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

Abstract

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 (RADT). Nevertheless, many RADT-negative patients 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 (PCR) and beta-hemolytic streptococci (culture) in the Skåne Region, Sweden 2013-2020. Patients with prior complications or antibiotics (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 ICD-10-codes. Cases with negative results (PCR 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% GCS/GGS, 10% GAS and 54% negative results. 30-day complication rates were high (20%). F. necrophorum OR 1.8 (95CI 1.5-2.1) and GAS OR 1.9 (95CI 1.5-2.5) were associated with complications whereas GCS/GGS were negatively associated with complications OR 0.7 (95CI 0.4-0.98). Conclusion Our results indicate F. necrophorum as a relevant pathogen in pharyngotonsillitis, whereas the relevancy of testing for GCS/GGS is questioned. Yet, which patient to test and treat for F. necrophorum remains to be defined.

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

“…By highlighting distinctive features of F. necrophorum pharyngotonsillitis in a large number of severely ill cases with pharyngotonsillitis, future guidelines are aided to provide better guidance, with the main predictor being age 13–30 years. Guidelines on management of pharyngotonsillitis might need revision following evidence during the last ten years establishing F. necrophorum as an important cause of pharyngotonsillitis [ 1 , 3 ], peritonsillar abscess [ 4 , 27 ] and with increasing incidence of invasive infections in adolescents and young adults [ 6 ].…”

“…N/total (%) is presented when any data were missing 1 According to the Charlson comorbidity index [23] 2 21% had missing data. When missing, data was imputed using multiple imputation (25 iterations) with predictive mean matching 3 No randomized controlled trial has investigated antibiotic therapy in F. necrophorum-pharyngotonsillitis. Yet, a Cochrane meta-analysis on antibiotic treatment in pharyngotonsillitis patients with negative cultures for betahaemolytic streptococci have shown symptom reduction following exposure to antibiotics [24].…”

“…Fusobacterium necrophorum is a common pharyngotonsillitis pathogen, found in 21% of pharyngotonsillitis cases overall [ 1 ], and in up to 48% of non-streptococcal cases in a study selecting patients aged 18–32 years [ 2 ]. Furthermore, a recent study highlighted similar complication rates when F. necrophorum or group A streptococci (GAS) were identified [ 3 ] and F. necrophorum is the most frequent cause of peritonsillar abscesses [ 4 ]. While the incidence of invasive F. necrophorum disease remains low, including severe manifestations such as Lemierre´s syndrome, it is increasing [ 5 – 8 ].…”

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

“…They concluded that S. dysgalactiae should be considered as a throat pathogen in line with S. pyogenes. In a study of 3,700 AT patients treated in primary health care, Nygren et al found lower complication rates among patients positive for Group C/G streptococci (16%) compared to those positive for S. pyogenes (28%) and F. necrophorum (26%) [ 21 ].…”

Proteomic Characterization of Plasma in Lemierre's Syndrome

“…Historically, it has been described to be part of the normal tonsillar flora, 1 yet a more accurate description is likely that transient carriage occurs among teenagers and adolescents. 9 F. necrophorum is increasingly recognized as a primary pathogen in local infections, for example, pharyngotonsillitis 10 11 12 13 14 and peritonsillar abscess 15 16 in addition to its role as the typical pathogen seen in Lemierre's syndrome. 1 Little is known of its pathogenicity, including the very particular presentation with thrombosis in Lemierre's syndrome.…”