Definition

• For example: splenectomy, multiple myeloma, ALL, CLL, sickle cell anemia, agammaglobulinemia

Etiology

• Encapsulated organisms: Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis
• Capnocytophaga canimorsus (dog bites)
• Intraerythrocytic parasites, e.g., malaria, babesiosis
• Others: Salmonella typhi, Klebsiella, herpes zoster, group B streptococci, enterococcus, Bacteroides