Risk and patterns of bacteraemia after splenectomy: a population-based study

During a period in which vaccination of splenectomized patients has been re commended, we analysed the patterns of severe post-splenectomy infections ( i.e, bacteraemia or meningitis) in a defined population-based cohort. A tot al of 561 patients undergoing splenectomy were identified during 1984-93 in a Danish county, and the 538 eligible patients were followed for 1731 pers on-years. After splenectomy, 38 patients contracted a bacteraemia, of which 45% occurred within 30 d (i.e during the postoperative period). No cases o f meningitis were found, Among splenectomized patients the incidence rate o f bacteraemia was 2.3 per 100 person-years at risk. Beyond the postoperativ e period we found an 8-fold increased risk of bacteraemia. Enterobacteria w ere the predominant cause (45%), and only 1 case due to Streptococcus pneum oniae was recorded. 89 (17%) died during the postoperative period, and the overall mortality rate was 18.4 per 100 person-years at risk. In all, 60% o f the patients had been given a pneumococcal vaccination, and a Cox proport ional hazard regression model showed that vaccination significantly reduced the risk of bacteraemia of any cause beyond the postoperative period. We c onclude that splenectomy increases the risk of severe infections, and that vaccinated patients carry a Lower risk of infection than non-vaccinated one s.