Group A Streptococcus Pharyngitis Research Articles

Eliminate all risks: A call to reexamine the link between canine scabies and rheumatic heart disease.

Rheumatic heart disease (RHD) and acute rheumatic fever (ARF) disproportionately affect individuals in low-resource settings. ARF is attributed to an immune response to Group A Streptococcus (GAS) following GAS pharyngitis and potentially GAS impetigo in which infection can be initiated by scabies infestation. The burden of ARF and RHD in Aboriginal and Torres Strait Islander people in Australia is among the highest globally. Following recent calls to include dog management programs in ARF and RHD prevention programs, we believe it is timely to assess the evidence for this, particularly since previous recommendations excluded resources to prevent zoonotic canine scabies. While phylogenetic analyses have suggested that the Sarcoptes mite is host specific, they have differed in interpretation of the strength of their findings regarding species cross-over and the need for canine scabies control to prevent human itch. Given that there is also indication from case reports that canine scabies leads to human itch, we propose that further investigation of the potential burden of zoonotic canine scabies and intervention trials of canine scabies prevention on the incidence of impetigo are warranted. Considering the devastating impacts of ARF and RHD, evidence is required to support policy to eliminate all risk factors.

Reduction in Acute Post-Streptococcal Glomerulonephritis Incidence in Counties Manukau, New Zealand, after the COVID-19 Pandemic.

The COVID-19 pandemic has altered the epidemiology of many common childhood infections, including Group A streptococcal (GAS) disease. Acute post-streptococcal glomerulonephritis (APSGN) is a nonsuppurative complication of GAS pharyngitis and pyoderma. It remains the most common cause of pediatric acute glomerulonephritis globally. In Counties Manukau, New Zealand, APSGN rates have previously been shown to be the highest in the country, with marked ethnic and socioeconomic disparities. We performed a retrospective review of children aged 0-14 years who were discharged from Kidz First Hospital, Counties Manukau, between 2015 and 2023 and met the Strep A Vaccine Global Consortium consensus definition of APSGN. We describe a marked, sustained reduction in APSGN hospitalizations, temporally associated with the COVID-19 pandemic. This ongoing reduction in APSGN incidence is notable in light of contrasting reports of increasing incidence of rheumatic fever in New Zealand and invasive GAS disease internationally.

Tonsils at Telethon: developing a standardised collection of tonsil photographs for group A streptococcal (GAS) research.

Group A streptococcus (GAS) infections, such as pharyngitis and impetigo, can lead to rheumatic fever and rheumatic heart disease (RHD). Australian Aboriginal and Torres Strait Islander populations experience high rates of RHD and GAS skin infection, yet rates of GAS pharyngitis are unclear. Anecdotally, clinical presentations of pharyngitis, including tonsillar hypertrophy and sore throat, are uncommon. This study aimed to develop a standardised set of tonsil photographs and determine tonsil size distribution from an urban paediatric population. A prospective cohort of children aged 3-15 years were recruited at the public events "Discover Day" and "Telethon Weekend" (October 2017) in Perth, Western Australia, Australia. Tonsil photographs, symptomatology, and GAS rapid antigen detection tests (RADT) were collected. Tonsil size was graded from the photographs using the Brodsky Grading Scale of tonsillar hypertrophy (Brodsky) by two independent clinicians, and inter-rater reliability calculated. Pharyngitis symptoms and GAS RADT were correlated, and immediate results provided. Four hundred and twenty-six healthy children participated in the study over three days. The median age was seven years [interquartile range (IQR) 5.9-9.7 years]. Tonsil photographs were collected for 92% of participants, of which 62% were rated as good-quality photographs and 79% were deemed of adequate quality for assessment by both clinicians. When scored by two independent clinicians, 57% received the same grade. Average Brodsky grades (between clinicians) were 11%, 35%, 28%, 22% and 5% of grades 0,1,2,3 and 4, respectively. There was moderate agreement in grading using photographs, and minimal to weak agreement for signs of infection. Of 394 participants, 8% reported a sore throat. Of 334 GAS RADT performed, <1% were positive. We report the first standardised use of paediatric tonsil photographs to assess tonsil size in urban-living Australian children. This provides a proof of concept from an urban-living cohort that could be compared with children in other settings with high risk of GAS pharyngitis or rheumatic fever such as remote-living Australian Indigenous populations.

Group A Streptococcus pyogenes in wastewater: Applicability of wastewater-based epidemiology for monitoring the prevalence of GAS pharyngitis during the late COVID-19 pandemic phase

Streptococcus pyogenes, Group A Streptococcus (GAS), is a human pathogen that causes a spectrum of diseases from mild to severe, including GAS pharyngitis, a common acute respiratory disease in developed countries. Although wastewater-based epidemiology (WBE) has been extensively used to monitor viral pathogens such as severe acute respiratory syndrome coronavirus 2, its applicability to S. pyogenes remains unexplored. This study was conducted to investigate the feasibility of detecting and quantifying S. pyogenes in wastewater by quantitative polymerase chain reaction (qPCR) and evaluate the applicability of WBE for monitoring the prevalence of GAS pharyngitis. A total of 52 grab influent samples were collected from a wastewater treatment plant in Japan once a week between March 2023 and February 2024. The samples were centrifuged, followed by nucleic acid extraction and qPCR for the S. pyogenes-specific genes speB and spy1258. Of the 52 samples, 90 % and 81 % were positive for speB and spy1258 genes, respectively, indicating the feasibility of S. pyogenes for wastewater surveillance. However, the percentage of quantifiable samples for speB gene was significantly higher in winter than in spring and summer. Similarly, the concentrations of both genes in wastewater samples were significantly higher in winter (speB, 4.1 ± 0.27 log10 copies/L; spy1258, 4.1 ± 0.28 log10 copies/L; One-way ANOVA, p < 0.01) than in spring and summer. Higher concentrations and detection ratios of S. pyogenes genes were observed during increased GAS pharyngitis cases in the catchment. Significant moderate correlations were observed between target gene concentrations and reported GAS pharyngitis cases. This study enhances the understanding role of WBE in monitoring and managing infectious diseases within communities.

Determination of the upper limit of normal for serum anti-streptolysin-O titre in primary school children in Southern Nigeria; A model for other low resource settings

The prevention and treatment of Rheumatic Heart disease is hinged on antibiotic administration in children with Group A Streptococcal (GAS) pharyngitis and Acute Rheumatic Fever (ARF). The Upper Limit of Normal (ULN) for serum Anti-streptolysin O titre (ASOT) has been employed as proof of antecedent GAS pharyngitis to fulfil the Jones’ criteria for diagnosis of ARF. This value has not been generated among West African children. Generalization of values from Caucasians (200 IU/ml) is likely to result in over-diagnosis, owing to higher GAS pharyngitis incidence in Africa. We aimed to determine the serum ASOT and its ULN in apparently healthy school-aged children in Egor Local Government Area (LGA), south-south Nigeria and to determine their relationship with socio-demographic characteristics.We recruited 384 apparently healthy school-aged pupils across eleven schools. Serum ASOT was determined by turbidimetry. Statistical analysis was done using student's t-test and Analysis of Variance (ANOVA). Level of significance was set at p < 0.05.The mean age was 8.53 ± 1.97(range 6–12) years and male-female ratio was 1.1:1. The ULN and geometric mean serum ASOT were 390.76 IU/ml and 230.04 ± 1.86 IU/ml respectively. No significant correlation was found between serum ASOT and age (r-value of −4.8%). The ULN did not vary significantly with gender, socio-economic class and the presence/absence of over-crowding in homes. The ULN for serum ASOT in apparently healthy school-aged children in Egor LGA is higher than the currently used international value. Clinicians in West Africa should consider applying higher cut-off values for the diagnosis of ARF.

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

To compare clinical and health systems outcomes of rapid molecular testing versus throat culture recovery for the management of group A Streptococcus (GAS) pharyngitis in a pediatric emergency department (PED). We conducted a single-center randomized trial of children (3-17 years) presenting to a PED with suspected GAS pharyngitis. A single dual-headed throat swab was collected, and participants were randomized to 1 of 2 parallel treatment groups with 1:1 allocation: point-of-care (POC) nucleic acid amplification testing or standard throat culture. The primary outcomes were time to throat pain +/- fever resolution. Secondary outcomes included absenteeism, length of stay, return visits to care, and antibiotic prescriptions and utilization. A total of 227 children were randomly assigned to culture (n = 115) or POC (n = 112) testing. Antibiotics were initiated earlier in the POC group by approximately 1 day (95% confidence interval, -0.40 to -1.58). No associated difference in time to throat pain or fever resolution was observed between groups. There was a decrease in the proportion of prescribed antibiotics in the POC group (0.35) compared with the culture group (0.79; P < 0.001). Otherwise, no significant differences in secondary outcomes were observed. Establishing a POC nucleic acid amplification testing program for GAS in a PED facilitates earlier treatment and fewer antibiotic prescriptions. Although this did not translate to improved clinical and health systems outcomes in our study, it may serve as an important tool amid evolving pediatric febrile illnesses and growing antimicrobial resistance patterns.

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.

Group A Streptococcus pharyngitis in Children: New Perspectives on Rapid Diagnostic Testing and Antimicrobial Stewardship.

The most common cause of bacterial pharyngitis is Group A Streptococcus (GAS). Accurate diagnosis of GAS pharyngitis is crucial to identify children who would benefit from antibiotic treatment. Rapid diagnosis has the potential to reduce antibiotic overuse. Current national guidelines differ in their recommendations for GAS testing. While rapid antigen detection tests (RADTs) are widely used, their sensitivity is considered too low for stand-alone testing by several expert bodies. Newer molecular tests using nucleic acid amplification show higher accuracy and fast results, but their cost, complexity, and very high sensitivity may limit widespread adoption. This review provides up-to-date evidence regarding rapid diagnostic testing and antimicrobial stewardship in children with sore throat. We discuss discrepancies across GAS testing guidelines at the international level, patient selection for testing for GAS, rapid test accuracy, and the potential role of rapid GAS tests to promote antibiotic stewardship, with emphasis on emerging rapid molecular tests.

Preadmission course and management of severe pediatric group A streptococcal infections during the 2022-2023 outbreak: a single-center experience.

The massive increase of infections with Group A Streptococcus (GAS) in 2022-2023 coincided in Switzerland with a change of the recommendations for the management of GAS pharyngitis. Therefore, the objective of the present study was to investigate whether the clinical manifestations and management before hospitalization for GAS infection differed in 2022-2023 compared with 2013-2022. Retrospective study of GAS infections requiring hospitalization in patients below 16years. Preadmission illness (modified McIsaac score), oral antibiotic use, and outcome in 2022-2023 were compared with 2013-2022. Time series were compared with surveillance data for respiratory viruses. In 2022-2023, the median modified McIsaac score was lower (2 [IQR 2-3] vs. 3 [IQR 2-4], p = < 0.0001) and the duration of preadmission illness was longer (4days [3-7] vs. 3 [2-6], p = 0.004) than in 2013-2022. In both periods, withholding of preadmission oral antibiotics despite a modified McIsaac score ≥ 3 (12% vs. 18%, n.s.) or ≥ 4 (2.4% vs. 10.0%, p = 0.027) was rare. Respiratory disease, skeletal/muscle infection, and invasive GAS disease were significantly more frequent in 2022-2023, but there were no differences in clinical outcome. The time course of GAS cases in 2022-2023 coincided with the activity of influenza A/B. We found no evidence supporting the hypothesis that the 2022-2023 GAS outbreak was associated with a change in preadmission management possibly induced by the new recommendation for GAS pharyngitis. However, clinical manifestations before admission and comparative examination of time-series strongly suggest that viral co-circulation played an important role in this outbreak.

Spatiotemporal Trends in Group A Streptococcal Pharyngitis in the United States.

Group A Streptococcus (GAS) causes an estimated 5.2 million outpatient visits for pharyngitis annually in the United States, with incidence peaking in winter, but the annual spatiotemporal pattern of GAS pharyngitis across the United States is poorly characterized. We used outpatient claims data from individuals with private medical insurance between 2010 and 2018 to quantify GAS pharyngitis visit rates across U.S. census regions, subregions, and states. We evaluated seasonal and age-based patterns of geographic spread and the association between school start dates and the summertime upward inflection in GAS visits. The South had the most visits per person (yearly average, 39.11 visits per 1000 people; 95% confidence interval, 36.21-42.01) and the West had the fewest (yearly average, 17.63 visits per 1000 people; 95% confidence interval, 16.76-18.49). Visits increased earliest in the South and in school-age children. Differences in visits between the South and other regions were most pronounced in the late summer through early winter. Visits peaked earliest in central southern states, in December to January, and latest on the coasts, in March. The onset of the rise in GAS pharyngitis visits correlated with, but preceded, average school start times. The burden and timing of GAS pharyngitis varied across the continental United States, with the South experiencing the highest overall rates and earliest onset and peak in outpatient visits. Understanding the drivers of these regional differences in GAS pharyngitis will help in identifying and targeting prevention measures.

Common Bacterial Infections during the 3-Month Period after SARS-CoV-2 Infection: A Retrospective Cohort Study.

Correlations between SARS-CoV-2 and bacterial infections have mainly been studied in hospitals, and these studies have shown that such interactions may be lethal for many. In the context of community flora, less is known of the trends and consequences of viral infections relative to subsequent bacterial infections. This study aims to explore the prevalence and characteristics of bacterial infections in the three months following SARS-CoV-2 infections, in a community, real-world setting. In this retrospective cohort study, we compared patients who completed a polymerase chain reaction (PCR) test or an antigen test for SARS-CoV-2 during January 2022, the peak of the Omicron wave, and examined bacterial infections following the test. We searched these cases for diagnoses of the following four bacterial infections for three months following the test: Group A Streptococcus (GAS) pharyngitis, pneumonia, cellulitis, and urinary tract infections (UTI). During January 2022, 267,931 patients tested positive and 261,909 tested negative for SARS-CoV-2. Test-positive compared to test-negative patients were significantly younger (42.5 years old vs. 48.5 years old, p < 0.001), smoked less, and had fewer comorbidities (including ischemic heart disease, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, and chronic renal failure). In the multivariable analysis, test-positive patients had an increased risk for GAS pharyngitis (adjusted odds ratio [aOR] = 1.25, 95% CI 1.14-1.38, p-value < 0.001) and pneumonia (aOR = 1.25, 95% CI 1.15-1.35, p-value < 0.001), a trend towards an increased prevalence of UTI (aOR = 1.05, 95% CI 0.99-1.12, p-value = 0.092), and lower risk for cellulitis (aOR = 0.92, 95% CI 0.86-0.99, p-value < 0.05). A history of SARS-CoV-2 infection in the past three months increased susceptibility to respiratory tract bacterial infections and the prevalence of UTI.

Utility of rapid antigen detection test in group A ß-haemolytic streptococcal pharyngitis at a tertiary hospital, Gombe, North-East, Nigeria

Background: Throat swab cultures still remain the gold standard for the confirmation of Group A Streptococcal (GAS) pharyngitis but Rapid Antigen detection Test (RADT) are increasingly becoming popular. Recent studies show RADT can be as sensitive and specific as the throat swab culture. This study aimed to determine the utility of RADT in the diagnosis of GAS pharyngitis in children at the Federal Teaching Hospital Gombe. Methods: A cross-sectional study that included 324 children aged 3- 18 years presenting with sore throat at the out-patient department, consecutively recruited between April and September 2018. Socio-demographic and clinical findings were document. Throat swab samples were taken for RADT using Encode strep A Rapid antigen test and culture on 5% sheep blood agar. The sensitivity, specificity and positive and negative predictive values of the RADT was determined against throat swab cultures, which is the gold standard. CC –BY 4.0 Results: There were 190 (58.6%) females and Male to Female ratio of 1:1.4. The mean age was 8.3± 3.9 years. Only 125 (38.6%) of the participants were from low social class and 162 (62.3%) are from overcrowded households. Sociodemographic factors have no effect on the performance of the RADT, however, the use of antibiotics within 2 weeks prior to presentation significantly affected the performance of the RADT 1.4% (1/64) compared to 28.1% (73/260) for those without prior antibiotics use p&lt;0.001. GAS was isolated in 73 (28.1%) of the children with pharyngitis. The RADT had sensitivity and specificity of 84.6% and 96.2% respectively and a PPV and NPV of 90.4% and 93.6% respectively. Conclusion: The RADT is reasonably sensitive and specific and can be used in the diagnosis of GAS pharyngitis in clinics as a substitute for throat swab cultures.

A Longitudinal Study of Group A Streptococcal Colonization and Pharyngitis in US Children.

Group A streptococci (GAS) are a major cause of pharyngitis in children. Recently, there were severe GAS outbreaks. The aims of this study were to assess pharyngeal colonization prevalence in healthy children, to assess different diagnostic definitions for GAS pharyngitis and to estimate incidence rates for these infections. A 2-year longitudinal study was conducted in healthy children in the United States. Pharyngeal swabs were cultured every 3 months for GAS colonization. Serum antistreptolysin O, antideoxyribonuclease B (DNaseB) and antistreptococcal C5a peptidase (SCP) antibody titers were assessed at baseline. When participants developed a sore throat, pharyngeal swabs were collected for rapid antigen detection test (RADT) and culture, and antibody titers were determined in serum samples. A range of case definitions were used for GAS pharyngitis. A total of 422 children 3-12 years old were enrolled (140, 141 and 141 were 3-5, 6-9 and 10-12 years of age, respectively). The overall prevalence of GAS colonization during the study was 48%. Baseline antistreptolysin O, anti-DNaseB and anti-SCP antibody titers were higher for children older than 5 years. The incidence of GAS pharyngitis per 100 person-years was 15.9 for RADT/culture-proven and 4.6 for serologically confirmed pharyngitis. GAS throat colonization and pharyngitis were frequent in children 3-12 years old. The case definition employed impacted the measured incidence of GAS pharyngitis, with higher rates detected using RADT/culture-based definitions. These data suggest that case definition is important and that young children are exposed to GAS, which may inform plans for vaccine development and implementation.

Overlapping Presentation of Group A Streptococcus and Upper Respiratory Infection in a Pediatric Patient: A Case Report

Group A Streptococcus (GAS) pharyngitis has increased in case presentations, higher than prepandemic data. GAS pharyngitis requires appropriate antibiotic treatment to reduce the risk of subsequent complications if not recognized and treated promptly. However, regional observations have noted an increase in overlapping symptoms of GAS pharyngitis and viral upper respiratory infection symptoms, making the decisions to test for GAS more complex. Current guidelines do not delineate testing and treatment guidelines for this presentation scenario. This case report describes a 5-year-old female with overlapping GAS and upper respiratory infection symptoms, who tested positive via rapid GAS pharyngeal test and was treated with oral antibiotics.

Time to negative throat culture following initiation of antibiotics for pharyngeal group A Streptococcus: a systematic review and meta-analysis up to October 2021 to inform public health control measures.

BackgroundPublic health guidance recommending isolation of individuals with group A streptococcal (GAS) infection or carriage for 12-24 h from antibiotic initiation to prevent onward transmission requires a strong evidence base.AimTo estimate the pooled proportion of individuals who remain GAS culture-positive at set intervals after initiation of antibiotics through a systematic literature review (PROSPERO CRD42021290364) and meta-analysis.MethodsWe searched Ovid MEDLINE (1946-), EMBASE (1974-) and Cochrane library. We included interventional or observational studies with ≥ 10 participants reporting rates of GAS throat culture positivity during antibiotic treatment for culture-confirmed GAS pharyngitis, scarlet fever and asymptomatic pharyngeal GAS carriage. We did not apply age, language or geographical restrictions.ResultsOf 5,058 unique records, 43 were included (37 randomised controlled studies, three non-randomised controlled trials and three before-and-after studies). The proportion of individuals remaining culture-positive on day 1, day 2 and days 3-9 were 6.9% (95% CI: 2.7-16.8%), 5.4% (95% CI: 2.1-13.3%) and 2.6% (95% CI: 1.6-4.2%). For penicillins and cephalosporins, day 1 positivity was 6.5% (95% CI: 2.5-16.1%) and 1.6% (95% CI: 0.04-42.9%), respectively. Overall, for 9.1% (95% CI: 7.3-11.3), throat swabs collected after completion of therapy were GAS culture-positive. Only six studies had low risk of bias.ConclusionsOur review provides evidence that antibiotics for pharyngeal GAS achieve a high rate of culture conversion within 24 h but highlights the need for further research given methodological limitations of published studies and imprecision of pooled estimates. Further evidence is needed for non-beta-lactam antibiotics and asymptomatic individuals.

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.

Diagnosis of group A streptococcal pharyngitis in the paediatric emergency department using a fluorescence-based RADT: predicted impact on antibiotic prescription.

Introduction. Using rapid antigen diagnostic tests (RADTs) in clinical practice has shown excellent specificity but often has diminished sensitivity.Gap Statement. Local data for evaluating the diagnostic performance of a new fluorescence-based RADT and its influence on the antibiotic prescription rate are not available.Aim. To evaluate the accuracy of fluorescent immunoassay (FIA)-RADTs for diagnosing group A streptococcal (GAS) pharyngitis among children and its estimated effect as a point of care test (POCT) on the antibiotic prescription rate at the paediatric emergency department.Methodology. A prospective study was conducted, comprising children 3 to 14 years old presenting with pharyngitis. Throat swab culture and FIA-RADTs were performed on all samples. Conventional PCR was performed on the discordant samples.Results. A total of 246 children were included in this study. The sensitivity, specificity, and positive and negative predictive values of the FIA-RADT, based on culture results and PCR detection combined, were 95.6, 96.8, 94.6 and 97.4 %, respectively. Antibiotics have been prescribed to 162 (65.9 %) children; however, if FIA-RADTs had been added in the clinical practice as a POCT, only 92 (37.4 %) children would have received antibiotics in total. Additionally, implementation of FIA-RADTs would significantly reduce the antibiotic prescription rate from 48.8 and 60.6 % to 9.5 and 31.9 % among patients with clinical scores of 2 and 3, respectively.Conclusion. The new FIA-RADT is simple, prompt and reliable. It is helpful in clinical settings and may be used to reduce antibiotic overprescription, especially for children who have a low risk for GAS pharyngitis, according to the clinical score.

1329. Pediatric Group A Streptococcus (GAS) Pharyngitis Incidence has Decreased During the COVID-19 Pandemic

Abstract Background The COVID-19 pandemic has affected respiratory disease epidemiology. Measures to reduce transmission of SARS-CoV-2 (e.g., masking, social distancing, school closures) have reduced the incidence of common infectious diseases. At least one early report described changes in rates of pediatric GAS pharyngitis. We sought to determine the difference in GAS pharyngitis rates before and after the onset of the pandemic at our children’s hospital. Methods Clinical pharyngeal specimens tested for GAS by rapid antigen tests (RADTs) or LAMP methodology (loop-mediated isothermal amplification of GAS DNA) from January 2019 to March 2022 at our children’s hospital were analyzed. Clinician’s evaluating patients for GAS pharyngitis perform a RADT, when positive the patient is treated for GAS pharyngitis. When the RADT is negative, a LAMP test is performed. Patients were considered test-positive if either test was positive regardless of clinical symptoms. Annual positivity rates were compared using statistical process control (SPC) charts with both 2019 and 2020 as baseline years (i.e., 2019 vs 2020-3/2022; 2020 vs 2021-3/2022). The change in GAS incidence rate (positive patients/1000 tested) between years was assessed by chi-square tests. Results 9,896 patients had throat swabs tested for GAS from January 2019 through March 2022. Using SPC with 2019 as a baseline, there was a 15.1% decrease in mean GAS positivity through 3/2022. With 2020 as baseline, there was a 13.0% decrease in mean GAS positivity through 3/2022. The incidence of positive GAS tests decreased significantly: 2019 vs. 2020-3/2022 (x2 = 84.97, p ≤0.00001) and 2020 vs. 2021-3/2022 (x2 = 154.01, p ≤0.00001). Figure 1. Conclusion Using throat swab results, the incidence of pediatric GAS pharyngitis at our hospital has decreased significantly during the COVID-19 pandemic. Implications: Pandemic-related risk mitigation measures, such as masking, social distancing, and school closures, were associated with significantly decreased incidence of GAS pharyngitis. It is likely that GAS colonization and invasive infections were also affected. Disclosures All Authors: No reported disclosures.

1321. Increased Prevalence of Group A Streptococcus (GAS) High Level Macrolide Resistance During the COVID-19 Pandemic

Abstract Background COVID-19 affected the epidemiology of many respiratory pathogens including GAS. Assessing genetic heterogeneity (emm type, antimicrobial resistance, virulence factors) can inform treatment recommendations and targets for potential GAS vaccines. We assessed GAS clinical antibiotic susceptibility and performed whole genome sequencing (WGS) among pediatric pharyngeal isolates from 2020–2022. Methods From 1/2020–3/2022 we collected throat swabs in pediatric clinics and EDs from children aged 3-18 years in Chicago, IL; Atlanta, GA; Portland, OR; and Phoenix, AZ: 1) with acute GAS pharyngitis and 2) among a convenience sample of asymptomatic children to assess for GAS colonization. Swabs were plated on blood agar. E-tests were used to assess clinical susceptibility to erythromycin (ERY) and ciprofloxacin (CIP). emm type and antimicrobial resistance genes (ERY, Clindamycin (CLI), and fluoroquinolones) were assessed by WGS. Results 1144 pharyngeal swabs were collected: 359/684 (52%) from children with GAS pharyngitis by rapid test and 20/460 (4.3%) from asymptomatic children yielded GAS on culture. Phenotypic resistance: 55/364 (15%) tested isolates were ERY resistant and 5/364 (1.4%) CIP resistant. The proportion of isolates with ERY resistance increased significantly from 2020 (6%) to 2021–2022 (25%) (χ2 = 23.70, p&amp;lt; .00001) (Figure 1). MICs were high among ERY resistant GAS (Table 1). Genotypic resistance: Of 304 sequenced GAS isolates 40/304 (13%) were ERY resistant, 35/304 (11.5%) were both ERY resistant and CLI (inducible or constitutive) resistant, and 4/304 (1.3%) fluoroquinolone resistant. ermB (62%) was the most common gene for ERY resistance and constitutive CLI resistance, followed by ermTR (23%) and ermT (11%) both conferring inducible CLI resistance. Among the 20 isolates from asymptomatic children no ERY, CLI, or CIP resistance occurred, and no resistance genes were identified. emm types 11, 9, 77, 58 and 94 were associated with ERY and CLI resistance. Conclusion ERY resistance increased from 2020–2022. The high rate of CLI resistance among ERY resistant GAS was associated with erm genes. These results are important to inform treatment recommendations for GAS pharyngitis and targets for vaccine development that can reduce antimicrobial-resistant GAS disease. Disclosures All Authors: No reported disclosures.

RARE CASE OF SEVERE NECROTIZING PNEUMONIA DUE TO STREPTOCOCCUS PYOGENES RESULTING IN REFRACTORY HYPOXEMIA

RARE CASE OF SEVERE NECROTIZING PNEUMONIA DUE TO STREPTOCOCCUS PYOGENES RESULTING IN REFRACTORY HYPOXEMIA