Tolerance and Efficacy of Interfering Alpha-streptococci in Recurrence of Streptococcal Pharyngotonsillitis: a Placebo-controlled Study

Abstract

A total of 342 patients with clinical signs of tonsillitis and suspected group A beta-haemolytic streptococci (GAS) aetiology, verified with rapid test and GAS culture, were enrolled in a randomized, placebo-controlled, double-blind, multicentre study. They received antibiotic treatment for 10 days, followed by 10 days of alpha-streptococcal or placebo spray treatment in the ratio of 2:1. Pharyngeal status, throat culture and adverse events were investigated up to 75 days after treatment. The frequency of bacteriologically verified clinical recurrence was 13% in the alpha-streptococcal group and 15% in the placebo group at the follow-up on day 22. The corresponding figures at the last valid visit after 45-75 days were 19% and 30%, respectively, a statistically significant difference (p=0.037). Furthermore, at the last valid visit 5% of subjects in the alpha-streptococcal and 12% in the placebo group were healthy carriers, bacteriological treatment failures, of GAS (p=0.029). Treatment with alpha-streptococci and placebo spray were equally well tolerated. Thus, re-colonization with alpha-streptococci seem to hinder late recurrences of GAS pharyngotonsillitis.