Interventions to de-implement unnecessary antibiotic prescribing for ear infections (DISAPEAR Trial): protocol for a cluster-randomized trial.

BACKGROUND: Watchful waiting management for acute otitis media (AOM), where an antibiotic is used only if the child's symptoms worsen or do not improve over the subsequent 2-3 days, is an effective approach to reduce antibiotic exposure for children with AOM. However, studies to compare the effectiveness of interventions to promote watchful waiting are lacking. The objective of this study is to compare the effectiveness and implementation outcomes of two pragmatic, patient-centered interventions designed to facilitate use of watchful waiting in clinical practice. METHODS: This will be a cluster-randomized trial utilizing a hybrid implementation-effectiveness design. Thirty-three primary care or urgent care clinics will be randomized to one of two interventions: a health systems-level intervention alone or a health systems-level intervention combined with use of a shared decision-making aid. The health systems-level intervention will include engagement of a clinician champion at each clinic, changes to electronic health record antibiotic orders to facilitate delayed antibiotic prescriptions as part of a watchful waiting strategy, quarterly feedback reports detailing clinicians' use of watchful waiting individually and compared with peers, and virtual learning sessions for clinicians. The hybrid intervention will include the health systems-level intervention plus a shared decision-making aid designed to inform decision-making between parents and clinicians with best available evidence. The primary outcomes will be whether an antibiotic was ultimately taken by the child and parent satisfaction with their child's care. We will explore the differences in implementation effectiveness by patient population served, clinic type, clinical setting, and organization. The fidelity, acceptability, and perceived appropriateness of the interventions among different clinician types, patient populations, and clinical settings will be compared. We will also conduct formative qualitative interviews and surveys with clinicians and administrators, focus groups and surveys of parents of patients with AOM, and engagement of two stakeholder advisory councils to further inform the interventions. DISCUSSION: This study will compare the effectiveness of two pragmatic interventions to promote use of watchful waiting for children with AOM to reduce antibiotic exposure and increase parent satisfaction, thus informing national antibiotic stewardship policy development. CLINICAL TRIAL REGISTRATION: NCT06034080.

Clinical Presentation of Blastomycosis is Associated With Infecting Species, Not Host Genotype.

Objective: To determine if host genetics may be a risk factor for severe blastomycosis.Design: A cohort of patients who had contracted blastomycosis underwent targeted SNP (single nucleotide polymorphism) genotyping. The genetics of these patients were compared to a set of age and gender-matched controls and between patients with severe versus mild to moderate blastomycosis.Setting: The Marshfield Clinic Health System in central and northern WisconsinParticipants: Patients with a diagnosis of blastomycosis prior to 2017 were contacted for enrollment in this study. A phone hotline was also set up to allow interested participants from outside the Marshfield Clinic Health System to request enrollment.Methods: SNP frequency was assessed for significant differences between the patient cohort and controls and between patients with severe versus mild to moderate blastomycosis. We also tested the effect of Blastomyces species identified in clinical isolates on disease symptoms and severity.Results: No significant differences were found in SNP frequency between cases and controls or between those with severe or mild to moderate blastomycosis. We did detect significant differences in symptom frequency and disease severity by Blastomyces species.Conclusions: Our study did not identify any genetic risk factors for blastomycosis. Instead, the species of Blastomyces causing the infection had a significant effect on disease severity.

Sustainability of Interventions to Increase Guideline-Concordant Durations of Antibiotic Therapy for Children with Acute Otitis Media.

Two low-cost pragmatic interventions (change in the options in the electronic health record; change in the electronic health record plus education plus feedback comparing prescribing with peers) to improve prescribing of guideline-concordant short antibiotic durations for children 2 years and older with uncomplicated acute otitis media were highly effective and results were sustained 18 months after discontinuation of the active components of the interventions.

Costs to Implement a Pediatric Weight Management Program Across 3 Distinct Contexts.

BACKGROUND: The Connect for Health program is an evidence-based program that aligns with national recommendations for pediatric weight management and includes clinical decision support, educational handouts, and community resources. As implementation costs are a major driver of program adoption and maintenance decisions, we assessed the costs to implement the Connect for Health program across 3 health systems that primarily serve low-income communities with a high prevalence of childhood obesity. METHODS: We used time-driven activity-based costing methods. Each health system (site) developed a process map and a detailed report of all implementation actions taken, aligned with major implementation requirements (eg, electronic health record integration) or strategies (eg, providing clinician training). For each action, sites identified the personnel involved and estimated the time they spent, allowing us to estimate the total costs of implementation and breakdown costs by major implementation activities. RESULTS: Process maps indicated that the program integrated easily into well-child visits. Overall implementation costs ranged from $77,103 (Prisma Health) to $84,954 (Denver Health) to $142,721 (Massachusetts General Hospital). Across implementation activities, setting up the technological aspects of the program was a major driver of costs. Other cost drivers included training, engaging stakeholders, and audit and feedback activities, though there was variability across systems based on organizational context and implementation choices. CONCLUSIONS: Our work highlights the major cost drivers of implementing the Connect for Health program. Accounting for context-specific considerations when assessing the costs of implementation is crucial, especially to facilitate accurate projections of implementation costs in future settings.

Utilization of nonguideline concordant antibiotic treatment following acute otitis media in children in the United States.

PURPOSE: Acute otitis media (AOM) is a common indication for antibiotics in children. We sought to characterize the frequency of nonguideline concordant antibiotic therapy for AOM in the United States, by agent and duration. METHODS: Using national administrative claims data (2016-2019), we identified children aged 6 months to 17 years with an oral antibiotic dispensed within 3 days of a new diagnosis of suppurative AOM. Use of nonguideline concordant agents and durations, defined based on national treatment guidelines, were summarized by age, race, rurality, region, and insurance type. Subsequent oral antibiotic dispensing within the year after AOM diagnosis was also evaluated. We created sunburst diagrams to visualize longitudinal patterns of within-person antibiotic utilization for AOM, by agent and duration. RESULTS: We identified 789 424 eligible commercially-insured and 502 239 medicaid-insured children. Among commercially insured children, 35% received nonguideline concordant agents for AOM, including cefdinir (16%), amoxicillin-clavulanate (12%), and azithromycin (7%). Fewer children age <2 years received a nonguideline concordant initial agent (27%) compared to age ≥6 years (41%). More children age <2 years received three or more antibiotics over the following year (34% vs. 3% for children age ≥6 years). The most common treatment duration was 10 days for all ages; treatment duration for the initial antibiotic was nonguideline concordant for 95% and 89% of children age 2-5 years and ≥6 years, respectively. Patterns were similar for medicaid-insured children. CONCLUSIONS: Nonguideline concordant antibiotic use is common when treating AOM in children, including use of broad-spectrum agents and longer-than-recommended antibiotic durations.

Increasing Guideline-Concordant Durations of Antibiotic Therapy for Acute Otitis Media.

OBJECTIVE: To compare the effectiveness of 2 interventions in improving prescribing of guideline-concordant durations of therapy for acute otitis media (AOM). STUDY DESIGN: This was a quasi-experimental mixed methods analysis that compared a bundled quality improvement intervention consisting of individualized audit and feedback, education, and electronic health record (EHR) changes to an EHR-only intervention. The bundle was implemented in 3 pediatric clinics from January to August 2020 and an EHR-only intervention was implemented in 6 family medicine clinics. The primary outcome measure was prescription of an institutional guideline-concordant 5-day duration of therapy for children ≥2 years of age with uncomplicated AOM. Propensity score matching and differences-in-differences analysis weighted with inverse probability of treatment were completed. Implementation outcomes were assessed using the Reach, Effectiveness, Adoption, Implementation, Maintenance Framework. Balance measures included treatment failure and recurrence. RESULTS: In total, 1017 encounters for AOM were included from February 2019 to August 2020. Guideline-concordant prescribing increased from 14.4% to 63.8% (difference = 49.4%) in clinics that received the EHR-only intervention and from 10.6% to 85.2% (difference = 74.6%) in clinics that received the bundled intervention. In the adjusted analysis, the bundled intervention improved guideline-concordant durations by an additional 26.4% (P < .01) compared with the EHR-only intervention. Providers identified EHR-prescription field changes as the most helpful components. There were no differences in treatment failure or recurrence rates between baseline and either intervention. CONCLUSIONS: Both interventions resulted in improved prescribing of guideline-concordant durations of antibiotics. The bundled intervention improved prescribing more than an EHR-only intervention and was acceptable to providers.

Amoxicillin Versus Other Antibiotic Agents for the Treatment of Acute Otitis Media in Children.

OBJECTIVES: The objective of the study was to compare the antibiotic treatment failure and recurrence rates between antibiotic agents (amoxicillin, amoxicillin-clavulanate, cefdinir, and azithromycin) for children with uncomplicated acute otitis media (AOM). STUDY DESIGN: We completed a retrospective cohort study of children 6 months-12 years of age with uncomplicated AOM identified in a nationwide claims database. The primary exposure was the antibiotic agent, and the primary outcomes were treatment failure and recurrence. Logistic regression was used to estimate ORs, and analyses were stratified by primary exposure, patient age, and antibiotic duration. RESULTS: Among the 1 051 007 children included in the analysis, 56.6% were prescribed amoxicillin, 13.5% were prescribed amoxicillin-clavulanate, 20.6% were prescribed cefdinir, and 9.3% were prescribed azithromycin. Most prescriptions (93%) were for 10 days, and 98% were filled within 1 day of the medical encounter. Treatment failure and recurrence occurred in 2.2% (95% CI: 2.1, 2.2) and 3.3% (3.2, 3.3) of children, respectively. Combined failure and recurrence rates were low for all agents including amoxicillin (1.7%; 1.7, 1.8), amoxicillin-clavulanate (11.3%; 11.1, 11.5), cefdinir (10.0%; 9.8, 10.1), and azithromycin (9.8%; 9.6, 10.0). CONCLUSIONS: Despite microbiologic changes in AOM etiology, treatment failure and recurrence were uncommon for all antibiotic agents and were lower for amoxicillin than for other agents. These findings support the continued use of amoxicillin as a first-line agent for AOM when antibiotics are prescribed.

Rates of Appropriate Treatment and Follow-Up Testing After a Gonorrhea and/or Chlamydia Infection in an Urban Network of Federally Qualified Health Center Systems.

BACKGROUND: Reinfection and partner transmission are common with Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT). We assessed treatment and follow-up laboratory testing for GC and CT and evaluated associations with patient- and system-level factors. METHODS: The analysis included positive GC and/or CT nucleic acid amplification test results from patients aged 14 to 24 years at a federally qualified health center system site in Denver, CO, from January 2018 to December 2019. Outcomes assessed include treatment within 14 days, HIV/syphilis testing within 6 months, and repeat GC and CT testing within 2 to 6 months. Bivariate and multivariable regression modeling assessed associated factors. RESULTS: Among 27,168 GC/CT nucleic acid amplification tests performed, 1.8% (484) were positive for GC and 7.8% (2125) were positive for CT. Within the assessed time frames, 87% (2275) of patients were treated, 54.1% (1411) had HIV testing, 50.1% (1306) had syphilis testing, and 39.9% (1040) had GC and CT retesting. Older patients were more likely to receive treatment (adjusted odds ratio 1.13; 95% confidence interval, 1.00-1.27; P = 0.05) than younger patients, whereas males were less likely to receive GC and CT retesting (adjusted odds ratio, 0.19; 95% confidence interval, 0.11-0.33; P < 0.001) than females. Patients treated on the day of testing were less likely to receive follow-up laboratory tests than those treated 2 to 14 days after. CONCLUSIONS: Although most patients received antibiotic treatment, only about half received HIV/syphilis testing and less than half received GC and CT retesting. It is critical to find innovative strategies to improve treatment and follow-up management of these infections to decrease complications, reduce transmission, and combat the rising rates of sexually transmitted infections.

Gonorrhea and Chlamydia Rates Among 12- to 24-Year-Old Patients in an Urban Health System.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infection rates continue to rise. Screening guidelines have largely focused on sexually active female individuals and men who have sex with men populations. Health care system testing and infection rates, particularly among heterosexual male individuals, are poorly understood. Our aim was to evaluate CT and GC testing and prevalence among 12- to 24-year-old patients in an urban federally qualified health center system. METHODS: This retrospective study analyzed electronic health record data from 2017 to 2019 in a large system of federally qualified health centers in Denver, CO. Abstracted data included demographics, sexual activity, sexual orientation, and laboratory results. χ2 Tests were used to evaluate differences between groups. RESULTS: Of the 44,021 patients included, 37.6% were tested, 15.0% were positive for CT, and 3.4% were positive for GC. Heterosexual male patients had a testing rate of 22.8% and positivity rates of CT and GC at 13.1% and 3.0%, respectively. Among tested patients documented as not sexually active, 7.5% were positive for CT. Multiple or reinfections were detected in 29% of patients. CONCLUSIONS: This study shows low testing rates and high rates of CT and GC infections among all patients, including heterosexual male patients and those documented as not sexually active. Improved screening of these populations in the primary care setting may be key to combating the sexually transmitted disease epidemic.

A Novel Approach to Evaluate Antibiotic Utilization Across the Spectrum of Inpatient and Ambulatory Care and Implications for Prioritization of Antibiotic Stewardship Efforts.

BACKGROUND: Antibiotic overuse remains a significant problem. The objective of this study was to develop a methodology to evaluate antibiotic use across inpatient and ambulatory care sites in an integrated healthcare system to prioritize antibiotic stewardship efforts. METHODS: We conducted an epidemiologic study of antibiotic use across an integrated healthcare system on 12 randomly selected days from 2017 to 2018. For inpatients and perioperative patients, administrations of antibiotics were recorded, whereas prescriptions were recorded for outpatients. RESULTS: On the study days, 10.9% (95% confidence interval [CI], 10.6%-11.3%) of patients received antibiotics. Of all antibiotics, 54.1% were from ambulatory care (95% CI, 52.6%-55.7%), 38.0% were from the hospital (95% CI, 36.6%-39.5%), and 7.8% (95% CI, 7.1%-8.7%) were perioperative. The emergency department/urgent care centers, adult outpatient clinics, and adult non-critical care inpatient wards accounted for 26.4% (95% CI, 25.0%-27.7%), 23.8% (95% CI, 22.6%-25.2%), and 23.9% (95% CI, 22.7%-25.3%) of antibiotic use, respectively. Only 9.2% (95% CI, 8.3%-10.1%) of all antibiotics were administered in critical care units. Antibiotics with a broad spectrum of gram-negative activity accounted for 30.4% (95% CI, 29.0%-31.9%) of antibiotics. Infections of the respiratory tract were the leading indication for antibiotics. CONCLUSIONS: In an integrated healthcare system, more than half of antibiotic use occurred in the emergency department/urgent care centers and outpatient clinics. Antibiotics with a broad spectrum of gram-negative activity accounted for a large portion of antibiotic use. Analysis of antibiotic utilization across the spectrum of inpatient and ambulatory care is useful to prioritize antibiotic stewardship efforts.

Antibiotic Prescribing Patterns for Acute Otitis Media for Children 2 Years and Older.

OBJECTIVE: To determine the frequency that non-first-line antibiotics, safety-net antibiotic prescriptions (SNAPS), and longer than recommended durations of antibiotics were prescribed for children ≥2 years of age with acute otitis media and examine patient and system level factors that contributed to these outcomes. STUDY DESIGN: Children age ≥2 years with acute otitis media seen at Denver Health Medical Center outpatient locations from January to December 2018 were included. The percentages of patients who received first-line antibiotics, SNAPs, and recommended durations of antibiotics were determined. Factors associated with non-first-line and longer than recommended antibiotic durations were evaluated using multivariate logistic regression modeling. RESULTS: Of the 1025 visits evaluated, 98.0% were prescribed an antibiotic; only 4.5% of antibiotics were SNAPs. Non-first-line antibiotics were prescribed to 18.8% of patients. Most antibiotic durations (94.1%) were longer than the institution recommended 5 days and 54.3% were ≥10 days. Private insurance was associated with non-first-line antibiotics (aOR, 1.89; 95% CI, 1; 14-3.14, P = .01). Patients who were younger (2-5 years; aOR 2.01; 95% CI, 1.32-3.05; P < .001) or seen in emergency/urgent care sites (aOR, 1.73; 95% CI, 1.26-2.38; P < .001) were more likely to receive ≥10 days of antibiotic compared with those in pediatric clinics. CONCLUSIONS: Antibiotic stewardship interventions that emphasize the duration of antibiotic therapy as well as the use of SNAPs or observation may be higher yield than those focusing on first-line therapy alone. Numerous system and patient level factors are associated with off-guideline prescribing.

Suspected Neuro-invasive Powassan Virus Infection in a Pediatric Patient.

Powassan virus lineage II (POWV), also known as deer tick virus, is an emerging tick-borne pathogen transmitted by Ixodes scapularis, the natural vector for the organisms that causes Lyme disease, babesiosis, and anaplasmosis. POWV is the only tick-borne flavivirus in North America known to cause disease in humans. We present a suspected pediatric case of POWV infection in northern Wisconsin.

Beta-Hemolytic Nongroup A Streptococcal Pharyngitis in Children.

OBJECTIVE: To evaluate the epidemiology, clinical features, and antibiotic prescribing patterns for nongroup A streptococci (NGAS) in children. STUDY DESIGN: Throat cultures obtained for pharyngitis were assessed at a large community-based health system over 10 years. Epidemiologic and clinical features of children with NGAS were compared with children with group A Streptococcus (GAS) and negative cultures. Antibiotic prescribing patterns were evaluated. RESULTS: A total of 224 328 rapid streptococcal antigen tests and 116 578 throat cultures were performed. Clinical analysis was completed for 602 GAS-positive patients, 535 NGAS-positive patients, and 480 patients with negative cultures. Incidence of NGAS did not vary annually or by season but increased with age from 2% at ≤5 years to 7% at 18 years of age. Patients with NGAS were more likely than those with negative cultures to have tonsillar exudate (20.3% vs 13.1%, P = .003) and enlarged tonsils (28.6% vs 19.3%, P < .001). Modified Centor scores did not differ between groups (score ≥2, P = 1.0; score ≥3, P = .50). Patients with GAS were more likely than those with NGAS to have fever (32.6% vs 24.5%, P = .003), palatal petechiae (14.0% vs 3.1%, P < .001), and modified Centor score ≥2 (47.8% vs 27.1%; P < .001). Of patients with NGAS, 65% were prescribed antibiotics. CONCLUSIONS: NGAS likely exist in both carriage and infectious states and incidence increases with age. Infections associated with NGAS are milder than with GAS, and complications are rare. Laboratory reporting of NGAS results in high antibiotic use, despite current recommendations against treatment.

Variability in Antibiotic Prescribing for Upper Respiratory Illnesses by Provider Specialty.

OBJECTIVE: To evaluate variation in antibiotic prescribing between pediatric and nonpediatric providers for common upper respiratory illnesses. STUDY DESIGN: Patient encounters for children aged <18 years from a regional health care system were identified. Electronic medical records from 2011 to 2016 were extracted for diagnoses of upper respiratory infection, pharyngitis, acute otitis media, and sinusitis. Encounters with competing medical diagnoses, recent hospitalization, and antibiotic prescriptions within 30 days were excluded. Adherence to antibiotic guidelines was assessed by provider training (pediatric, nonpediatric physicians, and advance practice providers). Additional factors assessed were calendar year, and patient's age, sex, insurance status, and number of sick visits in the prior year. RESULTS: Across 6 years, 141 361 visits were examined: 43 914 for upper respiratory infection, 43 701 for pharyngitis, 43 925 for acute otitis media, and 9821 for sinusitis. Pediatricians were more likely than Advanced practice providers (APP) and nonpediatric providers to have guideline-concordant prescribing for pharyngitis (pediatricians, 66.7% [95% CI, 54.5-77.0]; nonpediatricians, 49.1% [95% CI, 36.3-62.0], APPs, 52.2% [95% CI, 39.4-64.7]; P < .0001) and sinusitis (pediatricians, 70.8% [95% CI, 53.8-83.4], nonpediatricians, 63.3% [95% CI, 46.8-77.2], APPs, 62.1% [95% CI, 45.1-76.5]; P = .48) and to withhold antibiotics for upper respiratory infection than APPs and nonpediatric providers (pediatricians, 86.6% [95% CI, 81.2-90.6], nonpediatricians, 80.8% [95% CI, 73.0-86.8], APPs, 76.8% [95% CI, 68.4-83.5]; P < .0001). Pediatricians were less likely to prescribe antibiotics for pharyngitis without a positive test for group A Streptococcus than APPs and nonpediatric providers (pediatricians, 15.1% [95% CI, 10.4-21.6], nonpediatricians, 29.4% [95% CI, 20.8-39.6], APPs, 27.2% [95% CI, 19.3-36.9]; P < .0001). First-line antibiotic prescribing for acute otitis media did not differ between provider specialties. A trend toward more guideline-concordant prescribing was seen for pharyngitis and sinusitis over the study period. CONCLUSIONS: Pediatricians were more likely to adhere to guidelines for management of pediatric acute respiratory infections. Pediatric antibiotic stewardship efforts should also target nonpediatricians.

Infectious Mononucleosis and Lyme Disease as Confounding Diagnoses: A Report of 2 Cases.

Lyme disease and infectious mononucleosis are common illnesses that share similar clinical presentations. Significant cross-reactivity is known to occur between Lyme and EBV serologic assays complicating the diagnosis. To date, no prior cases of concurrent acute Lyme and EBV infections have been reported. We describe the clinical presentation of two children with confirmed early Lyme disease and features suggestive of infectious mononucleosis, including one case of probable Lyme and EBV co-infection.

Serologic Evidence of Powassan Virus Infection in Patients with Suspected Lyme Disease1.

Powassan virus (POWV) lineage II is an emerging tickborne flavivirus with an unknown seroprevalence in humans. In a Lyme disease-endemic area, we examined the seroreactivity to POWV in 2 patient cohorts and described the clinical features of the POWV-seroreactive patients. POWV disease might be less neuroinvasive than previously thought.

Development and validation of a novel single nucleotide polymorphism (SNP) panel for genetic analysis of Blastomyces spp. and association analysis.

BACKGROUND: Single nucleotide polymorphism (SNP) genotyping is increasingly being utilized for molecular typing of pathogens and is cost-effective, especially for large numbers of isolates. The goals of this study were 1) to develop and validate a SNP assay panel for genetic analysis of Blastomyces spp., 2) ascertain whether microsatellite genotyping and the SNP genotyping with the developed panel resolve identical genetic groups, and 3) explore the utility of SNPs for examining phylogenetic and virulence questions in humans. METHODS: Three hundred sixty unique Blastomyces spp. isolates previously genotyped with microsatellite markers were genotyped with the MassARRAY® SNP genotyping system (Agena Bioscience™, San Diego, CA), for a custom panel of 28 SNPs. Clinical presentation data was analyzed for association with SNP variants. RESULTS: Three hundred twenty-three Blastomyces spp. isolates (90 %) were successfully genotyped by SNP analysis, with results obtained for at least 27 of 28 assays. For 99.7 % of isolates tested by both genotyping methods, microsatellite genetic group assignment correlated with species assignment based on internal transcribed spacer 2 (ITS2) genotyping, with Group 1 (Gr 1) being equivalent to B. gilchristii and Group 2 (Gr 2) being equivalent to B. dermatitidis. Thirteen isolates were genetic hybrids by one or both methods of genotyping and were difficult to assign to a particular genetic group or species. Fifteen SNP loci showed significantly different alleles in cases of pulmonary vs disseminated disease, at a p-value of <0.01 or less. CONCLUSIONS: This study is the largest genotyping study of Blastomyces spp. isolates and presents a new method for genetic analysis with which to further explore the relationship between the genetic diversity in Blastomyces spp. and clinical disease presentation. We demonstrated that microsatellite Gr 1 is equivalent to B. gilchristii and Gr 2 is equivalent to B. dermatitidis. We also discovered potential evidence of infrequent recombination between the two Blastomyces spp. Several Blastomyces spp. SNPs were identified as associated with dissemination or pulmonary disease presentation, but additional work is needed to examine virulence SNPs separately within B. dermatitidis and B. gilchristii.

Blastomyces Antigen Detection for Diagnosis and Management of Blastomycosis.

Blastomyces spp. antigen testing was evaluated over a 10-year period in an area where blastomycosis is endemic. Antigen testing was less sensitive than previously reported, but serial urine testing was useful in monitoring disease resolution or progression. Culture and cytopathology remain the gold standard for diagnosis and exclusion of this infection.

Epidemiology and clinical presentation of parainfluenza type 4 in children: a 3-year comparative study to parainfluenza types 1-3.

BACKGROUND: Human parainfluenza viruses (HPIVs) are among the most common causes of respiratory tract infections in children. Little is known about the epidemiology and clinical presentation of HPIV type 4. METHODS: A retrospective chart review and comparison of patients positive for HPIV types 1-4 by multiplex polymerase chain reaction between 2009 and 2012 at Children's Hospital Colorado was performed. Patients who had only direct fluorescent antibody testing performed or concurrent viral infections were excluded. RESULTS: Of 11,533 samples, 752 (6.5%) were positive for HPIV. After exclusion criteria, 316 samples were included in the study. HPIV-4 had year-round prevalence with biennial peaks in odd-numbered years. HPIV-4 and HPIV-3 had similar clinical presentations. 50.8% and 51.5% of patients with HPIV-3-4 had hypoxia compared to 20.3% and 33.3% of patients with HPIV-1-2 (P < .01). HPIV-1 (23.6%) and HPIV-2 (24.2%) were more associated with stridor than HPIV-3 (6.6%) and HPIV-4 (0%) (P < .01). No patients with HPIV-4 had croup. Patients with HPIV-4 had similar lengths of stay and mortality as those with HPIV-1-3. CONCLUSIONS: This is the first large-scale analysis of HPIV-4 clinical and epidemiologic features. HPIV-4 was most similar to HPIV-3 in clinical presentation. HPIV-4 had year-round prevalence with peaks in the autumn of odd-numbered years. HPIV-4 is a common respiratory pathogen capable of causing significant morbidity in children.