Pharyngitis In Children Research Articles

Centor scores associated poorly with rapid antigen test findings in children with sore throat.

The Centor score alone does not seem to be of any utility in guiding the diagnosis of suspected streptococcal pharyngitis. Microbiological testing remains necessary for accurate diagnosis and CRP should not be used to differentiate viral and bacterial pharyngitis cases. • The Centor score is a clinical prediction model for differentiating Group A streptococcal (GAS) pharyngitis from viral pharyngitis. • Finnish Current Care Guideline recommends rapid antigen testing in patients with Centor score ≥ 3 for diagnosing GAS infections and antibiotics prescribed based on confirmed test results. • The Centor score alone does not seem to have any use in guiding the diagnosis of suspected streptococcal pharyngitis in children. • Microbiological testing remains necessary for accurate diagnosis in patients with sore throat.

Use of McIsaac Scoring and Rapid Streptococcal Antigen Detection Test for Diagnosis of Group A Streptococcal Pharyngitis in Children

Use of McIsaac Scoring and Rapid Streptococcal Antigen Detection Test for Diagnosis of Group A Streptococcal Pharyngitis in Children

Novel Diagnostic Approach for Acute Pharyngitis: Combining Machine Learning With Thermal Imaging.

We evaluated the effect of infrared thermography (IRT) on the clinical assessment of bacterial and viral pharyngitis and its impact on the predictive value of the McIsaac score algorithm for streptococcal pharyngitis in children. We also investigated if IRT could distinguish between bacterial and viral pharyngitis. The study included children aged 2-17 years presenting with sore throat and fever over 38°C from November 1, 2021, to April 30, 2022. Of the 76 assessed children, 16 were excluded due to missing data or technical issues, leaving 60 children (32 males, 28 females) divided into three groups: Group A with streptococcal pharyngitis (N = 30), viral pharyngitis (N = 16), and healthy controls (N = 14). McIsaac score and IRT imaging showed a 90% positive predictive value for streptococcal pharyngitis. While IRT alone could not distinguish between bacterial and viral infections, it significantly increased the predictive value when combined with the McIsaac score.

Frequency of Group A Streptococcus Infection and Analysis of Antibiotic Use in Patients with Pharyngitis-A Retrospective, Multicenter Study.

Streptococcus pyogenes is responsible for 20-30% of pharyngitis in children and 5-15% in adults. The ineffective treatment of group A Streptococcus (GAS) infections can result in postinfectious sequelae. This study aims to evaluate the frequency of GAS pharyngitis and assess the management of patients with pharyngitis and antibiotic use. We conducted a multicenter, retrospective analysis of medical records from nine primary care centers in Poland. The study enrolled 1949 medical records of patients (children 67.4%, adults 32.6%). An infection of Streptococcus pyogenes, based on a rapid strep test, was diagnosed in 830 patients (42.6%). In the comprehensive study group of 1949 patients, 1054 (54.1%) were given antibiotics. Notably, 224 patients had a negative rapid strep test result but still received antibiotic treatment, underscoring the complexity of treatment decisions. The most commonly used antibiotics were oral penicillin V in 431 cases (41%) and amoxicillin in 219 cases (20.8%). We observed no significant difference between positive rapid strep test results and patients' sociodemographic data and comorbidities. The prevalence of GAS was 42.6% in the analyzed records of patients with pharyngitis, and 54.1% were prescribed antibiotics. Antibiotics were overprescribed for sore throats. Strategies are needed to promote rational antibiotic use.

The Emergence and Impact of the M1UK Lineage on Invasive Group A Streptococcus Disease in Aotearoa New Zealand.

M1UK is associated with current surges in invasive infection globally, partly due to increased production of superantigen streptococcal pyrogenic exotoxin A. We show that M1UK is now the dominant invasive emm1 lineage in Aotearoa New Zealand and is genomically related to community infections, suggesting that measures that effectively prevent group A Streptococcus pharyngitis in children could reduce invasive disease.

Differential absorption and metabolic characteristics of organic acid components in pudilan xiaoyan oral liquid between young rats and adult rats

Ethnopharmacological relevancePudilan Xiaoyan Oral Liquid (PDL) is a proprietary Chinese medicinal preparation approved by the State for treating acute pharyngitis in both adults and children (Approval No. Z20030095). It is worth noting that children exhibit unique physiopathological characteristics compared to adults. However, the in vivo regulatory characteristics of PDL in treating acute pharyngitis in children remain incompletely understood. Aim of the studyThe differential absorption and metabolism characteristics of the main pharmacological components in PDL in young and adult rats were investigated with a view to providing a reference for preclinical data of PDL in medication for children. Materials and methodsThis study utilized UPLC-Q-TOF-MS to investigate the pharmacodynamic material basis of PDL. The focus was on the gastrointestinal digestion and absorption characteristics of organic acid components in PDL (PDL-OAC), known as the primary pharmacodynamic components in this formulation. The research combined in vitro dynamic simulation and a Quadruple single-pass intestinal perfusion model to examine these characteristics. The permeability properties of PDL-OAC were evaluated using an artificial parallel membrane model. Additionally, an acute pharyngitis model was established to evaluate the histopathological condition of the pharynx in young rats using H&E staining. The levels of IL-1β, TNF-α, IL-6, and IL-10 in blood and pharyngeal tissue homogenates of young rats were quantified using ELISA kits. ResultsA total of 91 components were identified in PDL, including 33 organic acids, 24 flavonoids, 14 alkaloids, 5 terpenoids and coumarins, 3 sugars, and 12 amino acids. The PDL-OAC exhibited a significant reduction in IL-1β, TNF-α, IL-6, and IL-10 levels in the pharyngeal tissues of young rats with acute pharyngitis. Results from dynamic simulation studies of gastrointestinal fluids revealed that the PDL-OAC (Specifically chlorogenic acid (CGA), gallic acid (GA), chicoric acid (CRA), and caffeic acid (CA)) were effectively stabilized in the gastrointestinal fluids of both children and adults in vitro. Young rats, characterized by thinner intestinal walls and higher permeability, efficiently absorbed the four organic acids across the entire intestinal segment. The absorption of CGA, GA, and CRA followed a concentration-dependent pattern, with CGA and GA absorption being influenced by exocytosis. ConclusionThe efficacy of the PDL-OAC in treating acute pharyngitis was demonstrated in young rats. The absorption rate of these components was observed to be faster in young rats compared to adult rats, underscoring the need for dedicated studies on the drug's usage in children. This research provides valuable insights for the appropriate clinical use of PDL in pediatric patients.

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.]

Antibiotic susceptibility of Streptococcus species that cause pharyngitis in children

Background: Group A Streptococcus (GAS) significantly impacts global health, especially among children aged 5–14 years, causing approximately 288 million episodes of sore throat annually and resulting in around 100,000 disability-adjusted life years (DALYs) each year. GAS infections are particularly prevalent in developing countries. Objective: To assess the patterns of antibiotic resistance of Streptococcus spp. that cause pharyngitis in children. Patients and Methods: It was collected 100 pediatric patients. It was taken throat swabs for Streptococcus species culture and antibiotic sensitivity test. In addition, it was recorded the data of patient’s age and gender. Results: It was shown in this study that an average age of 4.4 ± 3.7 years for pharyngitis in children. In this study was diagnosed that Streptococcus agalactiae (24%) and Streptococcus pyogenes (18%) as the common causes Streptococcus species causes pharyngitis in children. It was noted that the differences in bacterial species according to the patient’s ages. Antibiotic sensitivity testing determined that there are high sensitivity of S. pneumoniae and S. parasanguinis to multiple antibiotics. In addition, it was showed resistance of S. pyogenes to Metronidazole and Azithromycin. Conclusion: In this study, it was found that the risk age for pharyngitis in children is four years old. Streptococcus agalactiae and Streptococcus pyogenes are the common bacterial causes for this infection. In addition, it was shown that S. pneumoniae appeared a high sensitivity to Ceftriaxone, Ciprofloxacin, and Meropenem, and S. parasanguinis was sensitive to Azithromycin, Cefixime, and Cefotaxime, and S. pyogenes showed a high sensitivity to Meropenem and Imipenem. Keywords: Pharyngitis, Streptococcus pyogenes, Children infection, antibiotic resistance.

Antibiotic susceptibility of Streptococcus species that cause pharyngitis in children

Background: Group A Streptococcus (GAS) significantly impacts global health, especially among children aged 5–14 years, causing approximately 288 million episodes of sore throat annually and resulting in around 100,000 disability-adjusted life years (DALYs) each year. GAS infections are particularly prevalent in developing countries. Objective: To assess the patterns of antibiotic resistance of Streptococcus spp. that cause pharyngitis in children. Patients and Methods: It was collected 100 pediatric patients. It was taken throat swabs for Streptococcus species culture and antibiotic sensitivity test. In addition, it was recorded the data of patient’s age and gender. Results: It was shown in this study that an average age of 4.4 ± 3.7 years for pharyngitis in children. In this study was diagnosed that Streptococcus agalactiae (24%) and Streptococcus pyogenes (18%) as the common causes Streptococcus species causes pharyngitis in children. It was noted that the differences in bacterial species according to the patient’s ages. Antibiotic sensitivity testing determined that there are high sensitivity of S. pneumoniae and S. parasanguinis to multiple antibiotics. In addition, it was showed resistance of S. pyogenes to Metronidazole and Azithromycin. Conclusion: In this study, it was found that the risk age for pharyngitis in children is four years old. Streptococcus agalactiae and Streptococcus pyogenes are the common bacterial causes for this infection. In addition, it was shown that S. pneumoniae appeared a high sensitivity to Ceftriaxone, Ciprofloxacin, and Meropenem, and S. parasanguinis was sensitive to Azithromycin, Cefixime, and Cefotaxime, and S. pyogenes showed a high sensitivity to Meropenem and Imipenem.

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.

Досвід застосування засобу «Біоплазмікс спрей для горла» в комплексному лікуванні гострих вірусних фарингітів у дітей з атопічним фоном

The problem of therapy of acute respiratory infections in children remains relevant. The most common infectious pathology of the upper respiratory tract in both children and adults is acute viral pharyngitis. Irrational prescribing of antibiotics leads to medication-induced side effects and the spread of resistance of microorganisms to antibiotics in society. Topical application of respiratory probiotics may be an important component in the supportive treatment of acute respiratory infections and reducing antibiotic dependence. The use of probiotics in children with an atopic background is of particular importance due to the possible occurrence of adverse reactions. Purpose - to assess the safety and effectiveness of the local application of Bioplasmix throat spray in the complex treatment of acute viral pharyngitis in children with an atopic background. Materials and methods. 45 children aged 6-18 years with acute viral pharyngitis took part in the study. 2 research groups were formed: the Group I - main (n=25) - received protocol treatment + Bioplasmix throat spray locally and the Group II - comparison (n=20) - only protocol treatment. All patients were assessed for the severity of clinical symptoms (fever, headache, sore throat, scratching, cough) and oropharyngoscopy data (hyperemia, swelling of the mucous membrane of the oropharynx, granularity of the back wall of the pharynx) on the 1st, 2nd, 3rd, 4th, 5th and 7th days of using the product. Results. The use of the local application of Bioplasmix throat spray for acute pharyngitis in children ensures a faster reduction in the severity of the main clinical manifestations and signs of inflammation of the oropharynx. In the Group I, compared to the Group II, there were better indicators of a decrease in the severity of cough (1.2±0.91 points vs. 1.76±0.85 points), a scratching (1.12±0.92 points vs. 1.7±0.86 points), sore throat (1.6±0.81 points vs. 2.23±0.76 points) and hyperemia of the pharynx (1.4±0.7 points vs. 2.1±0.9 points) from the 3rd day, swelling of the pharynx (1.22±0.86 points vs. 1.8±1.04 points) from the 4th day. Adverse reactions were not noted during the use of the local application of Bioplasmix throat spray. Conclusions. Local probiotic therapy is an important component of the complex therapy of acute pharyngitis, the use of bacteria of the genus Bacillus in the form of Bioplasmix throat spray shows a positive effect on the course of acute viral pharyngitis in children, which manifests by a faster decrease in the severity of subjective symptoms of pharyngitis and inflammatory signs of the oropharynx. The research was carried out in accordance with the principles of the Helsinki Declaration. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors.

On the issue of the etiology of acute inflammatory pathology of the pharynx in children

To compare the microbiota of the oropharynx in healthy children and children with acute tonsillitis and pharyngitis. The study included two groups of patients (139 people) aged from 1 year to 17 years inclusive. The main group consisted of children with acute tonsillitis and acute pharyngitis (111 patients, average age 7±4 years), the control group consisted of 28 healthy children (average age 7±6 years) without signs of upper respiratory tract infection. All patients were examined and material was taken from the mucous membrane of the posterior pharyngeal wall and palatine tonsils, the samples obtained were subjected to bacteriological examination to isolate a pure culture and identify bacterial microorganisms and virological examination by polymerase chain reaction in order to isolate a number of typical respiratory viruses and herpes viruses. It was found that viral-bacterial associations predominate (66.7%) in patients with acute tonsillitis and pharyngitis (32% in healthy volunteers). The detection rates of typical respiratory viruses and herpes viruses in patients with acute tonsillitis and pharyngitis are comparable (44% and 40.5%, respectively). Streptococcus pyogenes (beta-hemolytic streptococcus group A, 6.3%), as well as Streptococcus pneumoniae, Moraxella catarrhalis, Klebsiella pneumoniae and Pseudomonas aeruginosa were detected only in patients with acute tonsillitis. Other microorganisms were isolated both in healthy patients and in children with acute tonsillitis and pharyngitis, but in the presence of inflammatory changes in the pharynx, the concentration of microorganisms was slightly higher than in a healthy state, which is especially significant for Staphylococcus aureus. In patients without signs of inflammation, typical respiratory viruses (rhinovirus, 14%) and herpes viruses (with a predominance of type 6 herpes virus - 28%) were also found in a percentage comparable to that of patients with acute tonsillitis and pharyngitis. The etiology of acute tonsillitis and pharyngitis in children is dominated by viral-bacterial associations, while rhinovirus (34%) and herpes virus type 6 (28%) are among the viruses. The detection rate of Streptococcus pyogenes in patients with acute tonsillitis was 6.3%. Typical respiratory viruses and herpes viruses can be found on the mucous membrane of the oropharynx and outside the phenomena of inflammation. This once again proves the importance of comparing the clinical manifestations observed in a patient and data on the structure of the microbiota of a particular locus, including to address the need for systemic or local antimicrobial therapy.

Оцінка обізнаності щодо діагностики та менеджменту фарингіту в дітей серед лікарів загальної практики

Sore throat and pharyngitis account for up to 5.0% of all medical visits to a general practitioner. The etiology of pharyngitis in both adults and children is dominated by viruses, but in 20.0-30.0% of children the cause may be bacteria, most often the Group A β-hemolytic streptococcus. Purpose - to assess the knowledge of general practitioners regarding the diagnosis and management of pharyngitis in children, to determine further ways to increase their level of awareness. Materials and methods. A survey of 60 general practitioners in the Ternopil region of Ukraine was conducted to determine their awareness of the diagnosis and management of pharyngitis in children. The questionnaire and statistical methods were used. Results. In total, 45.0% of general practitioners in individual cases prescribed bacteriological cultures from the oropharynx to patients with acute pharyngitis. However, they rarely (6.7%) used the Center or McIsaac criteria to choose a treatment strategy for acute pharyngitis. Antibiotic therapy for the treatment of pharyngitis was used in individual cases by 86.7% of respondents. Amoxicillin was chosen as a first-line antibiotic by 38.3% of respondents, while protected aminopenicillins were chosen by 36.6%. Only 10.0% of general practitioners indicated a 10-day course of antibiotic therapy. A little more than half of the correct answers were to questions related to the appointment of antibacterial therapy to healthy children in whom the Group A β-hemolytic streptococcus was detected during bacteriological examination or an increased level of antistreptolysin-O in the blood. Conclusions. The results of our study showed a different level of knowledge of general practitioners regarding some aspects of diagnosis and management of pharyngitis in children. Insufficient knowledge was demonstrated regarding the possibilities of diagnosing the streptococcal etiology of pharyngitis, in particular the use of both clinical and laboratory research methods. Despite good knowledge about prescribing antibacterial therapy, poor awareness about the duration of antibacterial therapy and incomplete knowledge about the choice of antibacterial agent are shown. Relatively satisfactory knowledge was demonstrated regarding the strategy of management of streptococcal carriage in healthy children. The presented data indicate the need to improve the awareness of general practitioners regarding the diagnosis and treatment of pharyngitis, taking into account the modern complications of streptococcal infection. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

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<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.

The rise and fall of acute rheumatic fever and rheumatic heart disease: a mini review.

The incidences of acute rheumatic fever (ARF) and rheumatic heart disease (RHD), which were leading causes of death in children in the 1920s, have decreased substantially. Considering the recent resurgence of scarlet fever and increased incidence of streptococcal pharyngitis in children, an investigation of the current status of ARF and RHD may be worthwhile. To summarize the prevalence trends, pathogenic factors, and prevention strategies for ARF and RHD in children. A selective search of literature published between January 1920 and February 2023 was done in PubMed, using the terms "acute rheumatic fever", "rheumatic heart disease", "group A Streptococcus", "pharyngitis", "pharyngeal tonsillitis", "scarlet fever", "impetigo", "obstructive sleep apnea syndrome" and "child". Overcrowded homes and inadequate sanitation led to recurrent group A streptococcal infection, and the causal relationship between group A streptococcal infection and ARF/RHD was well established. Streptococcal infectious diseases, such as group A streptococcal pharyngeal tonsillitis, SF, impetigo, and obstructive sleep apnea syndrome, were associated with the occurrence of ARF and RHD. ARF and RHD were still prevalent in young people of developing countries and economically poor populations of high-income countries. Universal disease registration systems were critical to locating disease outbreaks, tracking disease transmission, and identifying high-risk populations. Four-level prevention strategies were effective in reducing the incidence and mortality of ARF and RHD. Registry and preventive measures for ARF and RHD should be strengthened in areas of dense population; poor sanitation; resurgence of SF; and high incidence of streptococcal pharyngitis, impetigo, and obstructive sleep apnea syndrome.

Role of serotype and virulence determinants of Streptococcus pyogenes biofilm bacteria in internalization and persistence in epithelial cells in vitro.

Streptococcus pyogenes causes a multitude of local and systemic infections, the most common being pharyngitis in children. Recurrent pharyngeal infections are common and are thought to be due to the re-emergence of intracellular GAS upon completion of antibiotic treatment. The role of colonizing biofilm bacteria in this process is not fully clear. Here, live respiratory epithelial cells were inoculated with broth-grown or biofilm bacteria of different M-types, as well as with isogenic mutants lacking common virulence factors. All M-types tested adhered to and were internalized into epithelial cells. Interestingly, internalization and persistence of planktonic bacteria varied significantly between strains, whereas biofilm bacteria were internalized in similar and higher numbers, and all strains persisted beyond 44 hours, showing a more homogenous phenotype. The M3 protein, but not the M1 or M5 proteins, was required for optimal uptake and persistence of both planktonic and biofilm bacteria inside cells. Moreover, the high expression of capsule and SLO inhibited cellular uptake and capsule expression was required for intracellular survival. Streptolysin S was required for optimal uptake and persistence of M3 planktonic bacteria, whereas SpeB improved intracellular survival of biofilm bacteria. Microscopy of internalized bacteria showed that planktonic bacteria were internalized in lower numbers as individual or small clumps of bacteria in the cytoplasm, whereas GAS biofilm bacteria displayed a pattern of perinuclear localization of bacterial aggregates that affected actin structure. Using inhibitors targeting cellular uptake pathways, we confirmed that planktonic GAS mainly uses a clathrin-mediated uptake pathway that also required actin and dynamin. Clathrin was not involved in biofilm internalization, but internalization required actin rearrangement and PI3 kinase activity, possibly suggesting macropinocytosis. Together these results provide a better understanding of the potential mechanisms of uptake and survival of various phenotypes of GAS bacteria relevant for colonization and recurrent 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.

Prevalence, Antibiotic Susceptibility Profile and Associated Factors of Group A Streptococcal pharyngitis Among Pediatric Patients with Acute Pharyngitis in Gondar, Northwest Ethiopia.

Streptococcus pyogenes (S. pyogenes) or group A streptococcus is a common cause of bacterial pharyngitis in children. Since it is difficult to distinguish between viral and bacterial pharyngitis using solely signs and symptoms, culture-based diagnosis and treatment are critical for avoiding serious complications. Therefore, this study aimed to determine the prevalence, antimicrobial susceptibility patterns, and associated factors of S. pyogenes among pediatric patients with acute pharyngitis. A hospital-based cross-sectional study was conducted at the University of Gondar Comprehensive Specialized Hospital from April to June 2021. Standard microbiological procedures were used to collect and process throat swabs and to isolate and identify S. pyogenes. The disc diffusion method was used for antimicrobial susceptibility testing (AST). A total of 215 children with acute pharyngitis were included in this study. Of these, 23 (10.7%) were culture positive for S. pyogenes. The presence of an inflamed tonsil, tonsillar exudate, scalariform rash, and dysphagia were associated with streptococcal pharyngitis. Children aged 5 to 15 were more susceptible to streptococcal throat infection than younger children. Penicillin, vancomycin, chloramphenicol, clindamycin, and ceftriaxone were effective against 100%, 95.7%, 95.7%, 91%, and 87% of isolates, respectively. In contrast, 56.5%, 39.1%, and 30.4% of isolates showed at least reduced susceptibility to tetracycline, erythromycin, and azithromycin, respectively. Streptococcus pyogenes is responsible for 10.7% of acute pharyngitis cases among pediatric patients in the study area. Although all isolates remain sensitive to penicillin, many showed reduced susceptibility to tetracycline and macrolides. Therefore, prior to antibiotic prescription, screening children with acute pharyngitis for S. pyogenes and testing the antibiotic susceptibility of isolates is recommended.

The Epidemiology of Influenza Virus Infection and Group A Streptococcal Pharyngitis in Children Between 2011 and 2018 in an Outpatient Pediatric Clinic.

Background The frequency of influenza virus infections and group A beta-hemolytic streptococcus (GAS) pharyngitis varies according to populations. We aimed to investigate the frequency of influenza virus and streptococcal pharyngitis infections in a pediatric outpatient cohort with many pediatric admissions in Istanbul. Materials and methods Children with upper respiratory tract infection (URTI) symptoms between 2011 and 2018 who underwent rapid diagnostic tests for influenza virus or streptococcal infection were evaluated retrospectively. Results Thetotal number of pediatric cases admitted between 2011 and 2018 was 185,228, of which 119,928 were under five years oldand 66,300 were children over five years old. The mean frequency of the influenza virus was 1,283 per 100,000 children, and the mean frequency of streptococcal pharyngitis was 1,764 per 100,000 children. The frequency of influenza has increased over the years. The frequency of streptococcal infection is higher in children over five years of age, and its frequency has decreased in this group. Conclusions Thefrequency of influenza virus infection and GAS pharyngitis varies according to years and seasons. Winter and spring were the seasons with the most frequent positive influenza virus and GAS pharyngitis. Although influenza frequency increased annually, this phenomenon was not observed in the frequency of GAS pharyngitis.