Search

BackgroundEnterovirus (EV) and parechovirus type A3 (PeV-A3) cause infections ranging from asymptomatic to life-threatening. Host immune responses in children, particularly innate responses to PeV-A3, remain largely unknown. The aim of this study was to determine aspects of the cytokine/chemokine responses to EV and PeV-A3 in cerebrospinal fluid (CSF) and plasma obtained from children with systemic/central nervous system infection.MethodsA total of 74 salvaged CSF samples (27 with EV, 23 with PeV-A3, and 24 with neither EV nor PeV-A3) and 35 paired blood samples (10 with EV, 14 with PeV-A3, and 11 with neither) were studied. Concentrations of cytokines and chemokines were measured using a customized 21-plex MILLIPLEX MAP Human Cytokine/Chemokine Magnetic Bead Panel. Additionally, clinical characteristics data for all the patients were collected from electronic medical records to evaluate the potential association between the immune response and presentations.ResultsWe demonstrate that EV and PeV-A3 infections induce different cytokine/chemokine immune responses in children. EV induces more robust responses in CSF with significantly elevated levels of fractalkine, interferon (IFN)-α2, IFN-γ, interleukin (IL)-1Rα, IL-4, IL-8, and tumor necrosis factor α; PeV-A3 induces less robust or absent responses in CSF but robust responses in plasma, with significantly higher concentrations of IFN-α2, IL-15, IL-1Rα, interferon-γ-inducible protein–10, and monocyte chemoattractant protein–1.ConclusionsHigh cytokine/chemokine concentrations in the plasma of PeV-A3 patients compared with EV patients could explain higher/more prolonged fever in PeV-A3 patients, whereas relatively low cytokine/chemokine concentrations in PeV-A3 CSF might explain the absence of CSF pleocytosis.

Background Highly multiplexed molecular assays are popular in clinical laboratories due their high sensitivity, specificity and relatively rapid turn-around time (TAT) for results. Luminex™ respiratory viral panel (RVP) detects 12 respiratory viruses, while BioFire™ respiratory panel (RP) detects 20 respiratory pathogens (17 viruses, 3 bacteria). The aim of the current study was to compare the impact of RVP and RP assay on management of hospitalized children aged ≤24 months. Methods Retrospective data were collected to compare the clinical impact from two multiplex molecular assays (RVP, December 2008–May 2012; RP August 2012–June 2015) on management and outcomes of hospitalized patients. Patients aged ≤24 months and positive for at least one respiratory virus were included. Patients who were (1) receiving immune suppressive therapy, (2) neonates requiring intensive care, or (3) hospitalized for >7 days were excluded. Results A total of 810 patients in RVP and 2,095 patients in RP group were included. The median TAT for RVP and RP assay were 29 hours (IQR 26–58 hours) and 4 hours (IQR 2–8 hours), respectively (P Conclusion Rapid availability of test results from RP assay was associated with reduced antibiotic use, timely antiviral therapy and decreased LOH. The implementation of a more comprehensive respiratory multiplex molecular assay with rapid reporting of test results has the potential to improve management of hospitalized children, decrease unnecessary antibiotic therapy and reduce overall costs. Disclosures R. Selvarangan, BioFire Diagnostics: Board Member and Investigator, Consulting fee and Research grant; Luminex Diagnostics: Investigator, Research grant

Background Urinalysis (UA) has been routinely used as a screening tool prior to microbial culture set-up in many laboratories. BacterioScan 216Dx instrument utilizes laser light scattering technology to detect bacterial growth in urine and results are available in 3 hours. The aim of this study was to compare the performance of 216 DX and UA against culture as gold standard. Methods Clean-catch, unpreserved, either UA positive (leukocyte esterase > trace, or nitrite positive or white blood cells >5/hpf) or UA negative samples from children aged ≤18 years were tested by 216Dx within 24 hours of sample collection. “ Likely positive” samples by 216Dx were tested by MALDI-TOF for direct bacterial identification. Sensitivity and specificity of 216Dx and UA was determined against urine culture. Results Total of 205 urine samples were included in this study, of which 48.0% (98/205) and 52.0% (107/205) were UA positive and negative, respectively. 77.0% of samples were collected from female and median age was 108 months. Overall sensitivity, specificity, positive, and negative predictive value (PPV and NPV) of 216Dx and UA are shown in table below. Of 27 true positive (TP) samples by 216Dx, 77.0% (21/27) were successfully identified by MALDI-TOF. There were a total of 96 samples identified as contamination/normal flora by culture. Among these, 63 samples (65.0%) were detected as true negative (TN) by 216Dx vs. 50 samples (53.1%) as TN by UA. Two false negative (FN) samples by 216Dx and one FN by UA were K. oxytoca, S. epidermidis (both >100 K cfu/ml) and E. coli (>100 K cfu/mL), respectively. Conclusion Although sensitivity of both 216Dx and UA is comparable, specificity of 216Dx was higher than UA. Also, 216Dx showed better performance in detecting urine contamination, thus reducing laboratory reagent and labor cost. Faster turn-around-time of 216Dx coupled with rapid identification of uropathogen by MALDI-TOF has the potential to reduce unnecessary antibiotic use, improve patient management and reduce overall healthcare-related cost. Assay TP FP TN FN %Sensitivity (95% CI) %Specificity (95% CI) %PPV (95% CI) %NPV (95% CI) 216Dx 27 36 140 2 93.1 (75.7–98.8) 79.5 (72.6.0-85.1) 42.8 (30.6–55.9) 98.6 (94.4–99.7) UA 28 70 106 1 96.5 (80.3–99.8) 60.2 (52.5–67.4) 28.5 (20.1–38.7) 99.0 (94.1–99.9) Disclosures All authors: No reported disclosures.