Bacterial Meningitis in Adults After Splenectomy and Hyposplenic States

Objective: To examine the occurrence, disease course, prognosis, and vaccination status of patients with community-acquired bacterial meningitis with a history of splenectomy or functional hyposplenia. Patients and Methods: Patients with bacterial meningitis proven by cerebrospinal fluid culture were prospectively included in a nationwide cohort study between March 1, 2006, and September 1, 2011. Splenectomy or diseases associated with functional hyposplenia were scored for all patients. Vaccination status, clinical features, and outcome of patients with a history of splenectomy or functional hyposplenia were analyzed and compared with patients with normal spleen function. Results: Twenty-four of 965 patients (2.5%) had an abnormal splenic function: 16 had a history of splenectomy and 8 had functional hyposplenia. All patients had pneumococcal meningitis. Pre-illness vaccination status could be retrieved for 19 of 21 patients (90%), and only 6 patients (32%) were adequately vaccinated against pneumococci. Pneumococcal serotype was known in 21 patients; 52% of pneumococcal isolates had a serotype included in the 23-valent vaccine. Vaccine failure occurred in 3 patients. Splenectomized patients more often presented with signs of septic shock compared with patients with a normal spleen (63% vs 24%; P = .02). Outcome was unfavorable in 14 patients (58%), and 6 patients died (25%). Conclusion: Splenectomy or functional hyposplenia is an uncommon risk factor for bacterial meningitis but results in a high rate of mortality and unfavorable outcome. Most patients were not adequately vaccinated against Streptococcus pneumoniae. (C) 2013 Mayo Foundation for Medical Education and Research