The aetiology of pharyngotonsillitis in primary health care: a prospective observational study

Use of point-of-care tests in pharyngotonsillitis - a registry-based study in primary health care

BACKGROUND

Point-of-care (POC) tests, including C-reactive protein (CRP) tests and rapid antigen detection tests (RADT) for group A streptococci (GAS), are widely used in Swedish primary health care (PHC). This study quantifies their use in pharyngotonsillitis and explore their association with antibiotic prescribing.

MATERIAL AND METHODS

Retrospective data from 2012-2016 in Region Kronoberg, Sweden, included all PHC visits with a pharyngotonsillitis diagnosis. Patient characteristics, test usage and antibiotic prescriptions were linked by visit date and personal identification number. Descriptive statistics were used for POC test analysis. Logistic regression assessed the association between CRP levels and antibiotic prescribing.

RESULTS

Of 24,237 visits, 68% included RADT and 36% included a CRP test, with 89% of CRP tests performed alongside RADT. CRP testing was more frequent in patients with negative (56%) than positive RADTs (42%) (p < .001). Overall, 66% of RADTs were positive. Median CRP levels were 23 mg/l for positive RADT and 31 mg/l for negative RADT (p < .001). Antibiotics were prescribed for 95% of positive RADTs and 43% of negative RADTs (p < .001). In patients with negative RADTs, CRP testing was associated with higher antibiotic prescribing (57%) compared to no CRP testing (26%) (p < .001). Among these patients, CRP levels were associated with prescribing (aOR 1.032; 95% CI 1.029-1.035; p < .001), with 50% of prescriptions occuring at CRP levels ≤ 20 mg/l.

CONCLUSION

The use of RADTs and the proportion of positive test were higher than expected, indicating inappropriate use and diagnostic bias. CRP testing, contrary to guidelines, was common and associated with increased antibiotic prescribing.

Impact of COVID-19 health precautions on asymptomatic Streptococcus pyogenes carriage in palestinian children: a pre- and post-pandemic study

BACKGROUND

Streptococcus pyogenes (Group A Streptococcus, GAS) is a significant pathogen that causes diverse infections, ranging from pharyngitis to severe invasive diseases. Asymptomatic carriage in children is pivotal for transmission. The COVID-19 pandemic's health measures, including mask wearing and enhanced hand hygiene, likely influenced GAS transmission dynamics. This study evaluated the impact of these precautions on the prevalence of asymptomatic pharyngeal GAS carriage among schoolchildren in the southern West Bank, Palestine.

METHODS

This cross-sectional study was conducted in two phases: pre-COVID-19 (November 2019-January 2020) and post-COVID-19 (November 2023-April 2024). Throat swabs were collected from 701 children (345 pre-COVID-19, 356 post-COVID-19) via cluster sampling. The samples were tested with the ABON Strep A rapid test and confirmed by culture. Sociodemographic, health, and household data were also collected. The statistical analyses included descriptive statistics, chi-square tests, and binary logistic regression.

RESULTS

The prevalence of asymptomatic pharyngeal GAS carriage declined from 15.7% pre-COVID-19 to 10.4% post-COVID-19 (p = 0.038). Significant reductions were observed among urban residents (23.5-10.1%, p = 0.003) and those from medium socioeconomic backgrounds (16.0-9.1%, p = 0.008). Compared with urban residents, rural residents had lower GAS carriage rates (adjusted OR = 0.505, p = 0.023). Carriage rates also decreased among children with frequent sore throats (17.6-7.3%, p = 0.007) and those using private wells (52.5-14.9%, p < 0.001). Higher BMI was a significant risk factor (adjusted OR = 17.68, p < 0.001), whereas frequent tooth brushing (adjusted OR = 0.055, p < 0.001) and hand washing (adjusted OR = 0.367, p < 0.001) were protective factors.

CONCLUSIONS

COVID-19-related health precautions were correlated with a significant reduction in asymptomatic GAS carriage among Palestinian children. These findings suggest that public health measures, such as mask wearing and hand hygiene, can influence the transmission of respiratory pathogens. Ongoing surveillance and targeted interventions are essential for managing GAS infections, particularly in resource-limited settings.

MV130 in the Prevention of Recurrent Respiratory Tract Infections: A Retrospective Real-World Study in Children and Adults

Respiratory tract infections (RTIs) are among the most common and important problems in clinical medicine, making antibiotics the gold standard therapeutic option regardless of their frequent viral etiology. Their excessive and inappropriate use contributes to the rapid rise of antibiotic resistance and underscores the need for alternative strategies, especially when dealing with recurrent RTIs. Prevention is the ideal alternative, but specific vaccines targeting a wide range of respiratory pathogens are scarce. MV130 is a sublingual bacterial vaccine that induces trained immunity and provides non-specific protection against respiratory pathogens in various clinical settings according to the concept of TIbV (Trained Immunity-based Vaccine). A retrospective real-world study (RWS) was conducted to evaluate the annual incidence of RTIs and the consumption of antibiotics before and after the administration of MV130, using data sourced from the medical records of 599 patients (186 children and 413 adults) who suffered from recurrent RTIs. The median number of infectious episodes in children was significantly reduced by more than 70% from 5 episodes (interquartile range (IQR) 4.0-6.0) to 1 (IQR, 0.0-2.0) (p < 0.001) after MV130. Similarly, in adults, the median number of episodes before MV130 immunization was 5 (IQR, 4.0-6.0), which dropped by more than 80% to 1 (IQR, 0.0-1.0) during the year following MV130 immunization (p < 0.001). The median number of antibiotic courses also significantly decreased for both children and adults by over 80% (p < 0.001). This RWS showed that MV130 is an effective strategy for the prevention of respiratory infections and the reduction of associated antibiotic consumption.

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.

The use and usefulness of point-of-care tests in patients with pharyngotonsillitis - an observational study in primary health care

BACKGROUND

Rapid antigen detection tests (RADT) for Group A streptococci (GAS) and point-of-care tests for C-reactive protein (CRP) are commonly used in patients with pharyngotonsillitis in Sweden and Denmark although CRP testing is not supported by guidelines. We aimed to describe (1) the proportion of patients tested with RADT and/or CRP, (2) the relation between test results and antibiotic prescribing, and (3) the association between CRP level and microbial aetiology.

METHODS

We used a post-hoc-analysis of data collected in primary health care in a prospective aetiological study of 220 patients 15-45 years old diagnosed with pharyngotonsillitis. The outcomes of RADTs and CRP tests were related to antibiotic prescribing and microbial aetiology.

RESULTS

A RADT was used in 94% of the patients. A CRP test was used in 50% of the patients but more commonly in those with a negative RADT (59%) than in those with a positive RADT (38%) (p = 0.005). Most (74%) CRP tests were used in patients with a negative RADT. Antibiotic prescribing differed greatly between patients with a positive RADT (96%) and patients with a negative RADT (17%) (p < 0.001). In patients with a negative RADT, there was a positive association between CRP value and antibiotic prescribing (OR 1.05; 95% CI 1.02-1.07; p < 0.001). Patients with CRP values ≤ 30 mg/l were seldomly prescribed antibiotics. Patients with GAS in culture had the highest median CRP (46 mg/l), which was higher than in patients without GAS (8 mg/l; p < 0.001). However, the positive predictive value for GAS never exceeded 0.60 (95% CI 0.31-0.83) at the investigated CRP levels.

CONCLUSIONS

The widespread use of tests is a major deviation from national guidelines. Most CRP tests were used in patients with a negative RADT, suggesting a belief in the added value of a CRP test, and the CRP result seemed to influence antibiotic prescribing. However, as an aetiological test, CRP is not useful for predicting GAS.

Different antibiotic treatments for group A streptococcal pharyngitis

BACKGROUND

Antibiotics provide only modest benefit in treating sore throat, although their effectiveness increases in people with positive throat swabs for group A beta-haemolytic streptococci (GABHS). It is unclear which antibiotic is the best choice if antibiotics are indicated. This is an update of a review first published in 2010, and updated in 2013, 2016, and 2021.

OBJECTIVES

To assess the comparative efficacy of different antibiotics in: (a) alleviating symptoms (pain, fever); (b) shortening the duration of the illness; (c) preventing clinical relapse (i.e. recurrence of symptoms after initial resolution); and (d) preventing complications (suppurative complications, acute rheumatic fever, post-streptococcal glomerulonephritis). To assess the evidence on the comparative incidence of adverse effects and the risk-benefit of antibiotic treatment for streptococcal pharyngitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2023, Issue 2), MEDLINE Ovid, Embase Elsevier, and Web of Science (Clarivate) up to 19 March 2023.

SELECTION CRITERIA

Randomised, double-blind trials comparing different antibiotics, and reporting at least one of the following: clinical cure, clinical relapse, or complications and/or adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened trials for inclusion and extracted data using standard methodological procedures recommended by Cochrane. We assessed the risk of bias in the included studies according to the methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions, and used the GRADE approach to assess the overall certainty of the evidence for the outcomes. We reported the intention-to-treat analysis, and also performed an analysis of evaluable participants to explore the robustness of the intention-to-treat results.

MAIN RESULTS

We included 19 trials reported in 18 publications (5839 randomised participants): six trials compared penicillin with cephalosporins; six compared penicillin with macrolides; three compared penicillin with carbacephem; one compared penicillin with sulphonamides; one compared clindamycin with ampicillin; and one compared azithromycin with amoxicillin in children. All participants had confirmed acute GABHS tonsillopharyngitis, and ages ranged from one month to 80 years. Nine trials included only, or predominantly, children. Most trials were conducted in an outpatient setting. Reporting of randomisation, allocation concealment, and blinding was poor in all trials. We downgraded the certainty of the evidence mainly due to lack of (or poor reporting of) randomisation or blinding, or both, heterogeneity, and wide confidence intervals. Cephalosporins versus penicillin We are uncertain if there is a difference in symptom resolution (at 2 to 15 days) for cephalosporins versus penicillin (odds ratio (OR) for absence of symptom resolution 0.79, 95% confidence interval (CI) 0.55 to 1.12; 5 trials, 2018 participants; low-certainty evidence). Results of the sensitivity analysis of evaluable participants differed (OR 0.51, 95% CI 0.27 to 0.97; 5 trials, 1660 participants; very low-certainty evidence). Based on an analysis of evaluable participants, we are uncertain if clinical relapse may be lower for cephalosporins compared with penicillin (OR 0.55, 95% CI 0.30 to 0.99; number needed to treat for an additional beneficial outcome (NNTB) 50; 4 trials, 1386 participants; low-certainty evidence). Very low-certainty evidence showed no difference in reported adverse events. Macrolides versus penicillin We are uncertain if there is a difference between macrolides and penicillin for resolution of symptoms (OR 1.11, 95% CI 0.92 to 1.35; 6 trials, 1728 participants; low-certainty evidence). Sensitivity analysis of evaluable participants resulted in an OR of 0.79 (95% CI 0.57 to 1.09; 6 trials, 1159 participants). We are uncertain if clinical relapse may be different (OR 1.21, 95% CI 0.48 to 3.03; 6 trials, 802 participants; low-certainty evidence). Children treated with macrolides seemed to experience more adverse events than those treated with penicillin (OR 2.33, 95% CI 1.06 to 5.15; 1 trial, 489 participants; low-certainty evidence). However, the test for subgroup differences between children and adults was not significant. Azithromycin versus amoxicillin Based on one unpublished trial in children, we are uncertain if resolution of symptoms is better with azithromycin in a single dose versus amoxicillin for 10 days (OR 0.76, 95% CI 0.55 to 1.05; 1 trial, 673 participants; very low-certainty evidence). Sensitivity analysis for per-protocol analysis resulted in an OR of 0.29 (95% CI 0.11 to 0.73; 1 trial, 482 participants; very low-certainty evidence). We are also uncertain if there was a difference in relapse between groups (OR 0.88, 95% CI 0.43 to 1.82; 1 trial, 422 participants; very low-certainty evidence). Adverse events were more common with azithromycin compared to amoxicillin (OR 2.67, 95% CI 1.78 to 3.99; 1 trial, 673 participants; very low-certainty evidence). Carbacephem versus penicillin There is low-certainty evidence that compared with penicillin, carbacephem may provide better symptom resolution post-treatment in adults and children (OR 0.70, 95% CI 0.49 to 0.99; NNTB 14.3; 3 trials, 795 participants). Studies did not report on long-term complications, so it was unclear if any class of antibiotics was better at preventing serious but rare complications.

AUTHORS' CONCLUSIONS

We are uncertain if there are clinically relevant differences in symptom resolution when comparing cephalosporins and macrolides with penicillin in the treatment of GABHS tonsillopharyngitis. Low-certainty evidence in children suggests that carbacephem may be more effective than penicillin for symptom resolution. There is insufficient evidence to draw conclusions regarding the other comparisons in this review. Data on complications were too scarce to draw conclusions. Antibiotics have a limited effect in the treatment of GABHS pharyngitis and the results do not demonstrate that other antibiotics are more effective than penicillin. In the context of antimicrobial stewardship, penicillin can be used if treatment with an antibiotic is indicated. All studies were conducted in high-income countries with a low risk of streptococcal complications, so there is a need for trials in low-income countries and disadvantaged populations, where the risk of complications remains high.

What is the optimal strategy for managing primary care patients with an uncomplicated acute sore throat? Comparing the consequences of nine different strategies using a compilation of previous studies

OBJECTIVE

Identifying optimal strategies for managing patients of any age with varying risk of acute rheumatic fever (ARF) attending for an apparently uncomplicated acute sore throat, also clarifying the role of point-of-care testing (POCT) for presence of group A beta-haemolytic Streptococcus (GABHS) in these settings.

DESIGN

We compared outcomes of adhering to nine different strategies for managing these patients in primary healthcare.

SETTING AND PARTICIPANTS

The nine strategies, similar to guidelines from several countries, were tested against two validation data sets being constructs from seven prior studies.

MAIN OUTCOME MEASURES

The proportion of patients requiring a POCT, prescribed antibiotics, prescribed antibiotics having GABHS and finally having GABHS not prescribed antibiotics, if different strategies had been adhered to.

RESULTS

In a scenario with high risk of ARF, adhering to existing guidelines would risk many patients ill from GABHS left without antibiotics. Hence, using a POCT on all of these patients minimised their risk. For low-risk patients, it is reasonable to only consider antibiotics if the patient has more than low pain levels despite adequate analgesia, 3-4 Centor scores (or 2-3 FeverPAIN scores or 3-4 McIsaac scores) and a POCT confirming the presence of GABHS. This would require testing only 10%-15% of patients and prescribing antibiotics to only 3.5%-6.6%.

CONCLUSIONS

Patients with high or low risk for ARF needs to be managed very differently. POCT can play an important role in safely targeting the use of antibiotics for patients with an apparently uncomplicated acute sore throat.