I have asplenia due to a complete splenectomy in ~2010.
OPSI Symptoms
Although asplenia places someone at increased risk of a wide variety of infections, there are particular symptoms associated with overwhelming post-splenectomy infection (OPSI):
Initial presentation could be mild viral symptoms, such as fever or coughing.
Later symptoms may include shakes, shivers, chills, diarrhea, vomiting, malaise, myalgia, headache and abdominal pain.
May progress rapidly to coma, refractory septic shock, and finally death in as little as 24 hours.
OSPI Infections
Important infections that can be associated with overwhelming post-splenectomy infection are: