The aetiology of pharyngotonsillitis in adolescents and adults - Fusobacterium necrophorum is commonly found

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.

Symptoms predictive of Fusobacterium necrophorum pharyngotonsillitis - an observational study of cases presenting to hospitals in Southern Sweden

OBJECTIVES

Fusobacterium necrophorum is a common cause of pharyngotonsillitis. However, no guidelines exist on when to diagnose or treat it. We aimed to investigate associations between clinical criteria and F. necrophorum-positivity in pharyngotonsillitis and assess the predictive potential of a simple scoring system.

METHODS

Pharyngotonsillitis patients who were tested for F. necrophorum (PCR) and presented to hospitals in the Skåne Region, Sweden, between 2013-2020 were eligible. Data were retrieved from electronic chart reviews and registries. By logistic regression we investigated associations between F. necrophorum-positivity and pre-specified criteria: age 13-30 years, symptom duration ≤ 3 days, absence of viral symptoms (e.g. cough, coryza), fever, tonsillar swelling/exudate, lymphadenopathy and CRP ≥ 50 mg/L. In secondary analyses, associated variables were weighted by strength of association into a score and its predictive accuracy of F. necrophorum was assessed.

RESULTS

Among 561 cases included, 184 (33%) had F. necrophorum, which was associated with the following criteria: age 13-30, symptom duration ≤ 3 days, absence of viral symptoms, tonsillar swelling/exudate and CRP ≥ 50 mg/L. Age 13-30 had the strongest association (OR5.7 95%CI 3.7-8.8). After weighting, these five variables had a sensitivity and specificity of 68% and 71% respectively to predict F. necrophorum-positivity at the proposed cut-off.

CONCLUSION

Our results suggest that F. necrophorum cases presenting to hospitals might be better distinguished from other pharyngotonsillitis cases by a simple scoring system presented, with age 13-30 being the strongest predictor for F. necrophorum. Prospective studies, involving primary care settings, are needed to evaluate generalisability of findings beyond cases presenting to hospitals.

Proteomic Characterization of Plasma in Lemierre's Syndrome

BACKGROUND

 The underlying mechanisms of thrombosis in Lemierre's syndrome and other septic thrombophlebitis are incompletely understood. Therefore, in this case control study we aimed to generate hypotheses on its pathogenesis by studying the plasma proteome in patients with these conditions.

METHODS

 All patients with Lemierre's syndrome in the Skåne Region, Sweden, were enrolled prospectively during 2017 to 2021 as cases. Age-matched patients with other severe infections were enrolled as controls. Patient plasma samples were analyzed using label-free data-independent acquisition liquid chromatography tandem mass spectrometry. Differentially expressed proteins in Lemierre's syndrome versus other severe infections were highlighted. Functions of differentially expressed proteins were defined based on a literature search focused on previous associations with thrombosis.

RESULTS

 Eight patients with Lemierre's syndrome and 15 with other severe infections were compared. Here, 20/449 identified proteins were differentially expressed between the groups. Of these, 14/20 had functions previously associated with thrombosis. Twelve of 14 had a suggested prothrombotic effect in Lemierre's syndrome, whereas 2/14 had a suggested antithrombotic effect.

CONCLUSION

 Proteins involved in several thrombogenic pathways were differentially expressed in Lemierre's syndrome compared to other severe infections. Among identified proteins, several were associated with endothelial damage, platelet activation, and degranulation, and warrant further targeted studies.

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.

The impact of social restrictions on the incidence and microbiology of peritonsillar abscess: a retrospective cohort study

OBJECTIVES

We aimed to explore the impact of social distancing on the incidence and microbiology of peritonsillar abscess (PTA).

METHODS

We performed a cross-sectional analysis of all patients with PTA and their microbiological findings in the 2 years preceding versus the 2 years following the COVID-19 lockdown in Denmark (11 March 2020), who were admitted to the Ear-Nose-Throat Department, Aarhus University Hospital. Age-stratified population data for the catchment area were obtained from Statistics Denmark.

RESULTS

The annual incidence rate was significantly higher in the 2-year period before (21.8 cases/100 000 inhabitants) compared with after (14.9 cases/100 000) the lockdown (p < 0.001). The number of cases with growth of Streptococcus pyogenes was significantly higher in the period before (n = 67) compared with after (n = 28) the lockdown (p < 0.001), whereas the number of cases positive for Fusobacterium necrophorum (n = 60 vs. n = 64) and streptococcus anginosus group (SAG) (n = 37 vs. n = 43) were stabile (p 0.79 and p 0.58, respectively). The relative prevalence of S. pyogenes was significantly higher in the period before (67/246 cultures, 27%) compared with after (28/179, 16%) the lockdown (p 0.007). On the contrary, the relative prevalence of F. necrophorum and SAG is significantly lower before (60/246, 24% and 37/246, 15%) compared with after (64/179, 36% and 43/179, 24%) the lockdown (p 0.013 and p 0.023).

DISCUSSION

Social distancing had a significant impact on the incidence and microbiology of PTA. Our findings suggest that S. pyogenes-positive PTA is highly related to direct social interaction, and represents a contagious pathogen. By contrast, PTA development caused by F. necrophorum and SAG is unrelated to direct social interaction and may be derived from flora imbalance.

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.

Bacterial findings in patients referred to hospital for the treatment of acute tonsillitis with or without peritonsillar phlegmon

BACKGROUND

The vast majority of patients with acute tonsillitis (AT) are managed in general practice. However, occasionally patients are referred to hospital for specialized management because of aggravated symptoms and/or findings suggestive of peritonsillar involvement. No prospective studies have been conducted aiming to investigate the prevalent and significant microorganisms in this highly selected group of patients. We aimed to describe the microbiological findings of acute tonsillitis with or without peritonsillar phlegmon (PP) in patients referred for hospital treatment and to point out potential pathogens using the following principles to suggest pathogenic significance: (1) higher prevalence in patients compared to healthy controls, (2) higher abundance in patients compared to controls, and (3) higher prevalence at time of infection compared to time of follow up.

METHODS

Meticulous and comprehensive cultures were performed on tonsillar swabs from 64 patients with AT with (n = 25) or without (n = 39) PP and 55 healthy controls, who were prospectively enrolled at two Danish Ear-Nose-Throat Departments between June 2016 and December 2019.

RESULTS

Streptococcus pyogenes was significantly more prevalent in patients (27%) compared to controls (4%) (p < 0.001). Higher abundance was found in patients compared to controls for Fusobacterium necrophorum (mean 2.4 vs. 1.4, p = 0.017) and S. pyogenes (mean 3.1 vs. 2.0, p = 0.045) in semi-quantitative cultures. S. pyogenes, Streptococcus dysgalactiae, and Prevotella species were significantly more prevalent at time of infection compared to follow up (p = 0.016, p = 0.016, and p = 0.039, respectively). A number of species were detected significantly less frequently in patients compared to controls and the mean number of species was significantly lower in patients compared to controls (6.5 vs. 8.3, p < 0.001).

CONCLUSIONS

Disregarding Prevotella spp. because of the prevalence in healthy controls (100%), our findings suggest that S. pyogenes, F. necrophorum, and S. dysgalactiae are significant pathogens in severe AT with or without PP. In addition, infections were associated with reduced diversity (dysbacteriosis).

TRIAL REGISTRATION

The study is registered in the ClinicalTrials.gov protocol database (# 52,683). The study was approved by the Ethical Committee at Aarhus County (# 1-10-72-71-16) and by the Danish Data Protection Agency (# 1-16-02-65-16).

Clinical course of pharyngotonsillitis with group A streptococcus treated with different penicillin V strategies, divided in groups of Centor Score 3 and 4: a prospective study in primary care

Background

Sore throat is a common reason for prescribing antibiotics in primary care, and 10 days of treatment is recommended for patients with pharyngotonsillitis with group A streptococcus (GAS). Our group recently showed that penicillin V (PcV) four times daily for 5 days was non-inferior in clinical outcome to PcV three times daily for 10 days. This study compares duration, intensity of symptoms, and side effects in patients with a Centor Score (CS) of 3 or 4 respectively, after treatment with PcV for 5 or 10 days and evaluates whether all patients with pharyngotonsillitis with a CS of 3 or 4 should be treated for 5 days or if severity of symptoms or CS suggest a longer treatment period.

Method

Data on symptoms and recovery from patient diaries from 433 patients included in a RCT comparing PcV 800 mg × 4 for 5 days or PcV 1 g × 3 for 10 days was used. Patients six years and older with CS-3 or CS-4 and positive rapid antigen detection test for GAS-infection were grouped based on CS and randomized treatment. Comparisons for categorical variables were made with Pearson’s chi-squared test or Fisher’s exact test. Continuous variables were compared with the Mann–Whitney U test.

Results

Patients with CS-3 as well as patients with CS-4 who received PcV 800 mg × 4 for 5 days self-reported that they recovered earlier compared to patients with CS-3 or CS-4 who received treatment with PcV 1 g × 3 for 10 days. In addition, the throat pain as single symptom was relieved 1 day earlier in patients with CS-4 and 5 days of treatment compared to patients with CS-4 and 10 days of treatment. No differences in side effects between the groups were found.

Conclusion

Intense treatment with PcV four times a day for 5 days seems clinically beneficial and strengthens the suggestion that the 4-dose regimen with 800 mg PcV for 5 days may be the future treatment strategy for GAS positive pharyngotonsillitis irrespectively of CS-3 or CS-4.

Trail registration ClinicalTrials.gov ID: NCT02712307 (3 April 2016).

Associations Between Findings of Fusobacterium necrophorum or β-Hemolytic Streptococci and Complications in Pharyngotonsillitis-A Registry-Based Study in Southern Sweden

BACKGROUND

Most pharyngotonsillitis guidelines focus on the identification of group A streptococci (GAS), guided by clinical scores determining whom to test with a rapid antigen detection test. Nevertheless, many patients testing negative with this test are evaluated for group C/G streptococci (GCS/GGS) and Fusobacterium necrophorum, yet their importance remains debated. Our primary aim was to evaluate associations between complications and findings of F. necrophorum, GAS, or GCS/GGS in pharyngotonsillitis.

METHODS

This was a retrospective, registry-based study of pharyngotonsillitis cases tested for F. necrophorum (polymerase chain reaction) and β-hemolytic streptococci (culture) in the Skåne Region, Sweden, in 2013-2020. Patients with prior complications or antibiotics (within 30 days) were excluded. Data were retrieved from registries and electronic charts. Logistic regression analyses were performed with a dichotomous composite outcome of complications as primary outcome, based on International Classification of Diseases, Tenth Revision, codes. Cases with negative results (polymerase chain reaction and culture) were set as reference category. Complications within 30 days were defined as peritonsillar or pharyngeal abscess, otitis, sinusitis, sepsis or septic complications, recurrence of pharyngotonsillitis (after 15-30 days) or hospitalization.

RESULTS

Of 3700 registered cases, 28% had F. necrophorum, 13% had GCS/GGS, 10% had GAS, and 54% had negative results. The 30-day complication rates were high (20%). F. necrophorum (odds ratio, 1.8; 95% confidence interval, 1.5-2.1) and GAS (1.9; 1.5-2.5) were positively associated with complications, whereas GCS/GGS were negatively associated (0.7; 0.4-0.98).

CONCLUSIONS

Our results indicate that F. necrophorum is a relevant pathogen in pharyngotonsillitis, whereas the relevance of testing for GCS/GGS is questioned. However, which patient to test and treat for F. necrophorum remains to be defined.

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.

Seasonal variations in use and outcome of rapid antigen detection tests and cultures in pharyngotonsillitis: a register study in primary care

Background

Diagnosis and treatment of pharyngotonsillitis are commonly focused on group A streptococci (GAS), although the disease is often associated with other pathogens. While the incidence of pharyngotonsillitis is known to vary with season, seasonal variations in the prevalence of potential pathogens are sparsely explored. The aim of this study was to explore any seasonal variations in the use and outcome of rapid antigen detection tests (RADTs) for GAS and throat cultures among patients diagnosed with pharyngotonsillitis in primary care.

Methods

We retrieved and combined retrospective data from the electronic medical record system and the laboratory information system in Kronoberg County, Sweden. Primary care visits resulting in a diagnosis of tonsillitis or pharyngitis were included, covering the period 2013–2016. The monthly rate of visits was measured, along with the use and outcome of RADTs for GAS and throat cultures obtained on the date of diagnosis. The variations between calendar months were then analysed.

Results

We found variations between calendar months, not only in the mean rate of visits resulting in a diagnosis of pharyngotonsillitis (p < 0.001), but in the mean proportion of RADTs being positive for GAS among the diagnosed (p < 0.001), and in the mean proportion of visits associated with a throat culture (p < 0.001). A lower mean rate of visits in August and September coincided with a lower proportion of RADTs being positive for GAS among them, which correlated with a higher proportion of visits associated with a throat culture.

Conclusions

This study suggests that the role of GAS in pharyngotonsillitis in Sweden is less prominent in August and September than during the rest of the year.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06774-5.

High prevalence of pharyngeal bacterial pathogens among healthy adolescents and young adults

The pharyngeal mucosa can be colonized with bacteria that have potential to cause pharyngotonsillitis. By the use of culturing techniques and PCR, we aimed to assess the prevalence of bacterial pharyngeal pathogens among healthy adolescents and young adults. We performed a cross-sectional study in a community-based cohort of 217 healthy individuals between 16 and 25 years of age. Samples were analyzed for Group A streptococci (GAS), Group C/G streptococci (SDSE), Fusobacterium necrophorum, and Arcanobacterium haemolyticum. Compared to culturing, the PCR method resulted in more frequent detection, albeit in most cases with low levels of DNA, of GAS (20/217 vs. 5/217; p < 0.01) and F. necrophorum (20/217 vs. 8/217; p < 0.01). Culturing and PCR yielded similar rates of SDSE detection (14/217 vs. 12/217; p = 0.73). Arcanobacterium haemolyticum was rarely detected (3/217), and only by PCR. Overall, in 25.3% (55/217) of these healthy adolescents and young adults at least one of these pathogens was detected, a rate that is higher than previously described. Further studies are needed before clinical adoption of PCR-based detection methods for pharyngeal bacterial pathogens, as our findings suggest a high incidence of asymptomatic carriage among adolescents and young adults without throat infections.

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

Background

Few studies on pharyngotonsillitis have examined the clinical presentation of different aetiologies where pathogens have been detected using molecular methods. We aimed to assess how well clinical signs and symptoms can predict (1) the presence or absence of a broad range of viruses and bacteria, and (2) reconsultations for a sore throat or a complication.

Methods

In this descriptive observational prospective study in primary health care 220 patients aged 15–45 with suspected pharyngotonsillitis were sampled from nose, throat and blood and screened for 20 bacteria and viruses using polymerase chain reaction (PCR), culture and serology. Odds ratios (OR) and predictive values with 95% confidence intervals (CI) were used to show association between microbiological findings and clinical signs and symptoms. Patients were followed up after 3 months by reviewing electronic medical records.

Results

Both cough and coryza were more common in patients with only viruses (67%) than in patients with only bacteria (21%) (p < 0.001), whereas tonsillar coating was more common in patients with only bacteria (53%) than in patients with only viruses (29%) (p = 0.006). Tonsillar coating (adjusted OR 6.0; 95% CI 2.5–14) and a lack of cough (adjusted OR 3.5; 95% CI 1.5–8.0) were significantly associated with Streptococcus pyogenes (group A streptococci; GAS) and with any bacterial finding. A Centor score of 3–4 had a positive predictive value of 49% (95% CI 42–57) for GAS and 66% (95% CI 57–74) for any bacterial findings. The use of rapid antigen detection test for GAS increased the positive predictive value for this group to 93%.

Conclusions

Signs and symptoms, both single and combined, were insufficient to rule in GAS or other pathogens. However, both cough and coryza were useful to rule out GAS. The results support the clinical approach of restricting rapid antigen detection testing to patients with 3–4 Centor criteria. The low carriage rate of bacteria among asymptomatic controls implied that most detections in patients represented a true infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06665-9.

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.

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

PURPOSE

The main objective of this review was to describe and quantify the association between Fusobacterium necrophorum (FN) and acute sore throat in primary healthcare (PHC).

METHODS

In this systematic review and meta-analysis, we searched Scopus and PubMed for case-control studies reporting the prevalence of FN in patients attending primary care for an uncomplicated acute sore throat as well as in healthy controls. Only studies published in English were considered. Publications were not included if they were case studies, or if they included patients prescribed antibiotics before the throat swab, patients with a concurrent malignant disease, on immunosuppression, having an HIV infection, or patients having another acute infection in addition to a sore throat. Inclusion criteria and methods were specified in advance and published in PROSPERO. The primary outcome was positive etiologic predictive value (P-EPV), quantifying the probability for an association between acute sore throat and findings of FN in the pharynx. For comparison, our secondary outcome was the corresponding P-EPV for group A Streptococcus (GAS).

RESULTS

PubMed and Scopus yielded 258 and 232 studies, respectively. Removing duplicates and screening the abstracts resulted in 53 studies subsequently read in full text. For the four studies of medium to high quality included in the meta-analysis, the cumulative P-EPV regarding FN was 64% (95% CI 33% to 83%). GAS, based on data from the same publications and patients, yielded a positive EPV of 93% (95% CI 83% to 99%).

CONCLUSIONS

The results indicate that FN may play a role in PHC patients with an acute sore throat, but the association is much weaker compared with GAS.

Geographical differences in tonsillar carriage rates of Fusobacterium necrophorum - A cross-sectional study in Sweden and Zambia

While Fusobacterium necrophorum historically has been considered normal tonsillar flora, recent studies from Europe and the US have suggested that carriage occur transiently in adolescence and young adulthood. However, no studies originating from Africa exist. In this cross-sectional study of tonsillar carriage of F. necrophorum, we aimed to investigate geographical differences in tonsillar carriage rates of F. necrophorum in healthy participants aged 15-25 years in Sweden and Zambia and further investigate the age distribution of tonsillar carriage in Zambia. Specimens were obtained by tonsillar swabs and analyzed with real-time PCR for F. necrophorum. In participants aged 15-25 years, tonsillar carriage was more common in Sweden 21/100 (21%) than in Zambia 6/192 (3%), p < 0.001. In Zambian participants aged above 25 years tonsillar carriage was rare 1/76 (1%). In conclusion, the high rate of tonsillar carriage in participants aged 15-25 years in Sweden has implications on the interpretation of tonsillar findings in patients with pharyngotonsillitis. Interestingly, a geographical difference was found with tonsillar carriage rarely identified in Zambia.

Presence of microorganisms in children with pharyngotonsillitis and healthy controls: a prospective study in primary healthcare

Purpose

Most studies on paediatric pharyngotonsillitis focus on group A streptococci. This study, however, analyses a broad spectrum of bacteria and viruses related to paediatric pharyngotonsillitis and evaluates their associated clinical symptoms and courses.

Methods

This observational prospective study in primary healthcare includes 77 children aged < 15 with a sore throat and 34 asymptomatic children, all of whom were sampled from the tonsils with an E-swab^® for analysis with culture and PCR for 14 bacteria and 15 viruses. Patients were evaluated clinically, and their symptoms recorded in diaries for 10 days. Participants were followed up for 3 months by reviewing medical records.

Results

A pathogen was detected in 86% of patients and in 71% of controls (P = 0.06). Bacteria were found in 69% of patients and 59% of controls (P = 0.3), and viruses in 36% and 26%, respectively (P = 0.3). Group A streptococci was the most common finding, with a prevalence of 49% and 32%, respectively (P = 0.1). Clinical signs were not useful for distinguishing pathogens. None of the controls and 16% of the patients reconsulted for a sore throat within 3 months.

Conclusion

Bacteria were more common than viruses in both study groups. The high rate of pathogens in asymptomatic children interferes with diagnoses based on aetiology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01595-9.

Penicillin V four times daily for five days versus three times daily for 10 days in patients with pharyngotonsillitis caused by group A streptococci: randomised controlled, open label, non-inferiority study

OBJECTIVE

To determine whether total exposure to penicillin V can be reduced while maintaining adequate clinical efficacy when treating pharyngotonsillitis caused by group A streptococci.

DESIGN

Open label, randomised controlled non-inferiority study.

SETTING

17 primary healthcare centres in Sweden between September 2015 and February 2018.

PARTICIPANTS

Patients aged 6 years and over with pharyngotonsillitis caused by group A streptococci and three or four Centor criteria (fever ≥38.5°C, tender lymph nodes, coatings of the tonsils, and absence of cough).

INTERVENTIONS

Penicillin V 800 mg four times daily for five days (total 16 g) compared with the current recommended dose of 1000 mg three times daily for 10 days (total 30 g).

MAIN OUTCOME MEASURES

Primary outcome was clinical cure five to seven days after the end of antibiotic treatment. The non-inferiority margin was prespecified to 10 percentage points. Secondary outcomes were bacteriological eradication, time to relief of symptoms, frequency of relapses, complications and new tonsillitis, and patterns of adverse events.

RESULTS

Patients (n=433) were randomly allocated to the five day (n=215) or 10 day (n=218) regimen. Clinical cure in the per protocol population was 89.6% (n=181/202) in the five day group and 93.3% (n=182/195) in the 10 day group (95% confidence interval -9.7 to 2.2). Bacteriological eradication was 80.4% (n=156/194) in the five day group and 90.7% (n=165/182) in the 10 day group. Eight and seven patients had relapses, no patients and four patients had complications, and six and 13 patients had new tonsillitis in the five day and 10 day groups, respectively. Time to relief of symptoms was shorter in the five day group. Adverse events were mainly diarrhoea, nausea, and vulvovaginal disorders; the 10 day group had higher incidence and longer duration of adverse events.

CONCLUSIONS

Penicillin V four times daily for five days was non-inferior in clinical outcome to penicillin V three times daily for 10 days in patients with pharyngotonsillitis caused by group A streptococci. The number of relapses and complications did not differ between the two intervention groups. Five day treatment with penicillin V four times daily might be an alternative to the currently recommended 10 day regimen.

TRIAL REGISTRATION

EudraCT 2015-001752-30; ClinicalTrials.gov NCT02712307.

Signs and symptoms of Group A versus Non-Group A strep throat: A meta-analysis

INTRODUCTION

Both non-Group A streptococcal (non-GAS) pharyngitis and Group A streptococcal (GAS) pharyngitis are commonly found in patients with sore throat. It is not known whether or not they present with similar signs and symptoms compared to patients with non-streptococcal pharyngitis.

METHODS

MEDLINE was searched for prospective studies that reported throat culture for both GAS and non-GAS as a reference standard, and reported at least one sign, symptom, or the Centor score. Summary estimates of sensitivity, specificity, likelihood ratios (LR+ and LR-), and diagnostic odds ratios (DOR) were calculated using a bivariate random effects model. Summary receiver operating characteristic (ROC) curves were created for key signs and symptoms.

RESULTS

Eight studies met our inclusion criteria. Tonsillar exudate had the highest LR+ for both GAS and non-GAS pharyngitis (1.53 versus 1.71). The confidence intervals of sensitivity, LR+, LR-, and DOR for all signs, symptoms, and the Centor score between two groups overlapped, with the relative difference between sensitivities within 15% for arthralgia or myalgia, fever, injected throat, tonsillar enlargement, and tonsillar exudate. Larger differences in sensitivities were observed for sore throat, cervical adenopathy, and lack of a cough, although the difference for lack of a cough largely due to a single outlier.

DISCUSSION

Signs and symptoms of patients with GAS and non-GAS pharyngitis are generally similar. No signs or symptoms clearly distinguish GAS from non-GAS infection. Further work is needed to determine whether Group C streptococcus is a pathogen that should be treated.

A 2-year follow-up study of patients with pharyngotonsillitis

Background

Longtime follow-up studies on patients with pharyngotonsillitis are rare. We aimed to describe the patterns of new visits for a sore throat, complications and tonsillectomy during 2 years in a cohort of patients with pharyngotonsillitis and non-infected controls.

Methods

A retrospective chart review was performed on a cohort of patients with acute sore throat (n = 207), and non-infected controls (n = 108). New visits, complications and tonsillectomy within 2 years was recorded and analyzed in relation to microbiological findings at inclusion.

Results

Patients with Group A streptococci (GAS) (12/66) reconsulted more often within 30 days than patients with no GAS (9/141) (p = 0.009) and patients with F. necrophorum (2/29). After 2 years, we observed no significant differences in reconsultations with regard to aetiology at inclusion. A single complication was recorded and 5 patients were planned for tonsillectomy.

Conclusions

Group A streptococci were the sole aetiological agent associated with recurrent sore throat while F. necrophorum did not distinguish itself as a major cause of either recurrent infection or complications in this cohort. More studies, preferably with the focus on adolescents, are needed before F. necrophorum can be considered an important cause of pharyngotonsillitis.

Fusobacterium emphysematous pyomyositis with necrotizing fasciitis of the leg presenting as compartment syndrome: a case report

Background

Fusobacterium necrophorum is a common agent of disease in humans, but the occurrence of primary infections outside the head and neck area is extremely rare. While infection with Fusobacterium necrophorum has a rather benign course above the thorax, the organism is capable of producing very severe disease when located in unusual sites, including various forms of septic thrombophlebitis. No infections of the leg have been documented before; thus, antibiotic coverage for Fusobacterium is currently not recommended in this area.

Case presentation

A 50-year-old homeless African-American man presented complaining of severe pain in his right lower extremity. A clinical workup was consistent with emphysematous pyomyositis and compartment syndrome; he received limb-saving surgical intervention. The offending organism was identified as Fusobacterium necrophorum, and the antibiotic coverage was adjusted accordingly.

Conclusions

Bacteria typically involved in necrotizing infections of the lower extremity include Group A ß-hemolytic Streptococcus, Clostridium perfringens, and common anaerobic bacteria (Bacteroides, Peptococcus, and Peptostreptococcus). This case report presents a case of gas gangrene of the leg caused by Fusobacterium necrophorum, the first such case reported. Fusobacterium should now be included in the differential diagnosis of necrotizing fasciitis of the extremities.

Prevalence of Fusobacterium necrophorum in Children Presenting with Pharyngitis

Fusobacterium necrophorum, an obligate anaerobic bacterium, was recently reported to be an important cause of bacterial pharyngitis with a prevalence as high as that of group A Streptococcus (GAS) in adolescents and young adults. Importantly, F. necrophorum is the primary causative agent of the life-threatening Lemierre's syndrome, and screening of pharyngeal samples may be warranted for its early detection and prevention. The aim of this study was to determine the prevalences of F. necrophorum and groups A and C/G streptococci as agents of bacterial pharyngitis in children. Pharyngeal samples (n = 300) were collected from pediatric patients presenting to the emergency department with signs and symptoms of pharyngitis. Overall, 10 (3.3%), 79 (26.3%), and 4 (1.3%) patients were PCR positive for F. necrophorum, GAS, and group C/G streptococci, respectively. The prevalence of F. necrophorum was significantly higher in patients between the ages of 14 and 20 years at 13.5% than in patients aged 14 years and younger (1.9%, P < 0.001). All positive patients presented with signs and symptoms similar to GAS pharyngitis. Our data demonstrated a potential role for F. necrophorum as a pathogen of pharyngitis among young adults, but suggests that the prevalence of F. necrophorum is low in preadolescent patients.

Fusobacterium necrophorum Pharyngitis Complicated by Lemierre's Syndrome

We report the case of an 18-year-old woman who was referred to our outpatient clinic because of a 2-week history of sore throat, high fever, and neck tenderness unresponsive to a 7-day amoxicillin/clavulanic acid course. Infectious mononucleosis was initially suspected, but an extremely high value of procalcitonin and clinical deterioration suggested a bacterial sepsis, prompting the patient admission to our internal medicine ward. Blood cultures were positive for Fusobacterium necrophorum. CT scan detected a parapharyngeal abscess, a right internal jugular vein thrombosis, and multiple bilateral lung abscesses, suggesting the diagnosis of Lemierre's syndrome. The patient was treated with a 2-week course of metronidazole and meropenem with a gradual clinical recovery. She was thereafter discharged home with metronidazole and amoxicillin/clavulanic acid for 14 days and a 3-month course of enoxaparin, experiencing an uneventful recovery. The present case highlights the importance of taking into consideration the Lemierre's syndrome whenever a pharyngotonsillitis has a severe and unusual course.

Prevalence of Group C Streptococcus and Fusobacterium Necrophorum in Patients With Sore Throat: A Meta-Analysis

PURPOSE

The prevalence of Group C beta-hemolytic streptococcus and Fusobacterium necrophorum among patients with sore throat in the outpatient setting has not been previously summarized. We set out to derive prevalence information from the existing literature.

METHODS

We performed a systematic review of MEDLINE for studies reporting the prevalence of F necrophorum or Group C streptococcus or both in prospective, consecutive series of outpatients with sore throat, as well as laboratory-based studies of throat cultures submitted from primary care. We limited searches to studies where the majority of data was collected after January 1, 2000, to reflect contemporary microbiological methods and prevalences. Each author independently reviewed the articles for inclusion and abstraction of data; we resolved discrepancies by consensus discussion. We then performed a meta-analysis to calculate the pooled prevalence estimates using a random effects model of raw proportions.

RESULTS

A total of 16 studies met our inclusion criteria. The overall prevalences of Group C streptococcus and F necrophorum were 6.1% (95% CI, 3.2%-9.0%) and 18.9% (95% CI, 10.5%-27.2%), respectively. When stratified by study type, the prevalences of Group C streptococcus and F necrophorum in laboratory-based studies were 6.6% (95% CI, -1.0% to 14.2%) and 18.8% (95% CI, 6.5%-31.1%), respectively. In primary care patients with sore throat, Group C streptococcus had a prevalence of 6.1% (95% CI, 3.1%-9.2%), while F necrophorum had a prevalence of 19.4% (95% CI, 14.7%-24.1%).

CONCLUSIONS

Group C streptococcus and Fusobacterium necrophorum are commonly detected in patients with acute pharyngitis. Research is needed, however, to determine whether these bacteria are truly pathogenic in patients with pharyngitis and whether antibiotics reduce the duration of symptoms or the likelihood of complications.

Fusobacterium necrophorum findings in Denmark from 2010 to 2014 using data from the Danish microbiology database

Fusobacterium necrophorum findings in Denmark and estimation of the incidence of F. necrophorum bacteraemia was described using data from the nationwide Danish microbiology database (MiBa). All microbiological reports on any Fusobacterium species in Denmark were extracted for a period of 5 years from 2010 to 2014 from MiBa and from the local department of clinical microbiology. The overall incidence of F. necrophorum bacteraemia from 2010 to 2014 was 2.8 cases per million/year vs 9.4 in the age group 15-24 years. F. necrophorum was rare in blood cultures from children and middle-aged patients and then raised again. However, 48 of 232 cases of Fusobacterium bacteraemia were not identified to species level, so the incidences of F. necrophorum bacteraemia may be underestimated in our study. F. necrophorum was found in throat swabs in the age group between 13 and 40 years and in otitis media in children below 2 years in those departments which performed anaerobic culture. The incidence of F. necrophorum bacteraemia found was comparable to earlier reported figures for Lemierre's syndrome. Fusobacterium bacteraemia should always be identified to species level.

Peritonsillar Abscess: Complication of Acute Tonsillitis or Weber's Glands Infection?

OBJECTIVE

To review the literature concerning the 2 primary hypotheses put forth to explain the pathogenesis of peritonsillar abscess: "the acute tonsillitis hypothesis" (peritonsillar abscess is a complication of acute tonsillitis) and "the Weber gland hypothesis" (peritonsillar abscess is an infection of Weber's glands).

DATA SOURCES

PubMed, EMBASE.

REVIEW METHODS

Data supporting or negating one hypothesis or the other were elicited from the literature.

CONCLUSIONS

Several findings support the acute tonsillitis hypothesis. First, the 2 main pathogens in peritonsillar abscess have been recovered from pus aspirates and bilateral tonsillar tissues with high concordance rates, suggesting that both tonsils are infected in patients with peritonsillar abscess. Second, studies report signs of acute tonsillitis in the days prior to and at the time of peritonsillar abscess. Third, antibiotic treatment reduces the risk of abscess development in patients with acute tonsillitis. However, some findings suggest involvement of the Weber's glands in peritonsillar abscess pathogenesis. First, high amylase levels have been found in peritonsillar pus. Second, the majority of peritonsillar abscesses are located at the superior tonsillar pole in proximity of the Weber's glands. We propose a unified hypothesis whereby bacteria initially infect the tonsillar mucosa and spread via the salivary duct system to the peritonsillar space, where an abscess is formed.

IMPLICATIONS FOR PRACTICE

Our findings support the rationale for antibiotic treatment of patients with severe acute tonsillitis to reduce the risk of abscess development. Improved understanding of peritonsillar abscess pathogenesis is important for the development of efficient prevention strategies.

Tonsillar colonisation of Fusobacterium necrophorum in patients subjected to tonsillectomy

BACKGROUND

Fusobacterium necrophorum is a well-known cause of Lemirre's disease and accumulating evidence support its pathogenic role in peritonsillar abscess while its role in recurrent and chronic tonsillitis is uncertain. The objective of this study was to assess the prevalence of oropharyngeal colonisation with F. necrophorum and Beta-haemolytic streptococci in a cohort of patients scheduled for tonsillectomy due to recurrent or persistent throat pain, and to evaluate the dynamics of colonisation with repeated sampling during a follow-up time of 6 to 8 months.

METHODS

Fifty-seven (57) patients aged 15-52 years scheduled for tonsillectomy due to chronic/recurrent tonsillitis or recurrent peritonsillar abscess were included. Throat swabs for the detection of F. necrophorum and Beta-haemolytic streptococci and clinical data was collected at inclusion, at the time of surgery and 6 to 8 months after surgery. Statistical analysis was performed using the Chi-square, Fisher's exact and Mc Nemar tests.

RESULTS

Fusobacterium necrophorum was found in 28, 30 and 16% of the patients at inclusion, surgery and follow up respectively. The corresponding results for beta-haemolytic streptococci were 5, 9 and 5%. Patients colonised with F. necrophorum at follow-up, after tonsillectomy, were equally relieved from their previous throat pain as non-colonised patients. Looking at individual patients, the culture results for F. necrophorum varied over time, indicating a transient colonisation.

CONCLUSION

Fusobacterium necrophorum was frequently found in throat cultures in this cohort of patients with recurrent or chronic throat pain leading to tonsillectomy. Colonisation was equally frequent in the asymptomatic cohort post-tonsillectomy, indicating that F. necrophorum is not alone causative of the symptoms. In an individual perspective, colonisation with F. necrophorum was transient over time.