Acute sore throat and Fusobacterium necrophorum in primary healthcare: a systematic review and meta-analysis

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.

Best management of patients with an acute sore throat – a critical analysis of current evidence and a consensus of experts from different countries and traditions

BACKGROUND

There is a very large body of publications discussing the management of patients with an acute sore throat. Advocates for a restrictive antibiotic policy and advocates for a more liberal use of antibiotics emphasise different and valid arguments and to date have not been able to unite in a consensus. Contradicting guidelines based on the same body of knowledge is not logical, may cause confusion and cause unwanted variation in clinical management.

METHODS

In multiple video meetings and email correspondence from March to November 2022 and finally in a workshop at the annual meeting for the North American Primary Care Group in November 2022, experts from different countries representing different traditions agreed on how the current evidence should be interpreted.

RESULTS

This critical analysis identifies that the problem can be resolved by introducing a new triage scheme considering both the acute risk for suppurative complications and sepsis as well as the long-term risk of developing rheumatic fever.

CONCLUSIONS

The new triage scheme may solve the long-standing problem of advocating for a restrictive use of antibiotics while also satisfying concerns that critically ill patients might be missed with severe consequences. We acknowledge that the perspective of this problem is vastly different between high- and low-income countries. Furthermore, we discuss the new trend which allows nurses and pharmacists to independently manage these patients and the increased need for safety netting required for such management.

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.

Association between bacterial finding, antibiotic treatment and clinical course in patients with pharyngotonsillitis: a registry-based study in primary healthcare in Sweden

Background

The role of non-group A streptococci and Fusobacterium necrophorum in pharyngotonsillitis has been disputed and few prospective studies have evaluated the effect of antibiotic treatment. This study uses registry data to investigate the relation between antibiotic prescription for pharyngotonsillitis in primary healthcare and return visits for pharyngotonsillitis, complications, and tonsillectomy.

Methods

Retrospective data were extracted from the regional electronic medical record system in Kronoberg County, Sweden, for all patients diagnosed with pharyngotonsillitis between 2012 and 2016. From these data, two cohorts were formed: one based on rapid antigen detection tests (RADT) for group A streptococci (GAS) and one based on routine throat cultures for β-haemolytic streptococci and F. necrophorum. The 90 days following the inclusion visit were assessed for new visits for pharyngotonsillitis, complications, and tonsillectomy, and related to bacterial aetiology and antibiotic prescriptions given at inclusion.

Results

In the RADT cohort (n = 13,781), antibiotic prescription for patients with a positive RADT for GAS was associated with fewer return visits for pharyngotonsillitis within 30 days compared with no prescription (8.7% vs. 12%; p = 0.02), but not with the complication rate within 30 days (1.5% vs. 1.8%; p = 0.7) or with the tonsillectomy rate within 90 days (0.27% vs. 0.26%; p = 1). In contrast, antibiotic prescription for patients with a negative RADT was associated with more return visits for pharyngotonsillitis within 30 days (9.7% vs. 7.0%; p = 0.01). In the culture cohort (n = 1 370), antibiotic prescription for patients with Streptococcus dysgalactiae ssp. equisimilis was associated with fewer return visits for pharyngotonsillitis within 30 days compared with no prescription (15% vs. 29%; p = 0.03).

Conclusions

Antibiotic prescription was associated with fewer return visits for pharyngotonsillitis in patients with a positive RADT for GAS but with more return visits in patients with a negative RADT for GAS. There were no differences in purulent complications related to antibiotic prescription.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06511-y.