Snapshot A 13-year-old girl presents to her primary care physician for follow-up care of her recently diagnosed hereditary spherocytosis. She reports increasing fatigue and shortness of breath. She required a blood transfusion approximately 4 months prior to presentation. She has not received the PCV13 vaccine but has received the PPSV23 vaccine on year ago. Physical examination shows pallid conjunctiva and organomegaly in the left upper quadrant. Laboratory testing is significant for an elevated reticulocyte count and serum bilirubin. A decision has been made among the patient, her family, and physician to undergo an elective splenectomy. She is administred the PCV13 vaccine 14-days before her operation. Introduction Clinical definition absence of normal spleen function that can be secondary to surgical splenic removal congenital absence or abnormally reduced spleen splenic infarction such as in login to view 1 more bullet splenic infiltration such as in login to view 1 more bullet Under normal conditions the spleen is involved in filtering the blood through a series of capillaries, which results in login to view 2 more bullets the spleen is a lymphoid organ that contains B-lymphocytes which is involved in login to view 2 more bullets Patients with absent splenic function are therefore at risk of infection by encapsulated organisms such as Streptococcus pneumoniae (most important) Haemophilus influenzae Neisseria meningitidis other infectious agents include Capnocytophaga canimorsus login to view 1 more bullet Babesia Presentation Physical exam in cases of sepsis toxic appearing tachycardia evolving hypotension altered sensorium Studies Labs blood smear will show Howell-Jolley bodies target cells complete blood cell count (CBC) can show leukocytosis thrombocytosis Treatment Conservative immunization indication login to view 3 more bullets modality login to view 1 more bullet Medical antibiotic prophylaxis indication login to view 9 more bullets Complications Sepsis due to infection by encapsulated organisms