It is unknown whether febrile infants 29 to 60 days old with positive urinalysis results require routine lumbar punctures for evaluation of bacterial meningitis. OBJECTIVE:To determine the prevalence of bacteremia and/or bacterial meningitis in febrile infants ≤60 days of age with positive urinalysis (UA) results. METHODS:Secondary analysis of a prospective observational study of noncritical febrile infants ≤60 days between 2011 and 2019 conducted in the Pediatric Emergency Care Applied Research Network emergency departments. Participants had temperatures ≥38°C and were evaluated with blood cultures and had UAs available for analysis. We report the prevalence of bacteremia and bacterial meningitis in those with and without positive UA results. RESULTS:Among 7180 infants, 1090 (15.2%) had positive UA results. The risk of bacteremia was higher in those with positive versus negative UA results (63/1090 [5.8%] vs 69/6090 [1.1%], difference 4.7% [3.3% to 6.1%]). There was no difference in the prevalence of bacterial meningitis in infants ≤28 days of age with positive versus negative UA results (∼1% in both groups). However, among 697 infants aged 29 to 60 days with positive UA results, there were no cases of bacterial meningitis in comparison to 9 of 4153 with negative UA results (0.2%, difference -0.2% [-0.4% to -0.1%]). In addition, there were no cases of bacteremia and/or bacterial meningitis in the 148 infants ≤60 days of age with positive UA results who had the Pediatric Emergency Care Applied Research Network low-risk blood thresholds of absolute neutrophil count <4 × 103 cells/mm3 and procalcitonin <0.5 ng/mL. CONCLUSIONS:Among noncritical febrile infants ≤60 days of age with positive UA results, there were no cases of bacterial meningitis in those aged 29 to 60 days and no cases of bacteremia and/or bacterial meningitis in any low-risk infants based on low-risk blood thresholds in both months of life. These findings can guide lumbar puncture use and other clinical decision making.

Background: Urinary tract infections (UTIs) are the most common serious bacterial infection in young febrile infants, and the urinalysis (UA) is an accurate screening test for emergency department (ED) evaluation. Precise estimates of risk of concomitant bacteremia and/or bacterial meningitis (invasive bacterial infections; IBI) in febrile infants ≤ 60 days have been based on presence of UTIs rather than positive UAs, and lack large prospective study. Objective: We sought to determine the prevalence of IBIs in febrile infants 0-28 …

OBJECTIVES:Computed tomography (CT), the reference standard for diagnosis of intraabdominal injury (IAI), carries risk including ionizing radiation. CT-sparing clinical decision rules for children have relied heavily on physical examination, but they did not include focused assessment with sonography for trauma (FAST), which has emerged into widespread use during the past decade. We sought to determine the independent associations of physical examination, laboratory studies, and FAST with identification of IAI in children and to compare the test characteristics of these diagnostic variables. We hypothesized that FAST may add incremental utility to a physical examination alone to more accurately identify children who could forgo CT scan.METHODS:We reviewed a large trauma database of all children with blunt torso trauma presenting to a freestanding pediatric emergency department during a 20-month period. We used logistic regression to evaluate the association of FAST, physical examination, and selected laboratory data with IAI in children, and we compared the test characteristics of these variables.RESULTS:Among 354 children, 50 (14%) had IAI. Positive FAST (odds ratio [OR] = 14.8, 95% confidence interval [CI] = 7.5 to 30.8) and positive physical examination (OR = 15.2, 95% CI = 7.7 to 31.7) were identified as independent predictors for IAI. Physical examination and FAST each had sensitivities of 74% (95% CI = 60% to 85%). Combining FAST and physical examination as FAST-enhanced physical examination (exFAST) improved sensitivity and negative predictive value (NPV) over either test alone (sensitivity = 88%, 95% CI = 76% to 96%) and NPV of 97.3% (95% CI = 94.5% to 98.7%).CONCLUSIONS:In children, FAST and physical examinations each predicted the identification of IAI. However, the combination of the two (exFAST) had greater sensitivity and NPV than either physical examination or FAST alone. This supports the use of exFAST in refining clinical predication rules in children with blunt torso trauma.

STUDY OBJECTIVE:To estimate the minimum dose and total sedation time of rapidly infused ketamine that achieves 3 to 5 minutes of effective sedation in children undergoing abscess incision and drainage in the emergency department. METHODS:The Up-Down method was used to estimate the dose of intravenous ketamine infused over 5 seconds or less that provided effective sedation in 50% (ED50) and 95% (ED95) for healthy children aged 2 to 5 years and 6 to 11 years undergoing abscess incision and drainage. None were pretreated with opioids. Three investigators blinded to ketamine dose independently graded sedation effectiveness by viewing a video recording of the first 5 minutes of sedation. Recovery was determined when patients reached a Modified Aldrete score of 10. RESULTS:We enrolled 20 children in each age group. The estimated ED50 was 0.9 and 0.6 mg/kg for the 2 to 5 years and 6 to 11 years' groups and the estimated ED95 was 1.1 mg/kg for both groups. The median time to full recovery for the 2 groups was 20.5 and 17.5 minutes when only 1 dose of ketamine was administered and 27.5 and 35 minutes when additional doses of ketamine were administered. No participants experienced serious adverse events. CONCLUSIONS:We estimated ED50 and ED95 for rapidly infused ketamine for 2 age groups undergoing abscess incision and drainage. Further studies are needed to get a more precise estimate of ED95. The total sedation time with this technique in the abscess group was shorter than most previous studies and is consistent with our previous observations in patients undergoing fracture reduction.

Objective Adults presenting to pediatric emergency departments are transferred to general emergency departments in proportions between 20% and 60%. How illness severity is related to the decision to transfer is poorly understood. We compared the proportion of adults with emergent and nonemergent conditions with respect to their final disposition. We also determined characteristics associated with transfer. Methods We conducted a retrospective review of the electronic medical record and identified all patients 25 years and older presenting to a large urban freestanding pediatric emergency department from 2008 to 2013. We collected demographic and clinical information and used a preexisting algorithm to classify visits as emergent or nonemergent. We created a multivariate logistical regression model to determine independent variables associated with transfer. Results Among 246,694 encounters, 1182 (0.5%) patients were older than 25 years. We excluded 402 (34%) because they were not categorized. Of the 780 categorized, 32% had an emergent and 68% had a nonemergent condition. Only 22% were transferred. Compared with nonurgent patients, the proportion transferred was twice as high for emergent patients (36% vs 15%), but even for emergent patients, most (63%) were retained for definitive care and/or disposition. Emergent diagnosis, age 45 to 64 years, and higher triage acuity were independently associated with the decision to transfer. Conclusion Regardless of illness severity, a minority of adult patients were transferred away for definitive care. Factors independently associated with transfer were emergent condition, higher triage acuity, and older age.

OBJECTIVE Few prospective studies have assessed the occurrence of radiographic pneumonia in young febrile infants. We analyzed factors associated with radiographic pneumonias in febrile infants 60 days or younger evaluated in pediatric emergency departments. STUDY DESIGN We conducted a planned secondary analysis of a prospective cohort study within 26 emergency departments in a pediatric research network from 2008 to 2013. Febrile (≥38°C) infants 60 days or younger who received chest radiographs were included. Chest radiograph reports were categorized as "no," "possible," or "definite" pneumonia. We compared demographics, Yale Observation Scale scores (>10 implying ill appearance), laboratory markers, blood cultures, and viral testing among groups. RESULTS Of 4778 infants, 1724 (36.1%) had chest radiographs performed; 2.7% (n = 46) had definite pneumonias, and 3.9% (n = 67) had possible pneumonias. Patients with definite (13/46 [28.3%]) or possible (15/67 [22.7%]) pneumonias more frequently had Yale Observation Scale score >10 compared with those without pneumonias (210/1611 [13.2%], P = 0.002) in univariable and multivariable analyses. Median white blood cell count (WBC), absolute neutrophil count (ANC), and procalcitonin (PCT) were higher in the definite (WBC, 11.5 [interquartile range, 9.8-15.5]; ANC, 5.0 [3.2-7.6]; PCT, 0.4 [0.2-2.1]) versus no pneumonia (WBC, 10.0 [7.6-13.3]; ANC, 3.4 [2.1-5.4]; PCT, 0.2 [0.2-0.3]; WBC, P = 0.006; ANC, P = 0.002; PCT, P = 0.046) groups, but of unclear clinical significance. There were no cases of bacteremia in the definite pneumonia group. Viral infections were more frequent in groups with definite (25/38 [65.8%]) and possible (28/55 [50.9%]) pneumonias than no pneumonias (534/1185 [45.1%], P = 0.02). CONCLUSIONS Radiographic pneumonias were uncommon, often had viruses detected, and were associated with ill appearance, but few other predictors, in febrile infants 60 days or younger.

We used 20 de novo genome assemblies to probe the speciation history and architecture of gene flow in rapidly radiating Heliconius butterflies. Our tests to distinguish incomplete lineage sorting from introgression indicate that gene flow has obscured several ancient phylogenetic relationships in this group over large swathes of the genome. Introgressed loci are underrepresented in low-recombination and gene-rich regions, consistent with the purging of foreign alleles more tightly linked to incompatibility loci. Here, we identify a hitherto unknown inversion that traps a color pattern switch locus. We infer that this inversion was transferred between lineages by introgression and is convergent with a similar rearrangement in another part of the genus. These multiple de novo genome sequences enable improved understanding of the importance of introgression and selective processes in adaptive radiation.

Background: Febrile infants commonly present to emergency departments for evaluation. Objective: We describe the variation in diagnostic testing and hospitalization of febrile infants <= 60 days of age presenting to the emergency departments in the Pediatric Emergency Care Applied Research Network. Methods: We enrolled a convenience sample of non-critically ill-appearing febrile infants (temperatures >= 38.0 degrees C/100.4 degrees F) <= 60 days of age who were being evaluated with blood cultures in 26 Pediatric Emergency Care Applied Research Network emergency departments between 2008 and 2013. Patients were divided into younger (0-28 days of age) and older (29-60 days of age) cohorts for analysis. We evaluated diagnostic testing and hospitalization rates by infant age group using chi-square tests and by site using analysis of variance. Results: Four thousand seven hundred seventy-eight patients were eligible for analysis, of whom 1517 (32%) were 0-28 days of age. Rates of lumbar puncture and hospitalization were high (> 90%) among infants <= 28 days of age, with chest radiography (35.5%) and viral testing (66.2%) less commonly obtained. Among infants 29-60 days of age, lumbar puncture (69.5%) and hospitalization (64.4%) rates were lower and declined with increasing age, with chest radiography (36.5%) use unchanged and viral testing (52.7%) slightly decreased. There was substantial variation between sites in the older cohort of infants, with lumbar puncture and hospitalization rates ranging from 40% to 90%. Conclusions: The evaluation and disposition of febrile infants <= 60 days of age is highly variable, particularly among infants who are 29-60 days of age. This variation demonstrates an opportunity to modify diagnostic and management strategies based on current epidemiology to safely decrease invasive testing and hospitalization. (C) 2019 Elsevier Inc. All rights reserved.

ImportanceIn young febrile infants, serious bacterial infections (SBIs), including urinary tract infections, bacteremia, and meningitis, may lead to dangerous complications. However, lumbar punctures and hospitalizations involve risks and costs. Clinical prediction rules using biomarkers beyond the white blood cell count (WBC) may accurately identify febrile infants at low risk for SBIs.ObjectiveTo derive and validate a prediction rule to identify febrile infants 60 days and younger at low risk for SBIs.Design, Setting, and ParticipantsProspective, observational study between March 2011 and May 2013 at 26 emergency departments. Convenience sample of previously healthy febrile infants 60 days and younger who were evaluated for SBIs. Data were analyzed between April 2014 and April 2018.ExposuresClinical and laboratory data (blood and urine) including patient demographics, fever height and duration, clinical appearance, WBC, absolute neutrophil count (ANC), serum procalcitonin, and urinalysis. We derived and validated a prediction rule based on these variables using binary recursive partitioning analysis.Main Outcomes and MeasuresSerious bacterial infection, defined as urinary tract infection, bacteremia, or bacterial meningitis.ResultsWe derived the prediction rule on a random sample of 908 infants and validated it on 913 infants (mean age was 36 days, 765 were girls [42%], 781 were white and non-Hispanic [43%], 366 were black [20%], and 535 were Hispanic [29%]). Serious bacterial infections were present in 170 of 1821 infants (9.3%), including 26 (1.4%) with bacteremia, 151 (8.3%) with urinary tract infections, and 10 (0.5%) with bacterial meningitis; 16 (0.9%) had concurrent SBIs. The prediction rule identified infants at low risk of SBI using a negative urinalysis result, an ANC of 4090/µL or less (to convert to ×109per liter, multiply by 0.001), and serum procalcitonin of 1.71 ng/mL or less. In the validation cohort, the rule sensitivity was 97.7% (95% CI, 91.3-99.6), specificity was 60.0% (95% CI, 56.6-63.3), negative predictive value was 99.6% (95% CI, 98.4-99.9), and negative likelihood ratio was 0.04 (95% CI, 0.01-0.15). One infant with bacteremia and 2 infants with urinary tract infections were misclassified. No patients with bacterial meningitis were missed by the rule. The rule performance was nearly identical when the outcome was restricted to bacteremia and/or bacterial meningitis, missing the same infant with bacteremia.Conclusions and RelevanceWe derived and validated an accurate prediction rule to identify febrile infants 60 days and younger at low risk for SBIs using the urinalysis, ANC, and procalcitonin levels. Once further validated on an independent cohort, clinical application of the rule has the potential to decrease unnecessary lumbar punctures, antibiotic administration, and hospitalizations.

STUDY OBJECTIVE:To describe the current epidemiology of bacteremia in febrile infants 60 days of age and younger in the Pediatric Emergency Care Applied Research Network (PECARN).METHODS:We conducted a planned secondary analysis of a prospective observational study of febrile infants 60 days of age and younger presenting to any of 26 PECARN emergency departments (2008 to 2013) who had blood cultures obtained. We excluded infants with significant comorbidities or critically ill appearance. The primary outcome was prevalence of bacteremia.RESULTS:Of 7,335 screened infants, 4,778 (65.1%) had blood cultures and were enrolled. Of these patients, 84 had bacteremia (1.8%; 95% confidence interval [CI] 1.4% to 2.2%). The prevalence of bacteremia in infants aged 28 days or younger (47/1,515) was 3.1% (95% CI 2.3% to 4.1%); in infants aged 29 to 60 days (37/3,246), 1.1% (95% CI 0.8% to 1.6%). Prevalence differed by week of age for infants 28 days of age and younger (0 to 7 days: 4/156, 2.6%; 8 to 14 days: 19/356, 5.3%; 15 to 21 days: 15/449, 3.3%; and 22 to 28 days: 9/554, 1.6%). The most common pathogens were Escherichia coli (39.3%; 95% CI 29.5% to 50.0%) and group B streptococcus (23.8%; 95% CI 16.0% to 33.9%). Bacterial meningitis occurred in 19 of 1,515 infants 28 days of age and younger (1.3%; 95% CI 0.8% to 2.0%) and 5 of 3,246 infants aged 29 to 60 days (0.2%; 95% CI 0.1% to 0.4%). Of 84 infants with bacteremia, 36 (42.9%; 95% CI 32.8% to 53.5%) had urinary tract infections (E coli 83%); 11 (13.1%; 95% CI 7.5% to 21.9%) had bacterial meningitis.CONCLUSION:The prevalence of bacteremia and meningitis among febrile infants 28 days of age and younger is high and exceeds that observed in infants aged 29 to 60 days. E coli and group B streptococcus are the most common bacterial pathogens.

Linked-Read sequencing technology has recently been employed successfully for de novo assembly of human genomes, however, the utility of this technology for complex plant genomes is unproven. We evaluated the technology for this purpose by sequencing the 3.5-gigabase (Gb) diploid pepper ( Capsicum annuum ) genome with a single Linked-Read library. Plant genomes, including pepper, are characterized by long, highly similar repetitive sequences. Accordingly, significant effort is used to ensure that the sequenced plant is highly homozygous and the resulting assembly is a haploid consensus. With a phased assembly approach, we targeted a heterozygous F 1 derived from a wide cross to assess the ability to derive both haplotypes and characterize a pungency gene with a large insertion/deletion. The Supernova software generated a highly ordered, more contiguous sequence assembly than all currently available C. annuum reference genomes. Over 83% of the final assembly was anchored and oriented using four publicly available de novo linkage maps. A comparison of the annotation of conserved eukaryotic genes indicated the completeness of assembly. The validity of the phased assembly is further demonstrated with the complete recovery of both 2.5-Kb insertion/deletion haplotypes of the PUN1 locus in the F 1 sample that represents pungent and nonpungent peppers, as well as nearly full recovery of the BUSCO2 gene set within each of the two haplotypes. The most contiguous pepper genome assembly to date has been generated which demonstrates that Linked-Read library technology provides a tool to de novo assemble complex highly repetitive heterozygous plant genomes. This technology can provide an opportunity to cost-effectively develop high-quality genome assemblies for other complex plants and compare structural and gene differences through accurate haplotype reconstruction.

Objective The aim of this study was to ascertain potential factors associated with cervical spine injuries in children injured during sports and recreational activities. Methods This is a secondary analysis of a multicenter retrospective case-control study involving children younger than 16 years who presented to emergency departments after blunt trauma and underwent cervical spine radiography. Cases had cervical spine injury from sports or recreational activities (n = 179). Comparison groups sustained (1) cervical spine injury from other mechanisms (n = 361) or (2) other injuries from sports and recreational activities but were free of cervical spine injury (n = 180). Results For children with sport and recreational activity–related cervical spine injuries, common injury patterns were subaxial (49%) and fractures (56%). These children were at increased odds of spinal cord injury without radiographic abnormalities compared with children with cervical spine injuries from other mechanisms (25% vs 6%). Children with sport and recreational activity–related trauma had increased odds of cervical spine injury if they had focal neurologic findings (odds ratio [OR], 5.7; 95% confidence interval [CI], 3.5–9.4), had complaints of neck pain (OR, 3.1; 95% CI, 1.9–5.0), were injured diving (OR, 43.5; 95% CI, 5.9–321.3), or sustained axial loading impacts (OR, 2.2; 95% CI, 1.3–3.5). Football (22%), diving (20%), and bicycle crashes (11%) were the leading activities associated with cervical spine injury. Conclusions In children injured during sports and recreational activities, focal neurologic findings, neck pain, axial loading impacts, and the possibility of spinal cord injury without radiographic abnormality should guide the diagnostic evaluation for potential cervical spine injuries. Certain activities have a considerable frequency of cervical spine injury, which may benefit from activity-specific preventive measures.

Objectives Pediatric cervical injuries are uncommon. This study was to describe injury circumstances, clinical findings, and management among children diagnosed with atlantoaxial rotatory subluxation (AARS) to aid in its recognition and management. Methods Subanalysis of a large case-control study from January 2000 to December 2004 in 17 hospitals in the Pediatric Emergency Care Applied Research Network was performed. Cases were children younger than 16 years with AARS after blunt trauma (n = 55); controls were (a) children with other cervical spine injuries (other CSI, n = 485) and (b) those with normal imaging of the cervical spine (non-CSI, n = 1060). Results Children with AARS were younger (mean [SD] age, 7.7 [3.8] vs 10.7 [4.6]; Wilcoxon P < 0.01). Falls accounted for 36% of injuries; there were no diving mechanisms (vs other CSI, falls 19%, Fisher exact P < 0.01, and diving 7%, P = 0.04). Children with AARS sought medical care more than 24 hours after the injury event (21% vs 1% for non-CSI controls, P < 0.01). Clinical findings associated with AARS included neck pain (67%) and torticollis (57%) versus other CSI, pain (47%) and torticollis (5%, P < 0.01) for each, and versus non-CSI controls, pain (33%) and torticollis (6%, P < 0.01) for each. Management of AARS included no intervention (n = 6, 11%), soft or rigid collar only (n = 24, 44%), traction (n = 14, 25%), halo (n = 9, 16%), internal fixation (n = 2, 4%), and varied across institutions (P = 0.02). Conclusions Children with AARS often have a delayed presentation with neck pain and torticollis; falls are a common injury mechanism. Treatment varied across institutions. Further work is needed to identify optimal management.

Determining the genome sequence of an organism is challenging, yet fundamental to understanding its biology. Over the past decade, thousands of human genomes have been sequenced, contributing deeply to biomedical research. In the vast majority of cases, these have been analyzed by aligning sequence reads to a single reference genome, biasing the resulting analyses, and in general, failing to capture sequences novel to a given genome. Some de novo assemblies have been constructed free of reference bias, but nearly all were constructed by merging homologous loci into single "consensus" sequences, generally absent from nature. These assemblies do not correctly represent the diploid biology of an individual. In exactly two cases, true diploid de novo assemblies have been made, at great expense. One was generated using Sanger sequencing, and one using thousands of clone pools. Here, we demonstrate a straightforward and low-cost method for creating true diploid de novo assemblies. We make a single library from ∼1 ng of high molecular weight DNA, using the 10x Genomics microfluidic platform to partition the genome. We applied this technique to seven human samples, generating low-cost HiSeq X data, then assembled these using a new "pushbutton" algorithm, Supernova. Each computation took 2 d on a single server. Each yielded contigs longer than 100 kb, phase blocks longer than 2.5 Mb, and scaffolds longer than 15 Mb. Our method provides a scalable capability for determining the actual diploid genome sequence in a sample, opening the door to new approaches in genomic biology and medicine.

ObjectivesAdolescents and young adults are at high risk for sexually transmitted infections (STIs). We previously reported an increase in STI testing of adolescents in our ED by obtaining a sexual history using an Audio-enhanced Computer-Assisted Self-Interview (ACASI). We now examine associations among demographics, sexual behaviour, chief complaint and willingness to be tested.MethodsThis was a prospective study conducted in a paediatric ED between April and December 2011. After triage, eligible patients between 15 and 21 years presenting with non-life-threatening conditions were asked to participate in the study. Consenting participants used an ACASI to provide their demographic data and answer questions about their sexual history and willingness to be tested. Our primary outcome was the association of demographics, chief complaint and ACASI recommendation with the participant’s willingness to be tested.ResultsWe approached 1337 patients, of whom 800 (59%) enrolled and completed the ACASI. Eleven who did not answer questions related to their sexual history were excluded from analysis. Of 789 participants, 461 (58.4%) were female and median age was 16.9 years (IQR 16.0–17.8); 509 (64.5%) endorsed a history of anal, oral and/or vaginal intercourse. Disclosing a sexual history and willingness to be tested did not differ significantly by gender. 131 (16.6%) had a chief complaint potentially referable to an STI; among the 658 participants with non-STI-related complaints, 412 (62.6%) were sexually active, many of whom disclosed risky behaviours, including multiple partners (46.4%) and inconsistent condom use (43.7%). The ACASI identified 419 patients as needing immediate STI testing; the majority (81%) did not have a chief complaint potentially related to STIs. 697 (88.3%) participants were willing to receive STI testing. Most (94.6%) of the patients with STI-related complaints were willing to be tested, and 92.1% of patients with a recommendation for immediate testing by the ACASI indicated a willingness to be tested.ConclusionsAdolescents were willing to disclose sexual activity via electronic questionnaires and were willing to receive STI testing, even when their chief complaint was not STI related. The ACASI facilitated identification of adolescent ED patients needing STI testing regardless of chief complaint.

Current short-read methods have come to dominate genome sequencing because they are cost-effective, rapid, and accurate. However, short reads are most applicable when data can be aligned to a known reference. Two new methods for de novo assembly are linked-reads and restriction-site labeled optical maps. We combined commercial applications of these technologies for genome assembly of an endangered mammal, the Hawaiian Monk seal.We show that the linked-reads produced with 10X Genomics Chromium chemistry and assembled with Supernova v1.1 software produced scaffolds with an N50 of 22.23 Mbp with the longest individual scaffold of 84.06 Mbp. When combined with Bionano Genomics optical maps using Bionano RefAligner, the scaffold N50 increased to 29.65 Mbp for a total of 170 hybrid scaffolds, the longest of which was 84.78 Mbp. These results were 161X and 215X, respectively, improved over DISCOVAR de novo assemblies. The quality of the scaffolds was assessed using conserved synteny analysis of both the DNA sequence and predicted seal proteins relative to the genomes of humans and other species. We found large blocks of conserved synteny suggesting that the hybrid scaffolds were high quality. An inversion in one scaffold complementary to human chromosome 6 was found and confirmed by optical maps.The complementarity of linked-reads and optical maps is likely to make the production of high quality genomes more routine and economical and, by doing so, significantly improve our understanding of comparative genome biology.

IMPORTANCE:Young febrile infants are at substantial risk of serious bacterial infections; however, the current culture-based diagnosis has limitations. Analysis of host expression patterns ("RNA biosignatures") in response to infections may provide an alternative diagnostic approach.OBJECTIVE:To assess whether RNA biosignatures can distinguish febrile infants aged 60 days or younger with and without serious bacterial infections.DESIGN, SETTING, AND PARTICIPANTS:Prospective observational study involving a convenience sample of febrile infants 60 days or younger evaluated for fever (temperature >38° C) in 22 emergency departments from December 2008 to December 2010 who underwent laboratory evaluations including blood cultures. A random sample of infants with and without bacterial infections was selected for RNA biosignature analysis. Afebrile healthy infants served as controls. Blood samples were collected for cultures and RNA biosignatures. Bioinformatics tools were applied to define RNA biosignatures to classify febrile infants by infection type.EXPOSURE:RNA biosignatures compared with cultures for discriminating febrile infants with and without bacterial infections and infants with bacteremia from those without bacterial infections.MAIN OUTCOMES AND MEASURES:Bacterial infection confirmed by culture. Performance of RNA biosignatures was compared with routine laboratory screening tests and Yale Observation Scale (YOS) scores.RESULTS:Of 1883 febrile infants (median age, 37 days; 55.7% boys), RNA biosignatures were measured in 279 randomly selected infants (89 with bacterial infections-including 32 with bacteremia and 15 with urinary tract infections-and 190 without bacterial infections), and 19 afebrile healthy infants. Sixty-six classifier genes were identified that distinguished infants with and without bacterial infections in the test set with 87% (95% CI, 73%-95%) sensitivity and 89% (95% CI, 81%-93%) specificity. Ten classifier genes distinguished infants with bacteremia from those without bacterial infections in the test set with 94% (95% CI, 70%-100%) sensitivity and 95% (95% CI, 88%-98%) specificity. The incremental C statistic for the RNA biosignatures over the YOS score was 0.37 (95% CI, 0.30-0.43).CONCLUSIONS AND RELEVANCE:In this preliminary study, RNA biosignatures were defined to distinguish febrile infants aged 60 days or younger with vs without bacterial infections. Further research with larger populations is needed to refine and validate the estimates of test accuracy and to assess the clinical utility of RNA biosignatures in practice.

Background De novo reference assemblies that are affordable, practical to produce, and of sufficient quality for most downstream applications, remain an unattained goal for many taxa. Insects, which may yield too little DNA from individual specimens for long-read sequencing library construction and often have highly heterozygous genomes, can be particularly hard to assemble using inexpensive short-read sequencing data. The large number of insect species with medical or economic importance makes this a critical problem to address. Results Using the assembler DISCOVAR de novo , we assembled the genome of the African malaria mosquito Anopheles arabiensis using 250 bp reads from a single library. The resulting assembly had a contig N50 of 22,433 bp, and recovered the gene set nearly as well as the ALLPATHS-LG AaraD1 An. arabiensis assembly produced with reads from three sequencing libraries and much greater resources. DISCOVAR de novo appeared to perform better than ALLPATHS-LG in regions of low complexity. Conclusions DISCOVAR de novo performed well assembling the genome of an insect of medical importance, using simpler sequencing input than previous anopheline assemblies. We have shown that this program is a viable tool for cost-effective assembly of a modestly-sized insect genome.

Study objective: We estimate the minimum dose and total sedation time of rapidly infused ketamine that achieves 3 to 5 minutes of effective sedation in children undergoing forearm fracture reduction in the emergency department.Methods: We used the up-down method to estimate the median dose of intravenous ketamine infused during less than or equal to 5 seconds that provided effective sedation in 50% (ED50) and 95% (ED95) of healthy children aged 2 to 5, 6 to 11, or 12 to 17 years who were undergoing forearm fracture reduction. Most patients were pretreated with opioids. Three investigators blinded to ketamine dose independently graded sedation effectiveness by viewing a video recording of the first 5 minutes of sedation. Recovery was assessed by modified Aldrete score.Results: We enrolled 20 children in each age group. The estimated ED50 was 0.7, 0.5, and 0.6 mg/kg and the estimated ED95 was 0.7, 0.7, and 0.8 mg/kg for the groups aged 2 to 5,6 toll, and 12 to 17 years, respectively. For the group aged 2 to 5 years, an empirically derived ED95 was 0.8 mg/kg. All patients who received the empirically derived ED95 in the group aged 2 to 5 years or the estimated ED95 in the groups aged 6 to 11 and 12 to 17 years had effective sedation. The median total sedation time for the 3 age groups, respectively, was 25, 22.5, and 25 minutes if 1 dose of ketamine was administered and 35, 25, and 45 minutes if additional doses were administered. No participant experienced serious adverse events.Conclusion: We estimated ED50 and ED95 for rapidly infused ketamine for 3 age groups undergoing fracture reduction. Total sedation time was shorter than that in most previous studies.