Study: 5% of hospitalized firearm injury patients develop bacterial infections

Researchers at the University of Maryland School of Medicine examined a sobering reality of gunshot wounds: the infections that follow. Between January 2019 and May 2021, they tracked 24,024 adults hospitalized with firearm injuries across 323 hospitals nationwide. What they found was published in early August in JAMA Network Open—roughly one in twenty of these patients, about 1,236 people, developed a bacterial infection during their treatment.

The timing matters. Most of these infections took hold while patients were still in the hospital, not after they went home. Only 1.3 percent of infections emerged during the ninety-day period following discharge. This distinction shapes how doctors think about prevention and monitoring. The initial hospitalization is the critical window.

Not all gunshot wounds carry equal risk. Patients who underwent surgery involving the head, neck, spine, liver, or lower abdomen faced the steepest climb toward infection. The pathogens that took hold were familiar culprits: Escherichia coli, Staphylococcus aureus, and enterococci—bacteria that thrive in surgical wounds and can turn a survivable injury into a complicated recovery. Jonathan Baghdadi, the study's senior author and an associate professor of epidemiology at the medical school, noted that while firearm injury has long been recognized as a risk factor for infection, no large national study had previously mapped the landscape this clearly. "By identifying the patients most likely to develop these complications," he said, "we hope this work contributes to more informed clinical decision-making."

One finding offered a measure of reassurance: antibiotic use among patients who never developed infections was generally restrained, suggesting that current clinical practice already leans toward judicious prescribing rather than blanket prevention. This aligns with efforts to combat antibiotic resistance, a separate but related public health threat.

Yet the human weight of these infections extends beyond the hospital stay. Baghdadi emphasized that recovery from gunshot wounds is inherently complicated, and infections compound that burden. They can trigger long-term pain, disability, and the need for additional interventions. Notably, the study found that bacterial infection itself was not independently linked to higher mortality among patients who survived the first night—a finding that suggests these infections, while serious, are often manageable if caught and treated.

Melike Harfouche, a surgeon and study co-author, underscored the importance of close monitoring for patients undergoing head, neck, and spine procedures, the group at highest risk for both early and late infections. The research relied on administrative hospital data, which has its limits—complete follow-up information was not available for every patient—but the sheer scale of the dataset allowed the researchers to draw patterns across a broad and diverse population.

Baghdadi hopes the study's methodology will serve as a template for other researchers asking more targeted questions about infection risk and outcomes. The work points toward a future where clinical teams can identify vulnerable patients earlier and adjust their monitoring and treatment protocols accordingly, turning data into better care.