Early Vaccine-type Pneumococcal Acute Otitis Media Does not Predispose to Subsequent Otitis When Compared With Early Acute Otitis Media Due to Other Bacterial Etiology

Biofilm-Forming Bacteria Implicated in Complex Otitis Media in Children in the Post-Heptavalent Pneumococcal Conjugate Vaccine (PCV7) Era

Background: Chronic media with effusion (COME) and recurrent acute otitis media (RAOM) are closely related clinical entities that affect childhood. The aims of the study were to investigate the microbiological profile of otitis-prone children in the post-PCV7 era and, to examine the biofilm-forming ability in association with clinical history and outcome during a two-year post-operative follow-up. Methods: In this prospective study, pathogens from patients with COME and RAOM were isolated and studied in vitro for their biofilm-forming ability. The minimum inhibitory concentrations (MIC) of both the planktonic and the sessile forms were compared. The outcome of the therapeutic method used in each case and patient history were correlated with the pathogens and their ability to form biofilms. Results: Haemophilus influenzae was the leading pathogen (35% in COME and 40% in RAOM), and Streptococcus pneumoniae ranked second (12% in COME and 24% in RAOM). Polymicrobial infections were identified in 5% of COME and 19% of RAOM cases. Of the isolated otopathogens, 94% were positive for biofilm formation. Conclusions: This is the first Greek research studying biofilm formation in complex otitis media-prone children population in the post-PCV7 era. High rates of polymicrobial infections, along with treatment failure in biofilms, may explain the lack of antimicrobial efficacy in otitis-prone children.

Changes in Otitis Media Episodes and Pressure Equalization Tube Insertions Among Young Children Following Introduction of the 13-Valent Pneumococcal Conjugate Vaccine: A Birth Cohort-based Study

BACKGROUND

The impact of 13-valent pneumococcal conjugate vaccine (PCV13) introduction on the occurrence of first and subsequent otitis media (OM) episodes in early childhood is unclear. We compared the risk of OM episodes among children age <2 years before and after PCV13 introduction, accounting for the dependence between OM episodes.

METHODS

We identified consecutive annual (July-June) cohorts of Tennessee Medicaid-enrolled children (2006-2014) from birth through age 2 years. We identified OM episodes using coded diagnoses (we classified diagnoses <21 days apart as the same episode). We modeled adjusted hazard ratios (aHRs) for OM comparing 7-valent pneumococcal conjugate vaccine (PCV7)-era (2006-2010) and PCV13-era (2011-2014) birth cohorts, accounting for risk factors and dependence between first and subsequent episodes. Secondary analyses examined pressure equalization tube (PET) insertions and compared the risk of recurrent OM (≥3 episodes in 6 months or ≥4 episodes in 12 months) between PCV7- and PCV13-era birth cohorts.

RESULTS

We observed 618 968 OM episodes and 24 875 PET insertions among 368 063 children. OM and PET insertion rates increased during the PCV7 years and declined after PCV13 introduction. OM and PET insertion risks were lower in the 2013-2014 cohort compared with the 2009-2010 cohort (aHRs [95% confidence interval], 0.92 [.91-.93] and 0.76 [.72-.80], respectively). PCV13 introduction was associated with declines in the risk of first, subsequent, and recurrent OM.

CONCLUSIONS

The transition from PCV7 to PCV13 was associated with a decline of OM among children aged <2 years due to a reduction in the risk of both the first and subsequent OM episodes.