The ARROW study maps infection threats in prolonged field care to provide decision-support tools for frontline providers.
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| Under contested skies where evacuation timelines stretch from hours to days, the ARROW study seeks to provide frontline providers with decision-support tools to manage severe wound infections during prolonged field care before definitive care can be reached. (Photo credit: UK Ministry of Defence) |
October 8, 2026 by Hadiyah Brendel
During the post-9/11 conflicts in Iraq and Afghanistan, wounded service members were often evacuated by air within two hours to Role 2 forward surgical facilities. The ongoing conflict in Ukraine has presented a different operational environment, with evacuation times sometimes extending significantly longer. These conditions highlight the need for military medicine to prepare for scenarios in which evacuation may be delayed and prolonged field care may be required.
Recognizing that comprehensive medical support in modern warfare requires real-time awareness of shifting operational realities and evolving infection threats, the Uniformed Services University of the Health Sciences (USU) is supporting an international research collaboration, led by the University of Colorado Anschutz (CU Anschutz), called the ARROW study (Antimicrobial Resistance Research to Improve Outcomes of Traumatic Wounds).
Driven by a core narrative of operational readiness, the study applies hard-earned data frameworks from past conflicts to protect future warfighters globally, while also establishing a holistic approach to clinical support in Ukraine.
Cross-Institutional Collaboration
ARROW brings together expertise from several institutions, with each contributing a different piece of the research effort. CU Anschutz leads the study, with Dr. Adit Ginde serving as Principal Investigator and Dr. Corey Bills as Co-Principal Investigator overseeing day-to-day operations. The research is conducted in partnership with the CU Anschutz Combat Medicine Research Center, which carries out military trauma research in Ukraine and other austere environments. The study is supported through a funding mechanism managed by the Medical Technology Enterprise Consortium (MTEC).
USU's Infectious Disease Clinical Research Program (IDCRP) brings decades of experience studying infections in combat-injured patients to the effort. The USU team worked with CU Anschutz and Ukrainian collaborators to shape the study objectives and protocol, drawing in part on the experience of the Trauma Infectious Disease Outcomes Study (TIDOS), which has examined infectious complications and outcomes among combat-injured service members. That experience is particularly valuable in helping researchers determine which data are most important to collect and how the findings can ultimately inform clinical practice.
At Walter Reed Army Institute of Research (WRAIR), the Multidrug-resistant organism Repository and Surveillance Network (MRSN), led by Col. Jason Bennett, provides another critical piece of the effort by conducting advanced genomic characterization of bacterial samples collected through the study.
“USU IDCRP and TIDOS have a longstanding history of expertise in this field and have set the standard for this type of work. This partnership has been invaluable in implementation and interpreting the results of the ARROW study," said Bills.
Operations across five Ukrainian civilian hospitals—consisting of two frontline facilities and three back-line referral centers—are managed by Ukrainian Principal Investigator Dr. Roman Fishchuk, tracking an active cohort of over 900 adult combat trauma patients.
Dr. David Tribble, Science Director for the USU IDCRP cites the TIDOS collaboration with the Joint Trauma System as well, noting that it has “enabled prioritization of data collection to inform practice guidance and assess outcomes needed to advance combat casualty care best practices and improve outcomes in Ukraine.”
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| Researchers at the Multidrug-resistant organism Repository and Surveillance Network (MRSN) utilize advanced genetic testing to sequence Gram-negative pathogens isolated from wounded personnel. Data from the ARROW study, recently published in the New England Journal of Medicine, reveals that highly resistant strains carrying severe NDM and OXA-48 genes are established within the casualty evacuation chain almost immediately following injury. (Photo credit: U.S. Navy photo by Aleece Williams Released.jpg) |
Shifting Evacuation Timelines: The Impact on Wound Care
TIDOS, launched in 2009 by the USU IDCRP, tracked infectious complications of U.S. casualties evacuated from Iraq and Afghanistan and serves as the baseline for the current understanding of the epidemiology of combat wound infections.
"During those conflicts, the U.S. military maintained air superiority," Dr. Tribble explains. That air dominance created a reliable framework where rapid evacuation timelines allowed medical personnel to quickly clean and treat wounds, managing infections. Even though casualties in Iraq and Afghanistan experienced a 25 to 30 percent infection rate due to environmental contaminants like soil, rapid evacuation timelines allowed medical personnel to structurally manage and mitigate widespread resistance.
Prolonged delays in Ukraine directly impact wound care. Without immediate surgical debridement to clear dead tissue from the wound, patients are given broad-spectrum antibiotics out of necessity. As a result, bacteria face selective pressures that accelerate mutation and resistance to standard treatments.
Pathogen Profiles, Genetic Testing, and Early Resistance Timelines
Recent findings on the microbiology of war wounds from casualties of the Ukraine war, including those in the New England Journal of Medicine, detail the specific microbiological reality facing clinicians. Advanced genetic testing conducted by WRAIR MRSN has identified a heavy saturation of transmissible, Gram-negative pathogens, including Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa.
The resistance profiles of these isolates are notable for the presence of severe resistance genes, specifically NDM (New Delhi metallo-beta-lactamase) and OXA-48-like genes.
These specific genes act as instructions for bacteria to produce enzymes that destroy antibiotics. The NDM (New Delhi metallo-beta-lactamase) gene neutralizes carbapenems, a broad class of drugs normally reserved for the most severe infections. OXA-48-like genes rapidly break down both carbapenems and penicillins. When bacteria become "co-producing" strains—meaning they carry multiple resistance genes simultaneously—they can neutralize almost any broad-spectrum antibiotic a field medic might administer. This leaves frontline personnel with very few pharmaceutical options to stabilize a severe wound infection, sharply limiting the effectiveness of standard and last-resort antibiotics within the first seven days of injury.
This compressed timeline contrasts with traditional clinical models where extreme drug resistance typically develops as a late-stage complication of prolonged hospitalizations. Instead, the data demonstrate that high-level resistance is established almost immediately within the evacuation chain.
Operational Applications for Future Readiness
The data gathered from the ARROW study are being utilized to identify at-risk patients, as well as support clinical decision-making and practice guidance for frontline medical providers.
In future prolonged field care scenarios where medical evacuation is delayed, these data will support refinement of forward medical care and management of high-risk patients.
For the USU community, the ARROW study highlights the university's mandate to translate real-world clinical data into actionable doctrine, ensuring future military physicians are trained to mitigate emerging antimicrobial threats on the battlefield.