Recent advances in otitis media. 2. Epidemiology, natural history, and risk factors

Prospects for a vaccine against otitis media

Otitis media is a major cause of morbidity in 80% of all children less than 3 years of age and often goes undiagnosed in the general population. There is evidence to suggest that the incidence of otitis media is increasing. The major cause of otitis media is infection of the middle ear with microbes from the nasopharynx. The anatomical orientation of the eustachian tube, in association with a number of risk factors, predisposes infants and young children to the infection. Bacteria are responsible for approximately 70% of cases of acute otitis media, with Streptococcus pneumoniae, nontypeable Haemophilus influenzae and Moraxella catarrhalis predominating as the causative agents. The respiratory viruses, respiratory syncytial virus, rhinovirus, parainfluenza and influenza, account for 30% of acute otitis media cases. Over the past decade, there has been a profound increase in the reported resistance to antibiotics, which, with increased disease burden, has focussed attention on vaccine development for otitis media. A polymicrobial formulation containing antigens from all major pathogens would have the greatest potential to deliver a sustained reduction in the disease burden globally. The disappointing outcomes for otitis media seen with the polysaccharide pneumococcal conjugate vaccine have raised major challenges for the vaccination strategy. Clearly, more knowledge is required concerning immune mechanisms in the middle ear, as well as vaccine formulations containing antigens that are more representative of the polymicrobial nature of the disease. Antigens that have been extensively tested in animal models are now available for testing in human subjects.

Suture restriction of the temporal bone as a risk factor for acute otitis media in children: cohort study

BACKGROUND

Eustachian tube (ET) dysfunction plays an important role in the pathogenesis of acute otitis media (AOM). Unfortunately, there is a lack of knowledge about the exact role of the ET's bony support, the temporal bone, on occurrence of AOM. This study investigates whether severe suture restriction of the temporal bone is a risk factor for development of AOM in young children.

METHODS

Using a prospective cohort design, 64 children aged 6 to 18 months without prior history of AOM were followed during the cold season (September 2009 to April 2010). Temporal bone status (categorized as with or without severe suture restriction) was evaluated using palpation and a cranial bone mobility test. Information about potential baseline confounders and risk factors for AOM (gender, age, birth weight, gestational age, use of pacifier, daycare attendance, presence of siblings, low socioeconomic status, breastfeeding ≥ 6 months, parental smoking and history of upper respiratory tract infection) were also collected. Occurrence of AOM diagnosed by physicians blinded to temporal bone status was the main outcome. Data were analyzed using hierarchical linear and nonlinear (multilevel) models.

RESULTS

Severe suture restriction of the temporal bone was identified in 23 children (35.9%). At least one AOM episode was diagnosed in 14 (48.3%) of the ears associated with temporal bones previously identified as having severe suture restriction and in 28 (28.3%) of those without severe suture restriction. Higher risk for AOM was explained by severe suture restriction of the temporal bone (adjusted relative risk (RR), 2.26, 95% CI 1.43 to 2.91, p<.01), pacifier use (RR, 2.59, 95% CI 1.51 to 3.22, p<.01) and younger age (RR, 0.22, 95% CI 0.10 to 0.52, p=.001).

CONCLUSIONS

The study results indicate that severe suture restriction of the temporal bone is a risk factor for AOM in young children. Subsequent intervention studies are needed to determine if this mechanical risk factor can be modified in young children.

Host's response in otitis media: understanding genetic susceptibility

Increasing evidence is emerging on genetic factors affecting host's response to infection in the middle ear. This review summarizes current knowledge on the field and on the contribution of nonspecific barriers, innate, and adaptive immunity. Better understanding of susceptibility to this very common disease will facilitate identification of high-risk individuals and optimization of prevention and treatment.

The reliability of self-reported childhood otitis media by adults

OBJECTIVE

To estimate reliability of retrospective questionnaire data on childhood recurrent otitis media, and to identify factors influencing inconsistency in self-report.

METHODS

Retrospective questionnaire data from a population-based sample of 4430 Norwegian twins who participated in two questionnaire surveys, 6 years apart, containing identical questions on otitis media. Main outcome measure was individual consistency in reporting of otitis media. The tetrachoric correlation and Cohen's Kappa were used to measure reliability. Inconsistent and consistent responders were compared on medical history and mental distress. The use of twin data made it possible to test whether inconsistent responders represent a group with intermediate levels of otitis media severity.

RESULTS

The test-retest tetrachoric correlation was 0.82 and Kappa was 0.53. Inconsistency in response was not associated with mental distress, but related to reported number of otitis media episodes per year, use of medical services and history of ear surgery.

CONCLUSION

Retrospective self-reported otitis media is a relatively reliable measure. The study suggests that reporting inconsistency is likely to be associated with less severe disease. The finding that reporting pattern is related to disease severity is in accordance with the proposed need for a uniform agreement on the definition of the term "recurrent otitis media" for research purposes.

Otitis media: re-evaluation of diagnosis and treatment in the era of antimicrobial resistance, pneumococcal conjugate vaccine, and evolving morbidity

The changing susceptibility of bacterial otopathogens is only one aspect of the evolving concepts regarding pathogenesis, immunoprophylaxis, pharmacodynamics, and sequelae of acute otitis media that mandates new insights for achieving a successful outcome. 2004 guidelines by the American Academy of Pediatrics for the treatment of acute otitis media provide one perspective that proposes a rethinking of the routine use of antimicrobial therapy with the hope of preventing further increases in bacterial resistance among otopathogens. The goals of this article are to incorporate the advances in diagnosis, treatment, prevention, and management of sequelae into strategies that optimize the outcome of acute otitis media and limit further emergence of resistant otopathogens.

Comparison of caregiver otitis media risk factor knowledge in suburban and urban primary care environments

OBJECTIVE

There are many risk factors for otitis media. Some of these, such as passive tobacco smoke exposure and childcare arrangements; have the potential to be modified. The purpose of this study is to assess caregiver knowledge deficits about risk factors associated with otitis media and their willingness to modify behaviors associated with those risks.

RESEARCH DESIGN AND METHODS

This study is a prospective survey study investigating knowledge deficits of parents or guardians of children ages 6-36 months about the risk factors of otitis media. The patients were consecutively drawn from a suburban and an urban pediatric practice. Any difference in survey results between these two groups was also assessed. Participants completed a survey of 21 questions with content including demographic and OM risk factor data.

RESULTS

A total of 401 caregivers completed surveys, with 213 from an urban pediatric practice and 188 from a suburban practice. There was a significant difference in the ethnic distributions of the two populations. The suburban population had a significantly greater family history of ear infections, number of ear infections in the past 12 months, and number of previous ventilation tubes placed. The urban population had a significantly greater number of smokers in the household and decreased knowledge about day care as a risk for OM. The urban population's question responses suggested a greater willingness to change day care arrangements to reduce the risk of otitis media.

CONCLUSIONS

Both populations demonstrated knowledge deficits regarding risk factors associated with OM and both populations exhibited willingness to modify behaviors to reduce risk. These findings demonstrate that there are opportunities for improving education regarding OM risk factors and that this education could potentially reduce risk for OM and in turn reduce the incidence of OM in children.