Streptococcal pharyngitis in a paediatric emergency department

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.

Is Streptococcus pyogenes a pathogen or passenger in uncomplicated acute sore throat? A systematic review and meta-analysis

OBJECTIVES

The objective was to estimate the probability that finding a Streptococcus pyogenes (Group A Streptococcus) in a throat swab in a patient with a sore throat reflects the aetiology. We also investigated to what extent this is influenced by age, carrier rates of S. pyogenes and climate zone.

METHODS

We conducted a comprehensive search of Medline and Scopus up until October 2023 for case-control studies reporting the prevalence of S. pyogenes in patients with a sore throat and healthy controls. We only included studies with separate data for children and adults. We used the positive and negative etiologic predictive values (P-EPV and N-EPV) to estimate the probability of a link between a sore throat and a finding of S. pyogenes.

RESULTS

We included 15 studies in our meta-analysis. The overall P-EPV for children and adults were 63% (49-74%) and 92% (87-95%), respectively. The P-EPV rose to 83% (64-93%) for children and 94% (90-97%) for adults when only patients with 3-4 Centor criteria were included. The overall N-EPV was 97% (96-98%) for children and 96% (95-97%) for adults.

CONCLUSION

Detecting S. pyogenes in adult patients with an uncomplicated acute sore throat is useful to rule in S. pyogenes as the likely aetiologic agent. The P-EPV significantly increased for children when those with 3-4 Centor criteria were selected. A negative throat swab is always useful for both children and adults to rule out S. pyogenes as the cause of sore throat.

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.

Diagnosis of Epstein-Barr and cytomegalovirus infections using decision trees: an effective way to avoid antibiotic overuse in paediatric tonsillopharyngitis

BACKGROUND

The incidence of tonsillopharyngitis is especially prevalent in children. Despite the fact that viruses cause the majority of infections, antibiotics are frequently used as a treatment, contrary to international guidelines. This is not only an inappropriate method of treatment for viral infections, but it also significantly contributes to the emergence of antibiotic-resistant strains. In this study, EBV and CMV-related tonsillopharyngitis were distinguished from other pathogens by using machine learning techniques to construct a classification tree based on clinical characteristics.

MATERIALS AND METHODS

In 2016 and 2017, we assessed information regarding 242 children with tonsillopharyngitis. Patients were categorized according to whether acute cytomegalovirus or Epstein-Barr virus infections were confirmed (n = 91) or not (n = 151). Based on symptoms and blood test parameters, we constructed decision trees to discriminate the two groups. The classification efficiency of the model was characterized by its sensitivity, specificity, positive predictive value, and negative predictive value. Fisher's exact and Welch's tests were used to perform univariable statistical analyses.

RESULTS

The best decision tree distinguished EBV/CMV infection from non-EBV/CMV group with 83.33% positive predictive value, 88.90% sensitivity and 90.30% specificity. GPT (U/l) was found to be the most discriminatory variable (p < 0.0001). Using the model, unnecessary antibiotic treatment could be reduced by 66.66% (p = 0.0002).

DISCUSSION

Our classification model can be used as a diagnostic decision support tool to distinguish EBC/CMV infection from non EBV/CMV tonsillopharyngitis, thereby significantly reducing the overuse of antibiotics. It is hoped that the model may become a tool worth considering in routine clinical practice and may be developed to differentiate between viral and bacterial infections.

Retrospective study of group A Streptococcus oropharyngeal infection diagnosis using a rapid antigenic detection test in a paediatric population from the central region of Portugal

Group A Streptococcus (GAS) is one of the most important agents of oropharyngeal infection. To avoid unnecessary antibiotic prescription, it is recommended the confirmation of GAS infection in pharyngeal swabs using culture or rapid antigen detection test (RADT). This study aimed to retrospectively analyse the incidence of GAS oropharyngeal infection, detected by RADT, in a paediatric population in the Centre of Portugal. Data was collected from the database of the Paediatric Hospital Emergency Department (ED) regarding patients admitted with symptoms suggesting acute pharyngitis, from January 2013 to December 2018, in a total of 18,304 cases. Among these, 130 clinical files were searched for symptoms, complications and additional visits to the ED. The results showed an average GAS infection prevalence of 33%, with seasonal variation. In preschool children, especially in patients less than 3 years old, where the guidelines do not routinely encourage RADT, GAS tonsillitis assumed an unexpected importance, with 731 positive tests in a total of 3128 cases. Scarlatiniform rash and oral cavity petechiae had significant correlation with streptococcal aetiology (p < 0.05). The statistical analysis also showed that different signs and symptoms assume different weights depending on the age group of the patient. The main conclusion is that the incidence of GAS infection in the studied population is higher than generally described in preschool children, suggesting the need for a more cautious approach to children under 3 years presenting acute pharyngitis, and that RADT in this age group would contribute to a decrease in the number of unnoticed cases.

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

BACKGROUND AND AIMS

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

SETTINGS AND DESIGN

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

METHODS

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

STATISTICAL ANALYSIS USED

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

RESULTS

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

CONCLUSIONS

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

Clinical Screening Tools to Diagnose Group A Streptococcal Pharyngotonsillitis in Primary Care Clinics to Improve Prescribing Habits

This review highlights the clinical scoring tools used for the management of acute pharyngotonsillitis in primary care clinics. It will include the prevalence of group A pharyngotonsillitis among children and adults worldwide and the selective tests employed for diagnosing group A streptococcal pharyngotonsillitis. Pharyngotonsillitis is one of the common reasons for visits to primary care clinics worldwide, and physicians tend to prescribe antibiotics according to the clinical symptoms, which leads to overprescribing antibiotics. This in turn may lead to serious health impacts and severe reactions and may promote antibiotic resistance. These significantly add on to the health care costs. The available information from health organisations and previous studies has indicated the need to manage the diagnosis of pharyngotonsillitis to improve prescribing habits in primary care clinics.

Abdominal pain and nausea in the diagnosis of streptococcal pharyngitis in boys

Objectives

This study was designed to assess the accuracy of gastrointestinal symptoms, including abdominal pain, nausea, and vomiting, in the diagnosis of Group A streptococcal (GAS) pharyngitis in children and to determine differences in diagnostic accuracy in boys versus girls.

Methods

This retrospective cross-sectional study included 5,755 consecutive patients aged <15 years with fever in the electronic database at a primary care practice. Gastrointestinal symptoms were recorded in the database according to the International Classification of Primary Care codes, and the data were extracted electronically. The reference standard was GAS pharyngitis diagnosed with a rapid test. Patients with a clinical diagnosis of probable GAS pharyngitis were excluded from the primary analysis.

Results

Among the 5,755 children with fever, 331 (5.8%) were coded as having GAS pharyngitis, including 218 (65.9%) diagnosed with rapid tests and 113 (34.1%) clinically diagnosed with probable GAS pharyngitis. Among patients with fever and abdominal pain, rapid-test-confirmed GAS pharyngitis was significantly more common in boys (11/120, 9.2%) than in girls (3/128, 2.3%; p=0.026). The positive likelihood ratio of abdominal pain was 1.49 (95% CI =0.88–2.51): 2.41 (95% CI =1.33–4.36) in boys and 0.63 (95% CI =0.20–1.94) in girls. The positive likelihood ratio of nausea was 2.05 (95% CI =1.06–4.00): 2.74 (95% CI =1.28–5.86) in boys and 1.09 (95% CI =0.27–4.42) in girls. The association between abdominal pain and GAS pharyngitis was stronger in boys aged <6 years than in boys aged 6–15 years.

Conclusion

Abdominal pain and nausea were associated with GAS pharyngitis in boys, but not in girls. Abdominal pain and nausea may help determine the suitability of rapid tests in younger boys with fever and other clinical findings consistent with GAS pharyngitis, even in the absence of sore throat.

Selective testing strategies for diagnosing group A streptococcal infection in children with pharyngitis: a systematic review and prospective multicentre external validation study

BACKGROUND

Several clinical prediction rules for diagnosing group A streptococcal infection in children with pharyngitis are available. We aimed to compare the diagnostic accuracy of rules-based selective testing strategies in a prospective cohort of children with pharyngitis.

METHODS

We identified clinical prediction rules through a systematic search of MEDLINE and Embase (1975-2014), which we then validated in a prospective cohort involving French children who presented with pharyngitis during a 1-year period (2010-2011). We diagnosed infection with group A streptococcus using two throat swabs: one obtained for a rapid antigen detection test (StreptAtest, Dectrapharm) and one obtained for culture (reference standard). We validated rules-based selective testing strategies as follows: low risk of group A streptococcal infection, no further testing or antibiotic therapy needed; intermediate risk of infection, rapid antigen detection for all patients and antibiotic therapy for those with a positive test result; and high risk of infection, empiric antibiotic treatment.

RESULTS

We identified 8 clinical prediction rules, 6 of which could be prospectively validated. Sensitivity and specificity of rules-based selective testing strategies ranged from 66% (95% confidence interval [CI] 61-72) to 94% (95% CI 92-97) and from 40% (95% CI 35-45) to 88% (95% CI 85-91), respectively. Use of rapid antigen detection testing following the clinical prediction rule ranged from 24% (95% CI 21-27) to 86% (95% CI 84-89). None of the rules-based selective testing strategies achieved our diagnostic accuracy target (sensitivity and specificity>85%).

INTERPRETATION

Rules-based selective testing strategies did not show sufficient diagnostic accuracy in this study population. The relevance of clinical prediction rules for determining which children with pharyngitis should undergo a rapid antigen detection test remains questionable.

Detection of group a streptococcal pharyngitis by quantitative PCR

Background

Group A streptococcus (GAS) is the most common bacterial cause of sore throat. School-age children bear the highest burden of GAS pharyngitis. Accurate diagnosis is difficult: the majority of sore throats are viral in origin, culture-based identification of GAS requires 24–48 hours, and up to 15% of children are asymptomatic throat carriers of GAS. The aim of this study was to develop a quantitative polymerase chain reaction (qPCR) assay for detecting GAS pharyngitis and assess its suitability for clinical diagnosis.

Methods

Pharyngeal swabs were collected from children aged 3–18 years (n = 91) and adults (n = 36) located in the Melbourne area who presented with sore throat. Six candidate PCR assays were screened using a panel of reference isolates, and two of these assays, targeting speB and spy1258, were developed into qPCR assays. The qPCR assays were compared to standard culture-based methods for their ability to detect GAS pharyngitis. GAS isolates from culture positive swabs underwent emm-typing. Clinical data were used to calculate McIsaac scores as an indicator of disease severity.

Results

Twenty-four of the 127 samples (18.9%) were culture-positive for GAS, and all were in children (26%). The speB qPCR had 100% sensitivity and 100% specificity compared with gold-standard culture, whereas the spy1258 qPCR had 87% sensitivity and 100% specificity. Nine different emm types were found, of which emm 89, 3, and 28 were most common. Bacterial load as measured by qPCR correlated with culture load. There were no associations between symptom severity as indicated by McIsaac scores and GAS bacterial load.

Conclusions

The speB qPCR displayed high sensitivity and specificity and may be a useful tool for GAS pharyngitis diagnosis and research.

Accuracy and precision of the signs and symptoms of streptococcal pharyngitis in children: a systematic review

OBJECTIVE

To conduct a systematic review to determine whether clinical findings can be used to rule in or to rule out streptococcal pharyngitis in children.

STUDY DESIGN

Two authors independently searched MEDLINE and EMBASE. We included articles if they contained data on the accuracy of symptoms or signs of streptococcal pharyngitis, individually or combined into prediction rules, in children 3-18 years of age.

RESULTS

Thirty-eight articles with data on individual symptoms and signs and 15 articles with data on prediction rules met all inclusion criteria. In children with sore throat, the presence of a scarlatiniform rash (likelihood ratio [LR], 3.91; 95% CI, 2.00-7.62), palatal petechiae (LR, 2.69; CI, 1.92-3.77), pharyngeal exudates (LR, 1.85; CI, 1.58-2.16), vomiting (LR, 1.79; CI, 1.58-2.16), and tender cervical nodes (LR, 1.72; CI, 1.54-1.93) were moderately useful in identifying those with streptococcal pharyngitis. Nevertheless, no individual symptoms or signs were effective in ruling in or ruling out streptococcal pharyngitis.

CONCLUSIONS

Symptoms and signs, either individually or combined into prediction rules, cannot be used to definitively diagnose or rule out streptococcal pharyngitis.

Prevalence of streptococcal pharyngitis and streptococcal carriage in children: a meta-analysis

OBJECTIVES

Prevalence estimates can help clinicians make informed decisions regarding diagnostic testing of children who present with symptoms of pharyngitis. We conducted a meta-analysis to determine the (1) prevalence of streptococcal infection among children who presented with sore throat and (2) prevalence of streptococcal carriage among asymptomatic children.

METHODS

We searched Medline for articles on pediatric streptococcal pharyngitis. We included articles in our review when they contained data on the prevalence of group A Streptococcus (GAS) from pharyngeal specimens in children who were younger than 18 years. Two evaluators independently reviewed, rated, and abstracted data from each article. Prevalence estimates were pooled in a meta-analysis and stratified according to age group.

RESULTS

Of the 266 articles retrieved, 29 met all inclusion criteria. Among children of all ages who present with sore throat, the pooled prevalence of GAS was 37% (95% confidence interval [CI]: 32%-43%). Children who were younger than 5 years had a lower prevalence of GAS (24% [95% CI: 21%-26%]). The prevalence of GAS carriage among well children with no signs or symptoms of pharyngitis was 12% (95% CI: 9%-14%).

CONCLUSIONS

Prevalence rates of GAS disease and carriage varied by age; children who were younger than 5 years had lower rates of throat cultures that were positive for GAS.

Prospective surveillance of streptococcal sore throat in a tropical country

BACKGROUND

Acute rheumatic fever and rheumatic heart disease cause a high burden of disease in Fiji and surrounding Pacific Island countries, but little is known about the epidemiology of group A streptococcal (GAS) pharyngitis in the region. We designed a study to estimate the prevalence of carriage of beta-hemolytic streptococci (BHS) and the incidence of BHS culture-positive sore throat in school aged children in Fiji.

METHODS

We conducted twice-weekly prospective surveillance of school children aged 5 to 14 years in 4 schools in Fiji during a 9-month period in 2006, after an initial phase of pharyngeal swabbing to determine the prevalence of BHS carriage.

RESULTS

We enrolled 685 children. The prevalence of GAS carriage was 6.0%, while the prevalence of group C streptococcal (GCS) and group G streptococcal (GGS) carriage was 6.9% and 12%, respectively. There were 61 episodes of GAS culture-positive sore throat during the study period equating to an incidence of 14.7 cases per 100 child-years (95% CI, 11.2-18.8). The incidence of GCS/GGS culture-positive sore throat was 28.8 cases per 100 child-years (95% CI, 23.9-34.5). The clinical nature of GAS culture-positive sore throat was more severe than culture-negative sore throat, but overall was mild compared with that found in previous studies. Of the 101 GAS isolates that emm sequence typed there were 45 emm types with no dominant types. There were very few emm types commonly encountered in industrialized nations and only 9 of the 45 emm types found in this study are emm types included in the 26-valent GAS vaccine undergoing clinical trials.

CONCLUSIONS

GAS culture-positive sore throat was more common than expected. Group C and group G streptococci were frequently isolated in throat cultures, although their contribution to pharyngeal infection is not clear. The molecular epidemiology of pharyngeal GAS in our study differed greatly from that in industrialized nations and this has implications for GAS vaccine clinical research in Fiji and other tropical developing countries.

Variation in clinical presentation of childhood group A streptococcal pharyngitis in four countries

We conducted a cross-sectional study from September 2001 to August 2003 during which children between 2 and 12 years of age presenting with complaint of sore throat were recruited from urban pediatric clinics in Brazil, Croatia, Egypt and Latvia. The objective of the study was to compare clinical signs and symptoms of children presenting to urban pediatric clinics with sore throat in and between countries and to identify common clinical criteria predicting group A beta hemolytic streptococcal (GAS) pharyngitis. Using a single standard protocol in all four sites, clinical data were recorded and throat swabs obtained for standard GAS culture in 2040 children. Signs and symptoms were tested for statistical association with GAS positive/negative pharyngitis, and were compared using chi(2) tests, ANOVA and Odds Ratios. Clinical signs of GAS pharyngitis in children presenting to clinics varied significantly between countries, and there were few signs or symptom that could statistically be associated with GAS pharyngitis in all four countries, though several were useful in two or three countries. Our results indicate that the clinical manifestations of pharyngitis in clinics may vary by region. It is therefore critical that clinical decision rules for management of pharyngitis should have local validation.

Group A streptococcal infections in children

The group A streptococcus causes the widest range of disease in humans of all bacterial pathogens. Group A streptococcal diseases are more common in children than adults with diseases ranging from pharyngitis and impetigo to invasive infections and the post-streptococcal sequelae--acute rheumatic fever and acute post-streptococcal glomerulonephritis. The global burden of severe group A streptococcal disease is concentrated largely in developing countries and Indigenous populations such as Aboriginal Australians. Control of group A streptococcal disease is poor in these settings and the need for a vaccine has been argued. With an ever-increasing understanding of the group A streptococcus at a molecular level, new and sophisticated vaccines are currently in human trials and the next decade holds exciting prospects for curbing group A streptococcal diseases.

The incidence of group a beta hemolytic streptococci in throat specimens from upper respiratory infections

OBJECTIVE

The aim of the study is researching the incidence of group A beta hemolytic streptococci (GABHS) in upper respiratory tract infections in Turkey.

STUDY DESIGN

This is a descriptive study.

SUBJECT AND METHODS

Totally, 3964 throat swabs obtained from patients with upper respiratory tract infections were cultured for isolation of GABHS in Corlu Military Hospital, Department of Microbiology, between April 2002 and April 2004. Standard microbiological techniques were used in the screening.

RESULTS

In this study, GABHS were isolated from 230 (5.80%) of 3964 patients. The rate of isolation was 79 (5.65%)/914 in 2002 year, 103 (5.55%)/1857 in 2003 year, and 48 (6.77%)/709 in 2004 year. The rate of isolation was 50 (5.47%)/914 in the spring, 21 (3.21%)/642 in the summer, 49 (5.81%)/844 in the autumn, and 110 (7.03%)/1564 in the winter.

CONCLUSION

We found that the overall incidence of GABHS in respiratory tract infections (5.80%) was lower than other studies and the incidence was the highest in the winter.

One-off streptococcal serologic testing in young children with recurrent tonsillitis

OBJECTIVES

Recurrent acute tonsillitis in children under 4 years of age is usually viral, making antibiotic therapy inappropriate and the indication for tonsillectomy uncertain. Identifying those young children with bacterial infections is therefore important. The purpose of this study was to determine whether one-off streptococcal serologic testing is a useful tool in assessing recurrent acute tonsillitis in young children.

METHODS

We performed a retrospective study of 45 children (35 male and 10 female) under the age of 4 years who were found by a staff otolaryngologist to have recurrent acute tonsillitis over a 5-year period and had one-off serologic testing for anti-streptolysin O titers and anti-deoxyribonuclease B levels. Data were collected by chart review.

RESULTS

Three children (6.7%) had clearly positive titers for either one or both streptococcal antibodies. Children with negative serologic results were significantly less likely to have shown a significant response to antibiotic therapy for their acute episodes (26% versus 100%; p = .026). Nine children (20%) eventually underwent tonsillectomy, all of whom had negative serologic results.

CONCLUSIONS

Anti-streptolysin O and anti-deoxyribonuclease B levels may aid clinical evaluation of recurrent acute tonsillitis in young children in differentiating between those cases due to group A beta-hemolytic Streptococcus and those that are viral in origin.

Antibacterial resistance among children with community-acquired respiratory tract infections (PROTEKT 1999-2000)

OBJECTIVE

To determine the susceptibility of bacterial respiratory tract pathogens, isolated from children (0-12 years) as part of the global PROTEKT surveillance study (1999-2000), to a range of antibacterials, including the ketolide telithromycin.

METHODS

Minimum inhibitory concentrations of the antibacterials studied were determined at a central laboratory using the NCCLS microdilution broth method. Macrolide resistance mechanisms were detected by PCR.

RESULTS

Of 779 Streptococcus pneumoniae isolates worldwide, 43% were non-susceptible to penicillin (18% intermediate; 25% resistant) and 37% were resistant to erythromycin, with considerable intercountry variation. Eighteen per cent of 653 Haemophilus influenzae and >90% of 316 Moraxella catarrhalis isolates produced beta-lactamase. Of 640 Streptococcus pyogenes isolates, 10% were resistant to erythromycin, with considerable intercountry variation. All S. pneumoniae and 99.8% of H. influenzae isolates were susceptible to telithromycin using breakpoints proposed to the NCCLS (<or=1 and <or=4 mg/L, respectively). All M. catarrhalis and 97% of S. pyogenes and isolates were susceptible to <or=1 mg/L telithromycin.

CONCLUSIONS

Antibacterial resistance complicates the empirical treatment of respiratory tract infections in children and requires continued monitoring. Telithromycin may be a useful therapeutic alternative as it is highly active against strains exhibiting various resistance phenotypes.

Treatment of sore throat in light of the Cochrane verdict: is the jury still out?

There are few good-quality studies of the effectiveness of antibiotic treatment of proven group A streptococcal (GAS) pharyngitis in children; available data suggest that antibiotics may reduce symptom duration. While there is limited justification for antibiotic treatment of GAS pharyngitis to prevent acute rheumatic fever in non-Indigenous Australians, there is no justification for routine antibiotic treatment of all patients with sore throat. Two strategies are open to clinicians: not to treat GAS pharyngitis with antibiotics, in which case no investigations should be done; or to treat cases of sore throat with clinical features that suggest GAS, in which case diagnosis should be confirmed with a throat swab, and penicillin started while awaiting the result. Penicillin should be discontinued if the swab is negative, or continued for 10 days if it is positive for GAS. Surveillance of GAS infections and acute rheumatic fever is needed in Australia, as are further studies of effectiveness (including cost-effectiveness) of antibiotic treatment of proven GAS pharyngitis.

Multivariate predictive models for group A beta-hemolytic streptococcal pharyngitis in children

OBJECTIVES

To create predictive models for the clinical diagnosis of group A beta-hemolytic streptococcal (GABHS) pharyngitis in children.

METHODS

Patients aged 6 months to 18 years presenting to a pediatric ED with suspected GABHS pharyngitis were prospectively enrolled in the study. Clinicians recorded pertinent clinical information using a standardized form and obtained a throat swab to culture GABHS using a reference standard method. Twelve demographic and clinical features of patients with positive throat cultures were compared with the features of patients with negative throat cultures. Significantly different features were entered in a stepwise logistic regression analysis to create predictive models for the diagnosis.

RESULTS

Eighty-five patients (29%) were culture-positive and 212 (71%) were culture-negative for GABHS. Respective mean ages were 6.2 years and 6.1 years in the two groups. Univariate chi-square analysis of the 12 features identified six variables that were significantly associated with GABHS. All significant features were initially included in a stepwise logistic regression analysis. In model I, four independent variables were identified: moderate to severe presentation of tonsillar swelling, moderate to severe tenderness and enlargement of cervical lymph nodes, the presence of scarlatiniform rash, and the absence of moderate to severe coryza, yielding a 95% probability for GABHS. Excluding the rare scarlatiniform rash, the remaining variables were used in the second regression analysis. In model II, three independent variables were identified: moderate to severe tonsillar swelling, moderate to severe tenderness and enlargement of cervical lymph nodes, and absence of moderate to severe coryza, yielding a probability of 65% for the diagnosis. A probability of <15% was observed in the absence of scarlatiniform rash, the absence of moderate to severe tenderness and enlargement of cervical lymph nodes, and the presence of moderate to severe coryza.

CONCLUSIONS

In children with moderate to severe presentation of tonsillar swelling, tenderness and enlargement of cervical lymph nodes, and the absence of coryza, the probability of a positive throat culture is >65%. Conversely, in the absence of a moderate to severe presentation of tonsillar swelling, enlargement of cervical nodes, and the presence of coryza, the probability of a positive throat culture is <15%. If prospectively validated, these models could be integrated into a consistent treat, test, and no treatment/no testing approach to the clinical management of childhood pharyngitis.