Effect of recolonisation with "interfering" alpha streptococci on recurrences of acute and secretory otitis media in children: randomised placebo controlled trial.

To study the effect of recolonisation with alpha streptococci with the ability to inhibit the growth of otopathogens ("interfering" activity) on the recurrence of acute otitis media in susceptible children and the effect on the frequency of secretory otitis media. Double blind, randomised, placebo controlled study. Ear, nose, and throat clinic with three doctors. 130 children prone to otitis media aged between 6 months and 6 years, 108 of whom were eligible and followed for 3 months. Recurrence of otitis media during follow up and a normal tympanic membrane at the last valid visit. Children with no recurrences during the last month received phenoxymethylpenicillin (n=22), and those with a recurrence within 1 month received amoxicillin clavulanic acid (n=86), both twice daily for 10 days. These were followed by a streptococcal or placebo solution sprayed into the nose for a further 10 days. At day 60 the same spray was started for another 10 days. At 3 months 22 children (42%) given the streptococcal spray were healthy and had a normal tympanic membrane compared with 12 (22%) of those given placebo. This difference was shown separately for recurrences of both acute otitis media and secretory otitis media. Selected bacteria with the ability to inhibit the growth of common otopathogens can be used to protect against recurrent acute otitis media and secretory otitis media in children.