The changing epidemiology of pneumococcal pulmonary disease in the era of the heptavalent vaccine.

Since the pediatric pneumococcal 7-valent conjugate vaccine was licensed in the United States, dramatic changes have taken place in the occurrence of pneumococcal disease among children and adults. Incidence of invasive pneumococcal disease including bacteremic pneumonia has declined, but changes in noninvasive pulmonary disease have been more difficult to assess. This paper reviews evidence of the epidemiologic features of invasive pneumococcal disease and community-acquired pneumonia among children and adults since 2000. Despite some increases in non-vaccine-type disease, its use has resulted in major reductions in incidence of invasive pneumococcal disease in all age groups, particularly that of antibiotic-resistant disease and of pediatric pneumococcal pneumonia. Several studies show that changes in circulating pneumococcal strains may be producing differential changes in disease incidence and disease presentation in several populations, including HIV-infected individuals and Alaska Natives.