Congenital asplenia is a rare disorder commonly associated with other visceral and cardiac congenital anomalies. Isolated congenital asplenia is even less common than syndromic forms. The risk of severe bacterial infections associated with asplenia is the most concerning clinical implication and carries a significant mortality risk. Prophylactic measures against the clinical syndrome known as overwhelming postsplenectomy infections (OPSI) include vaccination, prophylactic and emergency antibiotics and health education including fever management and travel advice. This case series describes fourteen adults with congenital asplenia and polysplenia syndrome, most of whom were diagnosed incidentally as adults, and outlines the nature of their diagnosis, clinical phenotype, family history and key pathology findings.

An estimated 1 million people in the United States have functional or anatomic asplenia or hyposplenia. Infectious complications due to encapsulated organisms such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae can lead to fulminant sepsis and death, particularly in young children, in the period shortly after splenectomy, and in immunocompromised patients. Patients with asplenia are also at risk for less common infections due to Capnocytophaga, Babesia, and malaria. Antibiotic prophylaxis, vaccines, and patient and family education are the mainstays of prevention in these at-risk patients. Recommendations for antibiotic prophylaxis typically target high-risk periods, such as 1 to 3 years after splenectomy, children ≤5 years of age, or patients with concomitant immunocompromise. However, the risk for sepsis is lifelong, with infections occurring as late as 40 years after splenectomy. Currently available vaccines recommended for patients with asplenia include pneumococcal vaccines (13-valent pneumococcal conjugate vaccine followed by the 23-valent pneumococcal polysaccharide vaccine), meningococcal vaccines (meningococcal conjugate vaccines for serogroups A, C, Y and W-135 and serogroup B meningococcal vaccines), H. influenzae type b vaccines, and inactivated influenza vaccines. Ongoing booster doses are also recommended for pneumococcal and meningococcal vaccines to maintain protection. Despite the availability of prevention tools, adherence is often a challenge. Dedicated teams or clinics focused on patient education and monitoring have demonstrated substantial improvements in vaccine coverage rates for individuals with asplenia and reduced risk of infection. Future efforts to monitor the quality of care in patients with asplenia may be important to bridge the know-do gap in this high-risk population.

Asplenia, the lack of a spleen, can be congenital and increases susceptibility to severe infections caused by encapsulated bacteria, such as Streptococcus pneumoniae (S. pneumoniae). We report two cases of severe pneumococcal infection in two asplenic family members living in the same household. Patient 1, a 38-year-old man with a history of congenital hepatitis B infection and hypospadias, was brought to our emergency department with complaints of cyanosis, cough, and edema of his limbs. He was clinically diagnosed as hyposplenic with overwhelming pneumococcal sepsis. He was admitted to the intensive care unit and was administered antibiotics and catecholaminergic therapy but died 2 h after admission. Patient 2, a 63-year-old woman with a history of type 2 diabetes, was brought to our emergency department one month after admission of Patient 1. She was diagnosed as asplenic with overwhelming pneumococcal sepsis. History-taking revealed that she was the mother of Patient 1 and the two had lived in the same household. She was admitted to the intensive care unit and was rapidly provided antibiotics and catecholaminergic intervention but died one day after admission. Pneumococcal bacteremia caused by virulent S. pneumoniae may be transmitted within households. All residents of households where individuals with pneumococcal bacteremia are living should be educated about the risk of transmissibility. Family members of patients with congenital asplenia/hyposplenia, all family members should be examined to assess their splenic function.

Isolated congenital asplenia (ICA) is a rare and life-threatening condition that predisposes patients to severe bacterial infections. Most of the reported cases are familial and the mode of inheritance is usually autosomal dominant. Here, we report a case of sporadic isolated asplenia and review the literature while focusing on sporadic cases. We report the case of an 11-month-old female infant who developed fulminant pneumococcal meningitis. The pneumococcal vaccine-unimmunized patient was hospitalized with fever, irritability, and purpura, and was diagnosed as having meningitis, septic shock, and disseminated intravascular coagulation. Streptococcus pneumoniae was isolated from both cerebrospinal fluid and blood. She was successfully treated with prompt antibiotic therapy. During hospitalization, abdominal ultrasonography and computed tomography findings, scintigraphy results, and Howell-Jolly body-containing red blood cells indicated the presence of asplenia without any visceroarterial anomalies. Moreover, the findings of peripheral blood smears and spleen ultrasonographic examinations of her parents were normal. Majority of sporadic ICA cases were detected only after the onset of overwhelming infection and had a high mortality. In cases of severe invasive pneumococcal disease, a systematic search for Howell-Jolly bodies on blood smears and the presence of asplenia on abdominal imaging are essential for detecting ICA even in the absence of any family history. After the diagnosis of ICA, patient and parent education, vaccinations, antibiotic prophylaxis, and prompt empiric treatment of febrile episode should be provided.