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.

Background

Without prophylaxis, Pneumocystis jiroveci pneumonia (PCP) develops in 5%-15% of pediatric hematopoietic stem cell transplant (HCT) patients with mortality above 50%. Trimethoprim-sulfamethoxazole is a standard PCP prophylaxis; pentamidine is frequently used as second-line prophylaxis because of trimethoprim-sulfamethoxazole's potential for cytopenias. Monthly intravenous (IV) pentamidine has variable efficacy with PCP infection rates of 0%-10% in pediatric patients, and higher breakthrough rates in those younger than 2 years. We hypothesized that bimonthly (twice monthly) pentamidine might have equivalent safety and improved efficacy; therefore, we conducted a retrospective analysis of bimonthly pentamidine PCP prophylaxis.

Methods

We retrospectively reviewed records of all pediatric HCT patients who received bimonthly IV pentamidine between December 2006 and June 2013, and collected data regarding demographics, clinical course, prophylaxis rationale, laboratory values and adverse events.

Results

Between December 2006 and June 2013, 111 pediatric HCT patients received bimonthly IV pentamidine (574 doses, 8758 patient-days); 31 patients were younger than 2 years at initiation. In the majority (53% of courses), pentamidine was initiated because of cytopenias. Fourteen patients (12.6% of patients, 2.4% of doses) experienced a side-effect prompting discontinuation, including 3 patients with infusion-related hypotension/anaphylaxis and 3 with acute pancreatic dysfunction. No patients [0% (95% confidence interval: 0-3.2)] developed PCP during or after bimonthly IV pentamidine prophylaxis.

Conclusions

Bimonthly IV pentamidine for PCP prophylaxis in the HCT pediatric population has comparable safety to monthly IV pentamidine and was highly effective, including in the very young. Bimonthly IV pentamidine should be considered in pediatric patients as second-line PCP prophylaxis.

Objective

To assess the utility of a panviral DNA microarray platform (Virochip) in the detection of viruses associated with pediatric respiratory tract infections (RTIs).

Study design

The Virochip was compared with conventional direct fluorescent antibody (DFA)- and polymerase chain reaction (PCR)-based testing for the detection of respiratory viruses in 278 consecutive nasopharyngeal aspirate samples from 222 children.

Results

The Virochip was superior in performance to DFA, showing a 19% increase in the detection of 7 respiratory viruses included in standard DFA panels, and was similar to virus-specific PCR (sensitivity, 85% to 90%; specificity, >/=99%; positive predictive value, 94% to 96%; negative predictive value, 97% to 98%) in the detection of respiratory syncytial virus, influenza A, and rhinoviruses/enteroviruses. The Virochip also detected viruses not routinely tested for or missed by DFA and PCR, as well as double infections and infections in critically ill patients that DFA failed to detect.

Conclusions

Given its favorable sensitivity and specificity profile and expanded spectrum for detection, microarray-based viral testing holds promise for clinical diagnosis of pediatric RTIs.