Can inducing colonization with streptococci prevent recurrences of otitis media in children?

Journal of Family Practice, May, 2001 by James Brillhart

Roos K, Hakansson EG, Holm S. Effect of recolonisation with "interfering" alpha streptococci on recurrences of acute and secretory otitis media in children: randomized placebo controlled trial. BMJ 2001; 322:1-4.

* BACKGROUND The upper respiratory tract is usually colonized by nonpathogenic bacteria that provide a protective effect against the organisms that cause otitis media and pharyngotonsillitis. Alphastreptococci isolated from normal pharyngeal flora inhibit the growth of Group A [Beta]-hemolytic streptococcus (GAS) in vitro and prevent recurrence of GAS pharyngitis. Similarly, healthy children have higher levels of inhibitory [Alpha]-streptococci compared with children prone to otitis media. This investigation sought to determine whether recolonization of the nasopharynx with a nasal spray of [Alpha]-streptococci prevents the recurrence of otitis media in children.

* POPULATION STUDIED Three ear, nose, and throat (ENT) physicians enrolled 132 children with recurrent otitis media aged between 6 months and 6 years at an outpatient specialty clinic in Sweden. Each child had at least 2 episodes of otitis media in the previous 6 months or 5 episodes in the last year. When such children presented with acute otitis media, they were enrolled in the study and began a 10-day course of antibiotics. Children were excluded from the study if they had penicillin allergy, pressure equalizing tubes, chronic otitis media, serious underlying disease, or major oral lesions.

* STUDY DESIGN AND VALIDITY After completing the 10-day course of penicillin V or amoxicillin clavulanic acid, the children were randomized to receive either a nasal spray made with 5 strains of [Alpha]-streptococci or a placebo spray. Parents gave their children 3 puffs of spray in each nostril twice daily for 10 days. At day 60, a second course of spray was administered. Subjects were followed up for 3 months. Of 132 children enrolled, 108 (82%) were eligible for analysis of efficacy (using at least 50% of their sprays). The authors used concealed allocation; their randomization worked well; and the follow-up was satisfactory.

* OUTCOMES MEASURED Each subject had 5 scheduled visits to the ENT specialist during the course of the investigation. At each visit a detailed inspection of the tympanic membrane was performed using otomicroscopy. The clinical response to treatment was classified as cured, improved, secretory (serous) otitis media, or recurrent (acute otitis media). The main outcome measures were recurrence of otitis media and presence of a normal tympanic membrane at the last visit.

* RESULTS Children who received the cz-streptococcal spray had a significant reduction in recurrence of otitis media compared with those receiving placebo. During the investigation, 42% of the subjects who received the [Alpha]-streptococcal spray experienced no acute otitis media and had normal tympanic membranes at the last visit compared with 22% of the placebo group (adjusted relative risk [ARR]=20%; 95% confidence interval [CI], 2.8%-37%; number needed to treat [NNT]=5). There were fewer children in the treated group with secretory otitis media at the last visit (ARR=9%; 95% CI, 6.5%,28.5%; NNT=ll). Side effects were roughly the same in both groups; the only patients who dropped out because of adverse effects were in the placebo group.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Inducing recolonization of the nasal pharynx with protective cz-streptococci is a new "ecological" approach to the prevention of recurrent otitis media. This study suggests that recolonization may be an effective way to prevent recurrent otitis media and possibly reduce the need for antibiotics and surgical intervention. Since there is no commercial product available and further study is needed, this approach is not currently feasible. However, it represents a new and exciting approach to this common problem.

James Brillhart, MD, MPH & TM
University of Missouri--Columbia
E-mail: BrillhartJ@health.missouri.edu