Individuals without a spleen have an increased risk of overwhelming post-splenectomy infection (OPSI). Improved awareness in recent years has stimulated increased efforts to prevent OPSI. Published guidelines have described policies for immunization, chemoprophylaxis and other measures considered beneficial to asplenic patients, yet OPSI episodes continue to occur. In an attempt to investigate why serious infections are still being seen, we have conducted a nationally based survey of recent OPSI episodes, using mainly a network of medical microbiologists. Data including clinical background to both splenectomy and OPSI episode, immunization and chemoprophylaxis history have been collated.

Forty-two cases of overwhelming infection were reported by June 1996. Patients of all ages were affected with OPSI occurring up to 59 years after splenectomy. A mortality rate of 45% was seen. Pneumococcal infection caused at least 37 of 42 episodes, but only 12 patients had received pneumococcal vaccine. Four cases were possible vaccine failures. Only 22% of individuals had taken any chemoprophylaxis since splenectomy, and only one carried a medical alert card.

Much more needs to be done to ensure that asplenic patients are warned of the risks of infection, and given at least pneumococcal vaccine. The role of antibiotics for either continual prophylaxis or as a reserve supply for self-prescription at appropriate times also needs greater discussion. Further work on improving pneumococcal vaccine response together with suitable programmes for revaccination are required. Surveillance should continue until the incidence of OPSI reaches an irreducible minimum.