After the Battlefield: Infectious Complications among Wounded Warriors in the Trauma Infectious Disease Outcomes Study

Abstract

Introduction: During recent wars in Iraq and Afghanistan, improved survivability in severe trauma corresponded with a rise in the proportion of trauma-related infections, including those associated with multidrug-resistant organisms (MDROs). Significant morbidity was reported in association with the infections. There is also concern regarding potential long-term impacts of the trauma-related infectious complications. Therefore, to meet the critical need of prospective collection of standardized infection-related data to understand the disease burden and improve outcomes of wounded personnel, the Trauma Infectious Disease Outcomes Study (TIDOS) was developed. Herein, we review accomplishments and key peer-reviewed findings of TIDOS.

Methods: The TIDOS project is a multicenter observational study of short- and long-term infectious complications following deployment-related trauma. Wounded military personnel medevac'd to Landstuhl Regional Medical Center (LRMC; Germany) before transfer to a participating US military hospital between June 2009 and December 2014 were eligible for inclusion. An infectious disease module to supplement the Department of Defense Trauma Registry by collecting infection-related data from all trauma patients admitted to participating hospitals was developed. Specimens from trauma patients were also collected and retained in a microbiological isolate repository. During the initial hospitalization, patients were given the opportunity to enroll in a prospective follow-up cohort study. Patients who received Department of Veterans Affairs (VA) care were also given the opportunity to consent to ongoing VA follow-up.

Results: A total of 2,699 patients transferred to participating military hospitals in the USA, of which 1,359 (50%) patients enrolled in the TIDOS follow-up cohort. In addition, 638 enrolled in the TIDOS-VA cohort (52% of TIDOS enrollees who entered VA healthcare). More than 8,000 isolates were collected from infection control surveillance and diagnostic evaluations and retained in the TIDOS Microbiological Repository. Approximately 34% of the 2,699 patients at US hospitals developed a trauma-related infection during their initial hospitalization with skin and soft-tissue infections being predominant. After discharge from the US hospitals, approximately one-third of TIDOS cohort enrollees developed a new trauma-related infection during follow-up and extremity wound infections (skin and soft-tissue infections and osteomyelitis) continued to be the majority. Among TIDOS cohort enrollees who received VA healthcare, 38% developed a new trauma-related infection with the incident infection being diagnosed a median of 88 days (interquartile range: 19-351 days) following hospital discharge. Data from TIDOS have been used to support the development of Joint Trauma System clinical practice guidelines for the prevention of combat-related infections, as well as the management of invasive fungal wound infections. Lastly, due to the increasing proportion of infections associated with MDROs, TIDOS investigators have collaborated with investigators across military laboratories as part of the Multidrug-Resistant and Virulent Organisms Trauma Infections Initiative with the objective of improving the understanding of the complex wound microbiology in order to develop novel infectious disease countermeasures.

Conclusions: The TIDOS project has focused research on four initiatives: (1) blast-related wound infection epidemiology and clinical management; (2) DoD-VA outcomes research; (3) Multidrug- Resistant and other Virulent Organisms Trauma Infections Initiative; and (4) Joint Trauma System clinical practice guidelines and antibiotic stewardship. There is a continuing need for longitudinal data platforms to support battlefield wound research and clinical practice guideline recommendation refinement, particularly to improve care for future conflicts. As such, maintaining a research platform, such as TIDOS, would negate the lengthy time needed to initiate data collection and analysis.

Keywords: combat-related infections; military health; trauma-related infections; wound infections.

figure 1.

Timeline of events associated with the Trauma Infectious Disease Outcomes Study (TIDOS) and related research. BIRP – Blast Injury Research Program; BUMED – Navy Bureau of Medicine and Surgery; COCOM – Combatant Command; CPG – clinical practice guidelines; DHP – Defense Health Program; DMRDP – Defense Medical Research and Development Program; DoDTR – Department of Defense Trauma Registry; DSTI – deep soft-tissue infection; ID – infectious disease; GEIS – Global Emerging Infections Surveillance; IDCRP – Infectious Disease Clinical Research Program; IFI – invasive fungal wound infection; IRB – institutional review board; MDROs – multidrug-resistant organisms; MDR/VO – Multidrug-resistant and Virulent Organisms; MHSRS – Military Health System Research Symposium; MIDRP – Military Infectious Diseases Research Program; NIAID – National Institute of Allergy and Infectious Diseases; QA – quality assessment; SC2i – Surgical Critical Care Initiative; SMMAC – Senior Military Medical Advisory Committee; SRB – scientific review board; VA – Veterans Affairs; UK MOD - United Kingdom Ministry of Defence; UK WISP - WISP – United Kingdom Wound Infection Surveillance Programme; USAISR; US Army Institute of Surgical Research; USU – Uniformed Services University of the Health Sciences.

FIGURE 2.

US Wounded Military Personnel Population and TIDOS Cohort Enrollment. TIDOS year spans June 1 through May 30. Number of wounded in action from Defense Casualty Analysis System (https://dcas.dmdc.osd.mil/dcas/pages/casualties.xhtml). OEF – Operation Enduring Freedom; OIF – Operation Iraqi Freedom; OND – Operation New Dawn.

FIGURE 3.

Distribution of infection syndromes (N = 2,210) among wounded military personnel who transferred to participating US hospitals. BSI – bloodstream infection; CNS – central nervous system infection; SSTI – skin and soft-tissue infection; UTI – urinary tract infection.