Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation
Suvi-Tuuli Simojoki1, Vesa Kirjavainen, Jaana Rahiala
1Division of Pediatric Hematology, Oncology and Stem Cell Transplantation, Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
Insights
Weekly surveillance cultures in pediatric stem cell transplants rarely predicted infections or guided antibiotic use. These cultures offered minimal clinical benefit and were not cost-effective for managing patient care.
Area of Science:
- Infectious Diseases
- Hematology
- Microbiology
Background:
- Surveillance cultures are used to predict infections and guide antimicrobial therapy, but their value in pediatric stem cell transplant recipients is debated.
- Antibiotic resistance is a growing concern, particularly in immunocompromised patients.
Purpose of the Study:
- To evaluate the clinical utility and cost-effectiveness of weekly surveillance cultures in predicting systemic infections and guiding antimicrobial treatment in pediatric allogeneic stem cell transplant (allo-SCT) patients.
Main Methods:
- A retrospective analysis of 57 pediatric allo-SCTs performed between 2007 and 2009.
- Weekly surveillance cultures (fecal and throat) were analyzed for bacterial and fungal colonization.
- Clinical infection episodes and changes in antimicrobial treatment based on surveillance results were recorded.
Main Results:
- 24% of 2594 weekly surveillance samples were positive for bacteria or fungi.
- High rates of antibiotic resistance were observed in pre-transplant stool samples (74%).
- Surveillance cultures had low sensitivity (33.3%), specificity (47.4%), and positive predictive value (0.9%) for predicting bacteremia; antimicrobial treatment was changed in only 5 cases.
Conclusions:
- Weekly surveillance cultures provided limited clinical benefit in predicting infections or guiding antimicrobial therapy in pediatric allo-SCT recipients.
- The routine use of surveillance cultures in this population was found to be not cost-effective.
Abstract:
The value of surveillance cultures in predicting systemic infections and in guiding antimicrobial treatment is controversial. We investigated 57 pediatric allo-SCTs between 2007 and 2009. ALL (34), AML (5), and severe aplastic anemia (4) were the largest patient groups. Conditioning was TBI-based in 87% and 54% developed GVHD (21% grade III-IV). Of the 2594 weekly colonization samples, 24% were positive (fecal bacteria 86%, fecal fungi 16%, Clostridium difficile 16%; throat bacteria 17% and throat fungi 4%). Enterobacteria and enterococci were the most common fecal findings, staphylococci and streptococci in the throat. Of the bacterial stool samples pretransplant, 74% (mostly enterococci) were resistant to our first-line antibiotics (ceftazidime and cloxacillin). Candida species accounted for the majority of the fungal findings: 62% of the fecal and 78% in the throat. A total of 170 clinical infection episodes were recorded, and in 12 of these, the bacterial blood culture was positive. In 4/12 cases, the pathogen was detected in surveillance culture previously, leading to sensitivity and specificity of 33.3 and 47.4%, respectively. Positive predictive value of bacterial surveillance cultures was 0.9%. The antimicrobial treatment was changed in only five cases based on the surveillance culture results. Weekly surveillance cultures seldom provided clinical benefit and were not cost-effective.
