Table 1.

Comparison of Enrolled Case-patients (n = 187) to the Population of All Case-patients with Invasive Pneumococcal Disease Identified (n = 887)

CharacteristicEnrolled
Case-patients (%)
All
Case-patients (%)
Age group
 2 to 11 Mo57 (30)266 (30)
 12 to 23 Mo80 (43)387 (44)
 24 to 59 Mo50 (27)234 (26)
Underlying illness*18 (10)Not available
 Nonfocal bacteremia134 (72)646 (73)
 Pneumonia21 (11)136 (15)
 Meningitis11 (6)34 (4)
 Otitis media7 (4)55 (6)
Severity/Outcome:
 Hospitalized81 (44%)343 (39%)
 Died1 (0.5%)11 (1%)
  • * Underlying illnesses included immunodeficiency disorder (n = 12), sickle cell disease (n = 5), cancer (n = 3), kidney disease (n = 2), asplenia (n = 1). Some patients reported more than one underlying condition. Detailed information on underlying illness was not available on case-patients who were not enrolled in the case–control study.