Second Bacteremia During Antibiotic Treatment in Children With Acute Myeloid Leukemia: A Report From the Canadian Infections in Acute Myeloid Leukemia Research Group

From "More is Better" to "Less is More": A Commentary on Antimicrobial Use in Pediatric Oncology

Reducing avoidable antimicrobial exposure to pediatric patients with cancer is achievable and necessary to promote optimal short- and long-term outcomes. Multiple evidence-based practices are already well established but should be more consistently implemented. Important opportunities exist to further improve the evidence to guide selective antimicrobial use in pediatric oncology.

Cost-effectiveness of levofloxacin prophylaxis against bacterial infection in pediatric patients with acute myeloid leukemia

BACKGROUND

Infections are the leading cause of therapy-related mortality in pediatric patients with acute myeloid leukemia (AML). Although effectiveness of levofloxacin antibacterial prophylaxis in oncology patients is recognized, its cost-effectiveness is unknown. This study evaluated epidemiologic data regarding levofloxacin use and the cost-effectiveness of this strategy as the cost per bacteremia episode, intensive care unit (ICU) admission, and death avoided in children with AML.

PROCEDURE

A retrospective cohort study using the Pediatric Health Information System (PHIS) database compared demographic and clinical characteristics and receipt of levofloxacin prophylaxis in children with AML admitted for chemotherapy from January 1, 2014, through December 31, 2018. We then developed a decision analysis model in this population that compared costs associated with bacteremia, ICU admission, or death secondary to bacteremia to levofloxacin prophylaxis cost from a healthcare perspective. Time horizon is one chemotherapy cycle. Probabilistic and one-way sensitivity analyses evaluated model uncertainty.

RESULTS

Prophylaxis cost $8491 per bacteremia episode prevented compared with an average added hospital cost of $119 478. Prophylaxis cost $81 609 per ICU admission avoided, compared with an average added hospital cost of $94 181. Prophylaxis cost $220 457 per death avoided. In sensitivity analysis, at a willingness-to-pay threshold of $100 000 per bacteremia episode avoided, prophylaxis remained cost-effective in 94.6% of simulations. Prophylaxis use was more common in recent years in patients with relapsed disease and with chemotherapy regimens considered more intensive.

CONCLUSION

Prophylaxis is cost-effective in preventing bacterial infections in patients with AML. Findings support increased use in patients considered at high risk of bacterial infection secondary to myelosuppression.

Infections in children with acute myeloid leukemia: increased mortality in relapsed/refractory patients

The aim of this nationwide study was to describe the epidemiology and profile of bacterial infections (BI), invasive fungal disease (IFD) and viral infections (VI) in patients with de novo and relapsed/refractory (rel/ref) acute myeloid leukemia (AML). Within the studied group of 250 children with primary AML, at least one infectious complication (IC) was diagnosed in 76.0% (n = 190) children including 85.1% (n = 504) episodes of BI, 8.3% (n = 49) - IFD and 6.6% (n = 39) - VI. Among 61 patients with rel/ref AML, at least one IC was found in 67.2% (n = 41) of children including 78.8% (n = 78) of BI, 14.1% (n = 14) of IFD and 7.1% (n = 7) of VI. In all AML patients, within BI Gram-negative strains were predominant. Half of these strains were multi-drug resistant. Characteristics of IFD and VI were comparable for de novo and rel/ref AML. The infection-related mortality was significantly higher, while survival from infection was significantly lower in patients with rel/ref disease.

Repeat blood cultures in children with persistent fever and neutropenia: Diagnostic and clinical implications

BACKGROUND

Repeat blood cultures are frequently obtained in children with persistent fever and neutropenia (FN), but their clinical impact is uncertain.

METHODS

We identified children with persistent FN in the context of hematologic malignancy or hematopoietic stem cell transplantation from July 2006 to June 2012. For each episode, we reviewed blood cultures to determine the yield of true positive and false positive results. We then examined episode-level and culture-level predictors to determine factors associated with new bloodstream infections (BSI).

RESULTS

Among 135 children who met inclusion criteria, there were 184 persistent FN episodes, during which 17 new BSI were diagnosed after the first 24 hr of fever (9.2%; 95% CI 5.4-15.3%). After the first 24 hr, the incidence of new BSI was 1.5% (95% CI 1.0-2.4%) per day and the incidence of blood culture contamination was 1.1% (95% CI 0.6-2.1%) per day. Of 17 new BSI identified, 14 (82%) required changes in therapy, while all 12 contaminant blood cultures were followed by additional antibiotic therapy. Increased odds of new BSI were associated with a history of BSI within 30 days of the episode (OR 5.18; 95% CI 1.29-20.8) and increasing time between recurrent fevers (OR 1.29; 95% CI 1.06-1.57).

CONCLUSIONS

Repeat blood cultures have an important role in diagnosing new BSI and directing therapy in children with persistent FN. The current strategy could be improved by reducing the frequency of blood cultures after the first 24 hr, and targeting repeat cultures by risk.