Benjamin Estrada, MD

Many advances and challenges have occurred inthe field of pediatric infectious disease medicineduring the past 10 years. Because this is the 10thanniversary of this column, a summarization of what, inmy opinion, are the most clinically significant developmentsis presented here.

Since the licensure of the heptavalent pneumococcalconjugate vaccine (PCV7) in 2000, the prevalence ofinvasive pneumococcal disease (IPD) among childrenin the United States has decreased significantly. Theincidence of IPD caused by pneumococcal serotypes associatedwith PCV7 among children younger than 5 yearsdecreased from 80 cases per 100,000 population in 1998 to1999 to 4.6 cases per 100,000 population in 2003.1 Variousstudies have demonstrated that nasopharyngeal colonizationwith pneumococcal serotypes covered by thevaccine also has decreased. However, several studies suggestthat in some settings, these bacterial populationshave been replaced with Streptococcus pneumoniae serotypesnot covered by the vaccine.2,3