Burn Site Research Articles

Severe wildfire increased variability in the response of gross primary production to climate in an Eucalyptus dominated semi-arid woodland in South Australia

Frequency and severity of wildfires have intensified in many regions in the world. High severity fires often initiate vegetation regrowth and succession, and thus alter ecosystem processes and functioning. Understanding how high severity fire-induced variations in gross primary production (GPP) respond to climate variability is critically important. This study aimed to quantify fire-induced changes in the response of GPP to concurrent and antecedent precipitation and air temperature in a semi-arid woodland in South Australia, using MODIS derived near-infrared reflectance of vegetation (NIRv) time series data (2000–2021) and associated climate data. Additionally, the magnitude and time course of climate legacies on GPP of unburnt and severely burnt sites were determined. The results showed that fire severity increased the variability in post-fire vegetation recovery. Prior to fire disturbance, NIRv as a proxy of GPP, was predominately affected by both concurrent and antecedent precipitation. Pre-fire precipitation legacy was about 9 months. Post-fire precipitation legacy duration was shorter in the unburnt patches within fire scar (ca. 9 months) than outside the fire scar (ca. 15 months), suggesting that the unburnt patches remaining within fire scar were more vulnerable to climate change than the adjacent intact woodland. In addition, the temperature legacies varied over time, likely mediated by water availability in this woodland. Post-fire regrowth from lignotubers was not significantly affected by concurrent and antecedent climate variables, but dependent upon endogenous growth which depends on previous growth conditions. This may be due to the smaller root system which reduced the capacity for taking up rain water after the fire event when annual precipitation was relatively low. We suggest that higher temperature together with reduced and more variable precipitation in the future could induce greater uncertainty in recovery of Eucalyptus trees post-fire.

Understanding Epidemiological Trends in Geriatric Burn Injuries: A National Multicenter Analysis from NEISS 2004-2022.

Burn injuries pose a significant source of patient morbidity/mortality and reconstructive challenges for burn surgeons, especially in vulnerable populations such as geriatric patients. Our study aims to provide new insights into burn epidemiology by analyzing the largest national, multicenter sample of geriatric patients to date. Utilizing the National Electronic Injury and Surveillance System (NEISS) database (2004-2022), individuals with a "Burn" diagnosis were extracted and divided into two comparison age groups of 18-64 and 65+. Variables including sex, race, affected body part, incident location, burn etiology, and clinical outcomes were assessed between the two groups utilizing two proportion z-tests. 60,581 adult patients who sustained burns were identified from the NEISS database with 6,630 of those patients categorized as geriatric (65+). Geriatric patients had a significantly greater frequency of scald burns (36.9% vs. 35.4%; p<0.01), and third degree/full-thickness burns (10.4% vs 5.5%, p<0.01) relative to non-geriatric adult patients with most of these burns occurring at home (75.9% vs 67.4%; p<0.01). The top five burn sites for geriatric patients were the hand, face, foot, lower arm, and lower leg and the top five burn injury sources were hot water, cookware, oven/ranges, home fires, and gasoline. Geriatric patients had over two times greater risk of hospital admission (OR: 2.32, 95% CI: 2.17-2.49, p<0.01) and over five times greater risk of ED mortality (OR: 6.22, 95% CI: 4.00-9.66, p<0.01) after incurring burn injuries. These results highlight the need for stronger awareness of preventative measures for geriatric burn injuries.

Immediate Impacts of Wildfires on Ground-dwelling macroinvertebrate Communities under Stones in Mediterranean Oak Forests

Wildfires are considered a major disturbance to forest ecosystems in the Mediterranean countries of Southern Europe. Although ground-dwelling macroinvertebrates are crucial to many soil functions, there is a fundamental lack of understanding of how wildfires impact this community in the immediate term and of the role of stones in their survival. Hence, in the present study we assessed the immediate effects of wildfires in the ground-dwelling macroinvertebrate community found under stones by comparing communities in burnt and non-burnt Mediterranean oak forests. Our results revealed that stones allowed the survival of many taxa in the burnt area. However, abundance, richness, diversity, and equitability per stone were significantly lower at the burnt than unburnt sites. Furthermore, the results also showed that richness and abundance increased significantly with increasing stone depth and area, both at the burnt and unburnt sites. Significant changes at the trophic level were observed in the burnt area comparing to the unburnt, particularly a decline in predators. No significant differences were identified concerning habitat associations among taxa. Overall, this study stressed the role of stones as microhabitats and refuge for the ground-dwelling macroinvertebrate community during wildfires.

Using Sentinel-2 Imagery to Measure Spatiotemporal Changes and Recovery across Three Adjacent Grasslands with Different Fire Histories

As a result of the advocacy of Indigenous communities and increasing evidence of the ecological importance of fire, California has invested in the restoration of intentional burning (the practice of deliberately lighting low-severity fires) in an effort to reduce the occurrence and severity of wildfires. Recognizing the growing need to monitor the impacts of these smaller, low-severity fires, we leveraged Sentinel-2 imagery to reveal important inter- and intra-annual variation in grasslands before and after fires. Specifically, we explored three methodological approaches: (1) the complete time series of the normalized burn ratio (NBR), (2) annual summary metrics (mean, fifth percentile, and amplitude of NBR), and (3) maps depicting spatial patterns in these annual NBR metrics before and after fire. We also used a classification of pre-fire vegetation to stratify these analyses by three dominant vegetation cover types (grasses, shrubs, and trees). We applied these methods to a unique study area in which three adjacent grasslands had diverging fire histories and showed how grassland recovery from a low-severity intentional burn and a high-severity wildfire differed both from each other and from a reference site with no recent fire. On the low-severity intentional burn site, our results showed that the annual NBR metrics recovered to pre-fire values within one year, and that regular intentional burning on the site was promoting greater annual growth of both grass and shrub species, even in the third growing season following a burn. In the case of the high-severity wildfire, our metrics indicated that this grassland had not returned to its pre-fire phenological signals in at least three years after the fire, indicating that it may be undergoing a longer recovery or an ecological shift. These proposed methods address a growing need to study the effects of small, intentional burns in low-biomass ecosystems such as grasslands, which are an essential part of mitigating wildfires.

Bridging the Gap: Establishing Spatial Correlations and Type Conversion Relationships among Different Aerosol Idetification Methods

Effective identification of aerosol type is the basis of accurate quantification of aerosol-climate and aerosol-environment interactions. However, there are different aerosol category settings and identifying parameter selections among different aerosol identification methods, which causes incoherence in data comparisons and uncertainty in quantifying thier climate and environment effects. To bridge the gap, this study establishes spatial correlations and aerosol type conversion relationships among four commonly-used aerosol identification methods, which includes AOD-AE, AE-SSA, FMF-SSA, and SAE-AAE. Aerosol optical properties observed at 37 typical AERONET sites are selected as the testbed, including marine, desert dust, clean continent, urban industry, and biomass burning sites. Results show that marine and desert dust aerosols are the most effectively identified types, while urban industry and biomass burning aerosols overlap much in the identification spaces since they contain similar chemical components. Dust and marine aerosol generally have the best agreement among the four identification methods, because desert dust and marine particles have distinctive chemical components from other kinds, thus the category setting from the perspective of emission source, light absorbing ability, or chemical components has less influence on the identification results. Spatial correlation between the four commonly-used aerosol identification methods futher refines the correspondence of aerosol category, light absorption capacity, and chemical components. And we find that uncertain aerosols defined in FMF-SSA are mostly marine aerosols.

Artificial refuges did not increase small mammal abundance after fire

AbstractThe interacting threats of invasive predators and altered fire regimes are key conservation issues for many native species globally. Artificial refuges have been proposed as a potential conservation tool to provide prey species with protection from invasive predators after fire, but we do not yet know whether they improve animal survival. To address this knowledge gap, we experimentally tested how small mammal abundance and species richness were influenced by the provision of artificial refuges after prescribed burns. We surveyed small mammals across five unburnt sites, seven burnt sites with artificial refuges, and eight burnt control sites following two prescribed fires in southeastern Australia. There were negative and neutral responses of small mammals to the burns, and relative abundance was positively correlated with structurally complex vegetation. Artificial refuges had no impact on abundance or species richness, irrespective of burn coverage. These findings suggest that this artificial refuge design may not be an effective tool for improving small mammal population persistence postfire, and as such we should not yet scale up their application. However, given the inherent context‐dependency of field experiments involving fire, which include difficult‐to‐control variables such as fire severity, predator activity, and population dynamics, we encourage researchers to undertake further experiments with artificial refuges in fire‐affected areas, including after severe wildfires when less vegetation cover remains. Such studies will help to build our understanding of their utility as a conservation tool across different ecosystems and fire types.

Neurotrophic keratitis caused by lightning injury: a case report

BackgroundThis study aimed to report a case of neurotrophic keratitis caused by lightning.Case presentationA 38-year-old man was hit by lightning and suffered eye injury. He eventually developed neurotrophic keratitis.ResultsThe patient’s injury history and burn site were analyzed, and it was judged that lightning directly damaged his cornea, eventually resulting in neurotrophic keratitis. Fortunately, the patient’s vision improved after treatment.ConclusionLightning can cause eye damage, and the clinical manifestations are diverse. Lightning currents cause corneal nerve loss, resulting in neurotrophic keratitis. To maintain corneal integrity and prevent disease progression, early assessment and appropriate treatment are necessary.

Influence of tundra fire severity on vegetation recovery in the Northwest Territories

Anthropogenic climate change has driven an increase in the frequency, size, and severity of fires at high latitudes. Recent research shows that increasing fire severity in the subarctic is altering the trajectories of forest succession, but to date, research on the effect of fire severity on tundra succession has been limited. In this study, we investigated short-term recovery of shrub tundra communities following fire in the Tuktoyaktuk Coastal Plain and Anderson River Plain ecoregions of the Northwest Territories. To understand the effects of fire severity, we documented vegetation and permafrost recovery within moderately burned, severely burned, and unburned portions of six tundra fires that burned in 2012. We found that vegetation structure at moderately and severely burnt sites recovered rapidly toward pre-fire levels, but that differences in community composition, characterized by a decrease in shrub and lichen cover as well as an increase in abundance of ruderals and graminoids, persisted at severely burned sites. The persistence of thermal changes and increased thaw depth indicate that while biotic recovery can occur promptly, severe fire may have long-term impacts on belowground conditions.

Long-term post-fire succession of reptiles in an urban remnant in south-western Australia

Background Reptile responses to fire may differ between remnants and contiguous vegetation but this is poorly understood. Aims We aimed to explore long-term (≤15 years) post-fire responses of reptiles in an urban Banksia woodland remnant. Methods We trapped reptiles for 10 nights in November and December each year between 2009 and 2023 inclusive (except 2014 and 2019) to estimate relative abundance. We used mixed models to explore differences between unburnt and burnt sites and changes in both over time. Key results and conclusions The reptile community showed short-term negative responses to fire, but communities had returned to their pre-fire state within 3 years. Two species showed short-term (3 and 5 years respectively) negative responses to fire while two species showed positive responses; one in the first year post-fire only, and the other in sites &gt;8 years post-fire. There did not appear to be consistent differences in fire responses between this study and studies conducted in contiguous Banksia woodlands, although differences in study designs renders this conclusion equivocal. Implications Reptile communities in Banksia woodland remnants, and the species they contain appear to be relatively robust to a wide range of fire regimes.

Thermal damage to the skin from 8.2 and 95 GHz microwave exposures in swine

A study of burn thresholds from superficially penetrating radio-frequency (RF) energy at 8.2 and 95 GHz for swine skin was conducted. The study determined the thresholds for superficial, partial-thickness, and full-thickness burn severities after 5 seconds of exposure at power densities of 4–30 W/cm2 and 2–15 W/cm2 at 8.2 and 95 GHz, respectively. There were significant differences in the burn thresholds at the different severities between the two frequencies due to the large difference in energy penetration depths. Biopsies were collected from each burn site at 1, 24, 72, and 168 hr post exposure. Each sample was assessed by a burn pathologist against 20 histological factors to characterize the damage resulting from these RF overexposures. A one-dimensional, layered digital phantom that utilized realistic values for dielectric and thermal properties was used to explain some observed thresholds. The results of the heating and cooling response of the animal model and histology scores of each exposure are provided to enhance future efforts at simulation of RF overexposures and to establish damage thresholds.

Unearthing the legacy of wildfires: post fire pyrogenic carbon and soil carbon persistence across complex Pacific Northwest watersheds

Wildfires have the potential to dramatically alter the carbon (C) storage potential, ecological function, and the fundamental mechanisms that control the C balance of Pacific Northwest (PNW) forested ecosystems. In this study, we explored how wildfire influences processes that control soil C stabilization and the consequent soil C persistence, and the role of previous fire history in determining soil C fire response dynamics. We collected mineral soils at four depth increments from burned (low, moderate, and high soil burn severity classes) and unburned areas and surveyed coarse woody debris (CWD) in sites within the footprint of the 2020 Holiday Farm Fire and in surrounding Willamette National Forest and the H.J. Andrews Experimental Forest. We found few changes in overall soil C pools as a function of fire severity; we instead found that unburned sites contained high levels of pyrogenic C (PyC) that were commensurate with PyC concentrations in the high severity burn sites—pointing to the high background rate of fire in these ecosystems. An analysis of historical fire events lends additional support, where increasing fire count is loosely correlated with increasing PyC concentration. An unexpected finding was that PyC concentration was lower in low soil burn severity sites than in control sites, which we attribute to fundamental ecological differences in regions that repeatedly burn at high severity compared with those that burn at low severity. Our CWD analysis showed that high mean fire return interval (decades between fire events) was strongly correlated with low annual CWD accumulation rate; whereas areas that burn frequently had a high annual CWD accumulation rate. Within the first year postfire, trends in soil density fractions demonstrated no significant response to fire for the mineral-associated organic matter pool but slight increases in the particulate pool with increasing soil burn severity—likely a function of increased charcoal additions. Overall, our results suggest that these PNW forest soils display complex responses to wildfire with feedbacks between CWD pools that provide varying fuel loads and a mosaic fire regime across the landscape. Microclimate and historic fire events are likely important determinants of soil C persistence in these systems.

Burning Frequency Influences Plant Composition and Diversity and Mycorrhizal Spore Density in a Lateritic Dry Deciduous Sal Dominated Forest

Abstract: Burning in forest floor, specially, in deciduous forests is an annual practice of forest dwellers in some states of India to collect non timber forest produce at ease. Sometimes this springtime burning get out of control and damage the forest severely. Sal dominated mixed forest in Godapyasal range, Midnapore division, West Midnapore in south West Bengal, with different fire incidence histories was taken for the study. An intensive survey of sites with regular burning, occasional burning and no burning were done to study plant diversity and community composition and the results were compared within different sites. Severe burning regimes damaged the plant density drastically rendering the saplings of subdominants only near ground level as coppice. Mild fire frequencies, though not severely damaged plant community, differed from unburned area significantly. Fire hardy tree species are dominant and subdominant in both sites. In severe burned site, plant diversity increased with a number of invasive perennials and annuals and spiny undershrubs and show even distribution. Common plants in the three communities were observed to be affected in their community parameters with burning frequency. Frequent and occasional burning both reduced mycorrhizal population with larger spores drastically and not replaced even after nine months of burning. AMF with smaller spores are less affected.

Impact of Wildfires on Land Surface Cold Season Climate in the Northern High-Latitudes: A Study on Changes in Vegetation, Snow Dynamics, Albedo, and Radiative Forcing

Anthropogenic climate change is increasing the occurrence of wildfires, especially in northern high latitudes, leading to a shift in land surface climate. This study aims to determine the predominant climatic effects of fires in boreal forests to assess their impact on vegetation composition, surface albedo, and snow dynamics. The influence of fire-induced changes on Earth’s radiative forcing is investigated, while considering variations in burn severity and postfire vegetation structure. Six burn sites are explored in central Alaska’s boreal region, alongside six control sites, by utilizing Moderate Resolution Imaging Spectroradiometer (MODIS)-derived albedo, Leaf Area Index (LAI), snowmelt timing data, AmeriFlux radiation, National Land Cover Database (NLCD) land cover, and Monitoring Trends in Burn Severity (MTBS) data. Key findings reveal significant postfire shifts in land cover at each site, mainly from high- to low-stature vegetation. A continuous increase in postfire surface albedo and negative surface shortwave forcing was noted even after 12 years postfire, particularly during the spring and at high-severity burn areas. Results indicate that the cooling effect from increased albedo during the snow season may surpass the warming effects of earlier snowmelt. The overall climate impact of fires depends on burn severity and vegetation composition.

806 Autologous Skin Cell Suspension Demonstrates Successful Outcomes in the Treatment of Burn and Wound Sites

806 Autologous Skin Cell Suspension Demonstrates Successful Outcomes in the Treatment of Burn and Wound Sites

Post-fire stabilization of thaw-affected permafrost terrain in northern Alaska

In 2007, the Anaktuvuk River fire burned more than 1000 km2 of arctic tundra in northern Alaska, ~ 50% of which occurred in an area with ice-rich syngenetic permafrost (Yedoma). By 2014, widespread degradation of ice wedges was apparent in the Yedoma region. In a 50 km2 area, thaw subsidence was detected across 15% of the land area in repeat airborne LiDAR data acquired in 2009 and 2014. Updating observations with a 2021 airborne LiDAR dataset show that additional thaw subsidence was detected in < 1% of the study area, indicating stabilization of the thaw-affected permafrost terrain. Ground temperature measurements between 2010 and 2015 indicated that the number of near-surface soil thawing-degree-days at the burn site were 3 × greater than at an unburned control site, but by 2022 the number was reduced to 1.3 × greater. Mean annual ground temperature of the near-surface permafrost increased by 0.33 °C/yr in the burn site up to 7-years post-fire, but then cooled by 0.15 °C/yr in the subsequent eight years, while temperatures at the control site remained relatively stable. Permafrost cores collected from ice-wedge troughs (n = 41) and polygon centers (n = 8) revealed the presence of a thaw unconformity, that in most cases was overlain by a recovered permafrost layer that averaged 14.2 cm and 18.3 cm, respectively. Taken together, our observations highlight that the initial degradation of ice-rich permafrost following the Anaktuvuk River tundra fire has been followed by a period of thaw cessation, permafrost aggradation, and terrain stabilization.

Wildfire effects on the fate of deposited nitrogen in a boreal larch forest

The effects of nitrogen (N) deposition on forests largely depend on the ecosystem N status and the fates of deposited N. Boreal forests are typically N-limited ecosystems and are considered to be more efficient in retaining deposited N relative to temperate and tropical forests. As a primary disturbance in boreal forests, wildfires may alleviate N limitation in the burned ecosystem and increase mineralization, resulting in the altered outcomes of the N deposition. In order to explore the effects of a severe wildfire on the retention of deposited N, we investigated the fates of newly deposited N in burned and unburned boreal larch forests by applying 15NH4NO3 tracers to the forest floors. Results showed that total ecosystem retention for the deposited N was 60% in the forest recovering from a severe wildfire burned five years ago, significantly lower than in the unburned mature forest (89%). The difference was mainly attributed to the substantially lower retention in vegetation (8.3%) in the burned site than in the unburned forest (32.4%), as tracer recoveries in soil were similar (51.2 and 56.6%, respectively). Although most 15N tracer was immobilized in organic soil in both burned and unburned forests (33 and 47%, respectively), a noticeably higher amount of 15N was found in mineral soil in the burned forest (19%) than in the unburned forest (10%), suggesting mineral soil as a significant sink for N deposition in the burned forest. A higher total 15N retention in the unburned forest implies that more new N input may stimulate C sequestration and promote the productivity of the Eurasian boreal forest under the background of atmospheric N deposition. However, a considerable amount of deposited N may be lost from the disturbed boreal larch forest ecosystem after a severe wildfire.

Effect of Forest Fires on the Alpha and Beta Diversity of Soil Bacteria in Taiga Forests: Proliferation of Rare Species as Successional Pioneers

Forest fires are among the most influential drivers of changes in forest soil bacterial diversity. Nevertheless, little is known regarding the effects of forest fires on maintaining the complex interactions that preserve forest ecosystem stability. Therefore, this study characterized alterations in soil bacterial community composition and diversity within taiga forests subjected to varying disturbance intensities. Particularly, this study examined the bacterial community within a Larix gmelinii fire-burnt site in Daxinganling, analyzing the changes in bacterial community structure and function across light, moderate, and heavy fire-burnt sites, as well as a control sample site, utilizing Illumina MiSeq technology. Through an assessment of bacterial community diversity and soil physicochemical properties (moisture content (MC), pH, microbial biomass carbon (MBC), organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), available phosphorus (AP), and available potassium (AP)), we explored the influence of the soil microenvironment on the soil bacterial community structure at the burnt site under different disturbance intensities. Our findings demonstrated that (1) there was no significant change in the Chao index of soil bacteria in the burnt site under different disturbance intensities, whereas the Shannon index decreased significantly (p &lt; 0.05) and the Simpson index increased significantly (p &lt; 0.05) in the burnt site under light and moderate disturbance. (2) The relative abundance of dominant phyla, such as Proteobacteria, Proteobacteria, and Actinobacteriota, did not change significantly in the fire-burnt site under different disturbance intensities, whereas rare species, such as Acidipila, Occallatibacter, and Acidibacter, experienced a significant increase in relative abundance at the genus level. (3) The results of principal coordinates analysis (PCoA) and canonical correlation analysis (CCA) revealed significant differences in the Beta diversity of soil bacteria in the fire-burnt site under varying interference intensities. The Beta diversity of soil bacteria exhibited significant differences (p = 0.001), with MC, pH, TN, AN, and AK identified as significant influencing factors. (4) FAPROTAX functional prediction analyses were conducted to assess the changes in soil bacteria involved in Cellulolysis, Chemoheterotrophy, and Aerobic_Chemoheterotrophy in the fire-burnt site, with the relative abundance of bacteria involved in Chemoheterotrophy being significantly increased (p &lt; 0.05) under different disturbance intensities. Collectively, our findings demonstrated that different disturbance intensities caused by fires significantly affected the Alpha diversity, Beta diversity, and functional abundance of soil bacterial communities in taiga forests, with MC, pH, TN, AN, and AK being identified as key influencing factors. Additionally, the presence of numerous rare species suggests their role as pioneer communities in the succession of soil bacterial communities.

The impact of 2021 large forest fires on vegetation and soils, on the territory of distribution of light soil-forming rocks in Central Yakutia

The influence of catastrophic forest fires in 2021 on the vegetation cover and soils of the middle taiga on the territory of distribution of light soil-forming rocks of Central Yakutia has been studied. Obtained results showed the cardinal dynamics of species diversity and productivity of the larch and pine forests surface vegetation in their natural state and in burnt areas. The stock of grass-shrub cover aboveground phytomass on the control larch and pine forests is higher for 5 and 10 times than that in the burnt areas, respectively. The work carried out revealed the effect of forest fires on the morphological structure (formation of pyrogenic layer, manifestation of pyro- and cryoturbations), the depth of thawing, the water regime of permafrost soils under larch and pine forests on control and burnt sites in the first year after strong fires. The soils in the study area are predominantly permafrost illuvial-ferruginous podzols. The study revealed an increase in the permafrost table depth of these soils, an increase in the level of ground water, and a decrease in acidity in the upper part of the profile. Intense ash formation was found due to the burning of litter. The characteristic of the current state of vegetation and soil cover is given.

Analysis of epidemiological characteristics and risk factors of catheter-associated urinary tract infections in patients with perineal and/or hip burns

Objective: To explore the epidemiological characteristics and risk factors of catheter-associated urinary tract infections in patients with perineal and/or hip burns. Methods: This study was a retrospective case series study. From January 2018 to December 2022, 260 patients with perineal and/or hip burns and urinary catheters indwelling who met the inclusion criteria were admitted to the Department of Burns and Wound Repair of the Second Affiliated Hospital of Zhejiang University School of Medicine, including 192 males and 68 females, aged 20-93 years. The total incidence of catheter-associated urinary tract infections in patients with perineal and/or hip burns, the detection of pathogenic bacteria, and the resistance of major Gram-negative and Gram-positive bacteria to commonly used antimicrobial drugs in clinic were recorded. According to whether catheter-associated urinary tract infection occurred or not, the patients were divided into infection group (43 cases) and non-infection group (217 cases). The basic conditions including gender, age, total burn area, depth of perineal burn, depth of hip burn, and burn site on admission, complications of diabetes mellitus, inhalation injury, and hypoproteinaemia, invasive operations including tracheotomy and non-perineal/hip debridement/skin transplantation surgery, duration of catheter retention, number of urethral catheterization, and bladder irrigation of patients between the two groups were compared, and the independent risk factors influencing the occurrence of catheter-associated urinary tract infections in patients with perineal and/or hip burns were screened. Results: The total incidence of catheter-associated urinary tract infections in patients with perineal and/or hip burns in this study was 16.5% (43/260). The pathogens detected were predominantly Gram-negative, followed by fungi; the main Gram-negative bacterium was Klebsiella pneumoniae, and the main Gram-positive bacterium was Enterococcus faecalis. The resistance rates of Klebsiella pneumoniae to amoxicillin/clavulanic acid, amitraz, amikacin, ciprofloxacin, ceftriaxone, and levofloxacin were higher than 70.0%, the resistance rates of Klebsiella pneumoniae to cefoxitin, cefoperazone/sulbactam, cefepime, meropenem, imipenem, and piperacillin/tazobactam ranged from 56.3% to 68.8%, and the resistance rates of Klebsiella pneumoniae to ceftazidime and tigecycline were lower than 50.0%. The resistance rates of Enterococcus faecalis to ciprofloxacin and penicillin were both 85.7%, the resistance rates of Enterococcus faecalis to erythromycin, clindamycin, moxifloxacin, and tetracycline ranged from 14.3% to 57.1%, and the resistance rates of Enterococcus faecalis to linezolid, tigecycline, and vancomycin were all 0. The differences were statistically significant between the two groups in terms of gender, status of complication of hypoproteinaemia, depth of perineal burn, status of non-perineal/hip debridement/skin transplantation surgery, status of bladder irrigation, number of urethral catheterization, and duration of catheter retention of patients (with χ2 values of 7.80, 4.85, 10.68, 9.11, and 16.48, respectively, and Z values of -4.88 and -5.42, respectively, P<0.05). There were no statistically significant differences in the age, total burn area, complications of diabetes mellitus and inhalation injury, burn site, depth of hip burns, and status of tracheotomy of patients between the two groups (P>0.05). Multifactorial logistic regression analysis showed that gender, deep partial-thickness perineal burns, non-perineal/hip debridement/skin transplantation surgery, bladder irrigation, and duration of catheter retention were the independent risk factors for catheter-associated urinary tract infections in patients with perineal and/or hip burns (with odds ratios of 2.86, 2.63, 2.79, 2.34, and 1.04, respectively, with 95% confidence intervals of 1.21-6.73, 1.03-6.71, 1.03-7.59, 1.05-5.22, and 1.02-1.06, respectively, P<0.05). Conclusions: The incidence of catheter-associated urinary tract infections is high in patients with perineal and/or hip burns, with Klebsiella pneumoniae as the predominant pathogenic bacteria having a high resistance rate to commonly used antimicrobial drugs in clinic. Gender, deep partial-thickness perineal burns, non-perineal/hip debridement/skin transplantation surgery, bladder irrigation, and duration of catheter retention are the independent risk factors for catheter-associated urinary tract infections in patients with perineal and/or hip burns.

Burn Patients and Mental Health: A Matched Cohort Study.

To determine the association between burns and hospitalization for mental health disorders up to three decades later. Burns are associated with pain, disability, and scarring, but the long-term impact on mental health is unclear. We analyzed a cohort of 23,726 burn patients aged ≥10 years who were matched to 223,626 controls from Quebec, Canada, between 1989 and 2022. The main exposure was admission for a burn. We followed patients during 3,642,206 person-years of follow-up to identify future hospitalizations for psychiatric disorders, substance use disorders, and suicide attempts. We estimated adjusted hazard ratios (HR) with 95% confidence intervals (CI) for the association between burns and subsequent mental health hospitalization using Cox proportional hazards regression. Burn patients had 1.76 times greater risk of mental health hospitalization over time (95% CI 1.72-1.81), compared with controls. Associations were present regardless of burn site, but were greatest for burns covering ≥50% of the body (HR 3.29, 95% CI 2.61-4.15), third degree burns (HR 2.04, 95% CI 1.94-2.14), and burns requiring skin grafts (HR 2.00, 95% CI 1.90-2.10). Compared with controls, burn patients had more than two times the risk of hospitalization for eating disorders (HR 3.14, 95% CI 2.50-3.95), psychoactive substance use disorders (HR 2.27, 95% CI 2.17-2.39), and suicide attempts (HR 2.42, 95% CI 2.23-2.62). Risks were particularly elevated within 5 years of the burn, but persisted throughout follow-up. Burns are associated with an increased risk of hospitalization for mental health disorders up to 30 years later.