How Do Burns Affect Long-Term Infectious Disease Risk?

Sustaining a burn that lands a patient in the hospital may have long-term implications for that patient’s risk of infection. Taking its cue from recent studies that have demonstrated suppressed immune function after a burn, a research team from the University of Western Australia, Curtin University, and the Burns Service of Western Australia, all in Perth, sought to find out whether patients who suffered both severe and non-severe burns had increased incidences of hospitalization due to infectious disease during the months and years after being burned.

The team examined data culled from 30,997 individuals who had been admitted to hospitals in Western Australia for a “first burn” between the years of 1980 and 2012. Records for 123,399 individuals who had not been hospitalized for burns were randomly pulled from birth records and electoral rolls for comparison purposes. The result? Those who had been hospitalized for a burn later were admitted to the hospital for infectious disease at twice the rate of uninjured individuals, and spent three and a half times as many days in the hospital. This applied to individuals with both severe and minor burns; however, those with severe burns had 20% more infectious disease-related hospital admissions than those with less severe burns. The rate of hospital admission for infectious disease was greatest in the first 30 days after being discharged for a burn (5.2 times higher) and decreased as time went on. Generally, the first year after being burned presented the highest risk for readmission. Over a period of nine years, the risk of being hospitalized for infectious disease was about 1.4 times greater than for non-injured patients. Burn victims were also more likely to die from these infections than were uninjured patients—they had a mortality rate 1.75 times higher than the uninjured cohort during the five years post-burn—although there was no significant increase in mortality after that time.

The scientists concluded that sustaining a burn changes the immune system and its function. Apparently, injury to the skin causes tissue disturbances, including alteration of microflora, lowered resistance to microbes, and higher rates of inflammation, that can result in bloodstream infections, circulation impairment, and even cancer. The most common reasons for post-burn hospitalizations in the burn cohort in this study included infections of the lower respiratory tract, digestive tract, and skin and soft tissue—all of which accounted for 42% of admissions. The uninjured cohort also had its share of hospitalizations for infectious diseases in the digestive and lower respiratory tracts, although infections of the skin and soft tissue were less common than they were in the burn group. The researchers were careful to adjust for demographic factors such as age, smoking, nutrition, and physical activity, that could affect the rate of hospital admissions in either cohort.

The study authors noted that the rise in infectious disease in the skin, gastrointestinal, and respiratory-tract tissues—three different kinds of epithelial cells—of burn victims is indicative of a possible common pathophysiology as a result of a burn, although they don’t yet know exactly what this process is. “Further research to understand the underlying mechanisms are required to inform clinical interventions to mitigate infectious disease after burn and improve patient outcomes,” they wrote.

Laurie Saloman, MS, is a health writer with more than 20 years of experience working for both consumer and physician-focused publications. She is a graduate of Brandeis University and the Medill School of Journalism at Northwestern University. She lives in New Jersey with her family.