Evaluation of risk factors associated with hard-to-heal wound infection in a tertiary care hospital.

OBJECTIVE: The incidence of hard-to-heal wound infection, especially as a result of multidrug-resistant Gram-negative organisms, has increased in recent years. The reason for the increase is multifactorial and the ability of these pathogenic isolates to form biofilms is one of the important risk factors in wound infection. This study aimed to evaluate the risk factors associated with such cases. METHOD: This prospective analytical study, conducted over a period of two months, included pus or tissue samples from hospital inpatients with Gram-negative hard-to-heal wound infection. The samples were processed with conventional microbiological techniques. Patient demographic details and the presence of various risk factors were recorded. Biofilm production was detected by tissue culture plate method in the laboratory. The data were analysed using SPSS version 21 (IBM Ltd., US). RESULTS: The experimental cohort comprised 200 patients. Klebsiella spp. was the most common identified organism, followed by Escherichia coli and Pseudomonas spp. Carbapenem resistance was observed in 106 (53%) strains. Almost 66% of the strains showed biofilm formation. On evaluation of associated risk factors, age (p=0.043), presence of biofilms (p=0.0001), diabetes (p=0.002), hypertension (p=0.02) and medical device use (p=0.008) had significant association, whereas sex, previous surgery and prior antibiotic use had no significant impact on the chronicity of the wound. CONCLUSION: In this study, chronicity of wounds was observed to be associated with multiple risk factors, especially the biofilm-forming ability of the strain. Biofilms are difficult to eradicate and additional measures, such as physical debridement, are important for resolving chronicity. Knowledge about specific risk factors would also allow clinicians a better understanding of the healing process and drive appropriate wound care interventions. DECLARATION OF INTEREST: A grant was received from the Indian Council of Medical Research (ICMR) for this work (grant ID: 2017-02686). The authors have no conflicts of interest to declare.

Wound infection among children with moderate burns - An explorative review of the association between reported frequency and diagnosis.

INTRODUCTION: The Linkoping burn centre in Sweden has, even though being a high income country, reported high burn wound infections (BWI) frequencies in scalded children compared to similar populations in other parts of the world. AIM: The aim was to investigate possible explanations for differences in frequency of BWI among children with partial thickness burns treated at the Linköping burn centre in Sweden, and that reported in other studies. METHOD: In order to investigate what BWI criteria that were used in similar studies a literature search on PubMed Central was done along with a retrospective analysis of children previously diagnosed as infected to confirm or reject the high infection frequency reported earlier. RESULT: Of the 34 selected publications reporting on BWI frequency 16 (47%) did not define a criteria for the BWI diagnosis and almost a third did not report on wound culturing. Of those who did report the use a third do not mention any bacterial growth found is these cultures. The retrospective analysis on children at the centre did not show any decrease in infection frequency even with some disagreement on onset for the BWI. CONCLUSION: The reporting of criteria and diagnosis of burn wound infection is highly variable making it difficult to interpret results and come to conclusions. The high frequency of BWI at the centre might be a result of close monitoring due to study participation, use of clean instead of sterile routine at dressing changes or low thresholds for the diagnosis in respect to changes in infection markers.

Drug susceptibility, Prevalence and effect of Pseudomonas aeruginosa on wound healing of burn patients.

Objective: To determine the prevalence, antibiotic susceptibility and effect of Pseudomonas aeruginosa in relation to burn patients. METHODS: The cross-sectional study was conducted at the Centre for Advanced Studies in Vaccinology and Biotechnology, University of Balochistan, Quetta, Pakistan, from March 2018 to May 2021, and comprised pus swab cultures were isolated from inpatients with 2nd and 3rd degree burns aged up to 60 years at Bolan Medical Complex Hospital and Sandeman Provinical Hospital, the two main government tertiary care hospitals in Quetta. The samples were immediately cultured, and evaluated using biochemical tests, antibiotic susceptibility and molecular identification using polymerase chain reaction. Data was analysed using SPSS 20. RESULTS: Of the 720 burn wound samples, 424(58.9%) were positive for Pseudomonas aeruginosa; 304(42%) males and 120(16%) females (p<0.02). The overall mean age of the patients was 27.7±6.2 years (range: 1-60 years). The mean total burn surface area was not significantly different in positive 29.6±6.2% and negative 30.3±6.2% cases (p>0.05). The time leading to skin grafts in positive patients was 29.5±6.5 days compared to 22.3±6.3 days for negative patients (p< 0.007), and the time required for wound healing was 25.0±4.7 days and 16.7±5.2 days, respectively (p<0.001). Length of hospital stay of Pseudomonas aeruginosa positive patients was 38.0±7.8 days compared to 32.1±6.8 days for negative patients (p<0.001). Conclusion: Nosocomial infections and multidrug resistance species were observed frequently at the burn wound site. P. aeruginosa.

Incidence and Risk Factors for Wound Infections after Trimeresurus stejnegeri Snakebites in Taiwan.

Snakebite envenomation is a neglected tropical disease. Taiwan, with its subtropical and Southeast Asian environment, provides suitable habitat for several venomous snake species. Trimeresurus stejnegeri, an arboreal pit viper, is the most common cause of venomous snakebite in Taiwan. Trimeresurus stejnegeri envenomation can cause local swelling, occasional ecchymosis, and wound infection. The primary treatment of T. stejnegeri envenomation is the binary antivenom, vacuum freeze-dried F(ab')2 fragments of equine antibodies, against T. stejnegeri and Protobothrops mucrosquamatus. This study aimed to analyze the incidence of post-envenomation wound infections caused by T. stejnegeri based on data collected over a decade from institutions affiliated with the Chang Gung Memorial Hospital in Taiwan. A total of 254 patients were enrolled in this study. Clinical and laboratory data, treatment information, and patient outcomes were extracted from electronic medical records. Wound infection was associated with delay in antivenom initiation (adjusted odds ratio: 3.987; 95% CI: 1.406-11.302). The infection rates were 20.5%, 12.5%, 31.3%, and 48.1% for antivenom administration within 2 hours, 2-4 hours, 4-6 hours, and > 6 hours, respectively. Therefore, early initiation of antivenom treatment (within 6 hours) is recommended. Morganella morganii was cultured from wounds of the patients, whereas Enterobacter cloacae and Enterococcus faecalis were cultured from both the oral cavity of snakes and the wounds of the patients. For post-envenomation patients who develop a local infection, empiric antibiotics such as third-generation cephalosporins, quinolones, and piperacillin/tazobactam are recommended because snakebite wound infections are often polymicrobial in nature.

Seasonality of Microbiology of Combat-Related Wounds and Wound Infections in Afghanistan.

INTRODUCTION: Battlefield-related wound infections are a significant source of morbidity among combat casualties. Seasonality of these infections was demonstrated in previous conflicts (e.g., Korea) but has not been described with trauma-related health care-associated infections from the war in Afghanistan. METHODS: The study population included military personnel wounded in Afghanistan (2009-2014) medevac'd to Landstuhl Regional Medical Center and transitioned to participating military hospitals in the United States with clinical suspicion of wound infections and wound cultures collected ≤7 days post-injury. Analysis was limited to the first wound culture from individuals. Infecting isolates were collected from skin and soft-tissue infections, osteomyelitis, and burn soft-tissue infections. Data were analyzed by season (winter [ December 1-February 28/29], spring [March 1-May 31], summer [June 1-August 31], and fall [September 1-November 30]). RESULTS: Among 316 patients, 297 (94.0%) sustained blast injuries with a median injury severity score and days from injury to initial culture of 33 and 3.5, respectively. Although all patients had a clinical suspicion of a wound infection, a diagnosis was confirmed in 198 (63%) patients. Gram-negative bacilli (59.5% of 316) were more commonly isolated from wound cultures in summer (68.1%) and fall (67.1%) versus winter (43.9%) and spring (45.1%; P < .001). Multidrug-resistant (MDR) Gram-negative bacilli (21.8%) were more common in summer (21.8%) and fall (30.6%) versus winter (7.3%) and spring (19.7%; P = .028). Findings were similar for infecting Gram-negative bacilli (72.7% of 198)-summer (79.5%) and fall (83.6%; P = .001)-and infecting MDR Gram-negative bacilli (27.3% of 198)-summer (25.6%) and fall (41.8%; P = .015). Infecting anaerobes were more common in winter (40%) compared to fall (11%; P = .036). Gram-positive organisms were not significantly different by season. CONCLUSION: Gram-negative bacilli, including infecting MDR Gram-negative bacilli, were more commonly recovered in summer/fall months from service members injured in Afghanistan. This may have implications for empiric antibiotic coverage during these months.

High frequency and molecular characterization of ESBL-producing Enterobacteriaceae isolated from wound infections in North Lebanon.

BACKGROUND: Extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBL-PE) represent a major problem in wound infections. Here, we investigated the prevalence and molecular characterization of ESBL-PE associated with wound infections in North Lebanon. RESEARCH DESIGN AND METHODS: A total of 103 non-duplicated E. coli and K. pneumoniae strains isolated from 103 patients with wound infections, were collected from seven hospitals in North Lebanon. ESBL-producing isolates were detected using a double-disk synergy test. In addition, multiplex polymerase chain reaction (PCR) was used for the molecular detection of ESBLs genes. RESULTS: E. coli was the predominant bacteria (77.6%), followed by K. pneumoniae (22.3%). The overall prevalence of ESBL-PE was 49%, with a significantly higher rate among females and elderly patients. K. pneumoniae was the common MDR and ESBL-producer bacteria (86.95% and 52.17%) compared to E. coli (77.5% and 47.5%). Most of the isolated ESBL producers harbored multiple resistant genes (88%), where blaCTX-M was the most predominant gene (92%), followed by blaTEM (86%), blaSHV (64%), and blaOXA genes (28%). CONCLUSIONS: This is the first data on the ESBL-PE prevalence associated with wound infections in Lebanon, showing the emergence of multidrug-resistant ESBL-PE, the dominance of multiple gene producers, and the widespread dissemination of blaCTX-M and blaTEM genes.

Early wound excision within three days decreases risks of wound infection and death in burned patients.

INTRODUCTION: In lieu of limited studies on the timing of burn wound eschar excision for burns, a more comprehensive analysis is indicated to determine the effects of early wound excision following burns. This study aims to address the outcomes of early wound excision in burn patients. METHODS: Data collection were from TriNetX research database. Three groups of burn patients were stratified by the number of days in which they received burn wound excision within 14 days of injury. Five outcomes were observed: death, wound infection, sepsis, myocardial contractile dysfunction, and blood transfusion. Risk and incidence of various health outcomes were compared between the groups after propensity-matching age, sex, ethnicity, race and burn size using a z-test with p < 0.05 considered significant. RESULTS: We identified 6158 burn patients with wound excision within 14 days of injury, the majority of whom (60.1%) received burn wound excision between 0 and 3 days after burn. 72.5% of patients had burns covering less than 20% of total body surface area. After propensity matching, we found a significantly lower risk of mortality in those who received burn wound excision within the first three days (3.84%) as compared to 8-14 days after burn (6.09%) (p < 0.05). Moreover, we found a decreased risk of wound infection in patients with burn wound excision within 0-3 days (37.84%) compared to those 4-7 days (42.48%) (p < 0.05). No statistical difference was detected in propensity-matched groups for myocardial contractile dysfunction, blood transfusion, or sepsis. In addition, the risk of hypertrophic scaring significantly decreased when wound excision was performed within 0-3 days (22% within 0-3 days, 28% within 4-7 days, p < 0.05). CONCLUSION: Burn wound excision within 3 days of injury is beneficial when comparing to later treatment between 4 and 14 days, which results in a significantly lowered risk of mortality and infection in burn patient.

The Pathogen Isolates in Chronic Wound Infections in Poland.

Chronic wound infection is one of the factors that hinder or prevent its healing. The incidence of infection may vary depending on the type of wound. It is estimated that clinically significant infection in diabetic foot syndrome occurs in up to 30% of patients. Accurate diagnosis of infection features and proper microbiological tests are crucial for introducing of appropriate local and often systemic treatment. The aim of the study was a comparative analysis of the microbiota found in infected chronic wounds in patients from Poland, consulted on an outpatient basis at a wound care center in 2013-2021. The indication for microbiology culture tests was the detection of local signs of infection, and sampling was preceded by appropriate wound debridement. The standard culture technique was a deep-tissue biopsy. Material for the study was collected from 1,199 patients. Overall, 3,917 results of microbiological tests were subjected to retrospective analysis. The paper presents the results in the form of the number of cultured microorganisms and their relative incidence as percentages, considering the division into the types of wounds from which the material was obtained. The most frequently isolated microorganisms in the analyzed group were Staphylococcus aureus (14.3% of this group were MRSA - methicillin-resistant Staphylococcus aureus) and Enterococcus faecalis (2.4% of this group were VRE - vancomycin-resistant Enterococcus). Further analysis of such an extensive database, especially regarding drug susceptibility of isolated microorganisms, seems crucial to elaborate new recommendations for empirical antibacterial treatment of infected chronic wounds.

Research article network analysis of polymicrobial chronic wound infections in Masanga, Sierra Leone.

BACKGROUND: Chronic wounds are frequently colonized or infected with multiple bacterial or fungal species, which can both promote or inhibit each other. Network analyses are helpful to understand the interplay of these species in polymicrobial infections. Our aim was to analyse the network of bacterial and fungal species in chronic wounds. METHODS: Swabs (n = 163) from chronic wound infections (Masanga, Sierra Leone, 2019-2020) were screened for bacterial and fungal species using non-selective agars. Some of these wounds were suspected but not confirmed Buruli ulcer. Species identification was done with MALDI-TOF mass spectrometry. Network analysis was performed to investigate co-occurrence of different species within one patient. All species with n ≥ 10 isolates were taken into account. RESULTS: Of the 163 patients, 156 had a positive wound culture (median of three different species per patient; range 1-7). Pseudomonas aeruginosa (n = 75) was the dominating species with frequent co-detections of Klebsiella pneumoniae (21 cases; OR = 1.36, 95%CI: 0.63-2.96, p = 0.47), Staphylococcus aureus (14 cases; OR = 1.06, 95%CI: 0.44-2.55, p = 1) and Proteus mirabilis (13 cases; OR = 0.84, 95%CI: 0.35-1.99, p = 0.69). CONCLUSION: The culturome of chronic wounds in Sierra Leonean patients is highly diverse and characterized by the co-occurrence of P. aeruginosa, K. pneumoniae and S. aureus.

Changes in Burn Wound Microbiology Profile Over 14 Years of an Adult Tertiary Burn Center.

Burn wound colonization can progress to invasive infection. During 14 years of this study, the burn center was relocated to a center with improved infrastructure. This study investigates the association that infrastructure, geography, and time may have on colonization. Data were collected from October 2004 to August 2018, and relocation took place in June 2010, defining the two study periods. Admission swabs were within 48 hours. Unique isolates and resistance data were analyzed and compared statistically between the two study periods. In total, 2001 patients with 24,226 wound swabs were included. Median age was 45.4 (IQR 30.2-61.6), length of stay was 11 days (IQR 6-21), and %TBSA was 5.5 (IQR 2.5-11). Staph. aureus (33.7/100 patients) and Pseudomonas spp. (13.1/100 patients) were the most prevalent bacterial growths. After admission, the prevalence of methicillin resistant Staph. aureus, Coliform spp., and Aci. baumanni was greater in the first site, and Candida spp. colonization was higher in the second study period site. The prevalence of patients affected by multi-drug-resistant organisms was lower in the second study site (13.5/100 patients vs 16.6/100 patients; P < .05). There are differences in burn wound colonization across time, within the same region. Candida spp. growth has been shown to be increased over time and represents an added challenge. Awareness facilitates effective empirical antimicrobial therapies and protocols locally.

Diagnosis and treatment of infected wounds: A multi-centre audit of current clinical practice across the UK, Ireland and Scandinavia.

AIMS AND OBJECTIVES: Surveillance of wound infection including signs of infection alongside antimicrobial usage (types, duration, frequency) can highlight knowledge gaps and inconsistencies. This manuscript aims to highlight these, identify and inform opportunities for practice improvement and to show impact of infection management practice may be having on the issue of antimicrobial resistance. BACKGROUND: Infected wounds pose challenges to healthcare professionals. Balancing risk of wound deterioration and progression to systemic infection with appropriate use of antimicrobials is necessary to minimise development of resistance. METHODS: Analysis consisted of a practice survey of 9661 wounds across 70 community sites over a period of one week. Data were collected from projects between 2017 and 2020. The form was available to providers within the UK, Ireland, Norway, Denmark, Sweden and Finland. EQUATOR research guidelines were followed; STROBE checklist for observational research reporting was completed. RESULTS: Infection rates of 8.9% were reported from wounds assessed. These data indicate inconsistencies with diagnosis across practice with non-specialists more likely to be unsure of wound infection. Greater confidence in infection identification was observed as number of signs increased. Inconsistencies were also observed in appropriate treatment; antimicrobials were used in 35% of wounds considered not infected and not used in 41% of wounds that were identified as infected. CONCLUSIONS: This investigation of infection management practice of over 9000 wounds provides an insight into diagnosis and treatment of infection. Inconsistencies in diagnosis and treatment of wound infections reported highlight the need for increased education, awareness of diagnosis and treatment of infection. RELEVANCE TO CLINICAL PRACTICE: Variability in management of infected wounds highlights opportunities to aid more effective diagnosis and treatment of infected wounds. Incorporation of support tools or evidence-based pathways into practice may enhance confidence in management of local infection, balanced with appropriate use, potentially minimising resistance and improving outcomes.

Bacteriological profile of wound swab and their antibiogram pattern in a tertiary care hospital, Saudi Arabia.

OBJECTIVES: To assess the microbial profile of wound infection and their antibiogram pattern. METHODS: A retrospective study was carried out at King Abdulaziz University Hospital, Jeddah Saudi Arabia between December 2021 and July 2022 comprising data related to demographic, microbial profile and antibiotic sensitivity pattern of wound infection-suspected cases. RESULTS: A total of 305 wound swabs were collected; of which 56.1% showed microbial growth. Among 187 microbial isolates, 62% were gram-negative bacteria, 30.5% were gram-positive bacteria and 7.5% were fungi. Staphylococcus aureus was the prevailing isolates 17.1%, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa, each with 13.9% and Escherichia coli with 12.8 %. Providencia sp with 0.1% was the least isolated bacteria. Out of 173 bacterial isolates, 46.8% were sensitive to antimicrobial agents tested, while 53.2% were resistant to one and more drug tested. Of these isolates, 22% were found to be the MDR bacteria. The highest MDR percentages was noted among Acinetobacter baumannii (70%) followed by Klebsiella pneumoniae (53.9%), Escherichia coli (25%) and Pseudomonas aeruginosa (19.2%) and the least by (12.5%) by Staphylococcus aureus. CONCLUSION: The microbial isolation rates from wound infection was high, with Staphylococcus aureus being the most prevalent. Considerable antimicrobial resistance rate to the commonly used antibiotics was discovered. Thus, regular monitoring of microbial profile and their antimicrobial sensitivity pattern in the study region in attempt to contain antimicrobial resistance is highly recommended.

Fungal isolation from wound samples submitted for culture at a tertiary care hospital laboratory.

Fungal wound infections are increasing worldwide. The aim of this retrospective study, conducted at the Aga Khan University laboratory, Karachi, Pakistan, was to determine the frequency of fungal isolation in wound specimens. Data of wound samples received for culture from all over the country between September and October 2018 was reviewed. Samples were processed for bacterial cultures and additionally inoculated on Sabouraud's dextrose medium. Demographic information, medical history and information on the type of wound was collected. A total of 140 cases were included, of which 87 (81%) were culture positive, while 10 (7%) cases yielded fungi. Burn and blast wounds had the highest proportion of fungal isolation, i.e. 2 out of 4 (50%). Candida species were the most common fungi (n=4), followed by Fusarium species (n=3). This study reports an alarming rate of fungal wound infections. As fungal necrotising wound infections have high morbidity and mortality, it is, therefore, important to accurately diagnose and treat such infections in local setting.

Bite wounds to the hand - a review.

Bite wounds occur as a result of bite by an animal or a human. They are relatively frequent due to the growing number of pets living with people, as well as from inadequate human-animal interactions. The knowledge of most surgeons about the management of these injuries is relatively outdated, whereas the current literature points to important changes in this field. The article presents several aspects concerning epidemiology, classification, bacteriology, and characteristics of bite wounds to the hand. Based on the actual literature, detailed rules for the management of these injuries are described. This information may prove useful in the daily practice of surgeons and doctors at emergency departments who are frequently faced with bite wounds.

Virulence genes distributed among Staphylococcus aureus causing wound infections and their correlation to antibiotic resistance.

BACKGROUND: Staphylococcus aureus causes many human infections, including wound infections, and its pathogenicity is mainly influenced by several virulence factors. AIM: This study aimed to detect virulence genes (hla, sea, icaA, and fnbA) in S. aureus isolated from different wound infections among Egyptian patients admitted to Minia University Hospital. This study also aimed to investigate the prevalence of these genes in methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA), and vancomycin-resistant S. aureus isolates and the resistance and sensitivity to different antibiotic classes. METHODS: A cross-sectional study was carried out from November 2019 to September 2021. Standard biochemical and microbiological tests revealed 59 S. aureus isolates. The Kirby-Bauer disc diffusion method was used to determine antibiotic susceptibility. DNA was extracted using a DNA extraction kit, and polymerase chain reaction was used to amplify all genes. RESULTS: A total of 59 S. aureus isolates were detected from 51 wound samples. MRSA isolates accounted for 91.5%, whereas MSSA isolates accounted for 8.5%. The multidrug resistance (MDR) percentage in S. aureus isolates was 54.2%. S. aureus showed high sensitivity pattern against vancomycin, linezolid, and chloramphenicol. However, a high resistance pattern was observed against oxacillin and piperacillin. sea was the most predominant gene (72.9%), followed by icaA (49.2%), hla (37.3%), and fnbA (13.6%). sea was the commonest virulence gene among MRSA isolates (72.2%), and a significant difference in the distribution of icaA was found. However, sea and icaA were the commonest genes among MSSA isolates (79.9%). The highest distribution of sea was found among ciprofloxacin-resistant isolates (95.2%). CONCLUSION: The incidence of infections caused by MDR S. aureus significantly increased with MRSA prevalence. sea is the most predominant virulence factor among antibiotic-resistant strains with a significant correlation to piperacillin, gentamicin, and levofloxacin.

IDCRP Combat-Related Extremity Wound Infection Research.

INTRODUCTION: Extremity trauma is the most common battlefield injury, resulting in a high frequency of combat-related extremity wound infections (CEWIs). As these infections are associated with substantial morbidity and may impact wounded warriors long after initial hospitalization, CEWIs have been a focus of the Infectious Disease Clinical Research Program (IDCRP). Herein, we review findings of CEWI research conducted through the IDCRP and discuss future and ongoing analyses. METHODS: Military personnel with deployment-related trauma sustained between 2009 and 2014 were examined in retrospective analyses through the observational Trauma Infectious Disease Outcomes Study (TIDOS). Characteristics of wounded warriors with ≥1 open extremity wound were assessed, focusing on injury patterns and infection risk factors. Through a separate trauma-associated osteomyelitis study, military personnel with combat-related open fractures of the long bones (tibia, femur, and upper extremity) sustained between 2003 and 2009 were examined to identify osteomyelitis risk factors. RESULTS: Among 1,271 wounded warriors with ≥1 open extremity wound, 16% were diagnosed with a CEWI. When assessed by their most severe extremity injury (i.e., amputation, open fracture, or open soft-tissue wound), patients with amputations had the highest proportion of infections (47% of 212 patients with traumatic amputations). Factors related to injury pattern, mechanism, and severity were independent predictors of CEWIs during initial hospitalization. Having a non-extremity infection at least 4 days before CEWI diagnosis was associated with reduced likelihood of CEWI development. After hospital discharge, 28% of patients with extremity trauma had a new or recurrent CEWI during follow-up. Risk factors for the development of CEWIs during follow-up included injury pattern, having either a CEWI or other infection during initial hospitalization, and receipt of antipseudomonal penicillin for ≥7 days. A reduced likelihood for CEWIs during follow-up was associated with a hospitalization duration of 15-30 days. Under the retrospective osteomyelitis risk factor analysis, patients developing osteomyelitis had higher open fracture severity based on Gustilo-Anderson (GA) and the Orthopaedic Trauma Association classification schemes and more frequent traumatic amputations compared to open fracture patients without osteomyelitis. Recurrence of osteomyelitis was also common (28% of patients with open tibia fractures had a recurrent episode). Although osteomyelitis risk factors differed between the tibia, femur, and upper extremity groups, sustaining an amputation, use of antibiotic beads, and being injured in the earlier years of the study (before significant practice pattern changes) were consistent predictors. Other risk factors included GA fracture severity ≥IIIb, blast injuries, foreign body at fracture site (with/without orthopedic implant), moderate/severe muscle damage and/or necrosis, and moderate/severe skin/soft-tissue damage. For upper extremity open fractures, initial stabilization following evacuation from the combat zone was associated with a reduced likelihood of osteomyelitis. CONCLUSIONS: Forthcoming studies will examine the effectiveness of common antibiotic regimens for managing extremity deep soft-tissue infections to improve clinical outcomes of combat casualties and support development of clinical practice guidelines for CEWI treatment. The long-term impact of extremity trauma and resultant infections will be further investigated through both Department of Defense and Veterans Affairs follow-up, as well as examination of the impact on comorbidities and mental health/social factors.

Combat-Related Invasive Fungal Wound Infections.

INTRODUCTION: During Operation Enduring Freedom in Afghanistan, an outbreak of combat-related invasive fungal wound infections (IFIs) emerged among casualties with dismounted blast trauma and became a priority issue for the Military Health System. METHODS: In 2011, the Trauma Infectious Disease Outcomes Study (TIDOS) team led the Department of Defense IFI outbreak investigation to describe characteristics of IFIs among combat casualties and provide recommendations related to management of the disease. To support the outbreak investigation, existing IFI definitions and classifications utilized for immunocompromised patients were modified for use in epidemiologic research in a trauma population. Following the conclusion of the outbreak investigation, multiple retrospective analyses using a population of 77 IFI patients (injured during June 2009 to August 2011) were conducted to evaluate IFI epidemiology, wound microbiology, and diagnostics to support refinement of Joint Trauma System (JTS) clinical practice guidelines. Following cessation of combat operations in Afghanistan, the TIDOS database was comprehensively reviewed to identify patients with laboratory evidence of a fungal infection and refine the IFI classification scheme to incorporate timing of laboratory fungal evidence and include categories that denote a high or low level of suspicion for IFI. The refined IFI classification scheme was utilized in a large-scale epidemiologic assessment of casualties injured over a 5.5-year period. RESULTS: Among 720 combat casualties admitted to participating hospitals (2009-2014) who had histopathology and/or wound cultures collected, 94 (13%) met criteria for an IFI and 61 (8%) were classified as high suspicion of IFI. Risk factors for development of combat-related IFIs include sustaining a dismounted blast injury, experiencing a traumatic transfemoral amputation, and requiring resuscitation with large-volume (>20 units) blood transfusions. Moreover, TIDOS analyses demonstrated the adverse impact of IFIs on wound healing, particularly with order Mucorales. A polymerase chain reaction (PCR)-based assay to identify filamentous fungi and support earlier IFI diagnosis was also assessed using archived formalin-fixed, paraffin-embedded tissue specimens. Although the PCR-based assay had high specificity (99%), there was low sensitivity (63%); however, sensitivity improved to 83% in tissues collected from sites with angioinvasion. Data obtained from the initial IFI outbreak investigation (37 IFI patients) and subsequent TIDOS analyses (77 IFI patients) supported development and refinement of a JTS clinical practice guideline for the management of IFIs in war wounds. Furthermore, a local clinical practice guideline to screen for early tissue-based evidence of IFIs among blast casualties at the Landstuhl Regional Medical Center was critically evaluated through a TIDOS investigation, providing additional clinical practice support. Through a collaboration with the Uniformed Services University Surgical Critical Care Initiative, findings from TIDOS analyses were used to support development of a clinical decision support tool to facilitate early risk stratification. CONCLUSIONS: Combat-related IFIs are a highly morbid complication following severe blast trauma and remain a threat for future modern warfare. Our findings have supported JTS clinical recommendations, refined IFI classification, and confirmed the utility of PCR-based assays as a complement to histopathology and/or culture to promote early diagnosis. Analyses underway or planned will add to the knowledge base of IFI epidemiology, diagnostics, prevention, and management.

TLC-Ag dressings: a prospective, multicentre study on 728 patients with wounds at risk of or with local infection.

OBJECTIVE: This study aimed to evaluate the management of an unselected cohort of patients with wounds at risk of or with clinical signs of local infection, treated with two antimicrobial contact layers impregnated with silver (TLC-Ag healing matrix), under real-life conditions during the COVID-19 pandemic. METHOD: A large, prospective, multicentre, observational study with two TLC-Ag dressings (UrgoTul Ag/Silver and UrgoTul Ag Lite Border, Laboratoires Urgo, France) was conducted in Germany between May 2020 and May 2021. The main outcomes included a description of the treated patients and their wound management, the changes in wound infection and wound healing outcomes over a maximum period of four weeks of treatment, as well as the overall clinical assessment of the performance, local tolerance and acceptability of dressings. RESULTS: A total of 728 patients with wounds of various aetiologies and wound infection status were treated with the evaluated dressings in 39 centres for a mean duration of 26±19 days, with an intermediate visit conducted in 712 (97.8%) patients after a mean period of 12±9 days. At the initial visit, it was established that the majority of patients (60.4%) had a wound infection, while the remaining cohort presented first clinical signs of a local wound infection (25.1%) or were at risk of wound infection (13.2%) (unclear status in 1.2%). Throughout the study period, all the parameters of wound infection continuously decreased, resulting at the final visit in a reduction by 78.9% of the prevalence of local wound infections and by 72.0% of the clinical signs of wound infection, the most rapidly diminished clinical sign being wound deterioration. Concurrently, in terms of the healing process, 92.1% of the wounds healed or improved, 3.2% remained unchanged and 1.7% worsened (data missing for 3.0%), and an improvement of the periwound skin was reported in 65.7% of the patients. Overall, the two dressings were 'very well accepted' by the majority of patients, with no uncomfortable feeling at wearing and no pain at dressing removal, and were assessed by the physicians as 'very useful' in the majority of the cases with a 'very good' efficacy in terms of antimicrobial activity and promotion of the wound healing process. Similar results were reported regardless of the wound type treated or of the TLC-Ag dressing evaluated. CONCLUSION: These results are consistent with previous clinical evidence on TLC-Ag dressings. They support the good efficacy, good tolerability and usefulness of these antimicrobial dressings in the management of patients with wounds at risk or with clinical signs of local infection, in association with appropriate standard of care.

Animal bite wounds and their management in tropical Australia.

OBJECTIVE: To define the microbiologic characteristics of animal bites in tropical Australia and the appropriateness of current Australian antimicrobial guidelines for their management. METHODS: This retrospective audit examined hospitalizations in tropical Australia after an animal bite or animal-associated penetrating injury between 2013 and 2020. The primary outcome was a composite of death, intensive care unit admission, amputation, quaternary center transfer, or unplanned rehospitalization. RESULTS: A wide variety of animals were implicated, but snakes (734/1745, 42%), dogs (508/1745, 29%), and cats (153/1745, 9%) were the most common. Hospital presentation after 24 hours (odds ratio (OR) (95% confidence interval (CI)): 68.67 (42.10-112.01)) and a cat-related injury (OR (95% CI): 22.20 (11.18-44.08)) were independently associated with an increased risk of infection. A pathogen not covered by the relevant antimicrobial regimen recommended in Australian guidelines was identified in only 12/1745 (0.7%) cases. The primary outcome occurred in 107/1745 (6%) and was independently associated with tissue trauma (OR (95% CI): 9.29 (6.05-14.25), p<0.001), established deep infection at presentation (OR (95% CI): 2.95 (1.31-6.61), p=0.009) and hospital presentation after 24 hours (OR (95% CI): 1.77 (1.12-2.79), p=0.01). CONCLUSIONS: A wide variety of animals bite humans in tropical Australia, but empiric antimicrobial regimens recommended in current national guidelines cover almost all the microbiologic isolates from the resulting wounds.

Chronic wound isolates and their minimum inhibitory concentrations against third generation cephalosporins at a tertiary hospital in Uganda.

Globally, the burden of chronic wound infections is likely to increase due to the rising levels of bacterial resistance to antibiotics. In the United States of America alone, more than 6.5 million chronic wounds with evidence of bacterial infection are diagnosed every year. In addition, the polymicrobial environment in chronic wound infections has been observed from several studies as a risk factor for development of resistance to many antibiotics including the third generation cephalosporins currently used in Mbarara Regional Referral Hospital for treatment of chronic wound infections. Therefore the main objective of this study was to determine the prevalence of chronic wound isolates and their minimum inhibitory concentrations (MIC) against third generation cephalosporins. This study was a cross-sectional descriptive and analytical survey of bacterial isolates from chronic wound infection among 75 study participants admitted in the surgical ward of Mbarara Regional Referral Hospital (MRRH), a tertiary Hospital in Western Uganda. Standard laboratory bacterial culture and identification techniques as well as broth microdilution method were used to isolate, identify pathogens and test for MIC respectively. We found that 69/75 study participants had samples with bacterial growth and the most prevalent pathogens isolated were staphylococcus aureus (40.6%) and Klebsiella spp. (29%). Generally, most isolates were susceptible to cefoperazone + sulbactum 2 g (Sulcef) and ceftriaxone 1 g (Epicephin). The overall prevalence of isolates in chronic wound infection among patients admitted in the surgical ward of MRRH was 92% and the most prevalent isolates were Staphylococcus aureus, Klebsiella species and proteus species respectively. The observed MIC values were higher than the CLSI clinical breakpoint, implying a decreasing trend in susceptibility of chronic wound isolates to third generation cephalosporins.