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 electron ic 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 pharyngotonsil litis, whereas the relevancy of testing for GCS/GGS is questioned. Yet, which patient to test and treat for
F. necrophorum remains to be defined.
