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

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.