The rate of invasive pneumococcal disease (IPD) has decreased among both immunized children and nonimmunized adults since the licensure of a heptavalent pneumococcal conjugate vaccine (PCV7) for use in infants in the United States in 2000.
Temporal trends in IPD incidence, clinical syndromes, and underlying conditions were analyzed using active laboratory- and population-based surveillance data from the Centers for Disease Control and Prevention-sponsored Georgia Emerging Infections Program for the 20-county Metropolitan Atlanta, Georgia, for the period of July 1997 through June 2004. P values were determined by test for trend.
Since 2000, there have been significant decreases in the rates of invasive pneumococcal pneumonia (relative risk [RR], 0.80; P=.002) and meningitis (RR, 0.41; P=.003) in adults and for primary bacteremia, invasive pneumonia, and meningitis in children (RR, 0.16 [P<.001], 0.60 [P=.003], and 0.70 [P=.009], respectively). Among human immunodeficiency virus-infected persons, there were significant decreases in the overall rates of IPD (decrease of 43%; P<.001) and invasive pneumonia (decrease of 44%; P<.001) since 2000-2001, although the rate of IPD increased significantly (increase of 53%; P=.022) among patients with acquired immunodeficiency syndrome. There was a concurrent increase in the proportion of adults aged > or = 40 years with underlying comorbidities. Rates of non-PCV7 serotypes increased 1.61-fold and 1.28-fold from 2000-2001 to 2003-2004 in children and adults (P=.005 for both).
The decreasing incidence of IPD in Atlanta since 2000-2001 was associated with decreases in cases of pneumonia and meningitis in adult and pediatric subjects and in cases of primary bacteremia in children. The burden of serotype-replacement disease remained small. Adults with comorbidities represent a growing proportion of patients with IPD.