During a 5-year prospective study of nasopharyngeal (NP) colonization and acute otitis media (AOM) infections in children during the 7-valent pneumococcal conjugate vaccine (PCV) era (July 2006–June 2011) we studied risk factors for NP colonization and AOM. NP samples were collected at ages 6, 9, 12, 15, 18, 24, and 30 months during well-child visits. Additionally, NP and middle ear fluid (MEF) samples were collected at onset of every AOM episode. From 1825 visits (n = 464 children), 5301 NP and 570 MEF samples were collected and analysed for potential otopathogens. Daycare attendance, NP colonization by Moraxella catarrhalis, and siblings aged <5 years increased the risk of Streptococcus pneumoniae NP colonization. NP colonization with S. pneumoniae, M. catarrhalis, or Haemophilus influenzae and a family history of OM increased the risk of AOM. Risk factors that increase the risk of pneumococcal AOM will be important to reassess as we move into a new 13-valent PCV era, especially co-colonization with other potential otopathogens.

We conducted an epidemiological, observational cohort study to determine the incidence and complications of acute otitis media (AOM) in children aged <6 years. Data on physician-diagnosed AOM were collected from retrospective review of medical charts for the year preceding enrolment and then prospectively in the year following enrolment. The study included 5776 children in Germany, Italy, Spain, Sweden, and the UK. AOM incidence was 256/1000 person-years [95% confidence interval (CI) 243–270] in the prospective study period. Incidence was lowest in Italy (195, 95% CI 171–222) and highest in Spain (328, 95% CI 296–363). Complications were documented in <1% of episodes. Spontaneous tympanic membrane perforation was documented in 7% of episodes. Both retrospective and prospective study results were similar and show the high incidence during childhood in these five European countries. Differences by country may reflect true differences and differences in social structure and diagnostic procedures.

A randomised, double-blind, placebo-controlled study was conducted to determine whether probiotics might be effective in reducing the risk of infections in infancy. Infants requiring formula before the age of 2 months were recruited from community well-baby clinics. Infant formula supplemented with the probiotics Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb-12 or placebo was administered daily until the age of 12 months. Incidence of early infections (before the age of 7 months) and incidence of recurrent (three or more) infections during the first year of life were recorded as the main outcome measures of the study. During the first 7 months of life, seven out of thirty-two (22 %) infants receiving probiotics and twenty out of forty (50 %) infants receiving placebo experienced acute otitis media (risk ratio (RR) 0·44 (95 % CI 0·21, 0·90); P = 0·014) and antibiotics were prescribed for ten out of thirty-two (31 %) infants receiving probiotics and twenty-four out of forty (60 %) infants receiving placebo (RR 0·52 (95 % CI 0·29, 0·92); P = 0·015). During the first year of life, nine out of thirty-two (28 %) infants receiving probiotics and twenty-two out of forty (55 %) infants receiving placebo encountered recurrent respiratory infections (RR 0·51 (95 % CI 0·27, 0·95); P = 0·022). These data suggest that probiotics may offer a safe means of reducing the risk of early acute otitis media and antibiotic use and the risk of recurrent respiratory infections during the first year of life. Further clinical trials are warranted.

Acute mastoiditis, a destructive bacterial infection of the mastoid bone and air cell system, is relatively uncommon today but remains a potentially serious condition. There is a lack of information in the literature regarding the long term otological problems that children may face following an episode of this condition.

Objectives: Acute otitis media (AOM) is one of the most common diseases of childhood, representing a major disease burden on the society. New evidence-based guidelines for AOM, focusing on children under 7 years of age, were introduced in Finland in 1999. The aim of this study was to evaluate the cost-effectiveness of implementing those guidelines in Finland.

Methods: A 5-year prospective trial was conducted in thirty community primary healthcare centers in Finland. All AOM patients between 0 and 6 years of age visiting the study health centers for the first time, for this episode of illness, during 1 week in November 1998 (n = 579) and November 2002 (n = 369) were included in this study. The outcome measure was the percentage of symptom-free patients.

Results: The mean direct cost of an AOM episode per patient stayed almost the same after implementing the guidelines, €152 in 1998 and €150 in 2002. After implementing the guidelines, the percentage of symptom-free patients was 10 percentage points higher than before the guidelines. The treatment after the implementation of the guidelines, thus, was a dominant strategy.

Conclusions: Implementing the guidelines to the treatment of AOM in children was associated with extra health benefits at slightly lower direct costs and, thus, is a dominant strategy. The focus of this study was on the short-term effects of the treatment; including long-term effects in the analysis might affect the results.