ABSTRACT
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 (> or = 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.
