Who is at the highest risk for post-splenectomy sepsis: children under 5, adults with hereditary spherocytosis (a genetic disorder), or teenagers with a shattered spleen due to trauma?

From the Guidelines

Children under 5 years old are at the highest risk for post-splenectomy sepsis, with a risk of overwhelming post-splenectomy infection (OPSI) estimated to be 10-20 times higher than in adults. This increased risk is due to their immature immune systems and limited prior exposure to encapsulated bacteria, such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis 1. The spleen plays a crucial role in filtering blood and removing these bacteria, and young children rely more heavily on their spleen for this function as they haven't developed sufficient memory B-cells and antibodies against these pathogens.

According to the guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen, children under 5—and especially infants—have an infection rate of over 10%, much higher than adults (<1%) 2. The risk of OPSI is highest in the first year after splenectomy, but remains elevated for more than 10 years and probably for life 1.

Key factors that contribute to the increased risk of OPSI in children under 5 include:

• Immature immune system
• Limited prior exposure to encapsulated bacteria
• Increased reliance on the spleen for filtering blood and removing bacteria
• Higher risk of severe infection and death from OPSI

In contrast, adults with hereditary spherocytosis and teenagers with traumatic splenic injury also face increased infection risk post-splenectomy, but their more developed immune systems and greater immunological memory provide better protection compared to young children. Vaccination against encapsulated bacteria, such as pneumococcal, meningococcal, and Haemophilus influenzae type b vaccines, is essential for all splenectomized patients, and young children may require additional prophylactic antibiotics 1.

From the Research

Post-Splenectomy Sepsis Risk Factors

The risk of post-splenectomy sepsis (PSS) is a significant concern for individuals who have undergone splenectomy. The following factors contribute to the risk of PSS:

• Age: Children under 5 years are at a higher risk of PSS due to their immature immune system 3, 4
• Underlying condition: Patients with hereditary spherocytosis, a genetic disorder, are at a higher risk of PSS compared to those with other conditions 4
• Immunization status: Patients who are not immunized against encapsulated bacteria are at a higher risk of PSS 5

Comparison of Risk Groups

Comparing the risk of PSS among children under 5, adults with hereditary spherocytosis, and teenagers with a shattered spleen due to trauma:

• Children under 5 years are at the highest risk of PSS due to their age and immature immune system 3, 4
• Adults with hereditary spherocytosis are at a higher risk of PSS compared to the general population, but the risk is not as high as that for children under 5 4
• Teenagers with a shattered spleen due to trauma are at a lower risk of PSS compared to children under 5, but the risk is still significant due to the loss of splenic function 4

Preventive Measures

Preventive measures can reduce the risk of PSS, including:

• Immunization against encapsulated bacteria 5, 4
• Prophylactic antibiotics 5, 4
• Patient education on the risks of PSS and the importance of seeking medical attention promptly if symptoms occur 6