Current face of acute otitis media: microbiology and prevalence resulting from widespread use of heptavalent pneumococcal conjugate vaccine.

BACKGROUND

Many causes can be proposed for a change in the microbiologic makeup of a specific disease state. However, when viewed through the scope of recent events, only one is likely to be the true cause of a change in the microbiology of acute otitis media (AOM): the release and widespread use of heptavalent pneumococcal conjugate vaccine (PCV-7).

OBJECTIVE

The aim of this report was to review the microbiology and prevalence of AOM before and after the release and widespread use of PCV-7.

METHODS

For this brief review, we used a MEDLINE search to identify English-language literature related to the microbiology of AOM before and after the release of PCV-7 in 2000 in the United States (key terms: acute otitis media, AOM, Haemophilus influenzae, H influenzae, Streptococcus pneumoniae, and S pneumoniae; years: 1980-2005). Studies using tympanocentesis to identify the pathogen in recurrent or persistent AOM were examined; US studies reporting AOM microbiology before and after the release of PCV-7 in the same population were considered for the post-PCV-7 analysis.

RESULTS

Following the release of PCV-7, a decrease in the overall rates of AOM was noted. This decrease brings into question the resultant effect on the microbiology of AOM. Our literature search revealed 2 studies that examined the microbiology of AOM before and after the release of PCV-7 in the United States. These 2 studies, conducted in dispersed geographic regions (rural Kentucky and Rochester, New York), illustrated a change in the predominant causative pathogen in AOM, from S pneumoniae to H influenzae in the population of children 7 to 24 months of age with recurrent AOM. Given the time period of the change, these shifts could be related to the release and widespread use of PCV-7.

CONCLUSIONS

Since the 1990s, the predominant causative pathogen in recurrent AOM changed from S pneumoniae to H influenzae, possibly as a result of the release and widespread use of PCV 7. Although PCV-7 use was slowed from August 2001 to May 2003 and again from February to September 2004 by nationwide shortages, those shortages have now been resolved, and compliance with the full vaccine schedule is expected to increase.