Use of saliva-based qPCR diagnostics for the accurate, rapid, and inexpensive detection of strep throat.

OBJECTIVES: Outpatient health care facilities are essential for quickly diagnosing common infectious diseases such as bacterial and viral pharyngitis. The only form of pharyngitis requiring antibiotics is strep throat (ST); however, antibiotic prescription rates are much higher than ST prevalence, suggesting antibiotics are being inappropriately prescribed. Current rapid ST diagnostics may be contributing to this problem due to the low sensitivity and variable specificity of these tests. It is best practice to verify a negative ST diagnosis with a group A Streptococcus (GAS) culture, but many clinics do not perform this test due to the additional cost and 24-72 h required to obtain results. This indicates there is great need for more accurate rapid diagnostic tools in outpatient facilities. We hypothesized that next generation qPCR technology could be adapted to detect GAS DNA from saliva samples (instead of the traditional throat swab) by creating a simple, fast, and inexpensive protocol. METHODS: Saliva specimens collected from patients at James Madison University Health Center were used to test the effectiveness of our Chelex 100-based rapid DNA extraction method, followed by a fast protocol developed for the Open qPCR machine to accurately detect ST. RESULTS: Our final saliva processing and qPCR protocol required no specialized training to perform and was able to detect ST with 100 % sensitivity and 100 % specificity (n=102) in 22-26 min, costing only $1.12 per sample. CONCLUSIONS: Saliva can be rapidly analyzed via qPCR for the accurate and inexpensive detection of ST.

Internet Tool to Support Self-Assessment and Self-Swabbing of Sore Throat: Development and Feasibility Study.

BACKGROUND: Sore throat is a common problem and a common reason for the overuse of antibiotics. A web-based tool that helps people assess their sore throat, through the use of clinical prediction rules, taking throat swabs or saliva samples, and taking throat photographs, has the potential to improve self-management and help identify those who are the most and least likely to benefit from antibiotics. OBJECTIVE: We aimed to develop a web-based tool to help patients and parents or carers self-assess sore throat symptoms and take throat photographs, swabs, and saliva samples for diagnostic testing. We then explored the acceptability and feasibility of using the tool in adults and children with sore throats. METHODS: We used the Person-Based Approach to develop a web-based tool and then recruited adults and children with sore throats who participated in this study by attending general practices or through social media advertising. Participants self-assessed the presence of FeverPAIN and Centor score criteria and attempted to photograph their throat and take throat swabs and saliva tests. Study processes were observed via video call, and participants were interviewed about their views on using the web-based tool. Self-assessed throat inflammation and pus were compared to clinician evaluation of patients' throat photographs. RESULTS: A total of 45 participants (33 adults and 12 children) were recruited. Of these, 35 (78%) and 32 (71%) participants completed all scoring elements for FeverPAIN and Centor scores, respectively, and most (30/45, 67%) of them reported finding self-assessment relatively easy. No valid response was provided for swollen lymph nodes, throat inflammation, and pus on the throat by 11 (24%), 9 (20%), and 13 (29%) participants respectively. A total of 18 (40%) participants provided a throat photograph of adequate quality for clinical assessment. Patient assessment of inflammation had a sensitivity of 100% (3/3) and specificity of 47% (7/15) compared with the clinician-assessed photographs. For pus on the throat, the sensitivity was 100% (3/3) and the specificity was 71% (10/14). A total of 89% (40/45), 93% (42/45), 89% (40/45), and 80% (30/45) of participants provided analyzable bacterial swabs, viral swabs, saliva sponges, and saliva drool samples, respectively. Participants were generally happy and confident in providing samples, with saliva samples rated as slightly more acceptable than swab samples. CONCLUSIONS: Most adult and parent participants were able to use a web-based intervention to assess the clinical features of throat infections and generate scores using clinical prediction rules. However, some had difficulties assessing clinical signs, such as lymph nodes, throat pus, and inflammation, and scores were assessed as sensitive but not specific. Many participants had problems taking photographs of adequate quality, but most were able to take throat swabs and saliva samples.

Reducing Antibiotic Prescribing in Primary Care for Respiratory Illness.

BACKGROUND: One-third of outpatient antibiotic prescriptions for pediatric acute respiratory tract infections (ARTIs) are inappropriate. We evaluated a distance learning program's effectiveness for reducing outpatient antibiotic prescribing for ARTI visits. METHODS: In this stepped-wedge clinical trial run from November 2015 to June 2018, we randomly assigned 19 pediatric practices belonging to the Pediatric Research in Office Settings Network or the NorthShore University HealthSystem to 4 wedges. Visits for acute otitis media, bronchitis, pharyngitis, sinusitis, and upper respiratory infection for children 6 months to <11 years old without recent antibiotic use were included. Clinicians received the intervention as 3 program modules containing online tutorials and webinars on evidence-based communication strategies and antibioti c prescribing, booster video vignettes, and individualized antibiotic prescribing feedback reports over 11 months. The primary outcome was overall antibiotic prescribing rates for all ARTI visits. Mixed-effects logistic regression compared prescribing rates during each program module and a postintervention period to a baseline control period. Odds ratios were converted to adjusted rate ratios (aRRs) for interpretability. RESULTS: Among 72 723 ARTI visits by 29 762 patients, intention-to-treat analyses revealed a 7% decrease in the probability of antibiotic prescribing for ARTI overall between the baseline and postintervention periods (aRR 0.93; 95% confidence interval [CI], 0.90-0.96). Second-line antibiotic prescribing decreased for streptococcal pharyngitis (aRR 0.66; 95% CI, 0.50-0.87) and sinusitis (aRR 0.59; 95% CI, 0.44-0.77) but not for acute otitis media (aRR 0.93; 95% CI, 0.83-1.03). Any antibiotic prescribing decreased for viral ARTIs (aRR 0.60; 95% CI, 0.51-0.70). CONCLUSIONS: This program reduced antibiotic prescribing during outpatient ARTI visits; broader dissemination may be beneficial.

Assessment of Efficacy of BLIS-Producing Probiotic K12 for the Prevention of Group A Streptococcus Pharyngitis: a Short Communication.

The neutral outcome of the recently reported school-based trial of probiotic K12 (The effect of the oral probiotic Streptococcus salivarius K12 on group A streptococcus pharyngitis: a pragmatic trial in schools) can be attributed at least partially to several readily identifiable confounding factors. Mainly, the execution and outcome were negatively impacted by (a) the suboptimal efficacy and frequency of K12 administration, (b) the failure both clinically and microbiologically to adequately diagnose and distinguish active group A streptococci (GAS) pharyngitis from harmless GAS carriage, and (c) the exceptionally low occurrence of GAS in this population at the time of the probiotic intervention due to recent high-intensity antibiotic exposure.

The Impact of Clinical Pathways on Antibiotic Prescribing for Acute Otitis Media and Pharyngitis in the Emergency Department.

BACKGROUND: Although Italian pediatric antimicrobial prescription rates are among the highest in Europe, little action has been taken to improve the appropriateness of antimicrobial prescriptions. The primary aim of this study was to assess changes in antibiotic prescription before and after acute otitis media (AOM) and group A streptococcus (GAS) pharyngitis Clinical Pathway (CP) implementation; secondary aims were to compare treatment failures and to assess change in the total antibiotics costs before and after CP implementation. METHODS: Pre-post quasi-experimental study comparing the 6-month period before CP implementation (baseline period: October 15, 2014, through April 15, 2015) to the 6 months after intervention (postintervention: October 15, 2015, through April 15, 2016). RESULTS: Two hundred ninety-five pre- and 278 postintervention emergency department visits were associated with AOM. After CP implementation, there was an increase in "wait and see" approach and a decrease in overall prescription of broad-spectrum antibiotics from 53.2% to 32.4% (P < 0.001). One hundred fifty-one pre- and 166 postimplementation clinic visits were associated with GAS pharyngitis, with a decrease in broad-spectrum prescription after CP implementation (46.4% vs. 6.6%; P < 0.001). For both conditions, no difference was found in treatment failure, and total antibiotics cost was significantly reduced after CP implementation, with a decrease especially in broad-spectrum antibiotics costs. CONCLUSIONS: A reduction in broad-spectrum antibiotic prescriptions and a reduction in the total cost of antibiotics for AOM and GAS pharyngitis along with an increase in "wait and see" prescribing for AOM indicate effectiveness of CP for antimicrobial stewardship in this setting.

In vitro assessment of the ability of probiotics, blueberry and food carbohydrates to prevent S. pyogenes adhesion on pharyngeal epithelium and modulate immune responses.

Group A streptococci (GAS) cause 20-30% of pediatric pharyngitis episodes, which are a major cause of ambulatory care visits. Therefore, a strategy to prevent GAS dissemination in children could significantly benefit public healthcare. Contextually, we assessed the possibility of employing alternative food-grade strategies to be used with the oral probiotic L. helveticus MIMLh5 for the prevention of pharyngeal infections. First, we demonstrated through an antagonism-by-exclusion assay that guaran may potentially prevent S. pyogenes adhesion on pharyngeal cells. Subsequently, we showed that an anthocyanin-rich fraction extracted from wild blueberry (BbE) exerts anti-inflammatory effects on the human macrophage cell line U937. Finally, we showed that BbE reduces interferon-ß expression in MIMLh5-stimulated murine dendritic cells, resulting in a reduction in the pro-inflammatory cytokines IL-12 and TNF-α. In conclusion, this proof-of-concept study indicates that different food-grade strategies may be concomitantly adopted to potentially prevent GAS colonization and modulate local immune defences.

Throat swabs have no influence on the management of patients with sore throats.

BACKGROUND: Throat swabs are neither specific nor sensitive for micro-bacteria causing sore throat symptoms; however, current guidelines suggest they are still useful in some cases. METHOD: Retrospective and prospective analyses were conducted of throat swabs requested within the months of January 2016 and August 2016, respectively. RESULTS: The study comprised 247 patients. Fifty-nine (24 per cent) had a positive culture. Forty-six grew group A beta-haemolytic streptococci, with the remainder growing candida (n = 10), coliform (n = 1) and klebsiella (n = 2). There was no significant difference in culture rates between primary or secondary care sources (χ2 = 0.56, p = 0.45). None of the swabs influenced a variation in patient management from local antimicrobial policies. Current practice has an estimated annual financial impact of £3 434 340 on the National Health Service. CONCLUSION: Throat swabs do not influence the antimicrobial treatment for patients with sore throats, even under current guidelines, and incur unnecessary cost. Current clinical guidelines could be reviewed to reduce the number of throat swabs being conducted unnecessarily.

Development of a fast and low-cost qPCR assay for diagnosis of acute gas pharyngitis.

BACKGROUND: Group A streptococci (GAS) are the most common bacterial cause of acute pharyngitis and account for 15-30 % of cases of acute pharyngitis in children and 5-10 % of cases in adults. In this study, a real-time quantitative PCR (qPCR) based GAS detection assay in pharyngeal swab specimens was developed. METHODS: The qPCR assay was compared with the gold standard bacterial culture and a rapid antigen detection test (RADT) to evaluate its clinical performance in 687 patients. The analytical sensitivity of the assay was 240 cfu/swab. Forty-five different potential cross-reacting organisms did not react with the test. Four different laboratories for the reproducibility studies were in 100 % (60/60) agreement for the contrived GAS positive and negative swab samples. RESULTS: The relative sensitivities of the RADT and the qPCR test were 55.9 and 100 %; and the relative specificities were 100 and 96.3 %, respectively. Duration of the total assay for 24 samples including pre-analytical processing and analysis changed between 42 and 55 min depending on the type of qPCR instrument used. A simple DNA extraction method and a low qPCR volume made the developed assay an economical alternative for the GAS detection. CONCLUSION: We showed that the developed qPCR test is rapid, cheap, sensitive and specific and therefore can be used to replace both antigen detection and culture for diagnosis of acute GAS pharyngitis.

Variation in US outpatient antibiotic prescribing quality measures according to health plan and geography.

OBJECTIVES: Antibiotic prescribing has become increasingly viewed as an issue related to patient safety and quality of care. The objective of this study was to better understand the differences between health plan reporting and the geographic variation seen in quality measures related to antibiotic use. STUDY DESIGN: We focused on 3 measures from the Healthcare Effectiveness Data and Information Set (HEDIS) related to antibiotic prescribing and testing to guide antibiotic prescribing. METHODS: We analyzed data for 3 relevant measures for the years 2008 to 2012, including only commercial health plans. We analyzed the following 3 HEDIS measures: 1) "Appropriate Testing for Children With Pharyngitis," 2) "Appropriate Treatment for Children With Upper Respiratory Infections," and 3) "Avoidance of Antibiotic Treatment in Adults With Acute Bronchitis." RESULTS: Out of these 3 measures, health plans consistently performed poorly on the adult bronchitis measure. Performance was better on the 2 measures focused on the pediatric population. We also saw geographic variation between measures when looking at Census divisions across all years. CONCLUSIONS: There is wide variation between individual health plan performance on the measures related to antibiotic use. Geographic differences were also observed on these measures, with health plans in the South Central Census division performing worse than other parts of the country. Stakeholders, such as public health, advocacy groups, foundations, and professional societies, interested in improving the quality of care that patients receive related to antibiotic use in the outpatient setting should consider how existing measures and working with health plans could be used to improve prescribing.

The Effect of Rapid Antigen Detection Test on Antibiotic Prescription Decision of Clinicians and Reducing Antibiotic Costs in Children with Acute Pharyngitis.

We aimed to investigate the effect of rapid antigen detection test (RADT) in the diagnosis of streptococcal pharyngitis, its impact on antibiotic prescription decision of pediatricians and influence on reduction of antibiotic treatment costs in children with pharyngitis. The study group consisted of 223 patients who were diagnosed with pharyngitis by pediatricians. The sensitivity and specificity of RADT were 92.1% (95% Cl: 78.6-98.3%) and 97.3% (95% Cl: 93.8-99.1%), respectively. In the first assessment, before performing RADT, pediatricians decided to prescribe antibiotics for 178 (79.8%) patients with pharyngitis. After learning RADT results, pediatricians finally decided to prescribe antibiotics for 83 (37.2%) patients with pharyngitis, and antibiotic prescription decreased by 42.6%. Antibiotic costs in non-Group A streptococcus pharyngitis, Group A streptococcus pharyngitis and all subjects groups decreased by 80.8%, 48%, and 76.4%, respectively. Performing RADT in children with pharyngitis has an important impact on treatment decision of clinicians, reduction of unnecessary antibiotic prescriptions and antibiotic costs.

Randomised, double-blind, placebo-controlled studies on flurbiprofen 8.75 mg lozenges in patients with/without group A or C streptococcal throat infection, with an assessment of clinicians' prediction of 'strep throat'.

BACKGROUND: Diagnosing group A streptococcus (Strep A) throat infection by clinical examination is difficult, and misdiagnosis may lead to inappropriate antibiotic use. Most patients with sore throat seek symptom relief rather than antibiotics, therefore, therapies that relieve symptoms should be recommended to patients. We report two clinical trials on the efficacy and safety of flurbiprofen 8.75 mg lozenge in patients with and without streptococcal sore throat. METHODS: The studies enrolled adults with moderate-to-severe throat symptoms (sore throat pain, difficulty swallowing and swollen throat) and a diagnosis of pharyngitis. The practitioner assessed the likelihood of Strep A infection based on historical and clinical findings. Patients were randomised to flurbiprofen 8.75 mg or placebo lozenges under double-blind conditions and reported the three throat symptoms at baseline and at regular intervals over 24 h. RESULTS: A total of 402 patients received study medication (n = 203 flurbiprofen, n = 199 placebo). Throat culture identified Strep A in 10.0% of patients and group C streptococcus (Strep C) in a further 14.0%. The practitioners' assessments correctly diagnosed Strep A in 11/40 cases (sensitivity 27.5%, and specificity 79.7%). A single flurbiprofen lozenge provided significantly greater relief than placebo for all three throat symptoms, lasting 3-4 h for patients with and without Strep A/C. Multiple doses of flurbiprofen lozenges over 24 h also led to symptom relief, although not statistically significant in the Strep A/C group. There were no serious adverse events. CONCLUSIONS: The results highlight the challenge of identifying Strep A based on clinical features. With the growing problem of antibiotic resistance, non-antibiotic treatments should be considered. As demonstrated here, flurbiprofen 8.75 mg lozenges are an effective therapeutic option, providing immediate and long-lasting symptom relief in patients with and without Strep A/C infection.

Rapid antigen group A streptococcus test to diagnose pharyngitis: a systematic review and meta-analysis.

BACKGROUND: Pharyngitis management guidelines include estimates of the test characteristics of rapid antigen streptococcus tests (RAST) using a non-systematic approach. OBJECTIVE: To examine the sensitivity and specificity, and sources of variability, of RAST for diagnosing group A streptococcal (GAS) pharyngitis. DATA SOURCES: MEDLINE, Cochrane Reviews, Centre for Reviews and Dissemination, Scopus, SciELO, CINAHL, guidelines, 2000-2012. STUDY SELECTION: Culture as reference standard, all languages. DATA EXTRACTION AND SYNTHESIS: Study characteristics, quality. MAIN OUTCOME(S) AND MEASURE(S): Sensitivity, specificity. RESULTS: We included 59 studies encompassing 55,766 patients. Forty three studies (18,464 patients) fulfilled the higher quality definition (at least 50 patients, prospective data collection, and no significant biases) and 16 (35,634 patients) did not. For the higher quality immunochromatographic methods in children (10,325 patients), heterogeneity was high for sensitivity (inconsistency [I(2)] 88%) and specificity (I(2) 86%). For enzyme immunoassay in children (342 patients), the pooled sensitivity was 86% (95% CI, 79-92%) and the pooled specificity was 92% (95% CI, 88-95%). For the higher quality immunochromatographic methods in the adult population (1,216 patients), the pooled sensitivity was 91% (95% CI, 87 to 94%) and the pooled specificity was 93% (95% CI, 92 to 95%); however, heterogeneity was modest for sensitivity (I(2) 61%) and specificity (I(2) 72%). For enzyme immunoassay in the adult population (333 patients), the pooled sensitivity was 86% (95% CI, 81-91%) and the pooled specificity was 97% (95% CI, 96 to 99%); however, heterogeneity was high for sensitivity and specificity (both, I(2) 88%). CONCLUSIONS: RAST immunochromatographic methods appear to be very sensitive and highly specific to diagnose group A streptococcal pharyngitis among adults but not in children. We could not identify sources of variability among higher quality studies. The present systematic review provides the best evidence for the wide range of sensitivity included in current guidelines.

Oral corticosteroid use for clinical and cost-effective symptom relief of sore throat: study protocol for a randomized controlled trial.

BACKGROUND: Management of acute sore throat poses a significant burden on UK general practices, with almost 10% of registered patients attending their GP with sore throat every year. Nearly half of all patients presenting with acute sore throat are treated with antibiotics, despite their limited effect. In a recent systematic review we demonstrated that a single dose of steroids reduced the severity and time to resolution of sore throat. However, all of the trials included looked at the use of steroids alongside antibiotics and only one was in a primary care setting. This trial aims to assess the efficacy and cost-effectiveness of a single oral dose of corticosteroids on symptoms of sore throat in patients receiving either a delayed antibiotic prescription or no antibiotics at all in UK primary care. METHODS/DESIGN: A double-blind, two arm, randomized, placebo controlled trial in adults (≥ 18 years of age) presenting to primary care with acute sore throat (

PRImary care Streptococcal Management (PRISM) study: in vitro study, diagnostic cohorts and a pragmatic adaptive randomised controlled trial with nested qualitative study and cost-effectiveness study.

BACKGROUND: Antibiotics are still prescribed to most patients attending primary care with acute sore throat, despite evidence that there is modest benefit overall from antibiotics. Targeting antibiotics using either clinical scoring methods or rapid antigen detection tests (RADTs) could help. However, there is debate about which groups of streptococci are important (particularly Lancefield groups C and G), and uncertainty about the variables that most clearly predict the presence of streptococci. OBJECTIVE: This study aimed to compare clinical scores or RADTs with delayed antibiotic prescribing. DESIGN: The study comprised a RADT in vitro study; two diagnostic cohorts to develop streptococcal scores (score 1; score 2); and, finally, an open pragmatic randomised controlled trial with nested qualitative and cost-effectiveness studies. SETTING: The setting was UK primary care general practices. PARTICIPANTS: Participants were patients aged ≥ 3 years with acute sore throat. INTERVENTIONS: An internet program randomised patients to targeted antibiotic use according to (1) delayed antibiotics (control group), (2) clinical score or (3) RADT used according to clinical score. MAIN OUTCOME MEASURES: The main outcome measures were self-reported antibiotic use and symptom duration and severity on seven-point Likert scales (primary outcome: mean sore throat/difficulty swallowing score in the first 2-4 days). RESULTS: The IMI TestPack Plus Strep A (Inverness Medical, Bedford, UK) was sensitive, specific and easy to use. Lancefield group A/C/G streptococci were found in 40% of cohort 2 and 34% of cohort 1. A five-point score predicting the presence of A/C/G streptococci [FeverPAIN: Fever; Purulence; Attend rapidly (≤ 3 days); severe Inflammation; and No cough or coryza] had moderate predictive value (bootstrapped estimates of area under receiver operating characteristic curve: 0.73 cohort 1, 0.71 cohort 2) and identified a substantial number of participants at low risk of streptococcal infection. In total, 38% of cohort 1 and 36% of cohort 2 scored ≤ 1 for FeverPAIN, associated with streptococcal percentages of 13% and 18%, respectively. In an adaptive trial design, the preliminary score (score 1; n = 1129) was replaced by FeverPAIN (n = 631). For score 1, there were no significant differences between groups. For FeverPAIN, symptom severity was documented in 80% of patients, and was lower in the clinical score group than in the delayed prescribing group (-0.33; 95% confidence interval -0.64 to -0.02; p = 0.039; equivalent to one in three rating sore throat a slight rather than moderately bad problem), and a similar reduction was observed for the RADT group (-0.30; -0.61 to 0.00; p = 0.053). Moderately bad or worse symptoms resolved significantly faster (30%) in the clinical score group (hazard ratio 1.30; 1.03 to 1.63) but not the RADT group (1.11; 0.88 to 1.40). In the delayed group, 75/164 (46%) used antibiotics, and 29% fewer used antibiotics in the clinical score group (risk ratio 0.71; 0.50 to 0.95; p = 0.018) and 27% fewer in the RADT group (0.73; 0.52 to 0.98; p = 0.033). No significant differences in complications or reconsultations were found. The clinical score group dominated both other groups for both the cost/quality-adjusted life-years and cost/change in symptom severity analyses, being both less costly and more effective, and cost-effectiveness acceptability curves indicated the clinical score to be the most likely to be cost-effective from an NHS perspective. Patients were positive about RADTs. Health professionals' concerns about test validity, the time the test took and medicalising self-limiting illness lessened after using the tests. For both RADTs and clinical scores, there were tensions with established clinical experience. CONCLUSIONS: Targeting antibiotics using a clinical score (FeverPAIN) efficiently improves symptoms and reduces antibiotic use. RADTs used in combination with FeverPAIN provide no clear advantages over FeverPAIN alone, and RADTs are unlikely to be incorporated into practice until health professionals' concerns are met and they have experience of using them. Clinical scores also face barriers related to clinicians' perceptions of their utility in the face of experience. This study has demonstrated the limitation of using one data set to develop a clinical score. FeverPAIN, derived from two data sets, appears to be valid and its use improves outcomes, but diagnostic studies to confirm the validity of FeverPAIN in other data sets and settings are needed. Experienced clinicians need to identify barriers to the use of clinical scoring methods. Implementation studies that address perceived barriers in the use of FeverPAIN are needed. TRIAL REGISTRATION: Current Controlled Trials ISRCTN32027234. SOURCE OF FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 6. See the NIHR Journals Library website for further project information.

A cost-effective strategy for primary prevention of acute rheumatic fever and rheumatic heart disease in children with pharyngitis.

Primary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) in children depends on prompt and effective diagnosis and treatment of pharyngitis at the primary level of care. Cost-effectiveness modeling shows that the most cost-effective strategy for primary prevention in South Africa (SA) is to use a simple symptomatic clinical decision rule (CDR) to diagnose pharyngitis in children presenting at the primary level of care and then to treat them with a single dose of intramuscular penicillin. Treat All and CDR2+ strategies are affordable and simple and miss few cases of streptococcal pharyngitis at the primary level of care. The CDR2+ strategy is the most cost-effective for primary prevention of ARF and RHD in urban SA and should complement primordial and secondary prevention efforts.

Diagnosis of acute tonsillopharyngitis in primary care: a new approach for low-resource settings.

BACKGROUND: Diagnosing GABHS (Group A-beta Hemolytic Streptococcus) tonsillopharyngitis by clinical scoring is a recommended approach in developed countries, but there is still much controversy for low resource settings. AIM: We aimed to assess the impact of Centor criteria with the support of practical laboratory tests. METHODS: We prospectively included patients complaining sore throat (N = 282). We evaluated them in terms of Centor scoring and performed white blood cell count (WBC), C-reactive protein (CRP), rapid antigen detecting test, and throat culture. RESULTS: In GABHS cases (N = 32, 11·3%), two of the criteria were observed to be positive in more than half of the cases (N = 19, 59·3%), while 13 (40·7%) cases met three/four criteria. The specificity of having two criteria was found to be 65·5% and increased to 91·5% after including CRP and WBC. CONCLUSION: Centor criteria could be safely used to reduce unnecessary antibiotic usage for tonsillopharyngitis in developing countries.

Primary prevention of acute rheumatic fever and rheumatic heart disease with penicillin in South African children with pharyngitis: a cost-effectiveness analysis.

BACKGROUND: Acute rheumatic fever and subsequent rheumatic heart disease remain significant in developing countries. We describe a cost-effective analysis of 7 strategies for the primary prevention of acute rheumatic fever and rheumatic heart disease in children presenting with pharyngitis in urban primary care clinics in South Africa. METHODS AND RESULTS: We used a Markov model to assess the cost-effectiveness of treatment with intramuscular penicillin using each of the following strategies: (1) empirical (treat all); (2) positive throat culture (culture all); (3) clinical decision rule (CDR) score ≥2 (CDR 2+); (4) CDR score ≥3 (CDR 3+); (5) treating those with a CDR score ≥2 plus those with CDR score <2 and positive cultures (CDR 2+, culture CDR negatives); (6) treating those with a CDR score ≥3 plus those with CDR score <3 and positive cultures (CDR 3+, culture CDR negatives); and (7) treat none. The strategies ranked in order from lowest cost were treat all ($11.19 per child), CDR 2+ ($11.20); the CDR 3+ ($13.00); CDR 2+, culture CDR negatives ($16.42); CDR 3+, culture CDR negatives ($23.89); and culture all ($27.21). The CDR 2+ is the preferred strategy at less than $150/quality-adjusted life year compared with the treat all strategy. A strategy of culturing all children compared with the CDR 2+ strategy costs more than $125 000/quality-adjusted life year gained. CONCLUSIONS: Treating all children presenting with pharyngitis in urban primary care clinics in South Africa with intramuscular penicillin is the least costly. A strategy of using a clinical decision rule without culturing is overall the preferred strategy. A strategy of culturing all children may be prohibitively expensive.

Management of adults with acute streptococcal pharyngitis: minimal value for backup strep testing and overuse of antibiotics.

BACKGROUND: Rapid antigen detection tests (RADT) are commonly used to guide appropriate antibiotic treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis. In adults, there is controversy about the need for routine backup testing of negative RADT. OBJECTIVE: Estimate the costs and benefits in adults of routine backup testing by DNA Gen-probe of negative RADT (Acceava). DESIGN: Observational follow-up study. PARTICIPANTS: All patients aged 18 years and older visiting a Cleveland Clinic generalist physician in 2009 and 2010 with a visit diagnosis of acute pharyngitis (ICD codes 462, 034.0). MAIN MEASURES: The patients were identified using the Cleveland Clinic Epic Clarity database. We determined the proportion of false negative RADT, antibiotic prescription patterns and rate of serious suppurative complications within 30 days of the office visit. KEY RESULTS: Of 25,130 patients with acute pharyngitis, 19% had no testing and 81% were tested. Of the 15,555 patients that had a negative RADT and follow-up DNA probe, 6% had a positive DNA probe. Of the 953 patients who had a negative RADT and a positive DNA strep probe, 48% received an antibiotic prescription at the time of the visit and 51% received an antibiotic prescription after an average of 2.3 days. Only one patient with a negative RADT and no follow-up DNA probe developed a peritonsillar abscess. Overall, of the 15,555 DNA probes performed, management was altered in only 3% of the patients at a total cost of $1,757,715. Fifty-six percent received an antibiotic while only 19.5% had a confirmed strep throat diagnosis. CONCLUSIONS: The false negative rate of Acceava RADT for the diagnosis of GABHS pharyngitis was 6%. We question the benefit of routine DNA probe backup testing in adults because of its substantial cost, an average delay in antibiotic prescribing of over 2 days, and because suppurative complications are very uncommon. We found a high rate of inappropriate antibiotic prescribing.