A systematic review of Fusobacterium necrophorum-positive acute tonsillitis: prevalence, methods of detection, patient characteristics, and the usefulness of the Centor score

The purpose of this study was to review the current evidence for an association between Fusobacterium necrophorum (FN) and acute tonsillitis (AT), to assess the prevalence of FN in AT, to identify the better FN detection method, and to characterize the clinical characteristics of FN-positive patients with uncomplicated AT. A systematic literature search was conducted in the PubMed, EMBASE, and SweMed+ databases for studies reporting on the recovery rates of FN in patients with AT. A total of 498 unique records were identified. Eleven studies were included in a qualitative synthesis and six studies were included in a meta-analysis. Considerable heterogeneity (I(2) = 60 %) and risk of bias and confounders was found among the studies, though a subset of studies (prospective) had lower heterogeneity and higher study quality. FN was recovered significantly more frequently from patients (21.2 %) compared to healthy controls (7.6 %) (p < 0.001). FN recovery rates were similar between culture-based studies (20.3 %) and studies using polymerase chain reaction (PCR) methodology (22.2 %) (p = 0.462). The typical FN-positive AT patient was a smoking young (15-25 years) male presenting with tonsillar exudates and a Centor score of 2 or higher. A clear association between FN and AT was found. FN is likely to be a significant and prevalent pathogen in AT, especially in teenagers and young adults. However, no evidence for causality between FN and AT has been established and it is unexplored if timely antibiotic therapy directed against FN accelerates the resolution of symptoms and decreases the risk of complications.