The CBIC Certified Infection Control Exam Study Guide (6th edition) emphasizes that patients who have undergone splenectomy are at significantly increased risk for overwhelming postsplenectomy infection (OPSI), a rapidly progressive and potentially fatal condition. The spleen plays a critical role in clearing encapsulated organisms, and its absence markedly increases susceptibility to infections caused by these pathogens.
Among encapsulated bacteria, Streptococcus pneumoniae is the most common and most deadly cause of OPSI, making pneumococcal vaccination the single most important immunization for asplenic patients. Pneumococcal disease in individuals without a spleen can progress rapidly to sepsis, meningitis, or death, even in young and otherwise healthy adults. Therefore, ensuring pneumococcal vaccination—using the appropriate conjugate and polysaccharide vaccines according to age and immunization history—is a top priority.
While Haemophilus influenzae type B (Option A) and meningococcal vaccines are also recommended for asplenic patients, pneumococcal vaccination provides the greatest immediate protection against the most common cause of severe infection. Hepatitis B (Option C) and varicella (Option D) are important routine immunizations but are not specifically related to the increased infection risk associated with asplenia.
For the CIC® exam, it is critical to recognize that loss of splenic function necessitates prioritization of vaccines targeting encapsulated organisms, with pneumococcal vaccination being the most important.
