Contaminant Organism Growth in Febrile Infants at Low Risk for Invasive Bacterial Infection.

In this multicenter, cross-sectional, secondary analysis of 4042 low-risk febrile infants, nearly 10% had a contaminated culture obtained during their evaluation (4.9% of blood cultures, 5.0% of urine cultures, and 1.8% of cerebrospinal fluid cultures). Our findings have important implications for improving sterile technique and reducing unnecessary cultures.

Racial Differences in the Diagnosis of Lyme Disease in Children.

Black children with Lyme disease compared with children of other races were less likely to have an erythema migrans lesion diagnosed (adjusted odds ratio, 0.34; 95% confidence interval, .14-.79) but more likely to have a swollen joint (adjusted odds ratio, 3.68; 95% confidence interval, 2.13-6.36) after adjustment for age and local Lyme incidence.

A Clinical Prediction Rule for Bacterial Musculoskeletal Infections in Children with Monoarthritis in Lyme Endemic Regions.

STUDY OBJECTIVE: Children with a bacterial musculoskeletal infection (MSKI) require prompt identification and treatment. In Lyme disease endemic areas, children with an MSKI can present similarly to those with Lyme arthritis. Our goal was to derive a clinical prediction rule to accurately identify children at a low risk for an MSKI. METHODS: We enrolled children with monoarthritis presenting to 1 of 6 Pedi Lyme Net centers and performed a procalcitonin (PCT) and a first-tier Lyme C6 enzyme immunoassay (EIA) test. Our primary outcome was an MSKI (septic arthritis, osteomyelitis, or pyomyositis). Using recursive partitioning with k-fold cross validation, we derived a clinical prediction rule to identify children at a low risk of an MSKI. We calculated the accuracy of our novel rule in a derivation cohort. RESULTS: Of the 735 children in the derivation cohort with an available research biosample, 39 (5%) had an MSKI (18 had septic arthritis, 20 had osteomyelitis, and 1 had pyomyositis), 260 (37%) had Lyme arthritis, and 436 (53%) had other inflammatory arthritis. Children with a PCT level of more than or equal to 0.50 ng/mL and those with a C-reactive protein (CRP) level of more than or equal to 0.6 mg/dL with a negative Lyme C6 EIA were classified as not low risk for an MSKI. Of the 451 (61%) children categorized as low risk, none had an MSKI (sensitivity 100%, 95% confidence interval 91.0% to 100%; specificity 74.2%, 95% confidence interval 70.5% to 77.6%). CONCLUSION: A novel clinical decision rule that includes PCT, CRP, and a first-tier Lyme EIA was highly sensitive for MSKIs. Although broader external validation is required, the application of this rule may safely reduce invasive testing, procedures, and treatment for low risk children.

Outcomes of patients discharged from the pediatric emergency department with abnormal vital signs.

BACKGROUND: Vital signs (VS) are used to triage and identify children at risk for severe illness. Few studies have examined the association of pediatric VS at emergency department (ED) discharge with patient outcomes. OBJECTIVE: To determine if children discharged from the ED with abnormal VS have high rates of return visits, admission or adverse outcomes. METHODS: We conducted a retrospective cohort study of children discharged from 2 pediatric EDs with abnormal VS between July 2018-June 2019. We queried electronic health records (EHR) for children ages 0-18 years discharged from the ED with abnormal last recorded VS. VS were considered erroneously entered and thus excluded from analysis if heart rate was <30 or ≥ 300, respiratory rate was 0 or ≥ 100 or oxygen saturation was <50. Patients who were declared deceased at index visit were excluded. Demographic, clinical, and outcome data including return visits within 48 h and adverse outcomes after the initial ED discharge were obtained. RESULTS: Of the 97,824 children evaluated in the EDs during the study period, 17,661 (18.1%) were discharged with abnormal VS. 404 (2.28%) returned to the ED, of which 95 (23.5%) were admitted for the same chief complaint within 48 h. In comparison, the 48-h return rate for children discharged with normal VS was 2.45% (p = 0.219). Children discharged with abnormal VS were more likely to return if they had 2 or more abnormal VS (OR 1.6; 95% CI 1.23-2.07), were less than 3 years old (OR 1.69, 95% CI 1.39-2.06) or their initial acuity level was high (OR 1.34; 95% CI 1.1-1.63). Higher initial acuity level and age less than 3 years were also associated with admission at revisit (OR 2.58; 95% CI 1.59-4.2; OR 2.20, 95% CI 1.36-3.55). Four of the children who returned required PICU admission, but none died, required CPR or endotracheal intubation. CONCLUSION: Although many children were discharged from the ED with abnormal VS, few returned and required admission. Having 2 or more abnormal VS, age less than 3 years and higher acuity increased odds of revisit. Few children suffered serious adverse outcomes.

Validation of Septic Knee Monoarthritis Prediction Rule in a Lyme Disease Endemic Area.

OBJECTIVE: In Lyme disease endemic areas, Lyme and septic arthritis often present similarly. A published septic knee arthritis clinical prediction rule includes 2 high-risk predictors: absolute neutrophil count of 10,000 cells/mm3 or greater and erythrocyte sedimentation rate of 40 mm/h or greater. The objective of the study was to externally validate this prediction rule in a multicenter prospective cohort. METHODS: We enrolled a prospective cohort of children with knee monoarthritis undergoing evaluation for Lyme disease at 1 of 8 Pedi Lyme Net emergency departments located in endemic areas. We defined a case of septic arthritis with a positive synovial fluid culture or a synovial fluid white blood cell count of 50,000 or greater per high powered field with a positive blood culture and Lyme arthritis with a positive or equivocal C6 EIA, followed by a positive supplemental immunoblot. Other children were classified as having inflammatory arthritis. We report the performance of the septic arthritis clinical prediction rule in our study population. RESULTS: Of the 543 eligible children, 13 had septic arthritis (2.4%), 234 Lyme arthritis (43.1%), and 296 inflammatory arthritis (54.5%). Of the 457 children (84.2%) with available laboratory predictors, all children with septic arthritis were classified as high risk (sensitivity, 100%; 95% confidence interval [CI], 77.2%-100%; specificity, 68.1%; 95% CI, 63.6-73.3; negative predictive value, 278/278 [100%]; 95% CI, 98.6%-100%). Of the 303 low-risk children, 52 (17.2%) underwent diagnostic arthrocentesis. CONCLUSIONS: The septic knee arthritis clinical prediction rule accurately distinguished between septic and Lyme arthritis in an endemic area. Clinical application may reduce unnecessary invasive diagnostic procedures.

Electrocardiogram as a Lyme Disease Screening Test.

OBJECTIVE: To examine the association between electrocardiographic (ECG) evidence of carditis at the time of Lyme disease evaluation and a diagnosis of Lyme disease. STUDY DESIGN: We performed an 8-center prospective cohort study of children undergoing emergency department evaluation for Lyme disease limited to those who had an ECG obtained by their treating clinicians. The study cardiologist reviewed all ECGs flagged as abnormal by the study sites to assess for ECG evidence of carditis. We defined Lyme disease as the presence of an erythema migrans lesion or a positive 2-tier Lyme disease serology. We used logistic regression to measure the association between Lyme disease and atrioventricular (AV) block or any ECG evidence of carditis. RESULTS: Of the 546 children who had an ECG obtained, 214 (39%) had Lyme disease. Overall, 42 children had ECG evidence of carditis, of whom 24 had AV block (20 first-degree). Of the patients with ECG evidence of carditis, only 21 (50%) had any cardiac symptoms. The presence of AV block (OR 4.7, 95% CI 1.8-12.1) and any ECG evidence of carditis (OR 2.3, 95% CI 1.2-4.3) were both associated with diagnosis of Lyme disease. CONCLUSIONS: ECG evidence of carditis, especially AV block, was associated with a diagnosis of Lyme disease. ECG evidence of carditis can be used as a diagnostic biomarker for Lyme disease to guide initial management while awaiting Lyme disease test results.

Treatment of suspected sepsis and septic shock in children with chronic disease seen in the pediatric emergency department.

BACKGROUND: Research demonstrates that timely recognition and treatment of sepsis can significantly improve pediatric patient outcomes, especially regarding time to intravenous fluid (IVF) and antibiotic administration. Further research suggests that underlying chronic disease in a septic pediatric patient puts them at higher risk for poor outcomes. OBJECTIVE: To compare treatment time for suspected sepsis and septic shock in pediatric patients with chronic disease versus those without chronic disease seen in the Pediatric Emergency Department (PED). METHODS: We reviewed patient data from a pediatric sepsis outcomes dataset collected at two tertiary care pediatric hospital sites from January 2017-December 2018. Patients were stratified into two groups: those with and without chronic disease, defined as any patient with at least one of eight chronic health conditions. INCLUSION CRITERIA: patients seen in the PED ultimately diagnosed with sepsis or septic shock, patient age 0 to 20 years and time zero for identification of sepsis in the PED. EXCLUSION CRITERIA: time zero unavailable, inability to determine time of first IVF or antibiotic administration or patient death within the PED. Primary analysis included comparison of time zero to first IVF and antibiotic administration between each group. RESULTS: 312 patients met inclusion criteria. 169 individuals had chronic disease and 143 did not. Median time to antibiotics in those with chronic disease was 41.9 min versus 43.0 min in patients without chronic disease (p = 0.181). Time to first IVF in those with chronic disease was 22.0 min versus 12.0 min in those without (p = 0.010). Those with an indwelling line/catheter (n = 40) received IVF slower than those without (n = 272), with no significant difference in time to antibiotic administration by indwelling catheter status (p = 0.063). There were no significant differences in the mode of identification of suspected sepsis or septic shock between those with versus without chronic disease (p = 0.27). CONCLUSIONS: Study findings suggest pediatric patients with chronic disease with suspected sepsis or septic shock in the PED have a slower time to IVF administration but equivocal use of sepsis recognition tools compared to patients without chronic disease.

Pediatric Lyme Disease Biobank, United States, 2015-2020.

In 2015, we founded Pedi Lyme Net, a pediatric Lyme disease research network comprising 8 emergency departments in the United States. Of 2,497 children evaluated at 1 of these sites for Lyme disease, 515 (20.6%) were infected. This network is a unique resource for evaluating new approaches for diagnosing Lyme disease in children.

Exhaled end-tidal carbon dioxide as a predictor of lactate and pediatric sepsis.

OBJECTIVE: The objective of this study was to investigate the relationship between exhaled end-tidal carbon dioxide (ETCO2) and serum lactate via nasal capnography and to assess the ability of ETCO2 to predict disease severity in children with suspected sepsis in a pediatric emergency department. METHODS: This prospective study included patients (≥ 30 days to ≤21 years of age) who presented with suspected sepsis to a tertiary pediatric emergency department. Pearson correlation coefficient was generated to measure the linear relationship between ETCO2 and lactate. Receiver operating characteristic curves (ROC) were generated to assess the performance of ETCO2 to predict a lactate ≥2 mmol/L and severe disease. Severe disease was defined as severe sepsis and septic shock. RESULTS: From November 1, 2018 to March 31, 2020, 105 emergency department patients underwent evaluation for suspected sepsis. Sixty-nine patients met the inclusion criteria for the study. There was an inverse relationship between ETCO2 and lactate with a correlation coefficient of -0.34 (p = .005). Severe disease had lower ETCO2 (32 ± 6 mmHg, p < .001) and higher lactate (3.3 ± 1.7 mmol/L, p < .001). The area under the curve (AUC) for ETCO2 to predict severe disease was 0.75 (95% CI 0.63, 0.86). An ETCO2 cut off point of 30 mmHg correlated with a sensitivity of 93% and specificity of 32%. CONCLUSIONS: We observed a significant inverse relationship between ETCO2 and lactate in children presenting with suspected sepsis. A lower ETCO2 was predictive of severe disease.

Is lactic acidosis predictive of outcomes in pediatric diabetic ketoacidosis?

OBJECTIVES: The objective of this study was to investigate the significance and prevalence of lactic acidosis in pediatric diabetic ketoacidosis (DKA) presenting to the emergency department. METHODS: A retrospective cohort study of children (age ≤ 21 years) presenting to a tertiary care emergency department in DKA from December 1, 2015 to December 1, 2018. Patients needed to have DKA requiring admission to the pediatric intensive care unit and have had a lactate level collected while in the emergency department to be included. RESULTS: 92 patients resulting in 113 encounters had DKA and a lactate level collected in the emergency department. The mean lactate level was 3.5 mmol/L (±SD 2.1). 72 (63.7%) encounters had lactic acidosis (p < 0.001). There was no significant association between the presence of lactic acidosis and pediatric intensive care unit length of stay (p = 0.321), hospital length of stay (p = 0.426), morbidity (p = 0.552) and mortality (p = 1.000). Initial glucose levels were significantly higher in the patients presenting with lactic acidosis (p = 0.001). CONCLUSIONS: Lactic acidosis is a common finding in pediatric DKA patients presenting to the emergency department. Serum lactate alone should not be used as an outcome predictor in pediatric DKA.

Utility of applying white blood cell cutoffs to non-diagnostic MRI and ultrasound studies for suspected pediatric appendicitis.

BACKGROUND: Non-contrast magnetic resonance imaging (MRI) and ultrasound studies in pediatric patients with suspected appendicitis are often non-diagnostic. The primary objective of this investigation was to determine if combining these non-diagnostic imaging results with white blood cell (WBC) cutoffs improves their negative predictive values (NPVs). METHODS: A retrospective chart review was conducted including patients ≤18 years old with suspected appendicitis who had MRI performed with or without a preceding ultrasound study in a pediatric emergency department. Imaging results were sorted into 2 diagnostic and 5 non-diagnostic categories. NPVs were calculated for the non-diagnostic MRI and ultrasound categories with and without combining them with WBC cutoffs of <10.0 and <7.5 × 109/L. RESULTS: Of the 612 patients with MRI studies included, 402 had ultrasound studies performed. MRI with incomplete visualization of a normal appendix without secondary signs of appendicitis had an NPV of 97.9% that changed to 98.1% and 98.2% when combined with WBC cutoffs of <10.0 and <7.5, respectively. Ultrasound studies with incomplete visualization of a normal appendix without secondary signs had an NPV of 85.3% that improved to 94.8% and 96.5% when combined with WBC cutoffs of <10.0 and <7.5, respectively. CONCLUSIONS: In pediatric patients with suspected appendicitis, MRI studies with incomplete visualization of a normal appendix without secondary signs have a high NPV that does not significantly change with the use of these WBC cutoffs. In contrast, combining WBC cutoffs with ultrasound studies with the same interpretation identifies low-risk groups.

A Call to Restore Your Calling: Self-Care of the Emergency Physician in the Face of Life-Changing Stress-Part 3 of 6: Physician Illness and Impairment.

Physicians suffer from most medical conditions at the same rate as their lay peers. However, physicians' self-care is often sacrificed for patient care. This third article in our series examines physician and trainee illness and impairment. Presenteeism, physician impairment, and substance use disorder (SUD) are defined. We call attention to the potential for harm of dated cultural norms, which often fuel physicians' neglect of their own health and development of ill-advised coping skills.Although any medical condition may become a functional impairment, the primary cause of physician impairment is SUD. Alcohol and prescription opioids top the list of substances used in excess by physicians. Although SUD is less prevalent in residency, we focus on the rise of marijuana and alcohol use in emergency medicine trainees. A nonpunitive model for the prevention and treatment of SUD in residency is described.Physicians are ethically and legally mandated to report any concern for impairment to either a state physician health program or a state medical board. However, recognizing physician SUD is challenging. We describe its clinical presentation, voluntary and mandated treatment tracks, provisions for protecting reporters from civil liability, prognosis for return to practice, and prevention efforts. We underscore the need to model healthy coping strategies and assist trainees in adopting them.In closing, we offer our colleagues and trainees today's to-do list for beginning the journey of reclaiming your health. We also provide resources focused on the practical support of ill and/or impaired physicians.

A Call to Restore Your Calling: Self-care of the Emergency Physician in the Face of Life-Changing Stress-Part 1 of 6.

Few practicing emergency physicians will avoid life-changing stressors such as a medical error, personal illness, malpractice litigation, or death of a patient. Many will be unprepared for the toll they will take on their lives. Some may ultimately experience burnout, post-traumatic stress disorder, and suicidal ideation. Medical education, continuing education, and maintenance of certification programs do not teach physicians to recognize helplessness, moral distress, or maladaptive coping mechanisms in themselves. Academic physicians receive little instruction on how to teach trainees and medical students the art of thriving through life-changing stressors in their career paths. Most importantly, handling a life-changing stressor is that much more overwhelming today, as physicians struggle to meet the daily challenge of providing the best patient care in a business-modeled health care environment where profit-driven performance measures (eg, productivity tracking, patient reviews) can conflict with the quality of medical care they wish to provide.Using personal vignettes and with a focus on the emergency department setting, this 6-article series examines the impact life-changing stressors have on physicians, trainees, and medical students. The authors identify internal constraints that inhibit healthy coping and tools for individuals, training programs, and health care organizations to consider adopting, as they seek to increase physician satisfaction and retention. The reader will learn to recognize physician distress and acquire strategies for self-care and peer support. The series will highlight the concept that professional fulfillment requires ongoing attention and is a work in progress.

Impact of Enteroviral Polymerase Chain Reaction Testing on Length of Stay for Infants 60 Days Old or Younger.

OBJECTIVE: To determine the impact of a cerebrospinal fluid enterovirus polymerase chain reaction (PCR) test performance on hospital length of stay (LOS) in a large multicenter cohort of infants undergoing evaluation for central nervous system infection. STUDY DESIGN: We performed a planned secondary analysis of a retrospective cohort of hospitalized infants ≤60 days of age who had a cerebrospinal fluid culture obtained at 1 of 18 participating centers (2005-2013). After adjustment for patient age and study year as well as clustering by hospital center, we compared LOS for infants who had an enterovirus PCR test performed vs not performed and among those tested, for infants with a positive vs negative test result. RESULTS: Of 19 953 hospitalized infants, 4444 (22.3%) had an enterovirus PCR test performed and 945 (21.3% of tested infants) had positive test results. Hospital LOS was similar for infants who had an enterovirus PCR test performed compared with infants who did not (incident rate ratio 0.98 hours; 95% CI 0.89-1.06). However, infants PCR positive for enterovirus had a 38% shorter LOS than infants PCR negative for enterovirus (incident rate ratio 0.62 hours; 95% CI 0.57-0.68). No infant with a positive enterovirus PCR test had bacterial meningitis (0%; 95% CI 0-0.4). CONCLUSIONS: Although enterovirus PCR testing was not associated with a reduction in LOS, infants with a positive enterovirus PCR test had a one-third shorter LOS compared with infants with a negative enterovirus PCR test. Focused enterovirus PCR test use could increase the impact on LOS for infants undergoing cerebrospinal fluid evaluation.

The Impact of High-Profile Sexual Abuse Cases in the Media on a Pediatric Emergency Department.

High-profile media cases of sexual abuse may encourage disclosures of abuse from victims of unrelated assaults and also influence parental concerns, leading to increased emergency department visits. In the region of the study authors' institution, there are two recent high-profile sexual abuse cases with media coverage: Earl Bradley, a Delaware pediatrician, and Jerry Sandusky, a Pennsylvania college football coach. This is a retrospective cohort study of children evaluated for sexual abuse at a pediatric emergency department. Patients were classified as either presenting during a media period or non-media period. The media periods were one-month periods immediately following breaking news reports, when the cases were highly publicized in the media. The non-media periods were the 12-month periods directly preceding the first reports. The median number of emergency department visits per month during a non-media period was 9 visits (interquartile range 6-10). There were 11 visits in the month following the Sandusky case and 13 visits following the Bradley case. There was no statistical difference in number of emergency department visits for sexual abuse between the periods (p = .09). These finding have implications regarding use of resources in pediatric EDs after high-profile sexual abuse cases.

Race, Ethnicity, Language, and the Treatment of Low-Risk Febrile Infants.

Importance: Febrile infants at low risk of invasive bacterial infections are unlikely to benefit from lumbar puncture, antibiotics, or hospitalization, yet these are commonly performed. It is not known if there are differences in management by race, ethnicity, or language. Objective: To investigate associations between race, ethnicity, and language and additional interventions (lumbar puncture, empirical antibiotics, and hospitalization) in well-appearing febrile infants at low risk of invasive bacterial infection. Design, Setting, and Participants: This was a multicenter retrospective cross-sectional analysis of infants receiving emergency department care between January 1, 2018, and December 31, 2019. Data were analyzed from December 2022 to July 2023. Pediatric emergency departments were determined through the Pediatric Emergency Medicine Collaborative Research Committee. Well-appearing febrile infants aged 29 to 60 days at low risk of invasive bacterial infection based on blood and urine testing were included. Data were available for 9847 infants, and 4042 were included following exclusions for ill appearance, medical history, and diagnosis of a focal infectious source. Exposures: Infant race and ethnicity (non-Hispanic Black, Hispanic, non-Hispanic White, and other race or ethnicity) and language used for medical care (English and language other than English). Main Outcomes and Measures: The primary outcome was receipt of at least 1 of lumbar puncture, empirical antibiotics, or hospitalization. We performed bivariate and multivariable logistic regression with sum contrasts for comparisons. Individual components were assessed as secondary outcomes. Results: Across 34 sites, 4042 infants (median [IQR] age, 45 [38-53] days; 1561 [44.4% of the 3516 without missing sex] female; 612 [15.1%] non-Hispanic Black, 1054 [26.1%] Hispanic, 1741 [43.1%] non-Hispanic White, and 352 [9.1%] other race or ethnicity; 3555 [88.0%] English and 463 [12.0%] language other than English) met inclusion criteria. The primary outcome occurred in 969 infants (24%). Race and ethnicity were not associated with the primary composite outcome. Compared to the grand mean, infants of families that use a language other than English had higher odds of the primary outcome (adjusted odds ratio [aOR]; 1.16; 95% CI, 1.01-1.33). In secondary analyses, Hispanic infants, compared to the grand mean, had lower odds of hospital admission (aOR, 0.76; 95% CI, 0.63-0.93). Compared to the grand mean, infants of families that use a language other than English had higher odds of hospital admission (aOR, 1.08; 95% CI, 1.08-1.46). Conclusions and Relevance: Among low-risk febrile infants, language used for medical care was associated with the use of at least 1 nonindicated intervention, but race and ethnicity were not. Secondary analyses highlight the complex intersectionality of race, ethnicity, language, and health inequity. As inequitable care may be influenced by communication barriers, new guidelines that emphasize patient-centered communication may create disparities if not implemented with specific attention to equity.

Enteroviral testing and length of hospital stay for children evaluated for lyme meningitis.

BACKGROUND: In Lyme disease-endemic areas, many children with aseptic meningitis are hospitalized while awaiting Lyme serology results. Although Lyme serology takes several days, an enteroviral polymerase chain reaction (EV PCR) test takes only a few hours to return results. OBJECTIVE: Our aim was to measure the impact of EV PCR testing on duration of stay for children evaluated for Lyme meningitis. METHODS: A retrospective cohort study was performed with children evaluated for Lyme meningitis at 3 Emergency Departments located in Lyme disease-endemic areas. We defined Lyme meningitis using the Centers for Disease Control and Prevention criteria (either positive Lyme serology test result or an erythema migrans rash). The duration of stay was compared by EV PCR test result (positive, negative, and not obtained). RESULTS: There were 423 study patients identified, 117 (28%) of whom had Lyme meningitis and 209 (49%) had an EV PCR test performed. Median length of stay varied by the EV PCR test status: children with a positive EV PCR test (n = 103; 28 h; interquartile range 17-48 h), those with a negative EV PCR test (n = 106; 72 h; interquartile range 48-120 h), and those who did not have an EV PCR test obtained (n = 214; 48 h; interquartile range 24-96 h; p ≤ 0.001). CONCLUSIONS: Rapid EV PCR testing could assist clinical decision making by Emergency Physicians, avoiding potentially unnecessary hospitalization and parenteral antibiotics for children at low risk of Lyme meningitis.

Biomarkers for Pediatric Bacterial Musculoskeletal Infections in Lyme Disease-Endemic Regions.

OBJECTIVES: Bacterial musculoskeletal infections (MSKIs) are challenging to diagnose because of the clinical overlap with other conditions, including Lyme arthritis. We evaluated the performance of blood biomarkers for the diagnosis of MSKIs in Lyme disease-endemic regions. METHODS: We conducted a secondary analysis of a prospective cohort study of children 1 to 21 years old with monoarthritis presenting to 1 of 8 Pedi Lyme Net emergency departments for evaluation of potential Lyme disease. Our primary outcome was an MSKI, which was defined as septic arthritis, osteomyelitis or pyomyositis. We compared the diagnostic accuracy of routinely available biomarkers (absolute neutrophil count, C-reactive protein, erythrocyte sedimentation rate, and procalcitonin) to white blood cells for the identification of an MSKI using the area under the receiver operating characteristic curve (AUC). RESULTS: We identified 1423 children with monoarthritis, of which 82 (5.8%) had an MSKI, 405 (28.5%) Lyme arthritis, and 936 (65.8%) other inflammatory arthritis. When compared with white blood cell count (AUC, 0.63; 95% confidence interval [CI], 0.55-0.71), C-reactive protein (0.84; 95% CI, 0.80-0.89; P < .05), procalcitonin (0.82; 95% CI, 0.77-0.88; P < .05), and erythrocyte sedimentation rate (0.77; 95% CI, 0.71-0.82; P < .05) had higher AUCs, whereas absolute neutrophil count (0.67; 95% CI, 0.61-0.74; P < .11) had a similar AUC. CONCLUSIONS: Commonly available biomarkers can assist in the initial approach to a potential MSKI in a child. However, no single biomarker has high enough accuracy to be used in isolation, especially in Lyme disease-endemic areas.

Multiplex High-Definition Polymerase Chain Reaction Assay for the Diagnosis of Tick-borne Infections in Children.

Background: Ixodes scapularis ticks can carry Borrelia species as well as other pathogens that cause human disease. The frequency of tick-borne infections and coinfections in children with suspected Lyme disease is unknown, creating clinical uncertainty about the optimal approach to diagnosis. Methods: We enrolled children aged 1-21 years presenting to 1 of 8 Pedi Lyme Net emergency departments for evaluation of Lyme disease. We selected cases with serologically or clinically diagnosed Lyme disease (erythema migrans or early neurologic disease) matched by symptoms, age, gender, and center to control subjects without Lyme disease. We tested whole blood samples collected at the time of diagnosis using a multiplex high-definition polymerase chain reaction (HDPCR) panel to identify 9 bacterial or protozoan pathogens associated with human disease. We compared the frequency of tick-borne coinfections in children with Lyme disease to matched controls. Results: Of the 612 selected samples, 594 (97.1%) had an interpretable multiplex HDPCR result. We identified the following non-Borrelia tick-borne infections: Anaplasma phagocytophilum (2), Ehrlichia chaffeensis (1), and Babesia microti (12). Children with Lyme disease were more likely to have another tick-borne pathogen identified than matched controls (15/297 [5.1%] Lyme cases vs 0/297 [0%]; difference, 5.1% [95% confidence interval, 2.7%-8.2%]). Conclusions: Although a substantial minority of children with Lyme disease had another tick-borne pathogen identified, either first-line Lyme disease antibiotics provided adequate treatment or the coinfection was subclinical and did not require specific treatment. Further studies are needed to establish the optimal approach to testing for tick-borne coinfections in children.