Which type of infections is associated with the absence of a spleen?

The correct answer is associated with encapsulated bacteria due to the critical role the spleen plays in the immune response. The spleen is particularly important for filtering blood and helping to mount an immune response against polysaccharide-encapsulated organisms. In the absence of a spleen, such as in certain medical conditions or after surgical removal (splenectomy), individuals have a significantly increased risk of infections caused specifically by encapsulated bacteria, such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis.

These bacteria have a protective polysaccharide capsule that helps them evade the host immune system. A properly functioning spleen is essential for effectively clearing these types of infections, as it contains specific immune cells that can recognize and respond to these encapsulated organisms.

In contrast, while viral, fungal, and parasitic infections can occur in individuals without a spleen, they are not as prominently associated with splenic function as encapsulated bacterial infections are. This is due to the differing mechanisms of immune response and the types of pathogens involved. For instance, viral infections typically rely more on cellular immunity rather than opsonization mediated by the spleen, and while fungi and parasites can lead to infections, their