Streptococcus pneumoniae infections can cause serious systemic disease in patients following
hematopoietic stem cell transplantation (HSCT), and the response to
pneumococcal vaccine is inadequate in most HSCT recipients. We evaluated the clinical spectrum of
pneumococcal disease and
vaccine-breakthrough infections in HSCT recipients at our
cancer center in a retrospective analysis of all consecutive episodes of S. pneumoniae
infection from 1989 through 2005. During the study period, 7888 patients underwent HSCT at our center; we identified 47 HSCT recipients with 54 S. pneumoniae
infections. The overall incidence of S. pneumoniae
infection was 7 per 1000 HSCTs. The incidence was higher in recipients of allogeneic grafts than in recipients of autologous grafts (9 vs. 5 per 1000 HSCTs, respectively; p <or= 0.012). Thirty-two of the 47 patients (68%) had
leukemia or
lymphoma; 24 patients (51%) had a
malignancy that was
in complete remission. Seventeen patients (36%) had
graft-versus-host disease, which was chronic in 16. The 54 episodes of S. pneumoniae
infection occurred 433 +/- 669 days after HSCT; 5 patients (11%) had multiple episodes. Four episodes of S. pneumoniae
infection occurred within 100 days following
transplantation (45 +/- 49 d); 2 of these were during the pre-engraftment period and 3 were
nosocomial infections. All 50 late post-transplant episodes (93%), which occurred 473 +/- 671 days following
transplantation, were
community-acquired infections (p < 0.00016). Thirty-three episodes (61%) presented as bacteremic
pneumonia, 10 (19%) as
pneumonia, and 8 (15%) as uncomplicated S. pneumoniae
bacteremia alone. Logistic regression analysis showed that patients receiving systemic
corticosteroids had increased risk for bacteremic
pneumonia (odds ratio [OR], 11.7; 95% confidence intervals [CI], 1.371-99.280; p <or= 0.025). Patients with
lymphoma (OR, 6.101; 95% CI, 1.106-33.640; p <or= 0.04) were more likely to develop
pneumonia alone. In 27 episodes (93%) among 29 in which S. pneumoniae susceptibility testing was performed, the patients received concordant antimicrobials. Among the 6 patients (13%) who died of S. pneumoniae
infection, 4 had S. pneumoniae bacteremic
pneumonia and only 1 had chronic GVHD. Admission to a
critical care unit at the onset of
infection (OR, 15.5; 95% CI, 2.116-113.541; p <or= 0.007) and each unit increase in APACHE II score increase the probability of death (OR, 1.9; 95% CI, 1.181-3.054; p <or= 0.008). All 5 (11%) patients who developed
vaccine-breakthrough S. pneumoniae
infection (546 +/- 732 d following vaccination) had
pneumonia, and in 4 patients concurrent
bacteremia also occurred. A serious S. pneumoniae
infection in HSCT recipients occurred more commonly in patients with
lymphoma and patients receiving high-dose systemic
corticosteroid therapy. It is noteworthy that there were no cases of extrapulmonary organ
infection in HSCT recipients who presented with S. pneumoniae
infection at our institution.