Overwhelming post-splenectomy infection
An overwhelming post-splenectomy infection (OPSI) is a rare but rapidly fatal infection occurring in individuals following removal (or permanent dysfunction) of the spleen. The infections are typically characterized by either meningitis or sepsis, and are caused by encapsulated organisms including Streptococcus pneumoniae. It is a medical emergency and requires immediate treatment. Death has been reported to occur within 12 hours.
| Overwhelming post-splenectomy infection | |
|---|---|
| Other names | Overwhelming post-splenectomy sepsis (OPSS) |
| Specialty | Infectious disease |
| Usual onset | 24–48 hours following presentation with mild viral symptoms |
| Causes | Exposure to pathogens following splenectomy or asplenia |
| Risk factors | Splenectomy in the past 2–3 years, removal of spleen for hematological reasons, being under the age of 2 |
| Prognosis | Almost invariably fatal without treatment |
The spleen is necessary for protection against encapsulated bacteria (see Mechanism) and as such when removed by splenectomy it can lead to rapid unchallenged infection by encapsulated bacteria. The rapid progression from mild viral symptoms to sepsis is one of the things that makes OPSI particularly dangerous.
Another source of infection are species of Babesia, which are tick-borne parasites that cause babesiosis.