Colorado Department of Public Health and Environment

Objective:The aim was to describe the development and implementation of Firstline (www.Firstline.org), a mobile antimicrobial stewardship (ASP) application (app) created to address barriers to robust ASP in Colorado hospitals. Design:A mixed-methods pragmatic implementation study using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) framework was conducted from October 2023-December 2025. Methods:ASP teams at Children's Hospital Colorado and Denver Health partnered with Firstline to develop the app using locally curated content. The app launched in October 2023 with a multifaceted dissemination campaign. Reach was assessed using geocoded user data. Effectiveness and adoption were evaluated using cross-sectional surveys at two time points. Implementation was characterized by analyzing utilization patterns. Maintenance was assessed by tracking monthly active users over two years. Results:Within the first year, 4,409 unique Colorado users downloaded the app, representing 15% of state clinicians (19% in Denver Metro; 5-17% in rural regions). Survey respondents (n = 215) reported high satisfaction: 63.9% and 72.9% found the app very easy to use, 71.3% and 83.2% reported enhanced antibiotic selection knowledge, and 100% advocated for ongoing support. Among respondents, 10% reported their facilities had formally adopted Firstline guidelines. The most frequently accessed content included common, high-impact infections. Monthly active users remained stable (average 871) over two years. Conclusions:We demonstrated use of Firstline across Colorado, with increasing engagement in rural areas. High user satisfaction, sustained engagement, and emerging institutional adoption suggest this "stewardship in your pocket" model offers a unique, scalable approach to extending ASP support beyond academic medical centers.

Purpose To determine whether there is an association between hypertensive disease of pregnancy (HDP) and the development of retinopathy of prematurity (ROP). Methods This retrospective cohort study was based on the records of an ROP screening registry, which included infants who fulfilled the standard screening criteria for ROP. Analyses included multinomial logistic regression, with sensitivity analyses incorporating inverse probability weighting to account for potential collider bias arising from restriction to preterm infants and subgroups defined by gestational age (GA). Results In this cohort of 2,100 infants in the registry, 698 (33.2%) developed ROP, and 261 (12.4%) developed severe ROP (type 1 or type 2). Severe HDP (preeclampsia with severe features, HELLP, and eclampsia) was found in 644 infants from mothers (30.7%). The mean GA at delivery was 28.8 ± 2.5 weeks. Across GA, severe HDP was associated with a higher risk of severe ROP compared with normotensive pregnancies up to approximately 28-29 weeks’ gestation, with the largest differences observed between 26 and 27 weeks. Among infants born at ≤29 weeks, severe HDP was associated with severe ROP with respect to normotensive births and no ROP (adjusted odds ratio [AOR] = 1.5; 95% CI, 1.0-2.1; P = 0.04). In sensitivity analyses to account for selection into the preterm cohort, results were similar, with severe HDP related to the development of severe ROP (AOR = 1.7; CI, 1.5-2.0, P < 0.01). Conclusions The association of HDP with ROP varied with GA. Compared with normotensive pregnancies, severe HDP was a risk factor for severe ROP at earlier GA but not for infants born at 29 weeks’ gestation or later.

This study examines urban VOCs by analyzing summertime measurements of ambient air in Denver in 2024. Through a comparison of this dataset to similar measurements made in Los Angeles in 2022, this study investigates how differences between these two cities relate to differences between VOC emissions and chemistry. Six weeks of real-time VOC measurements were collected at both locations using a high-resolution Vocus protontransfer-reaction time-of-flight mass spectrometer. In Denver, significant daytime expansion of the planetary boundary layer diluted mixing ratios of VOCs. Sparser vegetation in Denver resulted in low regional biogenic VOC mixing ratios. Higher hydroxyl radical exposure in Denver suggests that photochemistry took place more rapidly relative to Los Angeles. Industrial activity to the northeast of Denver, including a large refinery, was a significant source of VOCs but did not dominate emissions in the region. Grouping VOCs into families based on their oxygen content revealed that increasingly oxygenated VOCs were more likely to be photochemically produced than directly emitted in both studies. The results of this work reveal the profound impact planetary boundary layer dynamics can have on ambient VOC mixing ratios.

Animal health remains largely absent from climate-health policy, despite growing evidence of climate-related health risks across species. Using Colorado as a model, we identify key climate hazards affecting animals and examine their overlap with human health risks. We synthesized national, regional, and state-specific climate and health, translating human health themes to 3 animal groups: companion animals, livestock (including horses), and wildlife. Findings were validated through interviews with subject-matter experts from state agencies, academia, and nonprofit organizations. Wildfire, air quality, extreme heat, and drought emerged as the most urgent hazards, with flooding, extreme storms, waterborne disease, and vector-borne disease also affecting animal populations across the state. Three crosscutting themes-animal welfare, food safety, and caregiver impacts-linked all hazards and highlighted the interdependence of animal and human well-being. Experts identified major gaps between human-focused resources and the limited animal-specific guidance. Transferable strategies such as air-quality advisories, heat-risk mitigation, and emergency preparedness were recognized but require adaptation across species and management settings. This work suggests 4 priority areas for climate action, emphasizing (1) animal-specific decision tools and surveillance; (2) integrated preparedness for concurrent hazards; (3) equitable access to veterinary and protective resources; and (4) cross-sector networks that harmonize animal, human, and ecosystem health. Aligning animal and public health systems offers a practical opportunity to strengthen climate resilience for animals, people, and ecosystems.

Accurate molecular epidemiology relies on recovering Clostridioides difficile from clinical specimens and is essential for informing public health responses, characterizing strains that cause disease, and tracking strain prevalence. We performed a cross-sectional study of the recovery of C. difficile isolates from test-positive stools received January 2020 through December 2022 from the Colorado and Georgia Emerging Infections Program sites. Multivariable logistic regression models determined the adjusted odds ratio (aOR) and 95% confidence intervals (CIs) for factors which may influence C. difficile recovery in specimens that tested positive by either a dedicated or multiplex polymerase chain reaction (PCR) as part of either a reverse testing algorithm (PCR-positive, arbitrated by toxin enzyme immunoassay [EIA]) or a PCR-only testing protocol. Whole-genome sequencing was performed to determine the multilocus sequence types. C. difficile was recovered by culture from 84.3% (1,527/1,811) of all specimens. In specimens tested with a reverse testing algorithm, C. difficile culture recovery was less likely with multiplex versus dedicated PCR (aOR: 0.53; 95% CI: 0.34-0.85) and more likely in toxin EIA-positive versus toxin EIA-negative specimens (aOR: 8.07; 95% CI: 4.10-18.31). Recovery of C. difficile from stool cultures in PCR-only protocol cases was less likely when C. difficile was detected by multiplex PCR (aOR: 0.16; 95% CI: 0.03-0.55). ST1 was associated with toxin EIA-positive specimens, whereas ST2/110 was associated with toxin EIA-negative specimens. These findings can be used to maximize C. difficile surveillance programs, thereby enhancing the ability to generate robust molecular epidemiology data to inform prevention and control efforts.IMPORTANCEPublic health surveillance of Clostridioides difficile is essential for tracking strains, understanding transmission, and informing public health strategies. The foundation of the surveillance is the successful recovery of C. difficile from clinical specimens for molecular typing. This study reveals that the choice of diagnostic test significantly impacts the ability to recover C. difficile by culture. These data reveal that culture recovery was lower from specimens that tested positive by syndromic multiplex polymerase chain reaction (PCR) panels compared to dedicated C. difficile PCR assays. Furthermore, recovery was more than eight times more likely from toxin enzyme immunoassay (EIA)-positive specimens than from toxin EIA-negative specimens, with high-virulence strains, such as PCR-ribotype 027, being associated with toxin EIA-positive results. These findings demonstrate that common diagnostic practices could introduce biases into surveillance data, potentially misrepresenting the true prevalence and epidemiology of clinically important strains. Understanding these factors is crucial for optimizing surveillance programs to generate accurate molecular epidemiologic data.