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

A highly sensitive 3base™ assay for detecting Streptococcus pyogenes in saliva during controlled human pharyngitis

Streptococcus pyogenes (Group A Streptococcus; GAS) is a Gram-positive bacterium responsible for substantial human mortality and morbidity. Conventional diagnosis of GAS pharyngitis relies on throat swab culture, a low-throughput, slow, and relatively invasive 'gold standard'. While molecular approaches are becoming increasingly utilized, the potential of saliva as a diagnostic fluid for GAS infection remains largely unexplored. Here, we present a novel, high-throughput, sensitive, and robust speB qPCR assay that reliably detects GAS in saliva using innovative 3base™ technology (Genetic Signatures Limited, Sydney, Australia). The assay has been validated on baseline, acute, and convalescent saliva samples generated from the Controlled Human Infection for Vaccination Against Streptococcus (CHIVAS-M75) trial, in which healthy adult participants were challenged with emm75 GAS. In these well-defined samples, our high-throughput assay outperforms throat culture and conventional qPCR in saliva respectively, affirming the utility of the 3base™ platform, demonstrating the feasibility of saliva as a diagnostic biofluid, and paving the way for the development of novel non-invasive approaches for the detection of GAS and other oropharyngeal pathogens.

Optimizing Antimicrobial Stewardship in the Emergency Department

Antibiotic stewardship is a core component of emergency department (ED) practice and impacts patient safety, clinical outcomes, and public health. The unique characteristics of ED practice, including crowding, time pressure, and diagnostic uncertainty, need to be considered when implementing antibiotic stewardship interventions in this setting. Rapid advances in pathogen detection and host response biomarkers promise to revolutionize the diagnosis of infectious diseases in the ED, but such tests are not yet considered standard of care. Presently, clinical decision support embedded in the electronic health record and pharmacist-led interventions are the most effective ways to improve antibiotic prescribing in the ED.

Molecular Point-of-Care Testing in the Emergency Department for Group A Streptococcus Pharyngitis: A Randomized Trial

OBJECTIVES

To compare clinical and health systems outcomes of rapid molecular testing versus throat culture recovery for the management of group A Streptococcus (GAS) pharyngitis in a pediatric emergency department (PED).

METHODS

We conducted a single-center randomized trial of children (3-17 years) presenting to a PED with suspected GAS pharyngitis. A single dual-headed throat swab was collected, and participants were randomized to 1 of 2 parallel treatment groups with 1:1 allocation: point-of-care (POC) nucleic acid amplification testing or standard throat culture. The primary outcomes were time to throat pain +/- fever resolution. Secondary outcomes included absenteeism, length of stay, return visits to care, and antibiotic prescriptions and utilization.

RESULTS

A total of 227 children were randomly assigned to culture (n = 115) or POC (n = 112) testing. Antibiotics were initiated earlier in the POC group by approximately 1 day (95% confidence interval, -0.40 to -1.58). No associated difference in time to throat pain or fever resolution was observed between groups. There was a decrease in the proportion of prescribed antibiotics in the POC group (0.35) compared with the culture group (0.79; P < 0.001). Otherwise, no significant differences in secondary outcomes were observed.

CONCLUSIONS

Establishing a POC nucleic acid amplification testing program for GAS in a PED facilitates earlier treatment and fewer antibiotic prescriptions. Although this did not translate to improved clinical and health systems outcomes in our study, it may serve as an important tool amid evolving pediatric febrile illnesses and growing antimicrobial resistance patterns.

Point of Care Molecular Testing: Current State and Opportunities for Diagnostic Stewardship

Inappropriate ordering practices, either under or over ordering of diagnostic tests, are recognized problems with possible negative downstream consequences. As the menu of clinical tests, especially molecular tests grows, it is becoming increasingly important to provide guidance to providers on the appropriate utilization. Diagnostic stewardship programs have been established at many institutions to help direct the appropriate utilization of laboratory testing to ultimately guide patient management and treatment decisions. Many molecular tests have now received Clinical Laboratory Improvement Amendments (CLIA)-waived status for use in a point-of-care (POC) setting; however, parallel diagnostic stewardship programs have not been established to help guide providers on how best to use these tests. In this article, we will discuss the available molecular POC tests and opportunities and challenges for establishing diagnostic stewardship programs for molecular testing performed in the POC setting.

Trends in Low-Value Care Among Children's Hospitals

BACKGROUND AND OBJECTIVES

Longitudinal pediatric low-value care (LVC) trends are not well established. We used the Pediatric Health Information System LVC Calculator, which measures utilization of 30 nonevidenced-based services, to report 7-year LVC trends.

METHODS

This retrospective cohort study applied the LVC Calculator to emergency department (ED) and hospital encounters from January 1, 2016, to December 31, 2022. We used generalized estimating equation models accounting for hospital clustering to assess temporal changes in LVC.

RESULTS

There were 5 265 153 eligible ED encounters and 1 301 613 eligible hospitalizations. In 2022, of 21 LVC measures applicable to the ED cohort, the percentage of encounters with LVC had increased for 11 measures, decreased for 1, and remained unchanged for 9 as compared with 2016. Computed tomography for minor head injury had the largest increase (17%-23%; P < .001); bronchodilators for bronchiolitis decreased (22%-17%; P = .001). Of 26 hospitalization measures, LVC increased for 6 measures, decreased for 9, and was unchanged for 11. Inflammatory marker testing for pneumonia had the largest increase (23%-38%; P = .003); broad-spectrum antibiotic use for pneumonia had the largest decrease (60%-48%; P < .001). LVC remained unchanged or decreased for most medication and procedure measures, but remained unchanged or increased for most laboratory and imaging measures.

CONCLUSIONS

LVC improved for a minority of services between 2016 and 2022. Trends were more favorable for therapeutic (medications and procedures) than diagnostic measures (imaging and laboratory studies). These data may inform prioritization of deimplementation efforts.

Practical Challenges of Point-of-Care Testing

The practical challenges of point-of-care testing (POCT) include analytical performance and quality compared with testing performed in a central laboratory and higher cost per test compared with laboratory-based tests. These challenges can be addressed with new test technology, consensus, and practice guidelines for the use of POCT, instituting a quality management system and data connectivity in the POCT setting, and studies that demonstrate evidence of clinical and economic value of POCT.

Point-of-Care and Rapid Tests for the Etiological Diagnosis of Respiratory Tract Infections in Children: A Systematic Review and Meta-Analysis

Fever is one of the most common causes of medical evaluation of children, and early discrimination between viral and bacterial infection is essential to reduce inappropriate prescriptions. This study aims to systematically review the effects of point-of-care tests (POCTs) and rapid tests for respiratory tract infections on changing antibiotic prescription rate, length of stay, duration of therapy, and healthcare costs. Embase, MEDLINE, and Cochrane Library databases were systematically searched. All randomized control trials and non-randomized observational studies meeting inclusion criteria were evaluated using the NIH assessment tool. A meta-analysis was performed to assess the effects of rapid influenza diagnostic tests and film-array respiratory panel implementation on selected outcomes. From a total of 6440 studies, 57 were eligible for the review. The analysis was stratified by setting and POCT/rapid test type. The most frequent POCTs or rapid tests implemented were the Rapid Influenza Diagnostic Test and film-array and for those types of test a separate meta-analysis assessed a significant reduction in antibiotic prescription and an improvement in oseltamivir prescription. Implementing POCTs and rapid tests to discriminate between viral and bacterial infections for respiratory pathogens is valuable for improving appropriate antimicrobial prescriptions. However, more studies are needed to assess these findings in pediatric settings.

Antimicrobial Stewardship Strategies Including Point-of-Care Testing (POCT) for Pediatric Patients with Upper-Respiratory-Tract Infections in Primary Care: A Systematic Review of Economic Evaluations

Upper-respiratory-tract infections (URTIs) are among the main causes of antibiotic prescriptions in pediatric patients. Over one-third of all antibiotic prescriptions for URTIs in children are estimated to be inappropriate, as the majority of URTIs are caused by viral agents. Several strategies, including clinical scoring algorithms and different point-of-care tests (POCTs) have been developed to help discriminate bacterial from viral URTIs in the outpatient clinical setting. A systematic review of the literature was conducted following PRISMA guidelines with the objective of summarizing evidence from health–economic evaluations on the use of POCT for URTIs in pediatric outpatients. A total of 3375 records identified from four databases and other sources were screened, of which 8 met the inclusion criteria. Four studies were classified as being of high reporting quality, and three were of medium quality. Five out of eight studies concluded in favor of strategies that included POCTs, with an additional study finding several POCTs to be cost-effective compared to usual care but over an acceptable WTP threshold. This review found POCT could be a valuable tool for antimicrobial stewardship strategies targeted towards childhood URTIs in primary care.

Organisation and quality monitoring for point-of-care testing (POCT) in Belgium: proposal for an expansion of the legal framework for POCT into primary health care

BACKGROUND

There is a trend towards decentralisation of laboratory tests by means of Point-of-Care testing (POCT). Within hospitals, Belgian law requires a POCT policy, coordinated by the clinical laboratory. There is however no legal framework for POCT performed outside the hospital: no reimbursement, no compulsory quality monitoring and no limits nor control on the prices charged to the patient. Uncontrolled use of POCT can have negative consequences for individual and public health.

PROPOSAL

We propose that POCT outside hospitals would only be reimbursed for tests carried out within a legal framework, requiring evidence-based testing and collaboration with a clinical laboratory, because clinical laboratories have procedures for test validation and quality monitoring, are equipped for electronic data transfer, are familiar with logistical processes, can provide support when technical issues arise and can organise and certify training. Under these conditions the government investment will be offset by health benefits, e.g. fall in antibiotic consumption with POCT for CRP in primary care, quick response to SARS-CoV2-positive cases in COVID-19 triage centres.

PRIORITIES

1° extension of the Belgian decree on certification of clinical laboratories to decentralised tests in primary care; 2° introduction of a separate reimbursement category for POCT; 3° introduction of reimbursement for a limited number of specified POCT; 4° setup of a Multidisciplinary POCT Advisory Council, the purpose of which is to draw up a model for reimbursement of POCT, to select tests eligible for reimbursement and to make proposals to the National Institute for Health and Disability Insurance (RIZIV/INAMI).

The impact of point-of-care polymerase chain reaction testing on prescribing practices in primary care for management of Strep A: a retrospective beforeafter study

Background

Rapid antigen detection tests (RADTs) are the standard of care (SOC) for testing in patients with suspected Group A β-hemolytic Streptococcus (Strep A) infection. Due to lower sensitivity, guidelines recommend confirmatory microbiological culture following negative RADT results. This process is time-consuming, and adherence is often poor, resulting in high rates of inappropriate antibiotic prescribing. We sought to evaluate the impact of switching from RADTs to point-of-care (POC) PCR testing on use of antibiotics in primary care, when used as part of an antibiotic stewardship initiative.

Methods

In this retrospective before–after study, electronic medical records of any patients presenting with suspected acute pharyngitis (June 2018–May 2019) across 15 outpatient primary care clinics were evaluated. Strep A was detected using the cobas  ® Strep A assay (cobas  ® Liat ® system).

Results

Analysis of 10,081 eligible patient records showed that POC PCR testing resulted in a 44.1% reduction in antibiotic prescribing for patients with a negative POC PCR test result (10.1% PCR vs 18.0% RADT; p&lt;0.0001). Rates of antibiotic prescription varied across clinical sites, ranging between 10.7–33.8% and 12.4–34.4% during the use of PCR tests and RADTs, respectively. POC PCR had no impact on prescription rates in patients with positive POC test results compared to RADTs (76.2% vs 76.5%, respectively). Over 99% of antibiotics were prescribed during the initial primary care encounter.

Conclusion

As part of a broader antibiotic stewardship initiative, implementation of POC PCR as SOC in outpatients with acute pharyngitis symptoms reduced the volume of inappropriate antibiotic prescriptions.

Simple Electric Device to Isolate Nucleic Acids from Whole Blood Optimized for Point of Care Testing of Brain Damage

BACKGROUND

Detection or monitoring of brain damage is a clinically crucial issue. Nucleic acids in the whole blood can be used as biomarkers for brain injury. Polymerase chain reaction (PCR) which is one of the most commonly used molecular diagnostic assays requires isolated nucleic acids to initiate amplification. Currently used nucleic acid isolation procedures are complicated and require laboratory equipments.

OBJECTIVE

In this study, we tried to develop a simple and convenient method to isolate nucleic acids from the whole blood sample using a tiny battery-powered electric device. The quality of the isolated nucleic acids should be suitable for PCR assay without extra preparation.

METHODS

A plastic device with separation chamber was designed and printed with a 3D printer. Two platinum electrodes were placed on both sides and a battery was used to supply the electricity. To choose the optimal nucleic acid isolation condition, diverse lysis buffers and separation buffers were evaluated, and the duration and voltage of the electricity were tested. Western blot analysis and PCR assay were used to determine the quality of the separated nucleic acids.

RESULTS

2ul of whole blood was applied to the cathode side of the separation chamber containing 78 ul of normal saline. When the electricity at 5 V was applied for 5 min, nucleic acids were separated from segment 1 to 3 of the separation chamber. The concentration of nucleic acids peaked around 7~8 mm from cathode side. PCR assay using the separation buffer as the template was performed successfully both in conventional and realtime PCR methods. The hemoglobin in the whole blood did not show the inhibitory effect in our separation system and it may be due to structural modification of hemoglobin during electric separation.

CONCLUSION

Our simple electric device can separate nucleic acids from the whole blood sample by applying electricity at 5 V for 5 min. The separation buffer solution taken from the device can be used for PCR assay successfully.

Point-of-Care Testing in Microbiology

Point-of-care (POC) or near patient testing for infectious diseases is a rapidly expanding space that is part of an ongoing effort to bring care closer to the patient. Traditional POC tests were known for their limited utility, but advances in technology have seen significant improvements in performance of these assays. The increasing promise of these tests is also coupled with their increasing complexity, which requires the oversight of qualified laboratory-trained personnel.

Single-centre, open-label, randomised, trial to compare rapid molecular point-of-care streptococcal testing to standard laboratory-based testing for the management of streptococcal pharyngitis in children: study protocol

INTRODUCTION

Streptococcal pharyngitis, which commonly occurs in children, should be treated with antibiotics. Clinical prediction rules to differentiate streptococcal pharyngitis from viral infection are not recommended in children. Rapid point-of-care (POC) antigen tests have limited sensitivity and so are not often used in Canadian paediatric emergency departments (EDs). Standard paediatric practice is to rely on laboratory-based testing, which often results in a delay before the results can be communicated to the patient; this may impede appropriate prescribing, decrease caregiver satisfaction and delay recovery. The objective of this study is to determine whether a novel rapid molecular POC assay for streptococcal pharyngitis leads to more appropriate antibiotic use in children seeking care in a paediatric ED than standard laboratory-based testing.

METHODS AND ANALYSIS

A randomised, superiority, open-label, trial with two parallel groups. Children presenting to a tertiary paediatric ED at least 3 years of age who have a throat swab ordered for diagnosis of streptococcal pharyngitis will be eligible; those who have taken antibiotics within 72 hours prior to presentation and those with additional active infections will be excluded. The primary study outcome will be appropriate antibiotic treatment at 3-5 days postenrolment. Secondary outcomes include time to symptom resolution, caregiver satisfaction, caregiver/child absenteeism, number of subsequent healthcare visits, clinician satisfaction and incremental cost-effectiveness of POC testing. A total of 352 participants will be needed.

ETHICS AND DISSEMINATION

All study documentation has been approved by the Hamilton Integrated Research Ethics board and informed consent will be obtained from all participants. Data from this trial will be presented at major conferences and published in peer-reviewed publications to facilitate collaborations with networks of clinicians experienced in the dissemination of clinical guidelines.

TRIAL REGISTRATION NUMBER

NCT04247243.

Rapid and Safe Detection of SARS-CoV-2 and Influenza Virus RNA using Onsite qPCR Diagnostic Testing from Clinical Specimens Collected in Molecular Transport Medium

BACKGROUND

The ability to rapidly detect SARS-CoV-2 and influenza virus infection is vital for patient care due to overlap in clinical symptoms. Roche's cobas® Liat® SARS-CoV-2 & Influenza A/B Nucleic Acid Test used on the cobas® Liat® was granted approval under FDA's Emergency Use Authorization (EUA) for nasopharyngeal (NP) and nasal swabs collected in viral/universal transport medium (VTM/UTM). However, there is a critical need for media that inactivates the virus, especially when specimens are collected in decentralized settings. This study aimed to investigate the use of PrimeStore Molecular Transport Medium® (PS-MTM®), designed to inactivate/kill and stabilize RNA/DNA for ambient transport and pre-processing of collected samples.

METHODS

A limit of detection (LOD) using serially diluted SARS-CoV-2 RNA in PS-MTM® and routine UTM was established using standard qPCR. Additionally, a clinical panel of NP and oral swabs collected in PS-MTM® collected during the 2020 coronavirus disease 2019 (COVID-19) pandemic were evaluated on the cobas® Liat® and compared to 'gold standard' qPCR on an ABI-7500 instrument.

RESULTS

SARS-CoV-2 RNA LOD using standard qPCR was equivalent on the cobas® Liat® instrument. cobas® Liat® detection from oral/NP swabs in PS-MTM® media exhibited equivalent positive percent agreement (100%) and negative percent agreement (96.4%).

CONCLUSION

PS-MTM® and the Roche cobas® Liat® are compatible and complimentary devices for respiratory specimen collection and rapid disease detection, respectively. PS-MTM® is equivalent to standard VTM/UTM with the added benefit of safe, non-infectious sample processing for near-patient testing.

Structured review of primary interventions to reduce group A streptococcal infections, acute rheumatic fever and rheumatic heart disease

Rheumatic heart disease (RHD) is a large, preventable, global public health burden. In New Zealand (NZ), acute rheumatic fever (ARF) and RHD rates are highest for Māori and Pacific children. This structured review explores the evidence for primary prevention interventions to diagnose and effectively treat group A Streptococcus (GAS) pharyngitis and skin infections to reduce rates of ARF and RHD. Medline, EMBASE and Scopus databases were searched as well as other electronic publications. Included were 50 publications from 1980 onwards. This review has identified that there is little available evidence for effective primary prevention strategies to reduce ARF rates in NZ. However, two primary intervention strategies that should be considered by communities at high-risk of ARF are: the use of school-based clinics to identify and treat GAS pharyngitis and GAS skin infections; and intramuscular benzathine penicillin G with lignocaine analgesia in children who present with a GAS positive throat.

An emm-type specific qPCR to track bacterial load during experimental human Streptococcus pyogenes pharyngitis

BACKGROUND

Streptococcus pyogenes causes a profound global burden of morbidity and mortality across its diverse clinical spectrum. To support a new controlled human infection ('challenge') model seeking to accelerate S. pyogenes vaccine development, we aimed to develop an accurate and reliable molecular method for quantifying bacterial load from pharyngeal swabs collected during experimental human pharyngitis.

METHODS

Combined sequential RNA + DNA extraction from throat swabs was compared to traditional separate RNA-only and DNA-only extractions. An emm-type specific qPCR was developed to detect the emm75 challenge strain. Results from the qPCR were compared to culture, using throat swab samples collected in a human challenge study.

RESULTS

The qPCR was 100% specific for the emm75 challenge strain when tested against a panel of S. pyogenes emm-types and other respiratory pathogens. Combined RNA + DNA extraction had similar yield to traditional separate extractions. The combined extraction method and emm75 qPCR had 98.8% sensitivity compared to culture for throat swabs collected from challenge study participants.

CONCLUSIONS

We have developed a reliable molecular method for measuring S. pyogenes bacterial load from throat swabs collected in a controlled human infection model of S. pyogenes pharyngitis.

TRIAL REGISTRATION

NCT03361163 on 4th December 2017.

Diagnostic accuracy of rapid nucleic acid tests for group A streptococcal pharyngitis: systematic review and meta-analysis

BACKGROUND

Acute pharyngitis is one of the most common conditions in outpatient settings and an important source of inappropriate antibiotic prescribing. Rapid antigen detection tests (RADTs) offer diagnosis of group A streptococcus at the point of care but have limited sensitivity. Rapid nucleic acid tests (RNATs) are now available; a systematic review of their accuracy is lacking.

OBJECTIVES

To evaluate the accuracy of RNATs in patients with pharyngitis; to explore test-level and study-level factors that could explain variability in accuracy; and to compare the accuracy of RNATs with that of RADTs.

DATA SOURCES

MEDLINE, Embase, Web of Science (1990-2020).

STUDY ELIGIBILITY CRITERIA

Cross-sectional studies and randomized trials.

PARTICIPANTS

Patients with pharyngitis.

INDEX TEST/S AND REFERENCE STANDARDS

RNAT commercial kits compared with throat culture.

METHODS

We assessed risk of bias and applicability using QUADAS-2. We performed meta-analysis of sensitivity and specificity using the bivariate random-effects model. Variability was explored by subgroup analyses and meta-regression.

RESULTS

We included 38 studies (46 test evaluations; 17 411 test results). RNATs were most often performed in a laboratory. The overall methodological quality of primary studies was uncertain because of incomplete reporting. RNATs had a summary sensitivity of 97.5% (95% CI 96.2%-98.3%) and a summary specificity of 95.1% (95% CI 93.6%-96.3%). There was low variability in estimates across studies. Variability in sensitivity and specificity was partially explained by test type (p < 0.05 for both). Sensitivity analyses limited to studies with low risk of bias showed robust accuracy estimates. RNATs were more sensitive than RADTs (13 studies; 96.8% versus 82.3%, p 0.004); there was no difference in specificity (p 0.92).

CONCLUSIONS

The high diagnostic accuracy of RNATs may allow their use as stand-alone tests to diagnose group A streptococcus pharyngitis. Based on direct comparisons, RNATs have greater sensitivity than RADTs and equal specificity. Further studies should evaluate RNATs in point-of-care settings.

A Comparison of Diagnostic Accuracy of a Rapid Antigen Detection Test in Screening for Group A Streptococcal Throat Infection Between 3- to 10-Year-Old (Children and Preadolescents) and 11- to 21-Year-Old (Adolescents)

Introduction

Pharyngitis is one of the most common childhood diseases worldwide. We intended to compare the performance of one such rapid antigen detection test (RADT) using lateral flow immunoassay technique, between 3- to 10-year-old (children and preadolescent) and 11- to 21-year-old (adolescents).

Methods

Children and adolescents attending the pediatric ED with complaints of throat pain and signs of pharyngeal and tonsillar inflammation were tested by both the RADT and throat culture (TC) directed towards group A streptococcal (GAS) between April and June of 2016. The prevalence, sensitivity (SN), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were calculated against throat culture, the gold standard for the diagnosis of GAS pharyngitis. Comparisons between the two age groups were made using the Chi-square test

Results

Of 202 patients, 123 (61%) patients were between 3-11 and 79 (39%) between 11-21 years of age. A positive throat culture was recorded in 56 patients yielding an overall prevalence of GAS pharyngitis at 28%. For the whole sample, the screening RADT had an SN, SP, PPV and NPV of 79%, 90%, 75%, and 92%, respectively. Also, there was no statistically significant difference between the two groups in terms of SN, SP, PPV and NPV.

Conclusion

The RADT in use at our institution, performed comparable to studies reported in the literature using a similar technique in both preadolescent and adolescent age groups.

Worldwide comparison of treatment guidelines for sore throat

Introduction

Sore throat (acute pharyngitis) is globally one of the most frequent reasons for seeking healthcare. Its etiology is mostly viral. In 15%‐30% of cases, group A streptococci (GAS) are detected, which may cause acute rheumatic fever. We have done a worldwide systematic review to compare diagnostic and therapeutic guidelines across countries and regions. Previous reviews of sore throat guidelines were limited to specific regions and/or language; this is the first global review.

Materials and Methods

Searches were performed in MEDLINE, EMBASE and COCHRANE (key words: sore throat, pharyngitis, tonsillitis or pharyngotonsillitis, and management, guidance, guideline or recommendation) and on the web sites of major health authorities and associated institutions from Africa, Asia, Europe, Middle East, North America, Oceania and South America.

Results

Thirty‐six guidelines were identified from 26 countries. Most common are recommendations relying on the symptom‐ and age‐based Centor or McIsaac scores. However, antibiotic treatment may be based on other symptomatic criteria; in the most extreme approach just sore throat in children. The recommendation of GAS‐specific diagnostic tests is mainly limited to countries where such tests are readily available, although some countries choose not to use them. Penicillins are consistently recommended as first‐line antibiotics. By contrast, guidance for symptomatic treatment is variable and mostly sparse or missing. African countries without sore throat guidelines and Asian countries bypassing them are afflicted by rising antibiotic resistance.

Conclusion

The availability of sore throat guidelines varies considerably by region and country. Moreover, important divergence is found among the guidelines regarding diagnostic and treatment criteria. This may be explained by the historical background or adoption of external guidelines, rather than local incidences of GAS infections or acute rheumatic fever. Absence of recommendations on symptomatic treatment in many guidelines is concerning, and raises issues about antimicrobial stewardship, as this should be the mainstay of sore throat management, rather than antibiotics.

Paediatrics: how to manage pharyngitis in an era of increasing antimicrobial resistance

The goal of this narrative review of pharyngitis is to summarize the practical aspects of the management of sore throat in children in high- and middle-income countries. A traditional review of the literature was performed. Most cases of pharyngitis are viral and self-limited, although rarely viral pharyngitis due to Epstein–Barr leads to airway obstruction. Bacterial pharyngitis is usually due to group A streptococcus (GAS), occurs primarily in children aged 5–15 years, and presents as sore throat in the absence of rhinitis, laryngitis or cough. Again, most cases are self-limited; antibiotics hasten recovery by only 1–2 days. Guidelines vary by country, but antibiotics are commonly recommended for proven GAS pharyngitis as they may prevent rare but severe complications, in particular rheumatic fever (RF). In this era of antimicrobial stewardship, it should be extremely rare that antibiotics are prescribed for presumed GAS pharyngitis until GAS has been detected. Even with proven GAS pharyngitis, it is controversial whether children at low risk for RF should routinely be prescribed antibiotics as the number needed to treat to prevent one case of RF is undoubtedly very large. When treatment is offered, the antibiotics of choice are penicillin or amoxicillin as they are narrow spectrum and resistance resulting in clinical failure is yet to be documented. A 10-day oral course is recommended as shorter courses appear to be less likely to clear carriage of GAS. However, the evidence that one needs to clear carriage to prevent RF is low quality and indirect.

Point-of-Care Testing for Pharyngitis in the Pharmacy

Pharyngitis (also known as sore throat) is a common, predominately viral, self-limiting condition which can be symptomatically managed without antibiotic treatment. Inappropriate antibiotic use for pharyngitis contributes to the development and spread of antibiotic resistance. However, a small proportion of sore throats caused by group A streptococcal (GAS) infection may benefit from the provision of antibiotics. Establishing the cause of infection is therefore an important step in effective antibiotic stewardship. Point-of-care (POC) tests, where results are available within minutes, can distinguish between viral and GAS pharyngitis and can therefore guide treatment in primary healthcare settings such as community pharmacies, which are often the first point of contact with the healthcare system. In this opinion article, the evidence for the use of POC testing in the community pharmacy has been discussed. Evidence suggests that pharmacy POC testing can promote appropriate antibiotic use and reduce the need for general practitioner consultations. Challenges to implementation include cost, training and 'who prescribes', with country and regional differences presenting a particular issue. Despite these challenges, POC testing for pharyngitis has become widely available in pharmacies in some countries and may represent a strategy to contain antibiotic resistance and contribute to antimicrobial stewardship.

Toward automated severe pharyngitis detection with smartphone camera using deep learning networks

PURPOSE

Severe pharyngitis is frequently associated with inflammations caused by streptococcal pharyngitis, which can cause immune-mediated and post-infectious complications. The recent global pandemic of coronavirus disease (COVID-19) encourages the use of telemedicine for patients with respiratory symptoms. This study, therefore, purposes automated detection of severe pharyngitis using a deep learning framework with self-taken throat images.

METHODS

A dataset composed of two classes of 131 throat images with pharyngitis and 208 normal throat images was collected. Before the training classifier, we constructed a cycle consistency generative adversarial network (CycleGAN) to augment the training dataset. The ResNet50, Inception-v3, and MobileNet-v2 architectures were trained with transfer learning and validated using a randomly selected test dataset. The performance of the models was evaluated based on the accuracy and area under the receiver operating characteristic curve (ROC-AUC).

RESULTS

The CycleGAN-based synthetic images reflected the pragmatic characteristic features of pharyngitis. Using the synthetic throat images, the deep learning model demonstrated a significant improvement in the accuracy of the pharyngitis diagnosis. ResNet50 with GAN-based augmentation showed the best ROC-AUC of 0.988 for pharyngitis detection in the test dataset. In the 4-fold cross-validation using the ResNet50, the highest detection accuracy and ROC-AUC achieved were 95.3% and 0.992, respectively.

CONCLUSION

The deep learning model for smartphone-based pharyngitis screening allows fast identification of severe pharyngitis with a potential of the timely diagnosis of pharyngitis. In the recent pandemic of COVID-19, this framework will help patients with upper respiratory symptoms to improve convenience in diagnosis and reduce transmission.

Point-of-Care Testing in Microbiology: A Mechanism for Improving Patient Outcomes

BACKGROUND

Increasingly, demands for improved health and quality of life conflict with the realities of delivering healthcare in an environment of higher expenditures, adherence to test utilization, and patient-centered experience. Patient-centered care is commonly identified as a goal of healthcare delivery, and yet healthcare systems struggle with delivery of care to patients, often failing to identify the seriously ill and capitalize on the predictive qualities of diagnostic testing. Point-of-care (POC) testing provides access to rapid diagnosis and predictive value key to realizing patient outcomes. An evaluation of cost-effective models and the clinical impact of POC testing for clinical microbiology is needed.

CONTENT

Accurate and rapid diagnostics have the potential to affect healthcare decisions to a degree well out of proportion to their cost. Contemporary healthcare models increasingly view POC testing as a mechanism for efficient deployment of healthcare. POC testing can deliver rapid diagnosis in environments where testing results can be used to direct management during patient visits and in areas where centralized laboratory testing may limit access to care. Nucleic acid assays, designed for POC testing, can match, or exceed, the sensitivity of conventional laboratory-based testing, eliminating the need for confirmation testing. Here, the goals of POC testing for microbiology, applications, and technologies, as well as outcomes and value propositions, are discussed.

SUMMARY

The combination of rapid reporting, an increasing array of organisms capable of causing disease, actionable resulting, and improved patient outcomes is key in the evolution of POC testing in clinical microbiology.

Efficacy and safety of rapid tests to guide antibiotic prescriptions for sore throat

BACKGROUND

Sore throat is a common condition caused by viruses or bacteria, and is a leading cause of antibiotic prescription in primary care. The most common bacterial species is group A streptococcus ('strep throat'). Between 50% to 70% of pharyngitis cases are treated with antibiotics, despite the majority of cases being viral in origin. One strategy to reduce antibiotics is to use rapid tests for group A streptococcus to guide antibiotic prescriptions. Rapid tests can be used alone or in combination with a clinical scoring system.

OBJECTIVES

To assess the efficacy and safety of strategies based on rapid tests to guide antibiotic prescriptions for sore throat in primary care settings.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Web of Science, and LILACS, as well as the trial registries ClinicalTrials.gov and the WHO ICTRP on 5 June 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing rapid tests with management based on clinical grounds to guide the prescription of antibiotics for people with a sore throat in ambulatory care settings. We included trials that randomised individuals, as well as cluster-RCTs in which individual practitioners (or practices) or emergency departments were randomised.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on the primary outcomes (number of participants provided with an antibiotic prescription; number of participants with an antibiotic dispensed) and secondary outcomes (duration of sore throat symptoms; duration of other symptoms; quality of life measures; number of participants with a complication attributed to the index infection; number of participants in need of re-consultation by the end of follow-up; number of participants in need of hospital admission by the end of follow-up; number of satisfied participants; number of participants with an adverse event attributed to the rapid test). We assessed the risk of bias of all included trials and used GRADE to assess the certainty of the evidence. We performed meta-analyses and sensitivity analyses when feasible.

MAIN RESULTS

We included five trials (2891 children and adult participants in total; 2545 participants after adjusting for clustering). Management in the intervention group was as follows: in three trials rapid tests were used in combination with a clinical scoring system; in one trial, some physicians were asked to use rapid tests alone, while others were asked to use rapid tests in combination with a clinical scoring system; in one trial, rapid tests were used alone. Based on data from five trials (2545 participants), a large reduction in prescribed antibiotics was found in the rapid test group (481/1197) versus management based on clinical grounds (865/1348), for a summary risk difference (RD) of -25%, 95% confidence interval (CI) -31% to -18%; I² = 62%; moderate-certainty evidence. Estimates of effect on antibiotic prescription rates were stable in various sensitivity analyses. Based on data from two trials (900 people) originating from the same overarching study, the evidence suggests that rapid tests may not reduce dispensed antibiotic treatments: rapid test group (156/445) versus management based on clinical grounds (197/455); summary RD -7%, 95% CI -17% to 2%; I² = 53%; low-certainty evidence. Four trials (2075 participants) reported data on the number of participants with a complication attributed to the index infection; the summary odds ratio (OR) was 0.85, 95% CI 0.03 to 26.65; P = 0.93; I² = 62%; very low-certainty evidence, which means that people in the rapid testing group were less likely to develop complications of the index infection, but the evidence is very uncertain. Two trials (1161 participants) reported on the number of participants in need of re-consultation by the end of follow-up; the summary OR was 1.12, 95% CI 0.57 to 2.21; P = 0.74; I² = 59%; low-certainty evidence, which means that participants in the rapid testing group were more likely to be in need of re-consultation by the end of the study follow-up, but the evidence is uncertain. Lack of data impeded assessment of other secondary outcomes (including safety outcomes) and of sources of heterogeneity.  AUTHORS' CONCLUSIONS: Rapid testing to guide antibiotic treatment for sore throat in primary care probably reduces antibiotic prescription rates by 25% (absolute risk difference), but may have little or no impact on antibiotic dispensing. More studies are needed to assess the efficacy and safety of rapid test-guided antibiotic prescribing, notably to evaluate patient-centred outcomes and variability across subgroups (e.g. adults versus children).

Group A Streptococcus Testing in Pediatrics: the Move to Point-of-Care Molecular Testing

Each year, there are an estimated 11 million visits to ambulatory care centers for pharyngitis in children between the ages of 3 and 18 years. While there are many causes of pediatric pharyngitis, group A streptococcal pharyngitis represents 15 to 30% of infections and is the only cause for which treatment is recommended. Unfortunately, clinical suspicion is insufficient for the accurate diagnosis of group A streptococcal pharyngitis, and laboratory testing for confirmation of Streptococcus pyogenes infection is required to prevent complications of infection. Traditionally, throat swabs are inoculated onto agar plates for isolation of the large-zone beta-hemolytic streptococcus. However, traditional culture methods present a potential delay in treatment due to turnaround times of 18 to 48 h. In order to improve turnaround times and enhance antimicrobial stewardship, multiple point-of-care assays have been developed. This review describes current point-of-care testing for group A streptococcal pharyngitis, including rapid antigen detection tests and more recent molecular methods. Additional attention is given to the diagnostic considerations when choosing a method for group A streptococcal point-of-care testing, implementation of molecular group A streptococcal testing, and the institutional cost of immunoassays compared to those of newer molecular methods.

Pharyngitis: Approach to diagnosis and treatment

OBJECTIVE

To provide family physicians with an updated approach to diagnosis and treatment of pharyngitis, detailing key symptoms, methods of investigation, and a summary of common causes.

SOURCES OF INFORMATION

The approach described is based on the authors' clinical practice and peer-reviewed literature from 1989 to 2018.

MAIN MESSAGE

Sore throat caused by pharyngitis is commonly seen in family medicine clinics and is caused by inflammation of the pharynx and surrounding tissues. Pharyngitis can be caused by viral, bacterial, or fungal infections. Viral causes are often self-limiting, while bacterial and fungal infections typically require antimicrobial therapy. Rapid antigen detection tests and throat cultures can be used with clinical findings to identify the inciting organism. Pharyngitis caused by Streptococcus pyogenes is among the most concerning owing to its associated severe complications such as acute rheumatic fever and glomerulonephritis. Hence, careful diagnosis of pharyngitis is necessary to provide targeted treatment.

CONCLUSION

A thorough history is key to diagnosing pharyngitis. Rapid antigen detection tests should be reserved for concerns about antibiotic initiation. Physicians should exercise restraint in antibiotic initiation for pharyngitis, as restraint does not delay recovery or increase the risk of S pyogenes infections.

[Not Available]

Objectif

Offrir aux médecins de famille une approche diagnostique et thérapeutique actualisée de la pharyngite, en décrivant en détail les principaux symptômes, les méthodes d’investigation et un résumé des causes courantes.

Sources d’information

L’approche décrite est basée sur la pratique clinique des auteurs et sur les publications revues par les pairs de 1989 à 2018.

Message principal

Le mal de gorge causé par la pharyngite est couramment observé dans les cliniques de médecine familiale; il est causé par l’inflammation du pharynx et des tissus environnants. La pharyngite est causée par une infection virale, bactérienne ou fongique. Les causes virales sont souvent spontanément résolutives, alors que les infections bactériennes et fongiques nécessitent habituellement l’antibiothérapie. Le test de détection rapide de l’antigène et la culture de gorge sont jumelés aux observations cliniques pour identifier l’organisme en cause. La pharyngite causée par streptococcus pyogenes fait partie des organismes les plus préoccupants en raison de ses complications graves, telles la fièvre rhumatismale aiguë et la glomérulonéphrite. Ainsi, il est nécessaire de poser un diagnostic attentif de pharyngite afin de pouvoir dispenser un traitement ciblé.

Conclusion

L’anamnèse détaillée est la clé du diagnostic de pharyngite. Le test de détection rapide de l’antigène doit être réservé aux cas où l’instauration de l’antibiothérapie est préoccupante. Les médecins doivent user de retenue lorsqu’ils instaurent l’antibiothérapie contre la pharyngite, puisque la retenue ne retarde pas le rétablissement ni n’augmente le risque d’infection à s. pyogenes.

Rapid diagnostic tests for infectious diseases in the emergency department

Background

Rapid diagnostic tests (RDTs) for infectious diseases, with a turnaround time of less than 2 hours, are promising tools that could improve patient care, antimicrobial stewardship and infection prevention in the emergency department (ED) setting. Numerous RDTs have been developed, although not necessarily for the ED environment. Their successful implementation in the ED relies on their performance and impact on patient management.

Objectives

The aim of this narrative review was to provide an overview of currently available RDTs for infectious diseases in the ED.

Sources

PubMed was searched through August 2019 for available studies on RDTs for infectious diseases. Inclusion criteria included: commercial tests approved by the US Food and Drug Administration (FDA) or Conformité Européenne (CE) in vitro diagnostic devices with data on clinical samples, ability to run on fully automated systems and result delivery within 2 hours.

Content

A nonexhaustive list of representative commercially available FDA- or CE-approved assays was categorized by clinical syndrome: pharyngitis and upper respiratory tract infection, lower respiratory tract infection, gastrointestinal infection, meningitis and encephalitis, fever in returning travellers and sexually transmitted infection, including HIV. The performance of tests was described on the basis of clinical validation studies. Further, their impact on clinical outcomes and anti-infective use was discussed with a focus on ED-based studies.

Implications

Clinicians should be familiar with the distinctive features of each RDT and individual performance characteristics for each target. Their integration into ED work flow should be preplanned considering local constraints of given settings. Additional clinical studies are needed to further evaluate their clinical effectiveness and cost-effectiveness.

Appropriate Use and Future Directions of Molecular Diagnostic Testing

Purpose of Review

Major technologic advances in two main areas of molecular infectious disease diagnostics have resulted in accelerated adoption or ordering, outpacing implementation, and clinical utility studies. Physicians must understand the limitations to and appropriate utilization of these technologies in order to provide cost-effective and well-informed care for their patients.

Recent Findings

Rapid molecular testing and, to a lesser degree, clinical metagenomics are now being routinely used in clinical practice. While these tests allow for a breadth of interrogation not possible with conventional microbiology, they pose new challenges for diagnostic and antimicrobial stewardship programs. This review will summarize the most recent literature on these two categories of technologic advances and discuss the few studies that have looked at utilization and stewardship approaches. This review also highlights the future directions for both of these technologies.

Summary

The appropriate utilization of rapid molecular testing and clinical metagenomics has not been well established. More studies are needed to assess their prospective impacts on patient management and antimicrobial stewardship efforts as the future state of infectious disease diagnostics will see continued expansion of these technologic advances.

Role of epidemiological risk factors in improving the clinical diagnosis of streptococcal sore throat in pediatric clinical practice

Background and Aims:

Antibiotics are frequently prescribed for sore throat in developing countries, that in turn leads to huge healthcare expenditure and their irrational use may lead to antimicrobial resistance in the community. The aim of this study is to investigate the effect of environmental factors on the frequency of occurrence of group A beta hemolytic streptococcus (GABHS) sore throat and to work out enhancing effect on the sensitivity and specificity and positive predictive value of the signs and symptoms of GABHS sore throat for facilitation of rational antibiotic use.

Settings and Design:

This was a prospective, cross sectional study conducted over period of one year in Pediatric Outpatient Department (OPD) of a Tertiary care teaching hospital.

Methods:

All the children between the age of 5 years and 15 years of age presenting in OPD with the signs and symptoms of sore throat were included in the study.

Statistical Analysis Used:

Statistical analysis was carried out by using Statistical Package for Social Sciences software and statistical tests of Pearson's Coefficient, Chi-square Test, Fischer's Test, Likelihood Ratio, Odds Ratio, and ROC Curve were applied.

Results:

Out of 225 children of the study group, 153 (68%) of the children were in the 5-10 years’ age group. Positive throat swab culture was found to be positively associated with high grade fever, pain in throat while swallowing, severely enlarged tonsils, tender lymphadenopathy, poor housing condition, fuel used for cooking, and presence of smoker in house.

Conclusions:

The study stresses on the need of carefully evaluating children presenting with the symptoms of sore throat as majority of the cases may be viral and thus, self-limiting. Poor housing conditions and indoor pollution contribute to the increased prevalence of sore throat.