Trends in microbial profile of burn patients following an event of dust explosion at a tertiary medical center.

BACKGROUND: Microbial infection is the main cause of increased morbidity and mortality in burn patients, especially infections caused by multiple drug-resistant organisms (MDRO). The purpose of this study was to explore major microbial trends in burn patients. METHODS: This retrospective study was conducted at burn wards and intensive care units, where burn patients were admitted following an event of dust explosion. Data were collected for a number of variables including severity of burns, demographic and clinical characteristics, laboratory data, and therapeutic devices. RESULTS: A total of 1132 specimens were collected from 37 hospitalized burn patients with mean TBSA of 46.1%.The most commonly isolated species were Staphylococcus spp. (22.4%). The highest rate of antibiotic resistance was observed in carbapenem-resistant A. baumannii (14.6%), followed by methicillin-resistant S. aureus (11.3%). For each additional 10% TBSA, the isolation of MDRO increased 2.58-17.57 times (p < 0.05); for each additional 10% of the third-degree burn severity, the risk of MDRO significantly decreased by 47% (95% CI, 0.38-0.73, p < 0.001) by Cox model. CONCLUSIONS: The proportion of overall microbial isolates increased with the increase in TBSA and duration of time after burns. The extent of TBSA was the most important factor affecting MDRO.

Intrawound Antibiotic Powder Decreases Frequency of Deep Infection and Severity of Heterotopic Ossification in Combat Lower Extremity Amputations.

BACKGROUND: Amputations sustained owing to combat-related blast injuries are at high risk for deep infection and development of heterotopic ossification, which can necessitate reoperation and place immense strain on the patient. Surgeons at our institution began use of intrawound antibiotic powder at the time of closure in an effort to decrease the rate of these surgical complications after initial and revision amputations, supported by compelling clinical evidence and animal models of blast injuries. Antibiotic powder may be useful in reducing the risk of these infections, but human studies on this topic thus far have been inconclusive. PURPOSE: We sought to determine whether administration of intrawound antibiotic powder at the time of closure would (1) decrease the risk of subsequent deep infections of major lower-extremity combat-related amputations, and (2) limit formation and decrease severity of heterotopic ossification common in the combat-related traumatic residual limb. METHODS: Between 2009 and 2015, 252 major lower extremity initial and revision amputations were performed by a single surgeon. Revision cases were excluded if performed specifically to address deep infection, leaving 223 amputations (88.5%) for this retrospective analysis. We reviewed medical records to collect patient information, returns to the operating room for subsequent infection, and microbiologic culture results. We also reviewed radiographs taken at least 3 months after surgery to determine the presence and severity of heterotopic ossification using the Walter Reed classification system. We grouped cases according to whether limbs underwent initial or revision amputations, and whether the limbs had a history of a prior infection. Apart from the use of antibiotic powder and duration of followup, the groups did not differ in terms of age, mechanism of injury, or sex. We then calculated the absolute risk reduction for infection and heterotopic ossification and the number needed to treat to prevent an infection. RESULTS: Overall, administration of antibiotic powder resulted in a 13% absolute risk reduction of deep infection (14 of 82 [17%] versus 42 of 141 [30%]; p = 0.03; 95% CI, 0.20%-24.72%). In revision amputation surgery, the absolute risk reduction of infection with antibiotic powder use was 16% overall (eight of 58 versus 17 of 57; 95% CI, 1.21%-30.86%), and 25% for previously infected limbs (eight of 46 versus 14 of 33; 95% CI, 4.93%-45.14%). The number needed to treat to prevent one additional deep infection in amputation surgery is eight in initial amputations, seven in revision amputations, and four for revision amputation surgery on previously infected limbs. With the numbers available, we observed no reduction in the risk of heterotopic ossification with antibiotic powder use, but severity was decreased in the treatment group in terms of the number of residual limbs with moderate or severe heterotopic ossification (three of 12 versus 19 of 34; p = 0.03). CONCLUSIONS: Our findings show that administration of intrawound antibiotic powder reduces deep infection in residual limbs of combat amputees, particularly in the setting of revision amputation surgery in apparently aseptic residual limbs at the time of the surgery. Furthermore, administration of antibiotic powder for amputations at time of initial closure decreases the severity of heterotopic ossification formation, providing a low-cost adjunct to decrease the risk of two complications common to amputation surgery.Level of Evidence Level III, therapeutic study.

The clinical and microbiological characteristics of infections in burn patients from the Formosa Fun Coast Dust Explosion.

BACKGROUND/PURPOSE: Bloodstream infection is a leading cause of mortality among burn patients. This study aimed to evaluate the risk factors, causative pathogens, and the relationship between bloodstream infections and other infections among burn patients from the Formosa Fun Coast Dust Explosion. METHODS: This retrospective study evaluated the demographic and clinical characteristics, infection types, causative pathogen(s), and isolates' antibiotic susceptibilities from patients who were hospitalized between June 27 and September 31, 2015. RESULTS: Fifty-eight patients were admitted during the study period (36 males, mean age: 22.6 years). The mean burned total body surface area (TBSA) was 40% for all patients. Eighteen (31%) patients with mean TBSA of 80% had 66 episodes of bloodstream infections caused by 92 isolates. Twelve (18.2%) episodes of bloodstream infections were polymicrobial. Acinetobacter baumannii (19, 20.7%), Ralstonia pickettii (17, 18.5%), and Chryseobacterium meningosepticum (13, 14.1%) were the most common pathogens causing bloodstream infections. A high concordance rate of wound cultures with blood cultures was seen in Staphylococcus aureus (3, 75%) and C. meningosepticum (8, 61.5%) infections. However, no Ralstonia isolate was found in burn wounds of patients with Ralstonia bacteremia. A high concordance rate of central venous catheter cultures with blood cultures was noted in Ralstonia mannitolilytica (5, 62.5%) and Chryseobacterium indologenes (3, 60%) infections. Approximately 21.1% of A. baumannii strains were resistant to carbapenem. All S. aureus isolates were susceptible to methicillin. CONCLUSIONS: Waterborne bacteria should be considered in patients of burns with possible water contact. Empirical broad-spectrum antibiotics should be considered for patients who were hospitalized for severe sepsis, or septic shock with a large burn. Antibiotic treatment should be administered based on the specific pathogens and their detection points.

Multi-Drug-Resistant Gram-Negative Infections in Deployment-Related Trauma Patients.

BACKGROUND: The contribution of multi-drug-resistant gram-negative bacilli infections (MDRGN-I) in patients with trauma is not well described. We present characteristics of MDRGN-Is among military personnel with deployment-related trauma (2009-2014). PATIENTS AND METHODS: Data from the Trauma Infectious Disease Outcomes Study were assessed for infectious outcomes and microbial recovery. Infections were classified using standardized definitions. Gram-negative bacilli were defined as multi-drug-resistant if they showed resistance to ≥3 antibiotic classes or were producers of extended-spectrum ß-lactamase or carbapenemases. RESULTS: Among 2,699 patients admitted to participating U.S. hospitals, 913 (33.8%) experienced ≥1 infection event, of which 245 (26.8%) had a MDRGN-I. There were 543 MDRGN-I events (24.6% of unique 2,210 infections) with Escherichia coli (48.3%), Acinetobacter spp. (38.6%), and Klebsiella pneumoniae (8.4%) as the most common MDRGN isolates. Incidence of MDRGN-I was 9.1% (95% confidence interval [CI]: 8.0-10.2). Median time to MDRGN-I event was seven days with 75% occurring within 13 days post-trauma. Patients with MDRGN-Is had a greater proportion of blast injuries (84.1% vs. 62.5%; p < 0.0001), traumatic amputations (57.5% vs. 16.3%; p < 0.0001), and higher injury severity (82.0% had injury severity score ≥25 vs. 33.7%; p < 0.0001) compared with patients with either no infections or non-MDRGN-Is. Furthermore, MDRGN-I patients were more frequently admitted to the intensive care unit (90.5% vs. 48.5%; p < 0.0001), colonized with a MDRGN before infection (58.0% vs. 14.7%; p < 0.0001), and required mechanical ventilation (78.0% vs. 28.8% p < 0.0001). Antibiotic exposure before the MDRGN-I event was significantly higher across antibiotic classes except first generation cephalosporins and tetracyclines, which were very commonly used with all patients. Regarding outcomes, patients with MDRGN-Is had a longer length of hospitalization than the comparator group (53 vs. 18 days; p < 0.0001). CONCLUSIONS: We found a high rate of MDRGN-I in our population characterized by longer hospitalization and greater injury severity. These findings inform treatment and infection control decisions in the trauma patient population.

Procalcitonin as a diagnostic biomarker for septic shock and bloodstream infection in burn patients from the Formosa Fun Coast dust explosion.

BACKGROUND/PURPOSE: Infection is the most common cause of death following burn injury. The study was conducted to compare the diagnostic value of serum procalcitonin (PCT) with the other current benchmarks as early predictors of septic shock and bloodstream infection in burn patients. METHODS: We included 24 patients admitted to the Burn Unit of a medical center from June 2015 to December 2015 from the Formosa Fun Coast dust explosion. We categorized all patients at initial admission into either sepsis or septic shock groups. Laboratory tests including the worst PCT and C-reactive protein (CRP) levels, platelet (PLT), and white blood cell (WBC) count were performed at <48 h after admission. Patients were also classified in two groups with subsequent bacteremia and non-bacteremia groups during hospitalization. RESULTS: Significantly higher PCT levels were observed among participants with septic shock compared to those with sepsis (47.19 vs. 1.18 ng/mL, respectively; p < 0.001). Patients with bacteremia had significantly elevated PCT levels compared to patients without bacteremia (29.54 versus 1.81 ng/mL, respectively, p < 0.05). No significant differences were found in CRP levels, PLT, and WBC count between the two groups. PCT levels showed reasonable discriminative power (cut-off: 5.12 ng/mL; p = 0.01) in predicting of bloodstream infection in burn patients and the area under receiver operating curves was 0.92. CONCLUSIONS: PCT levels can be helpful in determining the septic shock and bloodstream infection in burn patients but CRP levels, PLT, and WBC count were of little diagnostic value.

[CHARACTERISTICS OF ANTIBIOTICORESISTANCE OF MICROFLORA IN A COMBAT (THE GUN-SHOT ANO THE MINE-EXPLOSION) WOUNDS OF THE EXTREMITIES].

Abstract Results of bacteriological investigations of a gun-shot and a mine-explosion woundings of the extremities were analyzed in Military-Medical Clinical Centres (MMCC) of Kyiv, Lviv and Vinnytsya. Spectrum of the allotted microorganisms and profile of their antibioticoresistance were disclosed. The patterns of resistance were determined in accordance to offering of international experts of European Committee on Antimicrobial Susceptibility Testing (EUCAST). Dominating microflora in a Chief MMCC (Kyiv) and MMCC of a Western Region (Lviv) were various species of the Enterobacteriaceae and P. aeruginosa families, while in MMCC of a Central Region (Vinnytsya)--a gramm-negative non-fermentative bacilli of the Acinetobacter genus and Pseudomonas genus. The majority (79.5%) of isolates were characterized by polyresistance for antibiotics. Maximal quantity of strains with a widened spectrum of resistance was revealed in 2 - 3 weeks after a wounding--in 71.4 and 96.9% accordingly.

Dismounted Complex Blast Injuries Including Invasive Fungal Infections.

Large blast injuries during dismounted operations in southwest Afghanistan causing major limb amputations and perineal injuries associated with large blood volume resuscitation were associated with invasive fungal, primarily mold, infections. This article outlines the interventions undertaken to mitigate excess morbidity and mortality associated with invasive fungal infection. These interventions include defining the problem and associated risk with systemically collected and analyzed information, developing improved protective body armor for the thigh and perineal region, standardizing management through clinical practice guidelines that outlined risk, diagnostic and treatment recommendations with enhanced discussions on the weekly Theater Combat Casualty Care Conference that includes personnel from the combat zone, Germany, and the United States. The article concludes by explaining the key way forward with regarding an inner-war approach to sustained knowledge and skills.

Antifungal wound penetration of amphotericin and voriconazole in combat-related injuries: case report.

BACKGROUND: Survivors of combat trauma can have long and challenging recoveries, which may be complicated by infection. Invasive fungal infections are a rare but serious complication with limited treatment options. Currently, aggressive surgical debridement is the standard of care, with antifungal agents used adjunctively with uncertain efficacy. Anecdotal evidence suggests that antifungal agents may be ineffective in the absence of surgical debridement, and studies have yet to correlate antifungal concentrations in plasma and wounds. CASE PRESENTATION: Here we report the systemic pharmacokinetics and wound effluent antifungal concentrations of five wounds from two male patients, aged 28 and 30 years old who sustained combat-related blast injuries in southern Afghanistan, with proven or possible invasive fungal infection. Our data demonstrate that while voriconazole sufficiently penetrated the wound resulting in detectable effluent levels, free amphotericin B (unbound to plasma) was not present in wound effluent despite sufficient concentrations in circulating plasma. In addition, considerable between-patient and within-patient variability was observed in antifungal pharmacokinetic parameters. CONCLUSION: These data highlight the need for further studies evaluating wound penetration of commonly used antifungals and the role for therapeutic drug monitoring in providing optimal care for critically ill and injured war fighters.

Pathogens present in acute mangled extremities from Afghanistan and subsequent pathogen recovery.

Given the changing epidemiology of infecting pathogens in combat casualties, we evaluated bacteria and fungi in acute traumatic wounds from Afghanistan. From January 2013 to February 2014, 14 mangled lower extremities from 10 explosive-device injured casualties were swabbed for culture at Role 3 facilities. Bacteria were recovered from all patients on the date of injury. Pathogens recovered during routine patient care were recorded. The median injury severity score was 29, median initial Role 3/4 blood product support was 32 units, and median evacuation time was 42 minutes to first surgical care. Gram-positive bacteria were found in some wounds but not methicillin-resistant Staphylococcus aureus or vancomycin-resistant Enterococcus. Most wounds were colonized with low-virulence, environmental gram-negative bacteria, and not recovered again during therapy, reflecting wound contamination. Only one wound had the same bacteria (E. cloacae) throughout care at the Role 3, 4, and 5 facilities. Three cultures from two patients had multidrug-resistant bacteria (E. cloacae, E. coli), all detected at Role 5 facilities. Molds were not detected at Role 3, whereas one patient had a mold at Role 4 and 5. Mangled lower extremity injuries have a high contamination rate with environmental organisms, which are not typically associated with infections during the course of the patient's care.

[The role of the biological damaging factor in the explosive injury].

This article describes the specific features of the action of the biological damaging factors on the human organism associated with the explosive injury. Both the direct action of the damaging agents contained in the biological weapons and their secondary effects in the form of systemic and local infectious complications of the inflicted wounds are considered. The criteria for the evaluation of the degree of harm to the health of the victims of explosion attributable to the action of the biological damaging factor are proposed.

Effect of early screening for invasive fungal infections in U.S. service members with explosive blast injuries.

BACKGROUND: An outbreak of invasive fungal infections (IFI) began in 2009 among United States servicemen who sustained blast injuries in Afghanistan. In response, the military trauma community sought a uniform approach to early diagnosis and treatment. Toward this goal, a local clinical practice guideline (CPG) was implemented at Landstuhl Regional Medical Center (LRMC) in early 2011 to screen for IFI in high-risk patients using tissue histopathology and fungal cultures. METHODS: We compared IFI cases identified after initiation of the CPG (February through August 2011) to cases from a pre-CPG period (June 2009 through January 2011). RESULTS: Sixty-one patients were screened in the CPG period, among whom 30 IFI cases were identified and compared with 44 pre-CPG IFI cases. Demographics between the two study periods were similar, although significantly higher transfusion requirements (p<0.05) and non-significant trends in injury severity scores and early lower extremity amputation rates suggested more severe injuries in CPG-period cases. Pre-CPG IFI cases were more likely to be associated with angioinvasion on histopathology than CPG IFI cases (48% versus 17%; p<0.001). Time to IFI diagnosis (three versus nine days) and to initiation of antifungal therapy (seven versus 14 days) were significantly decreased in the CPG period (p<0.001). Additionally, more IFI patients received antifungal agent at LRMC during the CPG period (30%) versus pre-CPG period (5%; p=0.005). The CPG IFI cases were also prescribed more commonly dual antifungal therapy (73% versus 36%; p=0.002). There was no statistical difference in length of stay or mortality between pre-CPG and CPG IFI cases; although a non-significant reduction in crude mortality from 11.4% to 6.7% was observed. CONCLUSIONS: Angioinvasive IFI as a percentage of total IFI cases decreased during the CPG period. Earlier diagnosis and commencement of more timely treatment was achieved. Despite these improvements, no difference in clinical outcomes was observed compared with the pre-CPG period.

Prospective randomised controlled trial of nanocrystalline silver dressing versus plain gauze as the initial post-debridement management of military wounds on wound microbiology and healing.

INTRODUCTION: Recent conflicts have been characterised by the use of improvised explosive devices causing devastating injuries, including heavily contaminated wounds requiring meticulous surgical debridement. After being rendered surgical clean, these wounds are dressed and the patient transferred back to the UK for on-going treatment. A dressing that would prevent wounds from becoming colonised during transit would be desirable. The aim of this study was to establish whether using nanocrystalline silver dressings, as an adjunct to the initial debridement, would positively affect wound microbiology and wound healing compared to standard plain gauze dressings. METHODS: Patients were prospectively randomised to receive either silver dressings, in a nanocrystalline preparation (Acticoat™), or standard of care dressings (plain gauze) following their initial debridement in the field hospital. On repatriation to the UK microbiological swabs were taken from the dressing and the wound, and an odour score recorded. Wounds were followed prospectively and time to wound healing was recorded. Additionally, patient demographic data were recorded, as well as the mechanism of injury and Injury Severity Score. RESULTS: 76 patients were recruited to the trial between February 2010 and February 2012. 39 received current dressings and 37 received the trial dressings. Eleven patients were not swabbed. There was no difference (p=0.1384, Fishers) in the primary outcome measure of wound colonisation between the treatment arm (14/33) and the control arm (20/32). Similarly time to wound healing was not statistically different (p=0.5009, Mann-Whitney). Wounds in the control group were scored as being significantly more malodorous (p=0.002, Mann-Whitney) than those in the treatment arm. CONCLUSIONS: This is the first randomised controlled trial to report results from an active theatre of war. Performing research under these conditions poses additional challenges to military clinicians. Meticulous debridement of wounds remains the critical determinant in wound healing and infection and this study did not demonstrate a benefit of nanocrystaline silver dressing in respect to preventing wound colonisation or promoting healing, these dressings do however seem to significantly reduce the unpleasant odour commonly associated with battlefield wounds.

Mechanism of injury and microbiological flora of the geographical location are essential for the prognosis in soldiers with serious warfare injuries.

INTRODUCTION: Denmark has been engaged in the Afghanistan war and as a result, Rigshospitalet has received a number of multi-traumatized Danish soldiers. Lesions sustained in armed conflict differ from their civilian counterparts and knowledge of the pathophysiology related to these types of lesions is essential when engaging in the intensive care of these patients. MATERIAL AND METHODS: The study was conducted as a retrospective survey of Danish soldiers evacuated from Afghanistan to the Intensive Care Unit at Rigshospitalet in the 2002-2012 period. The following data were recorded: age, gender, hospitalization (days), mortality, organ involvement, respiratory therapy, dialysis, circulatory supportive care, antibiotic treatment and bacteriology. Furthermore, Acute Physiology and Chronic Health Evaluation, Simplified Acute Physiology Score and Sequential Organ Failure Assessment scores were calculated. RESULTS: A total of twenty patients were identified and included in the study. All patients had sustained serious blast injuries as a result of explosion. Primarily the central nervous system, respiratory, musculoskeletal and abdominal systems were affected by the explosions. Eighteen patients survived to discharge and two patients died. DISCUSSION: Explosion was the most frequent cause of injury in all cases and caused damage to several organ systems. Infections after combat injuries are a major problem because of the different microbiological profile. CONCLUSION: The use of explosives has been and remains a substantial part of warfare, and this review has showed us that the knowledge of the mechanism of injury is indeed essential, and that intelligence on the microbiological flora of the geographical location of the conflict is essential. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

Treatment of infected soft tissue blast injury in swine by regulated negative pressure wound therapy.

OBJECTIVE: This study was designed to investigate the therapeutic potential of regulated negative pressure wound therapy (RNPT) in treating infected blast injuries in swine. BACKGROUND: Approximately 30% to 80% of blast injuries develop infection, which increases the morbidity and mortality of these casualties. RNPT has been used in US military operations in Iraq; however, no randomized controlled study has been conducted on the use of RNPT to treat infected war injuries. METHODS: Infected soft tissue blast injuries were treated with gauze dressings or RNPT with different pressures ranging from -5 to -35 kPa. To evaluate the wound healing process, the wound area, wound depth, the number of proliferative cells, and the vascular endothelial cells in the granulation tissue were measured at different time points. Furthermore, to evaluate the infection and inflammation of the blast injury, the bacterial load, bacterial species, and several inflammatory markers were detected. RESULTS: Compared with gauze dressing treatments, RNPT reduced bacterial load more efficiently, initiated granulation tissue formation earlier, and increased the inflammation faster. Negative pressures ranging from -10 to -25 kPa applied on the RNPT group showed beneficial effects in treating the infected soft tissue blast injury. RNPT did not significantly change both the aerobic and anaerobic bacterial composition compared with those of the gauze dressing group. CONCLUSIONS: RNPT clearly shows beneficial effects in treating the infected soft tissue blast injury in comparison with the gauze dressing therapy in swine.

Invasive mold infections following combat-related injuries.

BACKGROUND: Major advances in combat casualty care have led to increased survival of patients with complex extremity trauma. Invasive fungal wound infections (IFIs) are an uncommon, but increasingly recognized, complication following trauma that require greater understanding of risk factors and clinical findings to reduce morbidity. METHODS: The patient population includes US military personnel injured during combat from June 2009 through December 2010. Case definition required wound necrosis on successive debridements with IFI evidence by histopathology and/or microbiology (Candida spp excluded). Case finding and data collected through the Trauma Infectious Disease Outcomes Study utilized trauma registry, hospital records or operative reports, and pathologist review of histopathology specimens. RESULTS: A total of 37 cases were identified: proven (angioinvasion, n=20), probable (nonvascular tissue invasion, n=4), and possible (positive fungal culture without histopathological evidence, n=13). In the last quarter surveyed, rates reached 3.5% of trauma admissions. Common findings include blast injury (100%) during foot patrol (92%) occurring in southern Afghanistan (94%) with lower extremity amputation (80%) and large volume blood transfusion (97.2%). Mold isolates were recovered in 83% of cases (order Mucorales, n=16; Aspergillus spp, n=16; Fusarium spp, n=9), commonly with multiple mold species among infected wounds (28%). Clinical outcomes included 3 related deaths (8.1%), frequent debridements (median, 11 cases), and amputation revisions (58%). CONCLUSIONS: IFIs are an emerging trauma-related infection leading to significant morbidity. Early identification, using common characteristics of patient injury profile and tissue-based diagnosis, should be accompanied by aggressive surgical and antifungal therapy (liposomal amphotericin B and a broad-spectrum triazole pending mycology results) among patients with suspicious wounds.

Aggressive soft tissue infections and amputation in military trauma patients.

Due to the nature of IED injuries, during the conflicts in Iraq and Afghanistan The traditional, two-stage amputation for unsalvageable combat lower limb injuries has evolved into a strategy of serial debridement and greater use of plastic surgical techniques in order to preserve residual limb length. This study aimed to characterise the current treatment of lower limb loss with particular focus on the impact of specific wound infections. The UK military trauma registry and clinical notes were reviewed for details of all lower limb amputation identifying: 51 patients with 70 lower limb amputations. The mean number of debridements per stump prior to closure was 4.1 (95% CI 3.5-4.7). A final more proximal amputation level was required in 21 stumps (30%). Recovery of A. hydrophillia from wounds was significantly associated with a requirement for a more proximal amputation level (p=0.0038) and greater number of debridements (p=0.0474) when compared to residual limb wounds withoutA. hydrophillia.

New swine model of infected soft tissue blast injury.

BACKGROUND: War injuries, especially blast injuries, have a high risk of infection. However, no animal models of infected war injuries have been built in large animals, which retards both the understanding and the treatment optimization of infected war injuries. METHODS: Soft tissue blast injuries were created by explosion of electric detonators in white domestic pigs. The ultra structure of the tissue around the wound was determined by transmission electron microscope. To develop infection of blast injury wounds, the pigs were housed in a standard animal house which was disinfected periodically, and the wounds were left untreated for 3 days. Wound specimens were collected daily to determine the bacterial load and bacterial components. To determine whether infection induces tissue necrosis in infected soft tissue blast injury wounds, uninfected blast injury wounds were created as controls of infected wounds by surgical debridement daily, and the wound area and wound depth of both wounds were measured. RESULTS: The wound area and the wound depth of the soft tissue blast injury created in this study fell in the range of human moderate soft tissue war injuries, and the ultra structure of the wounds was comparable with that of human blast injury wounds. The bacterial load of uninfected wounds was under 10 colony forming unit/g during the first 3 days of injury, while that of infected wounds was over 10 colony forming unit/g after 2 days of injury. The infected soft tissue blast injury wounds contained most of the bacteria frequently isolated in battlefield wounds. In addition, infection induced evident tissue necrosis in infected blast injury wounds. CONCLUSION: The infected soft tissue blast injury wounds mimic those in human, and they can be used to address key points of treatment optimization.

Multi-drug resistant Bacteroides fragilis recovered from blood and severe leg wounds caused by an improvised explosive device (IED) in Afghanistan.

This report summarizes the case of a 23 year-old otherwise healthy male that was injured in an improvised explosive device (IED) blast in support of Operation Enduring Freedom (OEF). He sustained bilateral open tibia and fibula fractures in the setting of being exposed to water contaminated with raw sewage. Despite long-term carbapenem therapy, the patient's wounds were repeatedly noted to have purulent drainage during surgical debridement and cultures from these wounds were persistently positive for Bacteroides fragilis. Apparent clinical failure persisted despite the addition of metronidazole to his regimen and an eventual trial of tigecycline. Susceptibility testing of the B. fragilis isolate was performed and resistance to penicillin, clindamycin,metronidazole, cefoxitin, meropenem, imipenem, piperacillin/tazobactam, and tigecycline was confirmed. The presence of a nimE gene on a potentially transferrable plasmid was also confirmed by plasmid sequencing. The only antibiotics that displayed in vitro susceptibility were moxifloxacin and linezolid. These antibiotics were initiated in combination with aggressive irrigation and serial surgical debridement. Conversion to left-sided internal fixation became feasible and his left lower extremity was salvaged without residual evidence of infection. The patient completed an eight week course of combination moxifloxacin and linezolid therapy without adverse event. This B. fragilis isolate displayed simultaneous high-level resistance to multiple antibiotics routinely utilized in anaerobic infections. This was evidenced by clinical failure, in vitro susceptibility testing, and demonstration of genes associated with resistance mechanisms. This case warrants review not only due to the rarity of this event but also the potential implications regarding anaerobic infections in traumatic wounds and the success of a novel treatment regimen utilizing combination therapy with moxifloxacin and linezolid.

Infectious complications in OIF/OEF veterans with traumatic brain injury.

Of veterans from the U.S. Global War on Terrorism who have sought care in the Department of Veterans Affairs, approximately 12% have an infectious disease diagnosis. Infections in those veterans with traumatic brain injury (TBI) include infections associated with blast injuries and burns, such as skin and soft tissue infections; infections as a result of retained bullet or shrapnel fragments; pulmonary infections resulting from lung injury, intubation, or resultant tracheostomy; hospital-acquired infections, such as those associated with methicillin-resistant Staphylococcus aureus and other antimicrobial resistant organisms such as Acinetobacter baumannii; and infections from implanted prosthetic devices, such as metal hardware or skull flaps. Longer-term cognitive impairment may result in behaviors that place veterans with TBI at risk for human immunodeficiency virus or hepatitis C virus infections. Finally, chronic infections acquired abroad, such as cutaneous leishmaniasis or Q-fever, may be diagnosed after veterans return to the United States. These infections present challenges in terms of added morbidity and costs associated with complex antimicrobial management; isolation requirements; and surgical procedures, such as those to remove infected retained fragments or prosthetic devices. In this review, providers will become more familiar with the scope and complexity of infectious disease management in veterans with TBI.