Rates of Microbiologically Diagnosed Infection and Pathogen Detection in Hematopoietic Stem Cell Transplant Patients

Prevalence of Clostridium difficile Infection in the Hematopoietic Transplantation Setting: Update of Systematic Review and Meta-Analysis

Hematopoietic stem cell transplant (HSCT) recipients are vulnerable to Clostridium difficile infection (CDI) due to risk factors such as immunosuppression, antimicrobial use, and frequent hospitalization. We systematically searched PubMed and Embase to screen relevant studies from April 2014 to November 2021. A meta-analysis was performed to identify the association between CDI and hematopoietic transplantation based on the standard mean difference and 95% confidence intervals (CIs). Among the 431 retrieved citations, we obtained 43 eligible articles, which included 15,911 HSCT patients at risk. The overall estimated prevalence of CDI was 13.2%. The prevalence of CDI among the 10,685 allogeneic transplantation patients (15.3%) was significantly higher than that among the 3,840 autologous HSCT recipients (9.2%). Different incidence rates of CDI diagnosis over the last 7 years were found worldwide, of which North America (14.1%) was significantly higher than Europe (10.7%) but not significantly different from the prevalence among Asia (11.6%). Notably, we found that the estimated prevalence of CDI diagnosed by polymerase chain reaction (PCR) (17.7%) was significantly higher than that diagnosed by enzyme immunoassay (11.5%), indicating a significant discrepancy in the incidence rate of CDI owing to differences in the sensibility and specificity of the detection methods. Recurrence of CDI was found in approximately 15% of the initial patients with CDI. Furthermore, 20.3% of CDI cases were severe. CDI was found to be a common complication among HSCT recipients, displaying an evident increase in the morbidity of infection.

Haploidentical Hematopoietic Stem Cell Transplantation Followed by 'Post-Cyclophosphamide': The Future of Allogeneic Stem Cell Transplant

Allogeneic hematopoietic cell transplant (Allo-HCT) is a potentially curative therapy for many malignant and nonmalignant hematological diseases. However, a suitable human leukocyte antigens (HLAs)-matched donor may not be available when the patient is in urgent need of a stem cell transplant. This challenge has been ameliorated to a large extent by the introduction of haploidentical donors. This type of donor shares one HLA haplotype with the recipient. Therefore, a patient's full sibling has a 50% chance of being haploidentical and a patient's biologic parents and children will all be haploidentical, thus providing an immediately accessible, motivated donor for almost every recipient. Haploidentical transplants previously incurred prohibitively poor outcomes, preventing their widespread use. However, several recent advances have dramatically improved the results, making them a more viable donor source. In this review, we discuss different types of donors used for Allo-HCT with a particular focus on the use of haploidentical donors and their future potential.

[Incidence of blood stream infections of 1265 patients with hematopoietic stem cell transplantation and analysis of pathogenic bacteria]

Objective: To analyze the incidence and microbiological features of blood stream infections (BSI) of patients with hematopoietic stem cell transplantation (HSCT) and to provide laboratory data for empirical use of antibiotic for the HSCT patients with BSI. Methods: The incidence of bloodstream infection, the positive rate of blood culture, bacterial spectrum and drug resistance were analyzed in 1 265 HSCT recipients during 2013 and 2015 were retrospectively studied. Results: Of 1265 patients undergoing HSCT, 1 422 cases of suspected BSI occurred in 784 patients (61.98%) , and 464 patients (59.2%) were in the stage of agranulocytosis (ANC<0.5×10(9)/L) . The detection rate of pathogens in 2013-2015 was about 20% and increase year after year. Of the 401 strains detected, 221 were Gram-negative (G(-)) bacteria (55.1%) , 165 Gram-positive (G(+)) bacteria (41.2%) and 15 fungi (3.7%) . Escherichia coli (16.0%) , Staphylococcus epidermidis (15.5%) and Klebsiella pneumoniae (11.2%) were listed the top three. The proportion of multidrug resistant Acinetobacter Bauman and Stenotrophomonas maltophilia was 64.70% and 63.64% respectively, and methicillin resistant Staphylococcus aureus (MRSA) was more than half (57.14%) . The ratio of vancomycin resistant Enterococci (VRE) and carbapenem resistant Enterobacteriaceae (CRE) was 14.29% and 6.78% respectively. More than 40% Enterobacteriaceae bacteria were resistant to three or four generation cephalosporin antibiotics, and less were resistant to the carbapenems (6.4%) . However, many non-fermentating bacteria were highly resistant to these antibiotics and showed diversity among different strains, with a rate of 47.8% resistance to carbapenems. All the Staphylococcus were sensitive to vancomycin, teicoplanin and linezolid. Conclusions: The incidence of BSI in patients with HSCT was high, and the pathogens were mainly G(-) bacteria. In addition to Enterobacteriaceae, the proportion of non-fermentative bacteria was quite high. No Staphylococcus detected were resistant to vancomycin, teicoplanin and linezolid.