Evaluating the Diagnostic Paradigm for Group A and Non–Group A Streptococcal Pharyngitis in the College Student Population

Background Acute pharyngitis is a frequent illness presenting in outpatient settings. Antibiotics are only recommended for bacterial pharyngitis caused by group A β-hemolytic streptococci (GAS); however, infections with non–group A β-hemolytic streptococci (NGAS) have similar clinical presentations and are common in young adult populations. The objective of this study was to analyze the performance of a current (expert) diagnostic algorithm for GAS pharyngitis, the Centor score, and compare it to alternative models developed to predict GAS and NGAS in a college student population. Methods Electronic health records were obtained for all patients who received a streptococcal rapid antigen detection test (RADT) and/or a bacterial throat culture (n = 3963) at a southeastern US university in 2014. Bivariate and multivariable regression models (least absolute shrinkage and selection operator [LASSO] and stepwise-selected) were fitted to assess and compare their diagnostic performances for GAS-positive and NGAS-positive infections. Results Prevalence of GAS was 18.8%. In the subset of RADT-negative patients who received bacterial throat cultures (n = 313), growth of NGAS occurred in 34.8%, with group C streptococci the most frequent isolate. Mean Centor score was higher for NGAS (3.2) vs GAS (2.9) infections (P = .0111). The area under the curve (AUC) for GAS prediction was 0.64 using the Centor score and 0.70 using the LASSO model. For NGAS, the most important features were cough, pharyngeal erythema, tonsillar exudate, and gastrointestinal symptoms (AUC = 0.63). Conclusions GAS and NGAS pharyngitis were indistinguishable among college students in this study utilizing a commonly applied decision score. Alternative models using additional clinical criteria may be useful for supporting diagnosis of this common illness.

Positive Rate of Tests for Group a Streptococcus and Viral Features in Children with Acute Pharyngitis

Group A streptococcus (GAS) is an important cause of acute pharyngitis. We investigated the positive rate of GAS tests and clinical viral features in children with acute pharyngitis. A retrospective review was conducted for patients <15 years old with both rapid antigen detection test (RADT) and throat culture results. Patients were excluded if they were diagnosed with influenza or had received antibiotics within two weeks before these tests. A total of 377 patients were eligible. The median age of patients was 3.5 years, and 45.4% of total patients were <3 years old. Among all patients, 68.7% had at least one viral feature, and 39% had more than two. The overall positiv rate for GAS was 11.4%. The GAS positive rate was significantly lower in patients <3 years old than in older patients (1.8% vs. 19.4%, p < 0.0001). The overall sensitivity and specificity of RADT were 75.0% (95% CI: 57.8–87.9) and 97.9% (95% CI: 95.8–99.2), respectively. The GAS positive rate was not significantly different between patients with and without viral features (12.4% vs. 9.3%, p = 0.4854). In patients aged 3–14 years, the GAS positive rate was not associated with the modified Centor score or the frequency of clinical viral features. Despite a low prevalence of GAS pharyngitis, testing for GAS was frequently performed in children <3 years old in this study. Appropriate use of laboratory testing for GAS pharyngitis and judicious prescription of antibiotics were imperative.

Trends in the use of antibiotics for pharyngitis in Saudi Arabia

Introduction: Pharyngitis is one of the most common diagnoses for antibiotic prescriptions worldwide. Antibiotics should be prescribed for bacterial pharyngitis to reduce its complications. The aims of this study were to assess antibiotic prescriptions for pharyngitis cases, and their relationship with physicians’ knowledge regarding its diagnosis and management. Methodology: A cross-sectional study was conducted. First, prescriptions for pharyngitis cases using the modified Centor criteria was evaluated at primary care centers in Saudi Arabia. Second, physicians’ knowledge of the modified Centor score and the diagnosis and management of pharyngitis was assessed using a self-administered questionnaire. Results: Out of 104 pharyngitis cases, 79% (n = 82) were prescribed antibiotics, of which 28% were evidence-based prescriptions. First-line antibiotics were prescribed in 34% of patients, and second-line (broad-spectrum) antibiotics such as amoxicillin/clavulanate were prescribed in half of the patients. The main significant predictors of antibiotic prescriptions were age < 3 years (odds ratio, 0.13; 95% CI, 0.02 to 0.97), tonsillar exudate (odds ratio, 21.14; 95% CI, 2.88 to 155.09), and throat erythema (odds ratio, 9.30; 95% CI, 1.18 to 73.41). Overall, physicians (n = 29) had adequate knowledge about the modified Centor score and the management of pharyngitis. Conclusions: Most prescribed antibiotics for pharyngitis were unnecessarily prescribed; the majority being broad-spectrum antibiotics. Despite physicians’ adequate knowledge of the modified Centor score and the management of pharyngitis, their practice failed to demonstrate that. Induction of the Saudi Antimicrobial Stewardship Program in the primary care centers, accessibility to diagnostic tools, and educational programs may help in reducing unnecessary antibiotic prescriptions.

Rapid Antigen Detection Test Using Rates of Family Physicians, Test Results and Its Impact on Their Prescription Behaviours

Aim: The aim of this study is to determine the rates of rapid antigen detection test use, test results and its relationship with Modified Centor Score and investigate the effect of rapid antigen detection test use on prescribing behaviour. Methods: This research was conducted by scanning the family physicians’ information system retrospectively. From the Family Medicine Information System, where polyclinics and prescription records of the family health centers where 12 family physicians work in Kayseri are located, the number and results of rapid antigen detection tests performed between February 2017 and April 2019, the Modified Centor Score automatically calculated by the system, the number of prescribed antibiotics and symptomatic treatment information was recorded. Results: The positivity of rapid antigen detection test was considered, cut-off value of Modified Centor Score was >2 (ROC EAA:63.9, Cl:0.95,0.61-0.66). Sensitivity rate of the test for diagnostic score was 86% and selectivity rate was 48.8%. Conclusion: Family physicians should be encouraged to use rapid antigen detection test. The fact that antibiotics are prescribed in rapid antigen detection testnegative patients may indicate that confidence level of the test is less than physical examination and clinical findings. Keywords: sore throat, primary care, score

Nasopharyngeal Isolates from a Cohort of Medical Students with or without Pharyngitis

Objectives: Few studies have investigated pharyngeal colonisation in the United Arab Emirates (UAE). This study aims to identify the pharyngeal organisms present in a cohort of medical students with and without symptomatic pharyngitis. Methods: This study was conducted between September 2016 and June 2018 at the College of Medicine and Health Sciences, UAE University, Al-Ain. Nasopharyngeal swabs were collected from preclinical and clinical medical students attending the college during the study period. The specimens were tested for 16 viral and nine bacterial pathogens using a real-time polymerase chain reaction assay. Results: A total of 352 nasopharyngeal swabs were collected from 287 students; of these, 22 (7.7%) had pharyngitis symptoms. Overall, the most common isolates were human rhinovirus, Streptococcus pneumoniae and Haemophilus influenzae, with no significant differences in terms of gender, year of study or stage of study. The prevalence of S. pyogenes in asymptomatic and symptomatic students was 1.1% and 0%, respectively. A Centor score of ≥2 was not associated with S. pyogenes-positive samples. Six pathogens were isolated from symptomatic students including H. influenzae. Fusobacterium necrophorum was not detected in any of the samples. Conclusion: The diagnosis and management of pharyngitis should be tailored to common pathogens in the region. This study found that S. pyogenes and F. necrophorum were not detected among students with symptoms of pharyngitis; moreover, Centor scores of ≥2 were not associated with the presence of S. pyogenes. This cut-off score therefore should not be employed as an empirical measure to initiate penicillin therapy in this population.Keywords: Pharyngitis; Pharynx; Asymptomatic Infections; Carrier State; Fusobacterium necrophorum; Streptococcus pyogenes; Penicillins; United Arab Emirates.

P028: Antibiotic prescribing and use of corticosteroids for the emergency department management of acute pharyngitis

Introduction: Acute pharyngitis is a common emergency department (ED) presentation. The Centor (Modified/McIsaac) score uses five criteria (age, tonsillar exudates, swollen tender anterior cervical nodes, absence of a cough, and history of fever) to predict Group A Streptococcus (GAS) infection. The recommendation is patients with a Centor score of 0-1 should not undergo testing and should not be given antibiotics, patients with a score of 2-3 may warrant throat cultures, and for patients with a score ≥ 4, empiric antibiotics may be appropriate. Associated pain is often first managed with acetaminophen or non-steroidal anti-inflammatory drugs, however recent evidence suggests a short course of low-to-moderate dose corticosteroids as adjunctive therapy may reduce inflammation and provide pain relief. The objective of this study was to describe the ED management of acute pharyngitis for adult patients presenting to an academic ED over a two-year study period. Methods: This was a retrospective chart review of all adult (> 17 years) patients presenting to Mount Sinai Hospital ED with a discharge diagnosis of acute pharyngitis (ICD-10 code J02.9) from January 1st 2016 to December 31st 2018. Trained research personnel reviewed medical records and extracted data using a computerized, data abstraction form. Results: Of the 638 patients included in the study, 286 (44.8%) had a Centor score of 0-1, 328 (51.4%) had a score of 2-3, and 24 (3.8%) had a score of ≥ 4. Of those with a Centor score of 0-1, 83 (29.0%) had a throat culture, 88 (30.8%) were prescribed antibiotics, 15 (5.2%) were positive for GAS and 74 (25.9%) were given corticosteroids in the ED or at discharge. Of those with a Centor score of 2-3, 156 (47.6%) had a throat culture, 220 (67.1%) were prescribed antibiotics, 44 (13.4%) were positive for GAS, and 145 (44.2%) were given corticosteroids. Of those with a Centor score ≥ 4, 14 (58.3%) had a throat culture, 18 (75.0%) were prescribed antibiotics, 7 (29.2%) were positive for GAS and 12 (50.0%) were given corticosteroids. Conclusion: As predicted, a higher Centor score was associated with higher risk of GAS infection, increased antibiotic prescribing and use of corticosteroids. Many patients with low Centor scores were prescribed antibiotics and also had throat cultures. Further work is required to understand clinical decision making for the management of acute pharyngitis.