic sensitivity was 92% (90% confidence interval (CI) 87-96%) and 72% (90% CI 65-79%), while the diagnostic specificity was 86% (90% CI 81-90%) and 98% (90% CI 96-99%) for QuickVue Dipstick Strep A test and DIAQUICK Strep A Blue Dipstick, respectively. Both RADTs obtained acceptable assessments for user-friendliness and fulfilled SKUP's quality goal for user-friendliness. The diagnostic sensitivity for QuickVue Dipstick Strep A test and the diagnostic specificity for DIAQUICK Strep A Blue Dipstick in this objective and supplier-independent evaluation were higher compared with previous meta-analyses of RADTs. However, the diagnostic specificity for QuickVue Dipstick Strep A test and the diagnostic sensitivity for DIAQUICK Strep A Blue Dipstick were lower compared with previous meta-analyses of RADTs.

False positive results in severe acute respiratory coronavirus 2 (SARS-CoV-2) rapid antigen tests for inpatients.

Severe acute respiratory syndrome coronavirus 2 rapid antigen detection (RAD) test kits are widely used as primary screening test in Japan because rapid diagnosis of coronavirus disease 2019 (COVID-19) is critical for infection control. We report cases with RAD test false-positive results in a ward for patients with disabilities. RAD tests potentially evoke hospital operational risk. It is desirable that performing PCR test appropriately when patients admitted to a medical treatment ward with COVID-19 symptoms instead of RAD test.

Accuracy of rapid antigen detection test for nasopharyngeal swab specimens and saliva samples in comparison with RT-PCR and viral culture for SARS-CoV-2 detection.

INTRODUCTION: Rapid antigen detection (RAD) tests are convenient tools for detecting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in clinics, and testing using saliva samples could decrease the risk of infection during sample collection. This study aimed to assess the accuracy of the SARS-CoV-2 RAD for testing of nasopharyngeal swab specimens and saliva samples in comparison with the RT-PCR tests and viral culture for detecting viable virus. METHODS: One hundred seventeen nasopharyngeal swab specimens and 73 saliva samples with positive results on RT-PCR were used. Residual samples were assayed using a commercially available RAD test immediately, and its positivity was determined at various time points during the clinical course. The concordance between 54 nasopharyngeal swab samples and saliva samples that were collected simultaneously was determined. Viral culture was performed on 117 samples and compared with the results of the RAD test. RESULTS: The positive rate of RAD test using saliva samples was low throughout the clinical course. Poor concordance was observed between nasopharyngeal swab specimens and saliva samples (75.9%, kappa coefficient 0.310). However, a substantially high concordance between the RAD test and viral culture was observed in both nasopharyngeal swab specimens (86.8%, kappa coefficient 0.680) and saliva samples (95.1%, kappa coefficient 0.643). CONCLUSIONS: The sensitivity of the SARS-CoV-2 RAD test was insufficient, particularly for saliva samples. However, a substantially high concordance with viral culture suggests its potential utility as an auxiliary test for estimating SARS-CoV-2 viability.

Clinical usefulness of a rapid molecular assay, ID NOW™ influenza A & B 2, in adults.

INTRODUCTION: ID NOW™ Influenza A & B 2 (ID NOW 2) is a rapid molecular assay that combines two characteristics, namely the rapidness of rapid antigen detection test (RADT) and the high sensitivity of molecular assay. METHODS: The clinical performance of ID NOW 2 compared with real-time RT-PCR was evaluated in adults. RESULTS: The sensitivity of ID NOW 2 over multiple seasons from 2016/2017 to 2019/2020 was 97.3% (95% CI: 90.7-99.7) for Type A, 100% (95% CI: 81.9-100) for Type B, and 97.8% (95% CI: 92.2-99.7) for influenza (Type A + Type B), and it was significantly higher than the sensitivity of RADT, which was 80.0% (95% CI: 69.2-88.4) for Type A, 73.3% (95% CI: 44.9-92.2) for Type B, and 78.9% (95% CI: 69.0-86.8) for influenza. The sensitivity of RADT tended to be lower in patients in the particularly early period, within 12 h from disease onset; however, the sensitivity of ID NOW 2 remained high, increasing the difference between the sensitivity of RADT and ID NOW 2. The viral loads were low within 12 h from onset, and it was considered this affected the sensitivity of RADT due to its low analytical sensitivity. The specificity of ID NOW 2 was 98% or greater in all groups. CONCLUSIONS: Since ID NOW 2 has a high sensitivity and specificity in adults, it is anticipated to be used in clinical practice, particularly in patients who require early and accurate diagnosis.

[Introduction of rapid streptococcal antigen test: can its use improve adherence to antibiotic therapy?] / Implantación de una prueba rápida de infección estreptocócica: ¿su uso también mejora la adherencia antibiótica?

OBJECTIVE: To evaluate the influence of the result of a rapid streptococcal antigen test in paediatric pharyngotonsillitis infections, in terms of improvement of antibiotic therapy adherence. DESIGN: Randomized community clinical trial with two study groups. LOCATION: Primary Care Centers in Central Catalonia. PARTICIPANTS: Patients aged from 3 to 15 years, who were attended at paediatric consultations on suspicion of pharyngotonsillitis caused by an infection between November 2010 and February 2011 (both included), were included in the study on a consecutive basis. 557 patients met the inclusion criteria and 519 were evaluated. INTERVENTION: The control group received the usual diagnostic-therapeutic algorithm. Rapid streptococcal antigen test was additionally performed to experimental group participants and it was indicated the more convenient treatment. MAIN MEASUREMENTS: Antibiotic adherence, non-adherence causes and socio-demographic risk factors were evaluated via telephone survey. RESULTS: Antibiotics were prescribed to 65.6% and paediatricians of the control group were more likely to prescribe antibiotic than the ones in the intervention group (88.5% vs 45.5%, p< 0.0001). 64.8% followed doctor's treatment orders, being failure following medication scheduling the main cause of non-adherence (25.6%). Medication adherence was higher in the experimental group (68%) than in the control group (62.9%) but no significant differences were found. CONCLUSION: Rapid strep test, complementing the use of Centor Criteria avoids unnecessary antibiotics prescriptions, but had not been proven to be effective in increasing medication adherence.

Rapid antigen detection test (RADT) for pharyngitis diagnosis in children: Public and pharmacist perception.

BACKGROUND: Most common sought antibiotic-self treated infection globally is pharyngitis (sore throat). The aim of this study is to assess public's acceptance and potential use of Rapid Antigen Detection Test at community pharmacies in the diagnosis of bacterial pharyngitis in children prior to antibiotic dispensing in Saudi Arabia. METHOD: A qualitative cross-sectional study was conducted on October 2017. Two self-conducted questionnaires were used. One targeted the public above 21 years old and was distributed via social media. The other randomly targeted community pharmacists in Jeddah. RESULT: A total of 689 of the public and 40 community pharmacists completed the survey. Moreover, 571 (82.9%) of the public received antibiotics without a prescription; for symptoms related to sore throat (71%) followed by flu-like symptoms (24%). Only (3.77%) and (5%) of both public and community pharmacies have heard about RADT respectively, however the majority (93.03%) and (90%) of both respectively support its use in community pharmacies. Coded reasons for its use was mainly to decrease antibiotic misuse and/or abuse, increased specificity, decreased antibiotic side effects including bacterial resistance, and ease of use. CONCLUSION: Both public and community pharmacists support the idea of using RADT. Future efforts should look into pharmacist's role in providing point of care tests that are cost-effective and convenient for the public.

Diagnosis of extrapulmonary tuberculosis using the MPT64 antigen detection test in a high-income low tuberculosis prevalence setting.

BACKGROUND: Extrapulmonary tuberculosis (EPTB) poses diagnostic challenges due to the paucibacillary nature of the disease. The immunochemistry-based MPT64 antigen detection test (MPT64 test) has shown promising results for diagnosing EPTB in previous studies performed in low-resource settings, with higher sensitivity than microscopy and culture. The aim of this study was to investigate the performance of the MPT64 test in a routine clinical setting in a high-income low TB prevalence country. METHODS: Extrapulmonary samples sent for TB diagnostics to microbiology and pathology laboratories at three regional tertiary care hospitals in Norway in a one-year period were included and subjected to the MPT64 test in parallel to the routine TB diagnostic tests. RESULTS: Samples from 288 patients were included and categorised as confirmed TB cases (n = 26), clinically diagnosed TB cases (n = 5), non-TB cases (n = 243) and uncategorised (n = 14), using a composite reference standard (CRS). In formalin-fixed biopsies, the sensitivity (95% CI) of the MPT64 test, microscopy, PCR-based tests pooled, and culture was 37% (16-62), 20% (4-48), 37% (16-62) and 50% (23-77), respectively, against the CRS. The MPT64 test showed a good positive predictive value (88%) and an excellent specificity (99, 95% CI 92-100) in formalin-fixed biopsies. In fine-needle aspirates, pus and fluid samples, the test performance was lower. CONCLUSIONS: The MPT64 test was implementable in pathology laboratories as part of routine diagnostics, and although the sensitivity of the MPT64 test was not better than culture in this setting, the test supplements other rapid diagnostic methods, including microscopy and PCR-based tests, and can contribute to strengthen the diagnosis of EPTB in formalin-fixed biopsies in the absence of culture confirmation.

Clinical evaluation of ID NOW influenza A & B 2, a rapid influenza virus detection kit using isothermal nucleic acid amplification technology - A comparison with currently available tests.

In this study, we evaluated the performance of ID NOW Influenza A & B 2 (ID NOW 2), a rapid molecular point-of-care test for influenza within 13 min, in comparison with currently available tests. A total of 254 nasopharyngeal swabs (NPS) and 271 nasopharyngeal aspirates (NPA) collected from 373 children and 152 adults with influenza-like illness were tested using ID NOW 2, viral culture, rapid antigen detection test, and loop-mediated isothermal amplification test to evaluate the sensitivity and specificity compared with real-time reverse transcription polymerase chain reaction as the reference method. The sensitivities of ID NOW 2 for influenza A were 95.9% and 95.7% in NPS and NPA, respectively, and for influenza B were 100% and 98.7% in NPS and NPA, respectively. The specificity was 100% for both influenza A and influenza B in NPS and NPA. Sensitivity of each test method reflected the difference of analytical sensitivity among the tests, and ID NOW 2 was not affected by time after illness onset and patient age. In conclusion, ID NOW 2 demonstrated a high sensitivity and specificity that is useful for diagnosis of influenza in the clinical setting and infection control.

Long-term impact of an intervention on rapid antigen detection tests in acute pharyngitis.

OBJECTIVE: This study was aimed at evaluating the appropriateness of use and interpretation of rapid antigen detection testing (RADT) and antibiotic prescribing for acute pharyngitis six years after a multifaceted intervention. DESIGN: Before-and-after audit-based study. LOCATION: Primary care centres in eight autonomous Communities. PARTICIPANTS: General practitioners (GP) who had participated in the HAPPY AUDIT intervention study in 2008 and 2009 were invited to participate in a third audit-based study six years later (2015). METHOD: RADTs were provided to the participating practices and the GPs were requested to consecutively register all adults with acute pharyngitis. A registration form specifically designed for this study was used. RESULTS: A total of 121 GPs out of the 210 who participated in the first two audits agreed to participate in the third audit (57.6%). They registered 3394 episodes of pharyngitis in the three registrations. RADTs were used in 51.7% of all the cases immediately after the intervention, and in 49.4% six years later. Antibiotics were prescribed in 21.3% and 36.1%, respectively (P<.001), mainly when tonsillar exudates were present, and in 5.3% and 19.2% of those with negative RADT results (P<.001). On adjustment for covariables, compared to the antibiotic prescription observed just after the intervention, significantly more antibiotics were prescribed six years later (odds ratio: 2.24, 95% confidence interval: 1.73-2.89). CONCLUSIONS: This study shows that that the long-term impact of a multifaceted intervention, focusing on the use and interpretation of RADT in patients with acute pharyngitis, is reducing.

Development of a Multiplexed Assay for Detection of Leishmania donovani and Leishmania infantum Protein Biomarkers in Urine Samples of Patients with Visceral Leishmaniasis.

Visceral leishmaniasis (VL) is a serious and fatal disease caused by the parasites Leishmania infantum and Leishmania donovani The gold standard diagnostic test for VL is the demonstration of parasites or their DNA in spleen, lymph node, or bone marrow aspirates. Serological tests exist but cannot distinguish active VL from either prior exposure to the parasites or previously treated VL disease. Using mass spectroscopy, we have previously identified three L. infantum protein biomarkers (Li-isd1, Li-txn1, and Li-ntf2) in the urine of VL patients and developed a sensitive and specific urine-based antigen detection assay for the diagnosis of VL that occurs in Brazil (where VL is caused by L. infantum). However, unpublished observations from our laboratory at DetectoGen showed that these biomarkers were detected in only 55% to 60% of VL patients from India and Kenya, where the disease is caused by L. donovani Here, we report the discovery and characterization of two new biomarkers of L. donovani (Ld-mao1 and Ld-ppi1) present in the urine of VL patients from these two countries. Capture enzyme-linked immunosorbent assays using specific rabbit IgG and chicken IgY were developed, and the assays had sensitivities of 44.4% and 28.8% for the detection of Ld-mao1 and Ld-ppi1, respectively. In contrast, a multiplexed assay designed to simultaneously detect all five leishmanial biomarkers markedly increased the assay sensitivity to 82.2%. These results validate the utility of leishmanial protein biomarkers found in the urine of VL patients as powerful tools for the development of an accurate diagnostic test for this disease.

Association between rapid antigen detection tests and antibiotics for acute pharyngitis in Japan: A retrospective observational study.

The application and clinical impact of rapid antigen detection test (RADT) in the treatment of acute pharyngitis is unknown in Japan. We aimed to examine the proportions of RADT usage to identify Group A ß-hemolytic Streptococcus (GAS) in outpatients with acute pharyngitis and evaluate the association between RADT and antibiotic treatment. We analyzed health insurance claims data from 2013 to 2015. Logistic regression models were used to analyze associated factors with RADT, overall antibiotic prescription, or penicillin use. We analyzed 1.27 million outpatient visits with acute pharyngitis, in which antibiotics were prescribed in 59.3% of visits. Of the total visits, 5.6% of patients received RADT, and 10.8% of the antibiotics were penicillin. Penicillin selection rates were higher in cases with RADT (25.4%) than those without RADT (9.7%). Compared to large-scale facilities, antibiotic prescription rates were higher in physicians' offices. For factor analysis, age (3-15 years), diagnosis code (streptococcal pharyngitis), size of the medical facility (large-scale hospitals), and physician's specialty (pediatrics) were associated with RADT use. Penicillin selection rate increased with RADT implementation (25.4% vs. 9.7%: adjusted odds ratio 1.55; 95% CI, 1.50-1.60). At 63% of the facilities, the RADT implementation rate was <5% of acute pharyngitis visits prescribed antibiotics. In conclusion, the proportion of RADT usage for outpatients with acute pharyngitis was low in Japan. With appropriate indication and evaluation, we expect that more utilization of RADT can help promote antimicrobial stewardship for outpatients with acute pharyngitis by prompting penicillin therapy. Further investigation with detailed clinical data are warranted.

Diagnosis and antibiotic treatment of group a streptococcal pharyngitis in children in a primary care setting: impact of point-of-care polymerase chain reaction.

BACKGROUND: To compare the sensitivity and specificity of the recommended 2-step rapid antigen detection test (RADT) with confirmatory culture vs the point-of-care (POC) polymerase chain reaction (PCR) Roche cobas® Liat® Strep A test for detection of group A Streptococcus (GAS) in pediatric patients with pharyngitis, and to investigate the impact of these tests on antibiotic use in a large pediatric clinic. METHODS: This prospective, open-label study was conducted at a single site during fall/winter 2016-2017. A total of 275 patients aged 3 to 18 years with symptoms of pharyngitis had a throat-swab specimen analyzed using RADT, POC PCR, and culture. The sensitivity, specificity, and percentage agreement (95% CI) between assays and a laboratory-based nucleic acid amplification test were calculated. DNA sequencing was used to adjudicate discrepancies. The RADT or POC PCR result was provided to clinicians on alternating weeks to compare the impact on antibiotic use. RESULTS: A total of 255 samples were evaluated; 110 (43.1%) were GAS positive. Sensitivities (95% CI) for POC PCR, RADT, and culture were 95.5% (89.7-98.5%), 85.5% (77.5-1.5%), and 71.8% (62.4-80.0%), respectively. Specificities (95% CI) for POC PCR, RADT, and culture were 99.3% (96.2-99.98%), 93.7% (88.5-97.1%), and 100% (97.5-100%), respectively. Compared with RADT, POC PCR resulted in significantly greater appropriate antibiotic use (97.1% vs 87.5%; P = .0065). CONCLUSION: Under real-world conditions, RADT results were less specific and culture results were less sensitive than found in established literature and led to increased rates of inappropriate antibiotic use. POC PCR had high sensitivity and specificity and rapid turnaround times, and led to more appropriate antibiotic use. TRIAL REGISTRATION: ID number ISRCTN84562679 . Registered October 162,018, retrospectively registered.

Comparison of Oropharyngeal and Nasopharyngeal Swab Specimens for the Detection of Mycoplasma pneumoniae in Children with Lower Respiratory Tract Infection.

The oropharyngeal swab specimen was superior to the nasopharyngeal swab specimen for the detection of Mycoplasma pneumoniae in children with lower respiratory tract infection. The oropharyngeal loop-mediated isothermal amplification had 100% sensitivity and specificity compared with polymerase chain reaction testing, whereas the oropharyngeal rapid antigen detection test using immunochromatographic assay had relatively low sensitivity (66%) and reasonable specificity (90.7%).