Most Common Source of Infection in Burn Patients
The burn wound itself is the most common source of infection in burn patients, representing the primary site from which infectious complications arise and the predominant origin of sepsis in this population. 1
Why the Burn Wound is the Primary Source
The thermal injury disrupts the skin barrier, making the burn wound the predominant site for infectious complications in the acute period following injury. 1
Most cases of sepsis in burn patients originate from infected burn wounds, establishing the wound as the critical source requiring surveillance and intervention. 2
Infections in burn patients are associated with extremely high mortality rates, with infections preceding multiorgan dysfunction in 83% of patients and considered the direct cause of death in 36% of patients. 1
Pathophysiology of Burn Wound Infection
Burn wounds are initially sterile immediately following thermal injury but rapidly become colonized with microorganisms. 1
Gram-positive bacteria from the patient's endogenous skin flora colonize first, followed by Gram-negative bacteria within one week of injury. 1, 3
If host defenses and therapeutic measures are inadequate, microorganisms can invade viable tissue, progressing from colonization to invasive burn wound infection. 1
Common Pathogens by Timeline
Early colonization (first few days):
- Staphylococcus aureus is the most common early isolate, accounting for approximately 48.7% of infections. 4, 5
- Other Gram-positive organisms including Staphylococcus epidermidis follow. 3, 5
Later colonization (after one week):
- Gram-negative bacteria predominate, particularly Pseudomonas aeruginosa (22.6%) and Acinetobacter baumannii (15.7%). 3, 4
- Burn wound infections are often polymicrobial, involving both Gram-positive and Gram-negative organisms. 3
Clinical Implications for Mortality
Patients with thermal injuries are at higher risk of death when sepsis is caused by Gram-negative bacteria (particularly Acinetobacter baumannii and Pseudomonas aeruginosa) versus Gram-positive bacteria. 6
Infection of blood and burn wound caused by the same bacteria (especially Pseudomonas aeruginosa and Acinetobacter baumannii) increases the risk of death due to sepsis. 6
Management Priorities
Early excision of eschar can substantially decrease the incidence of invasive burn wound infection, underscoring that the burn wound itself is the primary target for infection prevention strategies. 1
Quantitative wound cultures with tissue biopsy from the advancing margin are the gold standard for diagnosing burn wound infections, as surface colonization must be distinguished from invasive infection. 1, 3
Blood cultures should always be obtained to detect systemic disease secondary to the burn wound. 3