Bloodstream infections and multidrug resistant bacteria acquisition among burns patients in Australia and New Zealand: A registry-based study.

INTRODUCTION: This study interrogates infection related data in the Burns Registry of Australia and New Zealand (BRANZ), to examine associations of multi-drug resistant organisms (MDROs) and blood stream infection (BSI). METHODS: Data between July 2016 and June 2021 were analysed to determine prevalence, risk factors and outcomes associated with BSIs and MDROs: Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Pseudomonas spp. (CRP), and carbapenem-resistant Enterobacter (CRE). Data completeness and value for quality improvement activity were assessed. RESULTS: We found a low incidence (3.4%) of the resistant organisms of interest, and no change over the study period. Fequency varied between services and increased with age and size of burn. MRSA was the commonest organism in all age groups. A positive BSI result occurred in 1.6% of patients (12.1% of cultures taken) at a median time of 10.2 days post injury. Free text identification of organisms was inconsistently documented. CONCLUSIONS: The low rate and patterns of acquisition of MDROs of interest and BSIs is comparable with reports from countries with low incidence of massive burns. Wider adoption of a standardized laboratory reporting framework would help realise the potential of clinical quality registries to provide data which supports evidence based infection prevention initiatives.

Surviving Sepsis After Burn Campaign.

INTRODUCTION: The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes. METHODS: The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported. RESULTS: The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis. CONCLUSION: Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

Patterns of multidrug resistant organism acquisition in an adult specialist burns service: a retrospective review.

BACKGROUND: Multidrug resistant organisms (MDROs) occur more commonly in burns patients than in other hospital patients and are an increasingly frequent cause of burn-related mortality. We examined the incidence, trends and risk factors for MDRO acquisition in a specialist burns service housed in an open general surgical ward, and general intensive care unit. METHODS: We performed a retrospective study of adult patients admitted with an acute burn injury to our specialist statewide tertiary burns service between July 2014 and October 2020. We linked patient demographics, injury, treatment, and outcome details from our prospective burns service registry to microbiology and antimicrobial prescribing data. The outcome of interest was first MDRO detection, stratified into the following groups of interest: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), two groups of Pseudomonas (carbapenem resistant, and piperacillin-tazobactam or cefepime resistant), carbapenem-resistant Acinetobacter species, Stenotrophomonas maltophilia, carbapenem-resistant Enterobacteriaceae (CRE), and extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE). We used a Cox proportional hazards model to evaluate the association between antibiotic exposure and MDRO acquisition. RESULTS: There were 2,036 acute admissions, of which 230 (11.3%) had at least one MDRO isolated from clinical specimens, most frequently wound swabs. While acquisition rates of individual MDRO groups varied over the study period, acquisition rate of any MDRO was reasonably stable over time. Carbapenem-resistant Pseudomonas was acquired at the highest rate over the study period (3.5/1000 patient days). The 12.8% (29/226) of MDROs isolated within 48 h were predominantly MRSA and Stenotrophomonas. Median (IQR) time from admission to MDRO detection was 10.9 (5.6-20.5) days, ranging from 9.8 (2.7-24.2) for MRSA to 23.6 (15.7-36.0) for carbapenem-resistant P. aeruginosa. Patients with MDROs were older, had more extensive burns, longer length of stay, and were more likely to have operative burn management. We were unable to detect a relationship between antibiotic exposure and emergence of MDROs. CONCLUSIONS: MDROs are a common and consistent presence in our burns unit. The pattern of acquisition suggests various causes, including introduction from the community and nosocomial spread. More regular surveillance of incidence and targeted interventions may decrease their prevalence, and limit the development of invasive infection.

Extremely prolonged HIV seroconversion associated with an MHC haplotype carrying disease susceptibility genes for antibody deficiency disorders.

Severe immunodeficiency during primary human immunodeficiency virus (HIV) infection is unusual. Here, we characterized viral and immunological parameters in a subject presenting with Pneumocystis jirovecii pneumonia in the setting of prolonged primary HIV illness and delayed seroconversion. HIV antibody was only detected by enzyme-linked immunosorbent assay 12 months after presentation, and Western blot profiles remain indeterminate. Isolated virus was of R5 phenotype, exhibited poor viral fitness, but was otherwise unremarkable. Analysis of HIV antibody isotypes showed failure to mount a detectable HIV IgG response over nearly 2 years of infection, in particular IgG(1)- and IgG(3)-specific responses, despite normal responses to common infections and vaccines. Genetic analysis demonstrated homozygosity for part of an MHC haplotype containing susceptibility genes for common variable immunodeficiency (CVID) syndrome and other antibody deficiency disorders. Thus, a primary disorder of specific antibody production may explain exceptionally slow antibody development in an otherwise severe seroconversion illness. This highlights the need for multiparameter testing, in particular use of a fourth generation HIV test, for confirming HIV infection and underscores the importance of host factors in HIV pathogenesis.

Review of epiglottitis in the post Haemophilus influenzae type-b vaccine era.

BACKGROUND: This study reviewed the demographics, presentation, management, complications and outcomes of acute epiglottitis post Haemophilus influenzae type-b vaccine introduction in Australia. METHODS: Retrospective review of acute epiglottitis at four Victorian tertiary centres from 2011 to 2016 was conducted. Patient characteristics, presentation, investigations, management, complications and outcomes were recorded. Subgroup analysis aiming to identify risk factors for patients requiring acute airway management was performed. RESULTS: Eighty-seven adult and six paediatric cases were identified. The most frequent clinical findings in adults were sore throat (88.5%), dysphagia (71.3%), odynophagia (57.5%), dysphonia (56.3%) and fever (55.2%); 75.9% required intensive care unit admission. Airway compromise requiring intubation occurred in 27.6%, with 12.5% of these patients undergoing emergency surgical airways. Stridor, hypoxia, shortness of breath, odynophagia and lymphadenopathy were statistically more frequent amongst cases requiring airway intervention (P < 0.05). Cultures revealed mixed results with no aetiological pattern. H. influenzae type-b was never cultured. Amongst paediatric cases, fever, tachycardia and stridor were frequently observed and all were admitted to intensive care unit. Two of six required intubation and one underwent surgical intervention. There were no deaths, but one patient suffered a hypoxic brain injury. CONCLUSION: Modern epiglottitis is not the disease previously encountered by clinicians. With changing demographics and varying organisms, management is adapting to reflect this. Complications are rare, and symptomatology at presentation aids earlier recognition of patients who may require airway protection.

Evolution of carbapenem resistance in Acinetobacter baumannii during a prolonged infection.

Acinetobacter baumannii is a common causative agent of hospital-acquired infections and a leading cause of infection in burns patients. Carbapenem-resistant A. baumannii is considered a major public-health threat and has been identified by the World Health Organization as the top priority organism requiring new antimicrobials. The most common mechanism for carbapenem resistance in A. baumannii is via horizontal acquisition of carbapenemase genes. In this study, we sampled 20 A. baumannii isolates from a patient with extensive burns, and characterized the evolution of carbapenem resistance over a 45 day period via Illumina and Oxford Nanopore sequencing. All isolates were multidrug resistant, carrying two genomic islands that harboured several antibiotic-resistance genes. Most isolates were genetically identical and represented a single founder genotype. We identified three novel non-synonymous substitutions associated with meropenem resistance: F136L and G288S in AdeB (part of the AdeABC efflux pump) associated with an increase in meropenem MIC to ≥8 µg ml-1; and A515V in FtsI (PBP3, a penicillin-binding protein) associated with a further increase in MIC to 32 µg ml-1. Structural modelling of AdeB and FtsI showed that these mutations affected their drug-binding sites and revealed mechanisms for meropenem resistance. Notably, one of the adeB mutations arose prior to meropenem therapy but following ciprofloxacin therapy, suggesting exposure to one drug whose resistance is mediated by the efflux pump can induce collateral resistance to other drugs to which the bacterium has not yet been exposed.

Early pathogenic colonisers of acute burn wounds: A retrospective review.

BACKGROUND: Early excision of burns reduces the incidence of local and systemic infections caused by colonising microorganisms, and reduces mortality and length of hospital stay. Appropriate antibiotic prophylaxis can reduce the risk of postoperative wound infections and skin graft loss. Antibiotic selection should be based on likely pathogens. However, there are few studies that have investigated the early pathogenic colonisers of acute burn wounds. AIM: To describe pathogenic microorganisms found in acute burns and to make further recommendations on the use of early perioperative prophylactic antibiotics. METHODS: All burns patients admitted at the tertiary adult burns centre in Victoria over a 2-year period, who had surface swabs or tissue samples obtained from wounds within 24h of injury were included in this retrospective cohort study. Pathogenic organisms were examined with respect to patient characteristics, burn characteristics, treatment provided and immediate exposure to environmental contaminants. RESULTS: Nearly one third of burns patients had wounds colonised with pathogenic microorganisms. Gram-negative bacteria were isolated from 52% of these. Staphylococcus aureus was the most common isolate. Pseudomonas and Enterobacter species were the most common gram-negatives. The only independent risk factor associated with early colonisation with gram-negative bacteria was per cent TBSA burn. CONCLUSION: Increased colonisation of acute burn wounds with pathogenic gram-negative bacteria was associated with increased size of burn.

A Comparative Analysis Between Antibiotic- and Nonantibiotic-Associated Delayed Cutaneous Adverse Drug Reactions.

BACKGROUND: The difference in clinical presentation, causality assessments, and outcomes of patients with delayed antibiotic-associated cutaneous adverse drug reactions (AA-cADR) and nonantibiotic-associated (NA)-cADR is ill defined. OBJECTIVE: We examined the etiology of AA-cADR, with regard to the type of antibiotic exposure, allergy labeling, and patient outcomes, in comparison with NA-cADR. METHODS: A retrospective observational inpatient cohort study of cADR was performed from January 2004 to August 2014. Patients were divided into AA-cADR and NA-cADR groups for analysis. cADR was defined as erythema multiforme, fixed drug eruption, acute generalized erythematous pustulosis, drug reaction with eosinophilia and systemic symptoms (DRESS), drug-associated linear IgA disease, Stevens-Johnson syndrome, and toxic epidermal necrolysis. RESULTS: Of the 84 patients with cADR, 48% were AA-cADR. Male sex (60% vs 32%, P = .004), median length of stay (14.5 vs 11 days, P = .05), median Charlson comorbidity index (3 vs 1, P = .03), and inpatient mortality (20% vs 5%, P = .04) were higher in AA-cADR compared with NA-cADR. The median drug latency was lower in AA-cADR (6 vs 20 days, P = .001). Sulfonamide antibiotics and glycopeptides were implicated in 20% of AA-cADR. DRESS was more frequently reported in AA-cADR. After cADR diagnosis, further antibiotic therapy was administered in 64% of patients, higher in AA-cADR (75%, 30 of 40) compared with NA-cADR (55%, 24 of 44) (P = .06). Fluoroquinolones (53% vs 21%, P = .02), glycopeptides (vancomycin and teicoplanin; 70% vs 38%, P = .05), and carbapenems (33% vs 13%, P = .11) were used more commonly in AA-cADR. CONCLUSIONS: Antibiotics were the cause of cADR requiring hospital admission in 48% of episodes, and were associated with longer length of stay, higher age-adjusted Charlson comorbidity index, shorter drug latency, and mortality. In AA-cADR, glycopeptide and sulfonamide antibiotic exposure predominated.

Low risk of Japanese encephalitis in short-term Australian travelers to Asia.

The risk of Japanese encephalitis (JE) in travelers is unknown. In this prospective study, we investigated the incidence of JE in 387 short-term Australian travelers visiting Asia over a 32-month period from August 2007 to February 2010 by performing pre- and post-travel antibody testing. No travelers were infected with JE virus during travel, indicating a low risk of infection for short-term travelers.

Incidence and risk factors for acute respiratory illnesses and influenza virus infections in Australian travellers to Asia.

BACKGROUND: Respiratory infections including influenza are a common cause of acute short-term morbidity in travellers and yet the risk of these infections is poorly defined. OBJECTIVES: To estimate the incidence density of and risk factors for acute respiratory infections (ARIs) and influenza in Australian travellers to Asia. STUDY DESIGN: Travel-clinic attendees were prospectively identified and completed questionnaires (demographic data, travel itinerary, health and vaccination history) and also provided pre and post-travel serological samples for Influenza A and B (complement fixation test). Returned travellers with an ARI provided nasopharyngeal specimens for RT-PCR identification of respiratory viruses. RESULTS: In this cohort (n = 387) of predominantly (72%) short-term travellers, 58% were female, the median age was 37 years and 69% were tourists. ARIs occurred in 109 travellers (28%) translating to an incidence of 106.4 ARIs per 10,000 traveller days (95% confidence interval CI 88.6-126.7). The traveller type of missionary or aid worker was a risk factor for acquiring an ARI (p = 0.03) and ARIs occurred early (< 30 days) in the travel period (p = 0.001). Four travellers (1%) acquired influenza A during travel translating to an incidence density of 3.4 infections per 10,000 days of travel (95% CI 1.4-8.6). Influenza vaccination was reported in 49% of travellers with a 3.5-fold higher incidence of influenza in unvaccinated travellers compared to vaccinated travellers (p = 0.883). CONCLUSIONS: This is one of the largest prospective studies estimating the incidence of respiratory infections in travellers. These findings have important implications for practitioners advising prospective travellers and for public health authorities.