The pneumococcus Streptococcus pneumoniae commonly grows in pairs (diplococci) but also can grow in short chains. An outer polysaccharide capsule protects the organism against phagocytosis, and pneumococcal virulence is related to the composition and size of the capsule (1). There are 90 known capsular types. Anticapsular antibodies induced by infection or vaccination are protective in normal hosts. The pneumococcal cell wall lies directly beneath the capsule and is composed of murein and glycopeptides. Cell wall antigens are responsible for the intense inflammatory reaction associated with pneumococcal infections. Cell wall components also facilitate pneumococcal attachment to and entry into activated host cells. The phosphorylcholine moiety of lipoteichoic acid structurally mimics platelet-activating factor (PAF). This allows pneumococci to subvert and attach to PAF receptors on cell surfaces (2). Pneumolysin is another important virulence factor produced by virtually all pneumococcal clinical isolates. A potent cytotoxin, pneumolysin injures neutrophils, endothelial cells, and alveolar epithelial cells (3).