Early and late invasive pneumococcal infection following stem cell transplantation: a European Bone Marrow Transplantation survey

Abstract
Summary. Streptococcus pneumoniae (S. pneumoniae) may cause severe and lethal infections months and years following stem cell transplantation (SCT). In a prospective survey over a 3·5‐year period, we assessed the incidence, risk factors and outcome for invasive pneumococcal infection (IPI) following SCT. Fifty‐one episodes of IPI were reported: 43 episodes after bone marrow transplantation (BMT) and 8 after peripheral blood stem cell transplantation (PBSCT); 35 after allogeneic SCT and 16 after autologous SCT. Seven IPI episodes, all bacteraemias, were defined as early, occurring 1–35 d (median 3 d) post transplantation. Forty‐four episodes were defined as late (≥ 100 d post SCT), occurring 4 months to 10 years (median 17 months) post transplantation. The incidences of early and late IPI were 2·03/1000 and 8·63/1000 transplantations respectively (P = 0·001). A higher incidence of late IPI was observed after BMT than after PBSCT (10·99 versus 3·23/1000; P < 0·01) and after allogeneic versus autologous SCT (12·20 versus 4·60/1000; P < 0·01). There was a higher estimated incidence of IPI in allogeneic patients with than in those without graft‐versus‐host disease (GVHD) (18·85 versus 8·25/1000; P = 0·015). The mortality rate was 20%, including 2/7 of early and 8/44 of late IPI. S. pneumoniae is a rare but important complication during the aplastic phase after SCT. In conclusion, S. pneumoniae is a significant cause of morbidity late post‐transplantation, especially in allogeneic patients, and particularly those with GVHD. The high IPI mortality rate, both early and late post‐transplantation, requires preventive approaches, mainly effective immunization.