Large-scale validation of the Centor and McIsaac scores to predict group A streptococcal pharyngitis

Derivation and Internal Validation of a Novel Risk Assessment Tool to Identify Infants and Young Children at Risk for Post-Discharge Mortality in Dar es Salaam, Tanzania and Monrovia, Liberia

OBJECTIVE

To derive and validate internally a novel risk assessment tool to identify young children at risk for all-cause mortality ≤60 days of discharge from hospitals in sub-Saharan Africa.

STUDY DESIGN

We performed a prospective observational cohort study of children aged 1-59 months discharged from Muhimbili National Hospital in Dar es Salaam, Tanzania and John F. Kennedy Medical Center in Monrovia, Liberia (2019-2022). Caregivers received telephone calls up to 60 days after discharge to ascertain participant vital status. We collected socioeconomic, demographic, clinical, and anthropometric data during hospitalization. Candidate variables with P < .20 in bivariate analyses were included in a multivariable logistic regression model with best subset selection to identify risk factors for the outcome. We internally validated our tool using bootstrapping with 500 repetitions.

RESULTS

There were 1933 young children enrolled in the study. The median (IQR) age was 11 (4, 23) months and 58.7% were males. In total, 67 (3.5%) died during follow-up. Ten variables contributed to our tool (total possible score 82). Cancer (aOR 10.6, 95% CI 2.58, 34.6), pedal edema (aOR 6.94, 95% CI 1.69, 22.6), and leaving against medical advice (aOR 6.46, 95% CI 2.46, 15.3) were most predictive of post-discharge mortality. Our risk assessment tool demonstrated good discriminatory value (optimism corrected area under the receiver operating characteristic curve 0.77), high precision, and sufficient calibration.

CONCLUSIONS

After validation, this tool may be used to identify young children at risk for post-discharge mortality to direct resources for follow-up of high-risk children.

The relationship between group A streptococcus test positivity and clinical findings in tonsillopharyngitis in children: systematic review and meta-analysis

PURPOSE

This study aimed to present an evidence-based conclusion through a systematic meta-analysis to distinguish clinical signs and symptoms associated with the presence of group A beta-hemolytic streptococcus, as confirmed by throat culture or rapid test, from those in cases without culture confirmation.

METHODS

The study protocol has been published in PROSPERO (CRD42023450854). Studies published between January 1, 2013 and August 15, 2023 were scanned in seven databases. The methodological quality of the articles was assessed using The Joanna Briggs Institution (JBI) Cross-Sectional Studies and Cohort Studies checklist. Effect size calculations were made using fixed effects and random effects models.

RESULTS

A total of 22 articles were included in the systematic review, with 14 included in the meta-analysis. The prevalence of streptococcal pharyngitis in these studies ranged from 7.3 to 44.1%. According to the meta-analysis results, a significant association was observed between GAS test positivity and the presence of tonsillar exudate, palatal petechiae, tonsillar hypertrophy, dysphagia, fever, and cervical lymphadenopathy (p < 0.05). No significant relationship was found between GAS test positivity and symptoms such as headache, sore throat, cough, absence of cough, hoarseness, scarlatiniform rash, tonsillar erythema, vomiting, rhinorrhea, and abdominal pain (p > 0.05).

CONCLUSION

The findings of the meta-analysis suggest that, in addition to the Centor criteria, palatal petechiae, dysphagia, and tonsillar hypertrophy are noteworthy indicators of GAS infection. Contrary to previous studies, our meta-analysis indicates that symptoms such as headache, sore throat, cough, absence of cough, hoarseness, scarlatiniform rash, tonsillar erythema, vomiting, rhinorrhea, and abdominal pain may not be associated with streptococcal infection. Further research is needed to elucidate these findings.

The impact of national guidelines on the diagnostics of sore throat in children

BACKGROUND

The Finnish treatment guidelines for sore throat were updated in June 2020. The aim of this study was to determine how the publication of these guidelines affected the treatment of pediatric patients, particularly through the use of the Centor criteria, C-reactive protein tests, and microbiological testing in the diagnosis of Group A β-hemolytic streptococci tonsillitis.

METHODS

We conducted a retrospective single-center before-and-after cohort study in Finland from 2019 to 2022. We included all patients who visited the pediatric emergency department and were diagnosed with tonsillitis or pharyngitis.

RESULTS

We included 246 patients who were admitted before the guidelines were updated and 219 patients after. Only two patients in the after group had a Centor score reported in their patient records. Rapid antigen tests were administered to 231 patients (93.9%) before the update and 202 patients (92.2%) after (proportion difference of 1.7%, CI -3.0-6.6%). C-reactive protein was taken from 193 patients (78.5%) before the update and 189 patients (86.3%) after (proportion difference of 7.8%, CI 0.1-14.7%).

CONCLUSIONS

Centor scores were not used as recommended in the guidelines and did not impact the use of microbiological or C-reactive protein testing. More education and examining the preconceptions of health care personnel is required to implement the updated treatment guidelines in clinical practice.

Explainable AI decision support improves accuracy during telehealth strep throat screening

BACKGROUND

Artificial intelligence-based (AI) clinical decision support systems (CDSS) using unconventional data, like smartphone-acquired images, promise transformational opportunities for telehealth; including remote diagnosis. Although such solutions' potential remains largely untapped, providers' trust and understanding are vital for effective adoption. This study examines how different human-AI interaction paradigms affect clinicians' responses to an emerging AI CDSS for streptococcal pharyngitis (strep throat) detection from smartphone throat images.

METHODS

In a randomized experiment, we tested explainable AI strategies using three AI-based CDSS prototypes for strep throat prediction. Participants received clinical vignettes via an online survey to predict the disease state and offer clinical recommendations. The first set included a validated CDSS prediction (Modified Centor Score) and the second introduced an explainable AI prototype randomly. We used linear models to assess explainable AI's effect on clinicians' accuracy, confirmatory testing rates, and perceived trust and understanding of the CDSS.

RESULTS

The study, involving 121 telehealth providers, shows that compared to using the Centor Score, AI-based CDSS can improve clinicians' predictions. Despite higher agreement with AI, participants report lower trust in its advice than in the Centor Score, leading to more requests for in-person confirmatory testing.

CONCLUSIONS

Effectively integrating AI is crucial in the telehealth-based diagnosis of infectious diseases, given the implications of antibiotic over-prescriptions. We demonstrate that AI-based CDSS can improve the accuracy of remote strep throat screening yet underscores the necessity to enhance human-machine collaboration, particularly in trust and intelligibility. This ensures providers and patients can capitalize on AI interventions and smartphones for virtual healthcare.

Diagnosis and Treatment of Group A Streptococcal Pharyngitis in Children

The purpose of this review is to summarize the current evidence regarding the management of streptococcal pharyngitis in children. This article aims to provide a valid support to discriminate streptococcal pharyngitis from viral cases and treat it appropriately to avoid the development of complications. Differential diagnosis based only on clinical features is not always easy. For this reason, different clinical scores were created to provide an accurate diagnosis. Microbiological tests are valuable tools as well, but their use is not recommended unanimously. Concerning treatment, all guidelines agree on the drug to be used. However, doubts remain about the optimal duration of antibiotic therapy, especially in this specific historical moment as we are experiencing a peak in streptococcal infections. [Pediatr Ann. 2024;53(6):e234-e238.].

Barriers to Implementing Registered Nurse-Driven Clinical Decision Support for Antibiotic Stewardship: Retrospective Case Study

BACKGROUND

Up to 50% of antibiotic prescriptions for upper respiratory infections (URIs) are inappropriate. Clinical decision support (CDS) systems to mitigate unnecessary antibiotic prescriptions have been implemented into electronic health records, but their use by providers has been limited.

OBJECTIVE

As a delegation protocol, we adapted a validated electronic health record-integrated clinical prediction rule (iCPR) CDS-based intervention for registered nurses (RNs), consisting of triage to identify patients with low-acuity URI followed by CDS-guided RN visits. It was implemented in February 2022 as a randomized controlled stepped-wedge trial in 43 primary and urgent care practices within 4 academic health systems in New York, Wisconsin, and Utah. While issues were pragmatically addressed as they arose, a systematic assessment of the barriers to implementation is needed to better understand and address these barriers.

METHODS

We performed a retrospective case study, collecting quantitative and qualitative data regarding clinical workflows and triage-template use from expert interviews, study surveys, routine check-ins with practice personnel, and chart reviews over the first year of implementation of the iCPR intervention. Guided by the updated CFIR (Consolidated Framework for Implementation Research), we characterized the initial barriers to implementing a URI iCPR intervention for RNs in ambulatory care. CFIR constructs were coded as missing, neutral, weak, or strong implementation factors.

RESULTS

Barriers were identified within all implementation domains. The strongest barriers were found in the outer setting, with those factors trickling down to impact the inner setting. Local conditions driven by COVID-19 served as one of the strongest barriers, impacting attitudes among practice staff and ultimately contributing to a work infrastructure characterized by staff changes, RN shortages and turnover, and competing responsibilities. Policies and laws regarding scope of practice of RNs varied by state and institutional application of those laws, with some allowing more clinical autonomy for RNs. This necessitated different study procedures at each study site to meet practice requirements, increasing innovation complexity. Similarly, institutional policies led to varying levels of compatibility with existing triage, rooming, and documentation workflows. These workflow conflicts were compounded by limited available resources, as well as an implementation climate of optional participation, few participation incentives, and thus low relative priority compared to other clinical duties.

CONCLUSIONS

Both between and within health care systems, significant variability existed in workflows for patient intake and triage. Even in a relatively straightforward clinical workflow, workflow and cultural differences appreciably impacted intervention adoption. Takeaways from this study can be applied to other RN delegation protocol implementations of new and innovative CDS tools within existing workflows to support integration and improve uptake. When implementing a system-wide clinical care intervention, considerations must be made for variability in culture and workflows at the state, health system, practice, and individual levels.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04255303; https://clinicaltrials.gov/ct2/show/NCT04255303.

Is the Comparator in Your Diagnostic Cost-Effectiveness Model "Standard of Care"? Recommendations from Literature Reviews and Expert Interviews on How to Identify and Operationalize It

OBJECTIVES

This research aimed to develop best-practice recommendations for identifying the "standard of care" (SoC) and integrate it when it is the comparator in diagnostic economic models (SoC comparator).

METHODS

A multi-methods approach comprising 2 pragmatic literature reviews and 9 expert interviews was used. Experts rated their agreement with draft recommendations based on the authors' analysis of the reviews. These were refined iteratively to produce final recommendations.

RESULTS

Fourteen best-practice recommendations are provided. Care pathway mapping (using quantitative, qualitative, or mixed-methods approaches) should be used for identifying the SoC comparator. Guidelines analysis can be integrated with expert opinion to identify pathway variability and discrepancies from clinical practice. For integrating the SoC comparator into the model, recommendations around structure, input sourcing, data aggregation and reporting, input uncertainty, and model variability are presented. For example, modelers should consider that the reference standard is not synonymous with the SoC, and the SoC may not be the only comparator. The comparator limitations should be discussed with clinical experts, but elicitation of its diagnostic accuracy is not recommended. Probabilistic sensitivity analysis is recommended when evaluating the overall input uncertainty, and deterministic sensitivity analysis is useful when there is high model uncertainty or SoC variability. Consensus could not be reached for some topics (eg, the role of real-world data, model averaging, and alternative model structures), but the reported discussions provide points for consideration.

CONCLUSIONS

To our knowledge, this is the first guidance to support modelers when identifying and operationalizing the SoC comparator in diagnostic cost-effectiveness models.

Appropriateness of Use of Streptococcal Pharyngitis Testing and Associated Antibiotic Prescribing in the Urgent Care Setting

The primary objective was to evaluate Group A streptococcal (GAS) tests performed with a Modified Centor Criteria (MCC) Score < 3 at Urgent Care Clinics (UCC). Secondary objectives included evaluating the MCC sensitivity and specificity, antibiotics prescribed with an MCC score < 3, and association between palatal petechiae and GAS pharyngitis infections. This was a retrospective review from July 1, 2018, to June 30, 2019, of Rapid Antigen Detection Tests (RADTs) on patients with ICD codes associated with pharyngitis. Fifteen hundred patient charts were reviewed. The majority of MCC scores were < 3 at 60.0% (878/1464). Sensitivity of GAS testing (RADT/culture) slightly increased for MCC scores ≥ 3 and was better than the specificity of those scores. In comparison, MCC scores < 3, showed better specificity compared to sensitivity. Over 50% of RADTs performed were inappropriate per clinical guidelines. MCC score < 3 had higher rates of negative test results.

Identifying neonates at risk for post-discharge mortality in Dar es Salaam, Tanzania, and Monrovia, Liberia: Derivation and internal validation of a novel risk assessment tool

INTRODUCTION

The immediate period after hospital discharge carries a large burden of childhood mortality in sub-Saharan Africa. Our objective was to derive and internally validate a risk assessment tool to identify neonates discharged from the neonatal ward at risk for 60-day post-discharge mortality.

METHODS

We conducted a prospective observational cohort study of neonates discharged from Muhimbili National Hospital in Dar es Salaam, Tanzania, and John F Kennedy Medical Centre in Monrovia, Liberia. Research staff called caregivers to ascertain vital status up to 60 days after discharge. We conducted multivariable logistic regression analyses with best subset selection to identify socioeconomic, demographic, clinical, and anthropometric factors associated with post-discharge mortality. We used adjusted log coefficients to assign points to each variable and internally validated our tool with bootstrap validation with 500 repetitions.

RESULTS

There were 2344 neonates discharged and 2310 (98.5%) had post-discharge outcomes available. The median (IQR) age at discharge was 8 (4, 15) days; 1238 (53.6%) were male. In total, 71 (3.1%) died during follow-up (26.8% within 7 days of discharge). Leaving against medical advice (adjusted OR [aOR] 5.62, 95% CI 2.40 to 12.10) and diagnosis of meconium aspiration (aOR 6.98, 95% CI 1.69 to 21.70) conferred the greatest risk for post-discharge mortality. The risk assessment tool included nine variables (total possible score=63) and had an optimism corrected area under the receiver operating characteristic curve of 0.77 (95% CI 0.75 to 0.80). A score of ≥6 was most optimal (sensitivity 68.3% [95% CI 64.8% to 71.5%], specificity 72.1% [95% CI 71.5% to 72.7%]).

CONCLUSIONS

A small number of factors predicted all-cause, 60-day mortality after discharge from neonatal wards in Tanzania and Liberia. After external validation, this risk assessment tool may facilitate clinical decision making for eligibility for discharge and the direction of resources to follow-up high risk neonates.

Diagnostic performance of clinical prediction rules to detect group A beta-haemolytic streptococci in people with acute pharyngitis: a systematic review

OBJECTIVE

To assess and compare the diagnostic performance of Clinical Prediction Rules (CPRs) developed to detect group A Beta-haemolytic streptococci in people with acute pharyngitis (or sore throat).

STUDY DESIGN

A systematic review.

METHODS

We searched PubMed, Embase and Web of Science (inception-September 2022) for studies deriving and/or validating CPRs comprised of ≥2 predictors from an individual's history or physical examination. Two authors independently screened articles, extracted data and assessed risk of bias in included studies. A meta-analysis was not possible due to heterogeneity. Instead we compared the performance of CPRs when they were validated in the same study population (head-to-head comparisons). We used a modified grading of recommendations, assessment, development, and evaluations (GRADE) approach to assess certainty of the evidence.

RESULTS

We included 63 studies, all judged at high risk of bias. Of 24 derived CPRs, 7 were externally validated (in 46 external validations). Five validation studies provided data for head-to-head comparison of four pairs of CPRs. Very low certainty evidence favoured the Centor CPR over the McIsaac (2 studies) and FeverPain CPRs (1 study) and found the Centor CPR was equivalent to the Walsh CPR (1 study). The AbuReesh and Steinhoff 2005 CPRs had a similar poor discriminative ability (1 study). Within and between study comparisons suggested the performance of the Centor CPR may be better in adults (>18 years).

CONCLUSION

Very low certainty evidence suggests a better performance of the Centor CPR. When deciding about antibiotic prescribing for pharyngitis patients, involving patients in a shared decision making discussion about the likely benefits and harms, including antibiotic resistance, is recommended. Further research of higher rigour, which compares CPRs across multiple settings, is needed.

The use and usefulness of point-of-care tests in patients with pharyngotonsillitis - an observational study in primary health care

BACKGROUND

Rapid antigen detection tests (RADT) for Group A streptococci (GAS) and point-of-care tests for C-reactive protein (CRP) are commonly used in patients with pharyngotonsillitis in Sweden and Denmark although CRP testing is not supported by guidelines. We aimed to describe (1) the proportion of patients tested with RADT and/or CRP, (2) the relation between test results and antibiotic prescribing, and (3) the association between CRP level and microbial aetiology.

METHODS

We used a post-hoc-analysis of data collected in primary health care in a prospective aetiological study of 220 patients 15-45 years old diagnosed with pharyngotonsillitis. The outcomes of RADTs and CRP tests were related to antibiotic prescribing and microbial aetiology.

RESULTS

A RADT was used in 94% of the patients. A CRP test was used in 50% of the patients but more commonly in those with a negative RADT (59%) than in those with a positive RADT (38%) (p = 0.005). Most (74%) CRP tests were used in patients with a negative RADT. Antibiotic prescribing differed greatly between patients with a positive RADT (96%) and patients with a negative RADT (17%) (p < 0.001). In patients with a negative RADT, there was a positive association between CRP value and antibiotic prescribing (OR 1.05; 95% CI 1.02-1.07; p < 0.001). Patients with CRP values ≤ 30 mg/l were seldomly prescribed antibiotics. Patients with GAS in culture had the highest median CRP (46 mg/l), which was higher than in patients without GAS (8 mg/l; p < 0.001). However, the positive predictive value for GAS never exceeded 0.60 (95% CI 0.31-0.83) at the investigated CRP levels.

CONCLUSIONS

The widespread use of tests is a major deviation from national guidelines. Most CRP tests were used in patients with a negative RADT, suggesting a belief in the added value of a CRP test, and the CRP result seemed to influence antibiotic prescribing. However, as an aetiological test, CRP is not useful for predicting GAS.

Reducing prescribing of antibiotics for acute respiratory infections using a frontline nurse-led EHR-Integrated clinical decision support tool: protocol for a stepped wedge randomized control trial

BACKGROUND

Overprescribing of antibiotics for acute respiratory infections (ARIs) remains a major issue in outpatient settings. Use of clinical prediction rules (CPRs) can reduce inappropriate antibiotic prescribing but they remain underutilized by physicians and advanced practice providers. A registered nurse (RN)-led model of an electronic health record-integrated CPR (iCPR) for low-acuity ARIs may be an effective alternative to address the barriers to a physician-driven model.

METHODS

Following qualitative usability testing, we will conduct a stepped-wedge practice-level cluster randomized controlled trial (RCT) examining the effect of iCPR-guided RN care for low acuity patients with ARI. The primary hypothesis to be tested is: Implementation of RN-led iCPR tools will reduce antibiotic prescribing across diverse primary care settings. Specifically, this study aims to: (1) determine the impact of iCPRs on rapid strep test and chest x-ray ordering and antibiotic prescribing rates when used by RNs; (2) examine resource use patterns and cost-effectiveness of RN visits across diverse clinical settings; (3) determine the impact of iCPR-guided care on patient satisfaction; and (4) ascertain the effect of the intervention on RN and physician burnout.

DISCUSSION

This study represents an innovative approach to using an iCPR model led by RNs and specifically designed to address inappropriate antibiotic prescribing. This study has the potential to provide guidance on the effectiveness of delegating care of low-acuity patients with ARIs to RNs to increase use of iCPRs and reduce antibiotic overprescribing for ARIs in outpatient settings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04255303, Registered February 5 2020, https://clinicaltrials.gov/ct2/show/NCT04255303 .

Development of a prediction model for the acquisition of extended spectrum beta-lactam-resistant organisms in U.S. international travellers

BACKGROUND

Extended spectrum beta-lactamase producing Enterobacterales (ESBL-PE) present a risk to public health by limiting the efficacy of multiple classes of beta-lactam antibiotics against infection. International travellers may acquire these organisms and identifying individuals at high risk of acquisition could help inform clinical treatment or prevention strategies.

METHODS

We used data collected from a cohort of 528 international travellers enrolled in a multicentre US-based study to derive a clinical prediction rule (CPR) to identify travellers who developed ESBL-PE colonization, defined as those with new ESBL positivity in stool upon return to the United States. To select candidate features, we used data collected from pre-travel and post-travel questionnaires, alongside destination-specific data from external sources. We utilized LASSO regression for feature selection, followed by random forest or logistic regression modelling, to derive a CPR for ESBL acquisition.

RESULTS

A CPR using machine learning and logistic regression on 10 features has an internally cross-validated area under the receiver operating characteristic curve (cvAUC) of 0.70 (95% confidence interval 0.69-0.71). We also demonstrate that a four-feature model performs similarly to the 10-feature model, with a cvAUC of 0.68 (95% confidence interval 0.67-0.69). This model uses traveller's diarrhoea, and antibiotics as treatment, destination country waste management rankings and destination regional probabilities as predictors.

CONCLUSIONS

We demonstrate that by integrating traveller characteristics with destination-specific data, we could derive a CPR to identify those at highest risk of acquiring ESBL-PE during international travel.

Antibiotic Use for Common Infections in Pediatric Emergency Departments: A Narrative Review

Antibiotics are one of the most prescribed medications in pediatric emergency departments. Antimicrobial stewardship programs assist in the reduction of antibiotic use in pediatric patients. However, the establishment of antimicrobial stewardship programs in pediatric EDs remains challenging. Recent studies provide evidence that common infectious diseases treated in the pediatric ED, including acute otitis media, tonsillitis, community-acquired pneumonia, preseptal cellulitis, and urinary-tract infections, can be treated with shorter antibiotic courses. Moreover, there is still controversy regarding the actual need for antibiotic treatment and the optimal dosing scheme for each infection.

Identifying Group A Streptococcal Pharyngitis in Children Through Clinical Variables Using Machine Learning

Background Group A Streptococcus (GAS) is the most common bacterial cause of pharyngitis in children. GAS pharyngitis requires antimicrobial agents, and rapid antigen detection tests (RADTs) are currently considered useful for diagnosis. However, the decision to perform the test is based on the pediatrician's examination findings, but the indicators are not clear. Therefore, we used machine learning (ML) to create a model to identify GAS pharyngitis from clinical findings and to explore important features. Methods ML with Python programming language was used for this study. Data from the included study involved 676 children aged 3 to 15 years diagnosed with pharyngitis, with positive results on the RADT serving as exposures, and negative results serving as controls. The ML performances served as the outcome. We utilized six types of ML classifiers, namely, logistic regression, support vector machine, k-nearest neighbor algorithm, random forest, an ensemble of them, Voting Classifier, and the eXtreme Gradient Boosting (XGBoost) algorithm. Additionally, we used SHapley Additive exPlanations (SHAP) values to identify important features. Results Moderately performing models were generated for all six ML classifiers. XGBoost produced the best model, with an area under the receiver operating characteristics curve of 0.75 ± 0.01. The order of important features in the model was palatal petechiae, followed by scarlatiniform rash, tender cervical lymph nodes, and age. Conclusion Through this study, we have demonstrated that ML models can predict childhood GAS pharyngitis with moderate accuracy using only commonly recorded clinical variables in children diagnosed with pharyngitis. We have also identified four important clinical variables. These findings may serve as a reference for considering indicators under the current guidelines recommended for selective RADTs.

Assessment of adherence to guidelines for testing and treatment of pharyngitis among children in Palestine: A retrospective review study

Introduction

One of the most common reasons for pediatric outpatient visits is acute pharyngitis, an upper respiratory tract infection. Bacterial pharyngitis is caused by Group A beta-hemolytic Streptococcus (GABHS), also known as Streptococcus pyogenes. This research aimed to assess physicians' adherence to clinical guidelines for diagnosis, management, and selecting appropriate treatment for children suspected of bacterial pharyngitis.

Methods

A retrospective, observational study was conducted by reviewing patient charts for childred aged 3 to 13 years old diagnosed with pharyngitis from June 2019 until December 2019 at the Emergency Department of Palestine Medical Complex (PMC). The Modified Centor score, throat swab collections, and assessment of antimicrobial selection were used to assess the extent of physicians' adherence to clinical guidelines for appropriate diagnosis and management of pharyngitis. SPSS was used for data analysis.

Results

Out of 290 cases diagnosed with acute pharyngitis, 217 patients (74.8%) had a Modified Centor score of ≥2; 126 received antibiotics, and eight had their throat swabbed to confirm the diagnosis; furthermore, 73 patients (25.2%) had a Modified Centor score of <2; 34 of them received antibiotics. Azithromycin was the most commonly prescribed antibiotic (41.3%), followed by amoxicillin-clavulanic acid (38.1%). The frequency of empirical antibiotics prescribing was significantly higher among children with a Centor score >2, older children, and those presenting with fever.

Conclusions

Most cases were not appropriately tested to confirm the diagnosis of bacterial pharyngitis and were mostly treated with inappropriate antimicrobial agents such as azithromycin. Nonadherence to clinical guidelines is very evident in this study.

Diagnosis and management of acute pharyngotonsillitis among pediatric patients at Ribat Teaching Hospital: a prospective audit (2021-2022)

Diagnosis of pharyngotonsillitis is challenging due to the wide range of symptoms and signs. Sudan Federal Ministry of Health and Sudanese Association of Paediatricians, along with Sudan Heart Society reached a consensus about the clinical prediction rule which aids in diagnosing and managing bacterial pharyngotonsillitis. This audit aimed to assess doctors' knowledge and practice regarding diagnosis and management of bacterial pharyngotonsillitis at Ribat Teaching Hospital, Khartoum, Sudan. This audit was done at Pediatric Department, Ribat Teaching Hospital, and data collection was done over 2 weeks either in the first or the second cycle. Inclusion criteria were children who presented at the emergency room and were diagnosed with acute pharyngotonsillitis. The criteria used in this audit were from Sudan guidelines for prevention, diagnosis and management of rheumatic heart disease. Regular training sessions were done between the first and second cycles. There were 19 patients in the first cycle, 17 of them (89.4%) were diagnosed clinically with bacterial pharyngotonsillitis, and 8 of these 17 (47%) were fitting the criteria. Regarding the management of bacterial pharyngotonsillitis, no patient was given the recommended antibiotics in the guidelines (0.00%). In the second cycle, there were 21 patients, of whom 11 patients were diagnosed clinically with bacterial pharyngotonsillitis (52%). Of those 11, 8 patients were fitting the criteria (72.7%), and the recommended antibiotics were given in 9 of them (82%). The current practice toward acute pharyngotonsillitis management revealed a lack of doctors' knowledge about local guidelines which can be improved by simple ways such as posters, lectures, and focused group discussions.

Knowledge, Attitude, and Practice of House Officers to the Diagnosis and Management of Bacterial Pharyngitis: A Multicenter Cross-Sectional Study

BACKGROUND

Pharyngitis is one of the most common clinical presentations in pediatric clinics. Streptococcal pharyngitis reaches a nadir in the early school years, and it is vital to diagnose it early to avoid the serious complications that can arise from improper treatment, such as acute rheumatic fever and rheumatic heart disease.

MATERIALS AND METHODS

This is a cross-sectional multicenter study of medical house officers conducted from January to February 2018.

RESULTS

This study surveyed 135 house officers at Khartoum's primary health centers and hospitals. Most of the respondents were males (76/135; 56%). Most of the house officers reported seeing patients with throat complaints 1-2 times per week (58/135; 43%). The most common complication was acute rheumatic fever (65/135; 48%). Out of all the criteria of a Group A beta-hemolytic streptococcus (GAS) pharyngitis diagnosis, absence of cough and tender lymph nodes were the least recognized by house officers, i.e. 11.9% (16/135) and 45.2% (61/135), respectively. Only (4/135) 3% knew the full criteria for diagnosing bacterial pharyngitis. Throat culture was the most commonly used lab test to diagnose bacterial pharyngitis (115/135; 85.2%). The majority of participants did not recognize an IM injection of benzathine penicillin G as the first-line management of bacterial pharyngitis (101/135; 74.8%). The participants had moderate knowledge (93/135; 68.9%). Those with poor knowledge also happened to have poor practice (p = 0.009). Those who see more cases per week were also more likely to have good knowledge (p = 0.000). House officers with a moderate attitude constituted about 48.9% (66/135) of the whole sample. The most often prescribed medication was amoxicillin-clavulanic acid for one week (53/135; 39.3%). The practice score was associated with a lower knowledge (p = 0.009). Only 20.7% (28/135) of the participants in our study were adherent to the use of benzathine penicillin G as the first-line management of bacterial pharyngitis.

CONCLUSION

House officers had poor-to-moderate knowledge regarding the diagnosis and management of bacterial pharyngitis, especially in regard to what antibiotic to use. However, their fear of antibiotic resistance was a good behavior.

Clinical characteristics of Plasmodium falciparum infection among symptomatic patients presenting to a major urban military hospital in Cameroon

BACKGROUND

Urban malaria has received insufficient attention in the literature. The prevalence and clinical characteristics of Plasmodium falciparum infection amongst patients presenting with suspected malaria were investigated at a major urban hospital in Douala, Cameroon with a particular focus on anaemia.

METHODS

A cross-sectional, 18-week demographic and clinical survey was conducted of patients presenting to the Emergency Department of Douala Military Hospital with suspected malaria, largely defined by the presence or recent history of fever. Venous samples were tested for P. falciparum using rapid diagnostic tests and PCR, and anaemia was defined by haemoglobin level according to WHO definitions. Likelihood ratios (LR), odds ratios (OR), and population attributable risk percent (PARP) were calculated.

RESULTS

Participants were ages 8 months to 86 years, 51% were women (257/503), and all districts of Douala were represented. Overall, 38.0% (n = 189/497) were anaemic, including 5.2% (n = 26/497) with severe anaemia. Anaemia prevalence was significantly higher (OR: 2.20, 95% CI 1.41-3.45) among children < 15 years (53.1%, n = 52/98) compared to adults (34%, n = 133/392). Plasmodium falciparum was detected in 37.2% by nested PCR. Among all participants, several factors were associated with clinically significant LR for P. falciparum infection, including age 10-14 years (positive LR: 3.73), living in the island district of Douala VI (positive LR: 3.41), travel to any of three northern regions (positive LR: 5.11), and high fever > 40 °C at presentation (positive LR: 4.83). Among all participants, 8.7% of anaemia was associated with P. falciparum infection, while the PARP was 33.2% among those < 15 years of age and 81.0% among 10-14-year-olds.

CONCLUSIONS

The prevalence of P. falciparum infection in the urban hospital was high. Mirroring trends in many rural African settings, older children had the highest positivity rate for P. falciparum infection. Anaemia was also common in all age groups, and for those 10-14 years of age, 80% of the risk for anaemia was associated with P. falciparum infection. Malaria rates in major urban population centres can be high, and more research into the multifactorial causes of anaemia across the age spectrum are needed.

Improving Antibiotic Stewardship for Diarrheal Disease With Probability-Based Electronic Clinical Decision Support: A Randomized Crossover Trial

Importance

Inappropriate use of antibiotics for diarrheal illness can result in adverse effects and increase in antimicrobial resistance.

Objective

To determine whether the diarrheal etiology prediction (DEP) algorithm, which uses patient-specific and location-specific features to estimate the probability that diarrhea etiology is exclusively viral, impacts antibiotic prescriptions in patients with acute diarrhea.

Design, Setting, and Participants

A randomized crossover study was conducted to evaluate the DEP incorporated into a smartphone-based electronic clinical decision-support (eCDS) tool. The DEP calculated the probability of viral etiology of diarrhea, based on dynamic patient-specific and location-specific features. Physicians were randomized in the first 4-week study period to the intervention arm (eCDS with the DEP) or control arm (eCDS without the DEP), followed by a 1-week washout period before a subsequent 4-week crossover period. The study was conducted at 3 sites in Bangladesh from November 17, 2021, to January 21, 2021, and at 4 sites in Mali from January 6, 2021, to March 5, 2021. Eligible physicians were those who treated children with diarrhea. Eligible patients were children between ages 2 and 59 months with acute diarrhea and household access to a cell phone for follow-up.

Interventions

Use of the eCDS with the DEP (intervention arm) vs use of the eCDS without the DEP (control arm).

Main Outcomes and Measures

The primary outcome was the proportion of children prescribed an antibiotic.

Results

A total of 30 physician participants and 941 patient participants (57.1% male; median [IQR] age, 12 [8-18] months) were enrolled. There was no evidence of a difference in the proportion of children prescribed antibiotics by physicians using the DEP (risk difference [RD], -4.2%; 95% CI, -10.7% to 1.0%). In a post hoc analysis that accounted for the predicted probability of a viral-only etiology, there was a statistically significant difference in risk of antibiotic prescription between the DEP and control arms (RD, -0.056; 95% CI, -0.128 to -0.01). No known adverse effects of the DEP were detected at 10-day postdischarge.

Conclusions and Relevance

Use of a tool that provides an estimate of etiological likelihood did not result in a significant change in overall antibiotic prescriptions. Post hoc analysis suggests that a higher predicted probability of viral etiology was linked to reductions in antibiotic use.

Trial Registration

Clinicaltrials.gov Identifier: NCT04602676.

What is the optimal strategy for managing primary care patients with an uncomplicated acute sore throat? Comparing the consequences of nine different strategies using a compilation of previous studies

OBJECTIVE

Identifying optimal strategies for managing patients of any age with varying risk of acute rheumatic fever (ARF) attending for an apparently uncomplicated acute sore throat, also clarifying the role of point-of-care testing (POCT) for presence of group A beta-haemolytic Streptococcus (GABHS) in these settings.

DESIGN

We compared outcomes of adhering to nine different strategies for managing these patients in primary healthcare.

SETTING AND PARTICIPANTS

The nine strategies, similar to guidelines from several countries, were tested against two validation data sets being constructs from seven prior studies.

MAIN OUTCOME MEASURES

The proportion of patients requiring a POCT, prescribed antibiotics, prescribed antibiotics having GABHS and finally having GABHS not prescribed antibiotics, if different strategies had been adhered to.

RESULTS

In a scenario with high risk of ARF, adhering to existing guidelines would risk many patients ill from GABHS left without antibiotics. Hence, using a POCT on all of these patients minimised their risk. For low-risk patients, it is reasonable to only consider antibiotics if the patient has more than low pain levels despite adequate analgesia, 3-4 Centor scores (or 2-3 FeverPAIN scores or 3-4 McIsaac scores) and a POCT confirming the presence of GABHS. This would require testing only 10%-15% of patients and prescribing antibiotics to only 3.5%-6.6%.

CONCLUSIONS

Patients with high or low risk for ARF needs to be managed very differently. POCT can play an important role in safely targeting the use of antibiotics for patients with an apparently uncomplicated acute sore throat.

Valuing tonsillitis manifestations in schoolchildren in Rio de Janeiro

Objective:

To evaluate the importance attributed to tonsillitis by guardians and their level of knowledge about the disease, correlating their management with their schooling and socioeconomic profiles.

Methods:

A quantitative, descriptive and observational cross-sectional study involving students aged 5 to 17 years from state-owned and private schools. A questionnaire was applied on management of tonsillitis and knowledge about rheumatic fever, addressing demographic and socioeconomic data.

Results:

A total of 323 students were included, predominantly females (61.3%), from state-owned schools (77.1%), with a mean age of 9.7±0.3 years. Among the guardians, 48.6% completed high school. Among the students 75.2% had at least one episode of odynophagia in the previous 12 months. Considering the previous 2 years, 89.8% reported this symptom. There was no collection of bacteriological specimens in 67.8%, and in 83% if taking into account only the last episode, despite the search for medical care in most cases (92.6%). The use of anti-inflammatory drugs was very frequent (43.0% “always” and 42.4% “sometimes”). Among the guardians, 81.7% denied being aware of the relation between rheumatic fever and inappropriate treatment of odynophagia; 85.8% said they wished they had received more information.

Conclusion:

Although it is quite common in schoolchildren, tonsillitis is neglected by many guardians and health professionals, and the ignorance of its relation with rheumatic fever is practically universal, which may contribute to its high prevalence.

External validation of a mobile clinical decision support system for diarrhea etiology prediction in children: a multicenter study in Bangladesh and Mali

Background: Diarrheal illness is a leading cause of antibiotic use for children in low- and middle-income countries. Determination of diarrhea etiology at the point-of-care without reliance on laboratory testing has the potential to reduce inappropriate antibiotic use.

Methods: This prospective observational study aimed to develop and externally validate the accuracy of a mobile software application ('App') for the prediction of viral-only etiology of acute diarrhea in children 0-59 months in Bangladesh and Mali. The App used a previously derived and internally validated model consisting of patient-specific ('present patient') clinical variables (age, blood in stool, vomiting, breastfeeding status, and mid-upper arm circumference) as well as location-specific viral diarrhea seasonality curves. The performance of additional models using the 'present patient' data combined with other external data sources including location-specific climate, data, recent patient data, and historical population-based prevalence were also evaluated in secondary analysis. Diarrhea etiology was determined with TaqMan Array Card using episode-specific attributable fraction (AFe) >0.5.

Results: Of 302 children with acute diarrhea enrolled, 199 had etiologies above the AFe threshold. Viral-only pathogens were detected in 22% of patients in Mali and 63% in Bangladesh. Rotavirus was the most common pathogen detected (16% Mali; 60% Bangladesh). The present patient + viral seasonality model had an AUC of 0.754 (0.665-0.843) for the sites combined, with calibration-in-the-large α=-0.393 (-0.455 - -0.331) and calibration slope β=1.287 (1.207 - 1.367). By site, the present patient + recent patient model performed best in Mali with an AUC of 0.783 (0.705 - 0.86); the present patient + viral seasonality model performed best in Bangladesh with AUC 0.710 (0.595 - 0.825).

Conclusion: The App accurately identified children with high likelihood of viral-only diarrhea etiology. Further studies to evaluate the App's potential use in diagnostic and antimicrobial stewardship are underway.

Funding: Funding for this study was provided through grants from the Bill and Melinda Gates Foundation (OPP1198876) and the National Institute of Allergy and Infectious Diseases (R01AI135114). Several investigators were also partially supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (R01DK116163). This investigation was also supported by the University of Utah Population Health Research (PHR) Foundation, with funding in part from the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR002538. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The funders had no role in the study design, data collection, data analysis, interpretation of data, or in the writing or decision to submit the manuscript for publication.

Use of the McIsaac Score to Predict Group A Streptococcal Pharyngitis in Outpatient Nurse Phone Triage and Electronic Visits Compared With In-Person Visits: Retrospective Observational Study

Background

The McIsaac criteria are a validated scoring system used to determine the likelihood of an acute sore throat being caused by group A streptococcus (GAS) to stratify patients who need strep testing.

Objective

We aim to compare McIsaac criteria obtained during face-to-face (f2f) and non-f2f encounters.

Methods

This retrospective study compared the percentage of positive GAS tests by McIsaac score for scores calculated during nurse protocol phone encounters, e-visits (electronic visits), and in person f2f clinic visits.

Results

There was no difference in percentages of positive strep tests between encounter types for any of the McIsaac scores. There were significantly more phone and e-visit encounters with any missing score components compared with f2f visits. For individual score components, there were significantly fewer e-visits missing fever and cough information compared with phone encounters and f2f encounters. F2f encounters were significantly less likely to be missing descriptions of tonsils and lymphadenopathy compared with phone and e-visit encounters. McIsaac scores of 4 had positive GAS rates of 55% to 68% across encounter types. There were 4 encounters not missing any score components with a McIsaac score of 0. None of these 4 encounters had a positive GAS test.

Conclusions

McIsaac scores of 4 collected during non-f2f care could be used to consider empiric treatment for GAS without testing if significant barriers to testing exist such as the COVID-19 pandemic or geographic barriers. Future studies should evaluate further whether non-f2f encounters with McIsaac scores of 0 can be safely excluded from GAS testing.

Prediction across healthcare settings: a case study in predicting emergency department disposition

Several approaches exist today for developing predictive models across multiple clinical sites, yet there is a lack of comparative data on their performance, especially within the context of EHR-based prediction models. We set out to provide a framework for prediction across healthcare settings. As a case study, we examined an ED disposition prediction model across three geographically and demographically diverse sites. We conducted a 1-year retrospective study, including all visits in which the outcome was either discharge-to-home or hospitalization. Four modeling approaches were compared: a ready-made model trained at one site and validated at other sites, a centralized uniform model incorporating data from all sites, multiple site-specific models, and a hybrid approach of a ready-made model re-calibrated using site-specific data. Predictions were performed using XGBoost. The study included 288,962 visits with an overall admission rate of 16.8% (7.9–26.9%). Some risk factors for admission were prominent across all sites (e.g., high-acuity triage emergency severity index score, high prior admissions rate), while others were prominent at only some sites (multiple lab tests ordered at the pediatric sites, early use of ECG at the adult site). The XGBoost model achieved its best performance using the uniform and site-specific approaches (AUC = 0.9–0.93), followed by the calibrated-model approach (AUC = 0.87–0.92), and the ready-made approach (AUC = 0.62–0.85). Our results show that site-specific customization is a key driver of predictive model performance.

Seasonal variations in use and outcome of rapid antigen detection tests and cultures in pharyngotonsillitis: a register study in primary care

BACKGROUND

Diagnosis and treatment of pharyngotonsillitis are commonly focused on group A streptococci (GAS), although the disease is often associated with other pathogens. While the incidence of pharyngotonsillitis is known to vary with season, seasonal variations in the prevalence of potential pathogens are sparsely explored. The aim of this study was to explore any seasonal variations in the use and outcome of rapid antigen detection tests (RADTs) for GAS and throat cultures among patients diagnosed with pharyngotonsillitis in primary care.

METHODS

We retrieved and combined retrospective data from the electronic medical record system and the laboratory information system in Kronoberg County, Sweden. Primary care visits resulting in a diagnosis of tonsillitis or pharyngitis were included, covering the period 2013-2016. The monthly rate of visits was measured, along with the use and outcome of RADTs for GAS and throat cultures obtained on the date of diagnosis. The variations between calendar months were then analysed.

RESULTS

We found variations between calendar months, not only in the mean rate of visits resulting in a diagnosis of pharyngotonsillitis (p < 0.001), but in the mean proportion of RADTs being positive for GAS among the diagnosed (p < 0.001), and in the mean proportion of visits associated with a throat culture (p < 0.001). A lower mean rate of visits in August and September coincided with a lower proportion of RADTs being positive for GAS among them, which correlated with a higher proportion of visits associated with a throat culture.

CONCLUSIONS

This study suggests that the role of GAS in pharyngotonsillitis in Sweden is less prominent in August and September than during the rest of the year.

The aetiology of pharyngotonsillitis in primary health care: a prospective observational study

Background

Few studies on pharyngotonsillitis have examined the clinical presentation of different aetiologies where pathogens have been detected using molecular methods. We aimed to assess how well clinical signs and symptoms can predict (1) the presence or absence of a broad range of viruses and bacteria, and (2) reconsultations for a sore throat or a complication.

Methods

In this descriptive observational prospective study in primary health care 220 patients aged 15–45 with suspected pharyngotonsillitis were sampled from nose, throat and blood and screened for 20 bacteria and viruses using polymerase chain reaction (PCR), culture and serology. Odds ratios (OR) and predictive values with 95% confidence intervals (CI) were used to show association between microbiological findings and clinical signs and symptoms. Patients were followed up after 3 months by reviewing electronic medical records.

Results

Both cough and coryza were more common in patients with only viruses (67%) than in patients with only bacteria (21%) (p < 0.001), whereas tonsillar coating was more common in patients with only bacteria (53%) than in patients with only viruses (29%) (p = 0.006). Tonsillar coating (adjusted OR 6.0; 95% CI 2.5–14) and a lack of cough (adjusted OR 3.5; 95% CI 1.5–8.0) were significantly associated with Streptococcus pyogenes (group A streptococci; GAS) and with any bacterial finding. A Centor score of 3–4 had a positive predictive value of 49% (95% CI 42–57) for GAS and 66% (95% CI 57–74) for any bacterial findings. The use of rapid antigen detection test for GAS increased the positive predictive value for this group to 93%.

Conclusions

Signs and symptoms, both single and combined, were insufficient to rule in GAS or other pathogens. However, both cough and coryza were useful to rule out GAS. The results support the clinical approach of restricting rapid antigen detection testing to patients with 3–4 Centor criteria. The low carriage rate of bacteria among asymptomatic controls implied that most detections in patients represented a true infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06665-9.

Rapid antigen detection and molecular tests for group A streptococcal infections for acute sore throat: systematic reviews and economic evaluation

BACKGROUND

Sore throat is a common condition caused by an infection of the airway. Most cases are of a viral nature; however, a number of these infections may be caused by the group A Streptococcus bacterium. Most viral and bacterial sore throat infections resolve spontaneously within a few weeks. Point-of-care testing in primary care has been recognised as an emerging technology for aiding targeted antibiotic prescribing for sore throat in cases that do not spontaneously resolve.

OBJECTIVE

Systematically review the evidence for 21 point-of-care tests for detecting group A Streptococcus bacteria and develop a de novo economic model to compare the cost-effectiveness of point-of-care tests alongside clinical scoring tools with the cost-effectiveness of clinical scoring tools alone for patients managed in primary care and hospital settings.

DATA SOURCES

Multiple electronic databases were searched from inception to March 2019. The following databases were searched in November and December 2018 and searches were updated in March 2019: MEDLINE [via OvidSP (Health First, Rockledge, FL, USA)], MEDLINE In-Process & Other Non-Indexed Citations (via OvidSP), MEDLINE Epub Ahead of Print (via OvidSP), MEDLINE Daily Update (via OvidSP), EMBASE (via OvidSP), Cochrane Database of Systematic Reviews [via Wiley Online Library (John Wiley & Sons, Inc., Hoboken, NJ, USA)], Cochrane Central Register of Controlled Trials (CENTRAL) (via Wiley Online Library), Database of Abstracts of Reviews of Effects (DARE) (via Centre for Reviews and Dissemination), Health Technology Assessment database (via the Centre for Reviews and Dissemination), Science Citation Index and Conference Proceedings [via the Web of Science™ (Clarivate Analytics, Philadelphia, PA, USA)] and the PROSPERO International Prospective Register of Systematic Reviews (via the Centre for Reviews and Dissemination).

REVIEW METHODS

Eligible studies included those of people aged ≥ 5 years presenting with sore throat symptoms, studies comparing point-of-care testing with antibiotic-prescribing decisions, studies of test accuracy and studies of cost-effectiveness. Quality assessment of eligible studies was undertaken. Meta-analysis of sensitivity and specificity was carried out for tests with sufficient data. A decision tree model estimated costs and quality-adjusted life-years from an NHS and Personal Social Services perspective.

RESULTS

The searches identified 38 studies of clinical effectiveness and three studies of cost-effectiveness. Twenty-six full-text articles and abstracts reported on the test accuracy of point-of-care tests and/or clinical scores with biological culture as a reference standard. In the population of interest (patients with Centor/McIsaac scores of ≥ 3 points or FeverPAIN scores of ≥ 4 points), point estimates were 0.829 to 0.946 for sensitivity and 0.849 to 0.991 for specificity. There was considerable heterogeneity, even for studies using the same point-of-care test, suggesting that is unlikely that any single study will have accurately captured a test's true performance. There is some randomised controlled trial evidence to suggest that the use of rapid antigen detection tests may help to reduce antibiotic-prescribing rates. Sensitivity and specificity estimates for each test in each age group and care setting combination were obtained using meta-analyses where appropriate. Any apparent differences in test accuracy may not be attributable to the tests, and may have been caused by known differences in the studies, latent characteristics or chance. Fourteen of the 21 tests reviewed were included in the economic modelling, and these tests were not cost-effective within the current National Institute for Health and Care Excellence's cost-effectiveness thresholds. Uncertainties in the cost-effectiveness estimates included model parameter inputs and assumptions that increase the cost of testing, and the penalty for antibiotic overprescriptions.

LIMITATIONS

No information was identified for the elderly population or pharmacy setting. It was not possible to identify which test is the most accurate owing to the paucity of evidence.

CONCLUSIONS

The systematic review and the cost-effectiveness models identified uncertainties around the adoption of point-of-care tests in primary and secondary care settings. Although sensitivity and specificity estimates are promising, we have little information to establish the most accurate point-of-care test. Further research is needed to understand the test accuracy of point-of-care tests in the proposed NHS pathway and in comparable settings and patient groups.

STUDY REGISTRATION

The protocol of the review is registered as PROSPERO CRD42018118653.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 31. See the NIHR Journals Library website for further project information.

A controlled human infection model of Streptococcus pyogenes pharyngitis (CHIVAS-M75): an observational, dose-finding study

BACKGROUND

Streptococcus pyogenes is a leading cause of infection-related morbidity and mortality. A reinvigorated vaccine development effort calls for new clinically relevant human S pyogenes experimental infection models to support proof of concept evaluation of candidate vaccines. We describe the initial Controlled Human Infection for Vaccination Against S pyogenes (CHIVAS-M75) study, in which we aimed to identify a dose of emm75 S pyogenes that causes acute pharyngitis in at least 60% of volunteers when applied to the pharynx by swab.

METHODS

This observational, dose-finding study was done in a clinical trials facility in Melbourne (VIC, Australia). Groups of healthy volunteers aged 18-40 years, at low risk of complicated S pyogenes disease, and without high type-specific anti-emm75 IgG antibodies against the challenge strain were challenged and closely monitored as inpatients for up to 6 days, and then as outpatients for 6 months. Antibiotics were started upon diagnosis (clinical signs and symptoms of pharyngitis and a positive rapid molecular test) or after 5 days in those without pharyngitis. Rapid test results were confirmed by standard bacterial culture. After a sentinel participant, cohorts of five and then ten participants were challenged, with protocol-directed dose-escalation or de-escalation for subsequent cohorts. The primary outcome was the proportion of participants at each dose level with pharyngitis by day 5 after challenge. The study is registered with ClinicalTrials.gov, NCT03361163.

FINDINGS

Between July 10, 2018, and Sept 23, 2019, 25 healthy adults were challenged with emm75 S pyogenes and included in analyses. Pharyngitis was diagnosed in 17 (85%; 95% CI 62-97) of 20 participants at the starting dose level (1-3 × 10⁵ colony-forming units [CFU]/mL). This high proportion prompted dose de-escalation. At the lower dose level (1-3 × 10⁴ CFU/mL), pharyngitis was diagnosed in one of five participants. Immunological, biochemical, and microbiological results supported the clinical picture, with acute symptomatic pharyngitis characterised by pharyngeal colonisation by S pyogenes accompanied by significantly elevated C-reactive protein and inflammatory cytokines (eg, interferon-γ and interleukin-6), and modest serological responses to streptolysin O and deoxyribonuclease B. There were no severe (grade 3) or serious adverse events related to challenge.

INTERPRETATION

We have established a reliable pharyngitis human infection model with reassuring early safety findings to accelerate development of vaccines and other interventions to control disease due to S pyogenes.

FUNDING

Australian National Health and Medical Research Council.

Understanding the most commonly billed diagnoses in primary care: Acute pharyngitis

ABSTRACT

This is a 12-part series on the most commonly billed diagnoses in primary care. The article discusses the pathophysiologic processes of acute pharyngitis as well as the clinical manifestations and treatments and how they are linked to disease pathogenesis.

Unnecessary Antibiotic Prescribing in US Ambulatory Care Settings, 2010-2015

The proportion of antibiotic prescriptions prescribed in US physician offices and emergency departments that were unnecessary decreased slightly, from 30% in 2010-2011 to 28% in 2014-2015. However, a greater decrease occurred in children: 32% in 2010-2011 to 19% in 2014-2015. Unnecessary prescribing in adults did not change during this period.

Patient Factors in Inappropriate Antibiotic Prescribing for Upper Respiratory Tract Infection in the Emergency Department

Background

Emergency departments (EDs) are frequently misused for non-emergency cases such as upper respiratory tract infections (URTIs). Flooding of these cases may contribute to inappropriate antibiotic prescribing. The aim of this study was to determine the patient factors associated with inappropriate antibiotic prescribing for URTIs in the EDs.

Methods

This cross-sectional study involved patients over age 3 years old who presented with URTI to the green zone of the ED of a tertiary hospital on the east coast of Malaysia in 2018-2019. Convenient sampling was done. The patients were categorised into two groups according to their McIsaac scores: positive (≥ 2) or negative (< 2). Antibiotics given to the negative McIsaac group were considered inappropriate.

Results

A total of 261 cases were included - 127 with positive and 134 with negative McIsaac scores. The most common symptoms were fever and cough. About 29% had inappropriate antibiotic prescribing with a high rate for amoxycillin. Duration of symptoms of one day or less (OR 18.5; 95% CI: 1.65, 207.10; P = 0.018), presence of chills (OR 4.36; 95% CI: 1.13, 16.88; P = 0.033) and diagnosis of acute tonsillitis (OR 5.26; 95% CI: 1.76, 15.72; P = 0.003) were significantly associated with inappropriate antibiotic prescription.

Conclusion

Factors influencing inappropriate antibiotic prescribing should be pointed out to emergency doctors to reduce its incidence.

Exploring the appropriateness of antibiotic prescribing for common respiratory tract infections in UK primary care

OBJECTIVES

To use illness severity scores to evaluate the appropriateness of antibiotic prescribing in UK general practice.

METHODS

We describe variations in practice prescribing rates, taking account of illness severity. We used three scores in three studies to measure severity: 'FeverPAIN' in an adult acute sore throat cohort (n=12 829), the '3C score' in an adult acute lower respiratory tract infection cohort (n=28 883) and the STARWAVe score in an acute cough and respiratory infection children's cohort (n=8394). We calculated median ORs to quantify practice-level variation in prescribing rates, adjusted for illness severity.

RESULTS

There was substantial variability in practice prescribing rates (ranges of 0%-97%, 7%-100% and 0%-75% in the three cohorts, respectively). There was evidence that higher prescribing practices saw a higher proportion of unwell patients. At the individual level, patients who were more unwell were more likely to receive a prescription, but prescribing levels for those with low scores were still high. The median OR was 2.5 (95% credible interval=2.2-2.9) in the sore throat data set, 2.9 (95% credible interval=2.6-3.2) in the adult cough data set and 2.1 (95% credible interval=1.8-2.4) in the children's cough data set.

CONCLUSIONS

Higher prescribing practices may see more unwell patients with high illness severity scores, but the differences in scores account for a minority of between-practice prescribing variation. There is likely to be scope for further reductions in antibiotic prescribing among patients with low illness severity scores. Further research is needed to explore the additional factors that account for variation in prescribing levels.

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.

Clinical Practice Guideline: Sore Throat

BACKGROUND

Sore throat is a common reason for consultation of primary care physicians, pediatricians, and ENT specialists. The updated German clinical practice guideline on sore throat provides evidence-based recommendations for treatment in the German healthcare system.

METHODS

Guideline revision by means of a systematic search of the literature for international guidelines and systematic reviews. All recommendations resulted from interdisciplinary cooperation and were agreed by formal consensus. The updated guideline applies to patients aged 3 years and over.

RESULTS

In the absence of red flags such as immunosuppression, severe comorbidity, or severe systemic infection, acute sore throat is predominantly self-limiting. The mean duration is 7 days. Chronic sore throat usually has noninfectious causes. Laboratory tests are not routinely necessary. Apart from non-pharmacological self-management, ibuprofen and naproxen are recommended for symptomatic treatment. Scores can be used to assess the risk of bacterial pharyngitis: one point each is assigned for tonsil lesions, palpable cervical lymph nodes, patient age, disease course, and elevated temperature. If the risk is low (<3 points), antibiotics are not indicated; if at least moderate (3 points), delayed prescribing is recommended; if high (>3 points), antibiotics can be taken immediately. Penicillin remains the first choice, with clarithromycin as an alternative for those who do not tolerate penicillin. The antibiotic should be taken for 5-7 days.

CONCLUSION

After the exclusion of red flags, antibiotic treatment is unnecessary in many cases of acute sore throat. If administration of antibiotics is still considered in spite of consultation on the usual course of tonsillopharyngitis and the low risk of complications, a risk-adapted approach using clinical scores is recommended.

Antibiotic Prescription Rates After eVisits Versus Office Visits in Primary Care: Observational Study

Background

Direct-to-consumer telemedicine is an increasingly used modality to access primary care. Previous research on assessment using synchronous virtual visits showed mixed results regarding antibiotic prescription rates, and research on assessment using asynchronous chat-based eVisits is lacking.

Objective

The goal of the research was to investigate if eVisit management of sore throat, other respiratory symptoms, or dysuria leads to higher rates of antibiotic prescription compared with usual management using physical office visits.

Methods

Data from 3847 eVisits and 759 office visits for sore throat, dysuria, or respiratory symptoms were acquired from a large private health care provider in Sweden. Data were analyzed to compare antibiotic prescription rates within 3 days, antibiotic type, and diagnoses made. For a subset of sore throat visits (n=160 eVisits, n=125 office visits), Centor criteria data were manually extracted and validated.

Results

Antibiotic prescription rates were lower following eVisits compared with office visits for sore throat (169/798, 21.2%, vs 124/312, 39.7%; P<.001) and respiratory symptoms (27/1724, 1.6%, vs 50/251, 19.9%; P<.001), while no significant differences were noted comparing eVisits to office visits for dysuria (1016/1325, 76.7%, vs 143/196, 73.0%; P=.25). Guideline-recommended antibiotics were prescribed similarly following sore throat eVisits and office visits (163/169, 96.4%, vs 117/124, 94.4%; P=.39). eVisits for respiratory symptoms and dysuria were more often prescribed guideline-recommended antibiotics (26/27, 96.3%, vs 37/50, 74.0%; P=.02 and 1009/1016, 99.3%, vs 135/143, 94.4%; P<.001, respectively). Odds ratios of antibiotic prescription following office visits compared with eVisits after adjusting for age and differences in set diagnoses were 2.94 (95% CI 1.99-4.33), 11.57 (95% CI 5.50-24.32), 1.01 (95% CI 0.66-1.53), for sore throat, respiratory symptoms, and dysuria, respectively.

Conclusions

The use of asynchronous eVisits for the management of sore throat, dysuria, and respiratory symptoms is not associated with an inherent overprescription of antibiotics compared with office visits.

Trial Registration

ClinicalTrials.gov NCT03474887; https://clinicaltrials.gov/ct2/show/NCT03474887

Using a clinical prediction rule to prioritize diagnostic testing leads to reduced transmission and hospital burden: A modeling example of early SARS-CoV-2

BACKGROUND

Prompt identification of infections is critical for slowing the spread of infectious diseases. However, diagnostic testing shortages are common in emerging diseases, low resource settings, and during outbreaks. This forces difficult decisions regarding who receives a test, often without knowing the implications of those decisions on population-level transmission dynamics. Clinical prediction rules (CPRs) are commonly used tools to guide clinical decisions.

METHODS

Using early SARS-CoV-2 as an example, we used data from electronic health records to develop a parsimonious 5-variable CPR to identify those who are most likely to test positive. To consider the implications of gains in daily case detection at the population level, we incorporated testing using the CPR into a compartmentalized model of SARS-CoV-2.

RESULTS

We found that applying this CPR (AUC: 0.69 (95% CI: 0.68 - 0.70)) to prioritize testing increased the proportion of those testing positive in settings of limited testing capacity. We found that prioritized testing led to a delayed and lowered infection peak (i.e., "flattens the curve"), with the greatest impact at lower values of the effective reproductive number (such as with concurrent community mitigation efforts), and when higher proportions of infectious persons seek testing. Additionally, prioritized testing resulted in reductions in overall infections as well as hospital and intensive care unit (ICU) burden.

CONCLUSION

We highlight the population-level benefits of evidence-based allocation of limited diagnostic capacity.

McIsaac score for group A streptococcal infection: Comparison of electronic visits versus face-to-face visits

INTRODUCTION

Acute sore throat is a common complaint traditionally completed with an in-person visit. However, non-face-to-face telemedicine visits offer greater access at reduced cost. We evaluated patient/caregiver asynchronous text-based electronic visits (eVisits) for acute sore throat and whether there was concordance for individual components and total McIsaac score compared to a clinician's assessment. eVisits were completed by patients and/or their caregivers via a secure patient portal.

METHODS

In this retrospective study, we manually reviewed charts between February 2017 and July 2019 of patients who had an eVisit, in-person visit and group A streptococcal (GAS) test performed on the same day for an acute sore throat. We calculated a McIsaac score for eVisits and in-person visits, and compared each component and total score using Cohen's kappa agreement statistic.

RESULTS

There were 320 instances of patients who had an eVisit, in-person visit and GAS testing done on the same day. Approximately a third of eVisits were missing at least one McIsaac component, with the physical examination elements missing most commonly. Individual score congruence was moderate for cough (0.41), fair for fever (0.34) and slight for tonsillar swelling/exudate and lymphadenopathy (0.17 and 0.08, respectively), with total congruence being slight to fair (0.09-0.37). A McIsaac score of ≤1 showed moderate agreement (0.44). Visits with complete individual score components demonstrated improved congruence: substantial for cough (0.64), moderate for fever (0.57), fair for tonsillar swelling (0.3) and slight for lymphadenopathy (0.13).

DISCUSSION

Overall agreement for individual score components was better for symptoms than it was for examination components, and was improved when data were complete. A McIsaac score of 1 or 0 had moderate agreement and thus could reasonably be safely used to exclude patients from GAS testing.

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.

Diagnostic Methods, Clinical Guidelines, and Antibiotic Treatment for Group A Streptococcal Pharyngitis: A Narrative Review

The most common bacterial cause of pharyngitis is infection by Group A β-hemolytic streptococcus (GABHS), commonly known as strep throat. 5-15% of adults and 15-35% of children in the United States with pharyngitis have a GABHS infection. The symptoms of GABHS overlap with non-GABHS and viral causes of acute pharyngitis, complicating the problem of diagnosis. A careful physical examination and patient history is the starting point for diagnosing GABHS. After a physical examination and patient history is completed, five types of diagnostic methods can be used to ascertain the presence of a GABHS infection: clinical scoring systems, rapid antigen detection tests, throat culture, nucleic acid amplification tests, and machine learning and artificial intelligence. Clinical guidelines developed by professional associations can help medical professionals choose among available techniques to diagnose strep throat. However, guidelines for diagnosing GABHS created by the American and European professional associations vary significantly, and there is substantial evidence that most physicians do not follow any published guidelines. Treatment for GABHS using analgesics, antipyretics, and antibiotics seeks to provide symptom relief, shorten the duration of illness, prevent nonsuppurative and suppurative complications, and decrease the risk of contagion, while minimizing the unnecessary use of antibiotics. There is broad agreement that antibiotics with narrow spectrums of activity are appropriate for treating strep throat. But whether and when patients should be treated with antibiotics for GABHS remains a controversial question. There is no clearly superior management strategy for strep throat, as significant controversy exists regarding the best methods to diagnose GABHS and under what conditions antibiotics should be prescribed.

Improving the prediction of streptococcal pharyngitis; time to move past exudate alone

BACKGROUND

Palatal petechiae are predictive of Group A streptococcal (GAS) pharyngitis. We sought to (a) quantify the value of considering petechiae in addition to exudate, and (b) assess provider incorporation of petechiae's predictive nature for GAS into clinical decision making.

METHODS

We conducted a cross-sectional study of patients 3-21 years with sore throat and GAS testing performed in a pediatric emergency department (ED) in 2016. Patients were excluded if immunosuppressed, nonverbal, medically complex, had chronic tonsillitis, or received antibiotics in the preceding week. As a proxy of provider incorporation of petechiae into clinical decision making we assessed how often petechiae were documented, compared with exudate. We performed univariate analysis using χ² analysis for categorical data and Mann-Whitney U test for continuous data.

RESULTS

1574 patients met inclusion criteria. Median age 8 years [IQR 5, 13]; 54% female. 372 patients (24%) were GAS positive. Both palatal petechiae and tonsillar exudates were predictive of GAS [OR 8.5 (95% CI 5.2-13.9), and 1.9 (95% CI 1.4-2.6) respectively]. Examining petechiae or exudate vs. exudate alone increases OR from 1.9 to 2.9 (95% CI 2.2-3.8). Sensitivity improves (23% to 34%) with minimal change to specificity (87% to 85%). Among those with a normal or erythematous throat exam, petechiae were mentioned as a pertinent negative in 28%; absence of tonsillar exudate was mentioned in 78% (p = .02).

CONCLUSIONS

Palatal petechiae are highly associated with GAS, yet rarely addressed in documentation. Incorporating palatal petechiae into common scoring systems could improve prediction and disseminate this knowledge into practice.

Emergency Department Prescribing Patterns for Pharyngitis in Children

Pharyngitis is commonly diagnosed in the emergency department (ED) and accounts for substantial antibiotic burden in pediatrics. This study describes ED patterns of group A streptococcal (GAS) pharyngitis diagnosis and antibiotic prescribing patterns. This was a secondary data analysis of the National Hospital Ambulatory Medical Care Survey. Diagnosis and antibiotic treatment for GAS and non-GAS (viral) pharyngitis were reported in all ages and specifically examined in children <3 years of age from 2010 to 2015. GAS pharyngitis was diagnosed in 29% of visits for children with pharyngitis; however, 60% of patients with any pharyngitis received antibiotics. Twenty percent of children <3 years were diagnosed with GAS pharyngitis, yet over half were given antibiotics. Broad-spectrum antibiotics were commonly prescribed. Antibiotic treatment of pharyngitis, including broad-spectrum antibiotics, remains high when compared with the known prevalence of GAS pharyngitis. Diagnosis and treatment of GAS pharyngitis in patients <3 years persists despite recommendations against testing.

Extracellular bacterial lymphatic metastasis drives Streptococcus pyogenes systemic infection

Unassisted metastasis through the lymphatic system is a mechanism of dissemination thus far ascribed only to cancer cells. Here, we report that Streptococcus pyogenes also hijack lymphatic vessels to escape a local infection site, transiting through sequential lymph nodes and efferent lymphatic vessels to enter the bloodstream. Contrasting with previously reported mechanisms of intracellular pathogen carriage by phagocytes, we show S. pyogenes remain extracellular during transit, first in afferent and then efferent lymphatics that carry the bacteria through successive draining lymph nodes. We identify streptococcal virulence mechanisms important for bacterial lymphatic dissemination and show that metastatic streptococci within infected lymph nodes resist and subvert clearance by phagocytes, enabling replication that can seed intense bloodstream infection. The findings establish the lymphatic system as both a survival niche and conduit to the bloodstream for S. pyogenes, explaining the phenomenon of occult bacteraemia. This work provides new perspectives in streptococcal pathogenesis with implications for immunity.

Pathogenic agents can spread from an initial to a secondary site via the lymphatics. Here, using a mouse model of infection, the authors show that S. pyogenes readily transit through sequential lymph nodes within efferent lymphatics to reach the bloodstream and drive systemic infection, while remaining extracellular.

Three sequential outbreaks of Group A Streptococcus over a two-year period at the Canadian Forces Leadership and Recruit School, St. Jean Garrison, Québec

Background

Since December 2016, the basic military training (BMT) facility for the Canadian Armed Forces (CAF) has experienced repeated outbreaks of Group A Streptococcus (GAS). In 2018, a voluntary mass antibiotic prophylaxis (MAP) program was implemented to interrupt GAS transmission among recruits. The objective of this study was to describe the epidemiology of three GAS outbreaks and a period of increased pharyngitis infections at the CAF BMT facility in Québec over a two-year span, and to detail the prevention and control measures implemented to mitigate the risk to recruit health.

Methods

Descriptive data were collected on invasive and severe GAS cases along with laboratory data including genotyping of throat swabs from recruits presenting with pharyngitis. A laboratory-based acute respiratory infection surveillance system was used to aid in monitoring and decision-making. Close contacts of recruits were assessed for asymptomatic GAS carriage and MAP adverse events surveillance was conducted.

Results

Three distinct GAS outbreaks occurred at the Canadian Forces Leadership and Recruit School totaling eight invasive (iGAS) and 13 severe (sGAS) cases over two years. All iGAS/sGAS cases, apart from one instructor, were among recruits. The predominant strain in all three outbreaks was type emm6.4. A total of 11,293 recruits received MAP (penicillin G benzathine or azithromycin) between March 7, 2018 and November 18, 2019. There were eight reported serious adverse events related to penicillin administration.

Conclusion

The CAF BMT facility experienced three GAS outbreaks over the course of two years, and despite the use of enhanced hygiene measures, only MAP has been effective in quelling these outbreaks.