Maritime Applications of Prolonged Casualty Care Sepsis on a Destroyer During Distributed Maritime Operations.

During distributed maritime operations, individual components of the naval force are more geographically dispersed. As the U.S. Navy further develops this concept, smaller vessels may be operating at a significant time and distance away from more advanced medical capabilities. Therefore, during both current and future contested Distributed Maritime Operations, Role 1 maritime caregivers such as Independent Duty Corpsman will have to manage patients for prolonged periods of time. This manuscript presents an innovative approach to teaching complex operational medicine concepts (including Prolonged Casualty Care [PCC]) to austere Role 1 maritime caregivers using a hypothetical scenario involving a patient with sepsis and septic shock. The scenario incorporates the Joint Trauma System PCC Clinical Practice Guidelines (CPG) and other standard references. The scenario includes a stem clinical vignette, expected clinical changes for the affected patient at specific time points (e.g., time 0, 1, 2, and 48h), and expected interventions based on the PCC CPG and available shipboard equipment. Epidemiology of sepsis in the deployed environment is also reviewed. This process also identifies opportunities to improve training, clinical skills sustainment, and standard shipboard medical supplies.

Maritime Applications of Prolonged Casualty Care: A Series Introduction.

The current United States Navy and North Atlantic Treaty Organization (NATO) maritime strategy is coalescing around the concept of Distributed Maritime Operations (DMOs) to prepare for future large-scale combat operations with peer or near-peer competitors. As a result, individual components of naval forces will be more geographically dispersed and oper- ating at a significant time and distance from higher levels of medical care. We developed a series of educational scenarios informed by real-world events to enhance the ability of Role 1 medical caregivers to apply the principles of Prolonged Ca- sualty Care during current routine, crisis, and contingency DMOs.

Subarachnoid hemorrhage diagnosed by lumbar puncture after negative computed tomography angiography head.

Acute headache is a common emergency department (ED) chief complaint that usually has a benign course. Rare etiologies such as subarachnoid hemorrhage (SAH) can lead to extensive disability or even death. If suspected, SAH requires an intricate and intensive diagnostic investigation. Classic teaching recommends computed tomography head imaging without contrast which, if negative, is followed by lumbar puncture (LP) to rule out SAH. With improvements in computed tomography (CT), practice patterns have begun to adjust to allow computed tomography angiography (CTA) to rule out SAH. This case report describes a 23-year-old woman presenting with headache, neck, and back pain. Her initial CT head and CTA head imaging was negative for SAH. However, 3 days later upon re-presentation to the ED with the same symptoms, an LP was positive for increasing red blood cell count in subsequent tubes. She was transferred to a facility with interventional neurology capabilities where digital subtraction angiography showed a left anterior choroidal saccular aneurysm for which she underwent coiling. Given recent changes in SAH clinical practice guidelines, this case highlights the importance of understanding the current limitations of CT imaging, understanding the risks and benefits of both CT and LP, and always maintaining a high suspicion for especially lethal and disabling conditions such as SAH.

Diurnal Flight Activity of House Flies (Musca domestica) is Influenced by Sex, Time of Day, and Environmental Conditions.

House flies (Musca domestica L.) are common synanthropic pests associated with confined animal operations, including dairy farms. House flies can cause substantial nuisance and may transmit human and animal pathogens. Surprisingly little is known about the daily flight activity of house flies. This study examined diurnal house fly flight activity on two southern California dairies using clear sticky traps to capture flies over hourly intervals. Flight activity for both males and females combined started near dawn and generally increased to a single broad activity peak during mid to late morning. Male flight activity peaked earlier than female flight activity and this separation in peak activity widened as mean daytime temperature increased. Flight activity for both sexes increased rapidly during early morning in response to the combined effects of increasing light intensity and temperature, with decreasing flight activity late in the day as temperature decreased. During midday, flight activity was slightly negatively associated with light intensity and temperature. Collection period (time of day) was a useful predictor of house fly activity on southern California dairies and the diurnal pattern of flight activity should be considered when developing house fly monitoring and control programs.

Mortality Rate of House Flies (Diptera: Muscidae) Exposed to Insecticidal Granular Fly Baits Containing Indoxacarb, Dinotefuran, or Cyantraniliprole.

The mortality rate of a field population of house fly (Musca domestica L.) was determined for a granular fly bait containing the active ingredient indoxacarb, which was compared to two commercially available granular fly baits containing either dinotefuran or cyantraniliprole. Indoxacarb was applied at three different application rates 0.498, 0.986, and 1.972 g/m2 (low, medium, and high). Time to 50% mortality was fastest for dinotefuran (5.7 h) and slowest for the low application rate of indoxacarb (10.3 h). Time to 90% mortality was fastest for the high application rate of indoxacarb (27.7 h) and slowest for dinotefuran (51.0 h) and cyantraniliprole (45.9 h). Among the three indoxacarb application rates, the high rate reached both 50 and 90% fly mortality significantly faster than the low rate. The medium rate did not significantly differ from either the high or low application rates. Dinotefuran bait produced greater fly mortality than all other treatments at 30-min post-exposure, with mortality for remaining baits exceeding controls by 3- to 6-h post-exposure. All insecticidal baits produced similar fly mortality by 6-h post-exposure and >94% fly mortality by 96-h post-exposure, indicating that each may be effective in a fly management program. Flies consumed a similar amount of the indoxacarb (regardless of application rate) and dinotefuran baits, but consumed less of the cyantraniliprole bait, suggesting a feeding irritancy or toxicity effect manifested during consumption. Nevertheless, flies consumed enough cyantraniliprole bait to cause mortality similar to other baits by 6-h post-exposure.

Pathogen acquisition in patients with cystic fibrosis receiving ivacaftor or lumacaftor/ivacaftor.

BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) modulators ivacaftor and lumacaftor/ivacaftor improve the status of existing infections in patients with cystic fibrosis (CF). It is unknown how well these drugs protect patients against incident infections. We hypothesized that CFTR modulator treatment would decrease new infections with Pseudomonas aeruginosa or Staphylococcus aureus. METHODS: We retrospectively studied a single-center cohort of patients with CF during two time periods (2008-2011, Era 1) and (2012-2015, Era 2) based on the January 2012 approval of ivacaftor. Using Kaplan-Meier analysis, we compared the time to any new infection with P. aeruginosa, methicillin-resistant S. aureus (MRSA), or methicillin-sensitive S. aureus (MSSA) that was absent during a 2-year baseline. We stratified the analysis based on whether patients received ivacaftor or lumacaftor/ivacaftor during Era 2. We used the log-rank test and considered P < 0.05 statistically significant. RESULTS: For patients receiving ivacaftor or lumacaftor/ivacaftor in Era 2, there was a statistically significant delay in the time to new bacterial acquisition in Era 2 vs. Era 1 ( P = 0.008). For patients who did not receive CFTR modulators, there was a trend toward slower acquisition of new bacterial infections in Era 2 compared to Era 1, but this was not statistically significant ( P = 0.10). CONCLUSIONS: Patients receiving ivacaftor or lumacaftor/ivacaftor for CF had significantly delayed acquisition of P. aeruginosa and S. aureus after these drugs were released. This method for analyzing incident infections may be useful for future studies of CFTR modulators and bacterial acquisition in CF registry cohorts.

Investigating the impact of clinical anaesthetic practice on bacterial contamination of intravenous fluids and drugs.

Syringes (N = 426), ventilator machine swabs (N = 202) and intravenous (IV) fluid administration sets (N = 47) from 101 surgical cases were evaluated for bacterial contamination. Cultures from the external surface of syringe tips and syringe contents were positive in 46% and 15% of cases, respectively. The same bacterial species was cultured from both ventilator and syringe in 13% of cases, and was also detected in the IV fluid administration set in two cases. A significant association was found between emergency cases and contaminated syringes (odds ratio 4.5, 95% confidence interval 1.37-14.8; P = 0.01). Other risk factors included not using gloves and failure to cap syringes.

Epidemiological investigation of Pseudomonas aeruginosa isolates from a six-year-long hospital outbreak using high-throughput whole genome sequencing.

Although previous bacterial typing methods have been informative about potential relatedness of isolates collected during outbreaks, next-generation sequencing has emerged as a powerful tool to not only look at similarity between isolates, but also put differences into biological context. In this study, we have investigated the whole genome sequence of five Pseudomonas aeruginosa isolates collected during a persistent six-year outbreak at Nottingham University Hospitals National Health Service (NHS) Trust ­ City Campus, United Kingdom. Sequencing, using both Roche 454 and Illumina, reveals that most of these isolates are closely related. Some regions of difference are noted between this cluster of isolates and previously published genome sequences. These include regions containing prophages and prophage remnants such as the serotype-converting bacteriophage D3 and the cytotoxin-converting phage phi CTX. Additionally, single nucleotide polymorphisms (SNPs) between the genomic sequence data reveal key single base differences that have accumulated during the course of this outbreak, giving insight into the evolution of the outbreak strain. Differentiating SNPs were found within a wide variety of genes, including lasR, nrdG, tadZ, and algB. These have been generated at a rate estimated to be one SNP every four to five months. In conclusion, we demonstrate that the single base resolution of whole genome sequencing is a powerful tool in analysis of outbreak isolates that can not only show strain similarity, but also evolution over time and potential adaptation through gene sequence changes.

Medial foot pain in a runner: a case presentation.

A 27-year-old runner presented to our sports medicine clinic with 4 months of medial foot pain after an eversion ankle sprain. Initial radiographs were negative for fracture. Her symptoms improved but plateaued after 1 month. She was unable to continue running and noticed a new prominence at her right medial foot. Results of a physical examination showed pes planus, a prominent navicular in her right foot and mild weakness of inversion at the right ankle. Magnetic resonance imaging showed bone edema adjacent to a navicular synchondrosis, which confirmed a diagnosis of type 2 accessory navicular with synchondrosis injury. The patient was treated conservatively with a progressive rehabilitation course.

Emollient molecule effects on the drying stresses in human stratum corneum.

BACKGROUND: Emollient molecules are widely used in skin care formulations to improve skin sensory properties and to alleviate dry skin but little is understood regarding their effects on skin biomechanical properties. OBJECTIVES: To investigate the effects of emollient molecules on drying stresses in human stratum corneum (SC) and how these stresses are related to SC components and moisture content. METHODS: The substrate curvature method was used to measure the drying stresses in isolated SC following exposure to selected emollient molecules. While SC stresses measured using this method have the same biaxial in vivo stress state and moisture exchange with the environment, a limitation of the method is that moisture cannot be replenished by the underlying skin layers. This provides an opportunity to study the direct effects of emollient treatments on the moisture content and the components of the SC. Attenuated total reflectance Fourier transform infrared spectroscopy was used to determine the effects of emollient molecules on SC lipid extraction and conformation. Results Emollient molecules resulted in a complex SC drying stress profile where stresses increased rapidly to peak values and then gradually decreased to significantly lower values compared with the control. The partially occlusive treatments also penetrated into the SC where they caused extraction and changes in lipid conformation. These effects together with their effects on SC moisture content are used to rationalize the drying stress profiles. CONCLUSIONS: Emollient molecules have dramatic effects on SC drying stresses that are related to their effects on intercellular lipids and SC moisture content.

Application of substrate curvature method to differentiate drying stresses in topical coatings and human stratum corneum.

SYNOPSIS: Despite the extensive use of topical coatings in cosmetics, their effect on the mechanical properties of human skin and the perception of skin tightness in the form of drying stresses is not well understood. We describe the application of a recently developed substrate curvature technique to characterize stresses in drying and non-drying occlusive topical coatings. We then extend the technique to measure the combined effects of the coating applied to human stratum corneum (SC) where the overall drying stresses may have contributions from the coating, the SC and the interaction of the coating with the SC. We show how these separate contributions in the coating and SC layers can be differentiated.

Drying stress and damage processes in human stratum corneum.

SYNOPSIS: The drying stresses that develop in stratum corneum (SC) are crucial for its mechanical and biophysical function, its cosmetic feel and appearance, and play a central role in processes of dry skin damage. However, quantitative methods to characterize these stresses are lacking and little understanding exists regarding the effects of drying environment, chemical exposures and moisturizing treatments. We describe the application of a substrate curvature technique adapted for biological tissue to accurately characterize SC drying stresses as a function of time following environmental pre-conditioning and chemical treatment in a range of drying environments. SC stresses were observed to increase to stress levels of up to approximately 3 MPa over periods of 8 h depending on pretreatment and drying environment. A unique relationship between the SC stress and water in the drying environment was established. The effect of glycerol on lowering SC stresses and damaging surfactants on elevating SC stresses were quantified. Extensions of the method to continuous monitoring of SC stresses in response to changes in environmental moisture content and temperature are reported. Finally, a biomechanics framework to account for the SC drying stress as a mechanical driving force for dry skin damage is presented.

Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards.

Clostridium difficile causes serious healthcare-associated infections. Infection control is difficult, due in part to environmental contamination with C. difficile spores. These spores are relatively resistant to cleaning and disinfection. The activity of a dry mist hydrogen peroxide decontamination system (Sterinis) against environmental C. difficile contamination was assessed in three elderly care wards. Initial sampling for C. difficile was performed in 16 rooms across a variety of wards and specialties, using Brazier's CCEY (cycloserine-cefoxitin-egg yolk) agar. Ten rooms for elderly patients (eight isolation and two sluice rooms) were then resampled following dry mist hydrogen peroxide decontamination. Representative isolates of C. difficile were typed by polymerase chain reaction ribotyping. C. difficile was recovered from 3%, 11% and 26% of samples from low, medium and high risk rooms, respectively. In 10 high risk elderly care rooms, 24% (48/203) of samples were positive for C. difficile, with a mean of 6.8 colony-forming units (cfu) per 10 samples prior to hydrogen peroxide decontamination. Ribotyping identified the presence of the three main UK epidemic strains (ribotypes 001, 027 and 106) and four rooms contained mixed strains. After a single cycle of hydrogen peroxide decontamination, only 3% (7/203) of samples were positive (P<0.001), with a mean of 0.4 cfu per 10 samples ( approximately 94% reduction). The Sterinis hydrogen peroxide system significantly reduced the extent of environmental contamination with C. difficile in these elderly care rooms. This relatively quick and user-friendly technology might be a more reliable method of terminally disinfecting isolation rooms, following detergent cleaning, compared to the manual application of other disinfectants.

Genetic diversity of carbapenem-resistant isolates of Acinetobacter baumannii in Europe.

In total, 96 carbapenem-resistant isolates of Acinetobacter baumannii were obtained from 25 hospitals in 17 European countries. Imipenem MICs ranged from <4 to 128 mg/L on retesting by Etest, with MICs > or =16 mg/L being associated with the carriage of genes encoding at least one other class D carbapenemase in addition to the intrinsic OXA-51-like enzyme. Molecular typing results obtained by random amplified polymorphic DNA analysis, followed by pulsed-field gel electrophoresis (PFGE) of ApaI-digested chromosomal DNA, were highly congruent, with 17 different PFGE types being delineated at a cut-off similarity level of 85%. With few exceptions, multiple isolates from a single hospital belonged to the same PFGE type. Seven sequence groups were identified among the 96 A. baumannii isolates, with the majority of isolates (n = 81) belonging to the previously defined sequence groups 1 and 2, which each included eight PFGE types. These two multinational lineages included the previously defined European clones II and I, respectively, but the problem of resistant A. baumannii in Europe appeared not to be confined solely to these two European clones. Rather, two broader lineages of carbapenem-resistant A. baumannii now seem to be spreading throughout Europe.

Evaluation of the sensitivity of a rapid polymerase chain reaction for detection of group B streptococcus.

The objective of this study was to compare detection of group B streptococcal (GBS) carriage using 'real-time' polymerase chain reaction (PCR) and microbiological standard culture. The study design was a test accuracy study comparing a novel molecular technique against the standard microbiological cultural technique in normal pregnant women. The setting and population consisted of 143 pregnant women with pre-labour rupture of the membranes, recruited from two large teaching hospitals in the UK. The study examined the efficacy of a polymerase chain reaction (PCR) assay for screening pregnant women who presented with term rupture of the membranes. Low vaginal specimens were obtained from the women. The specimens were tested for GBS by conventional culture and with a GBS-specific real-time PCR assay. The main outcome measure was the sensitivity and specificity of the PCR assay with 95% confidence intervals (CI) compared with the standard culture. The length of time to obtain a result was also reported for both methods. Among the 143 women, the results of the culture were positive (at least one colony) for GBS in 20 women (14%). The PCR assay detected GBS carriage in 10 women (7%). As compared with the culture method, the sensitivity and specificity of the PCR assay were 45% and 99%, respectively. The positive and negative predictive values of the PCR assay were 90% and 92%, respectively. The length of time required to obtain results for the majority of women (94%) was <2.5 h for the PCR assay and at least 24 h for culture. While a rapid result (within 3 h) of carriage of GBS can be obtained by the PCR assay, at present, it cannot replace conventional culture without further optimisation of the DNA extraction method. The sensitivity may further be improved by testing both low vaginal and rectal specimens.

Rapid detection of methicillin-resistant Staphylococcus aureus from screening enrichment broths by real-time PCR.

The aim of this study was to evaluate real-time PCR (LightCycler) kits for the detection of methicillin-resistant Staphylococcus aureus in enrichment broth using 200 sets of patient screening swab samples. One hundred sets were processed using a lysostaphin/lysozyme extraction method and a further 100 were tested using a column extraction kit. The PCR kits with lysostaphin/lysozyme lysis showed 95.7% sensitivity, 90.8% specificity, and negative and positive predictive values of 98.6% and 75.9%, respectively, compared with 88%, 95.9%, 84.6% and 95.9%, respectively, with the column extraction kit.

Evaluation of a real-time PCR hybridization assay for rapid detection of Legionella pneumophila in hospital and environmental water samples.

A real-time LightCycler assay for Legionella pneumophila was evaluated with 120 water samples potentially contaminated with PCR inhibitors. Results were obtained within five hours, with a detection limit equivalent to 800 cells/L. However, 11 of 22 culture-positive samples containing < 100 CFU/L were also positive by LightCycler assay, indicating the presence of significant numbers of non-viable cells. Following extraction, amplification inhibitors remained in four culture-positive samples, but only one contained > 800 CFU/L. The assay seemed suitable for rapidly screening large sample numbers for heavy contamination with L. pneumophila, but conventional culture should continue to be used to detect low contamination levels.

Molecular detection of anthrax spores on animal fibres.

AIMS: To develop a rapid, specific and sensitive diagnostic test for the detection of the spores of Bacillus anthracis on commercial samples of animal fibres (e.g. wool and cashmere). METHODS AND RESULTS: Extraction of DNA from spores using a mechanical disruption method based on bead beating was evaluated but subsequently abandoned as it compromised the sensitivity of the overall protocol. A multiplex PCR and two nested amplification reactions designed for B. anthracis were developed during this study. CONCLUSIONS: A simple selective incubation step in combination with multiplex PCR was found to be more effective than generic DNA extraction coupled to a sensitive nested amplification reaction. SIGNIFICANCE AND IMPACT OF THE STUDY: The rapid diagnostic test could be applied to the analysis of commercial fibre samples for the detection of anthrax as required by health and safety legislation resulting in considerable savings in time and expense.