Management of non-compressible torso hemorrhage of the abdomen in civilian and military austere environments: a scoping review.

Background: Non-compressible abdominal hemorrhage (NCAH) is the leading cause of potentially preventable deaths in both civilian and military austere environments, and an improvement in mortality due to this problem has not been demonstrated during the past quarter century. Several innovations have been developed to control hemorrhage closer to the point of injury. Objective: This review assessed NCAH interventions in civilian and military settings, focusing on austere environments. It identified innovations, effectiveness, and knowledge gaps for future research. Methodology: The Joanna Briggs Institute for Evidence Synthesis methodology guided this scoping review to completion. Studies evaluating NCAH with human participants in civilian and military austere environments that were eligible for inclusion were limited to English language studies published between December 1990 and January 2023. The PCC (Participant, Concept, Context) framework was used for data synthesis. Deductive and inductive thematic analyses were used to assess the literature that met inclusion criteria, identify patterns/themes to address the research questions and identify common themes within the literature. A stakeholder consultation was conducted to review and provide expert perspectives and opinions on the results of the deductive and inductive thematic analyses. Results: The literature search identified 868 articles; 26 articles met the inclusion criteria. Textual narrative analysis of the 26 articles resulted in the literature addressing four main categories: NCAH, penetrating abdominal trauma, resuscitative endovascular balloon occlusion of the aorta (REBOA), and ResQFoam. The deductive thematic analysis aimed to answer three research questions. Research question 1 addressed the effectiveness of REBOA, damage control resuscitation, and damage control surgery in managing NCAH in austere environments. No effectiveness studies were found on this topic. Research question 2 identified three knowledge gaps in NCAH management in austere environments. The analysis identified early hemorrhage control, prehospital provider decision-making ability, and REBOA implementation as knowledge gaps in NCAH. Research question 3 identified five innovations that may affect the management of NCAH in the future: transport of patients, advanced resuscitative care, expert consultation, REBOA implementation, and self-expanding foam implementation. The inductive thematic analysis resulted in four recurrent themes from the literature: prehospital care, decision-making, hemorrhage control, and mortality in NCAH. During the stakeholders' consultation, the results of the deductive and inductive thematic analyses were reviewed and agreed on by the stakeholders. Special emphasis and discussion were given to prehospital management, expert opinions in the prehospital environment, decision-making in the prehospital environment, transport and resuscitation in the prehospital setting, REBOA, alternative discussion for research, and research gaps. Conclusion: NCAH is still a significant cause of preventable death in both military and civilian austere environments, even with ongoing research and interventions aimed at extending survival in such conditions. This scoping review has identified several potential concepts that could reduce the mortality associated with a preventable cause of death due to hemorrhage in austere environments.

Cow-baited tents are highly effective in sampling diverse Anopheles malaria vectors in Cambodia.

BACKGROUND: The accurate monitoring and evaluation of malaria vectors requires efficient sampling. The objective of this study was to compare methods for sampling outdoor-biting Anopheles mosquitoes in Cambodia. METHODS: In the Cambodian provinces of Pursat, Preah Vihear, and Ratanakiri, six different mosquito trapping methods were evaluated: human landing collection (HLC), human-baited tent (HBT), cow-baited tent (CBT), CDC miniature light trap (LT), CDC miniature light trap baited with molasses and yeast (LT-M), and barrier fence (F) in a Latin square design during four or six consecutive nights at the height of the malaria transmission season. RESULTS: Using all traps, a total of 507, 1175, and 615 anophelines were collected in Pursat, Preah Vihear, and Ratanakiri, respectively. CBTs captured 10- to 20-fold more anophelines per night than the other five sampling methods. All 2297 Anopheles mosquitoes were morphologically identified and molecularly typed using standard morphological keys and sequencing the rDNA ITS2 region to distinguish cryptic species, respectively. Overall, an extremely diverse set of 27 known Anopheles species was sampled. CBTs captured the same molecular species that HLCs and the other four traps did, as well as additional species. Nine specimens representing five Anopheles species (Anopheles hyrcanus, Anopheles barbirostris sensu stricto, Anopheles barbirostris clade III, Anopheles nivipes, and Anopheles peditaeniatus) were infected with Plasmodium falciparum and were exclusively captured in CBTs. CONCLUSIONS: These data indicate that cow-baited tents are highly effective in sampling diverse Anopheles malaria vectors in Cambodia. This sampling method captured high numbers of anophelines with limited sampling effort and greatly reduced human exposure to mosquito bites compared to the gold-standard human landing collection.

Population Structure Shapes Copy Number Variation in Malaria Parasites.

If copy number variants (CNVs) are predominantly deleterious, we would expect them to be more efficiently purged from populations with a large effective population size (Ne) than from populations with a small Ne. Malaria parasites (Plasmodium falciparum) provide an excellent organism to examine this prediction, because this protozoan shows a broad spectrum of population structures within a single species, with large, stable, outbred populations in Africa, small unstable inbred populations in South America and with intermediate population characteristics in South East Asia. We characterized 122 single-clone parasites, without prior laboratory culture, from malaria-infected patients in seven countries in Africa, South East Asia and South America using a high-density single-nucleotide polymorphism/CNV microarray. We scored 134 high-confidence CNVs across the parasite exome, including 33 deletions and 102 amplifications, which ranged in size from <500 bp to 59 kb, as well as 10,107 flanking, biallelic single-nucleotide polymorphisms. Overall, CNVs were rare, small, and skewed toward low frequency variants, consistent with the deleterious model. Relative to African and South East Asian populations, CNVs were significantly more common in South America, showed significantly less skew in allele frequencies, and were significantly larger. On this background of low frequency CNV, we also identified several high-frequency CNVs under putative positive selection using an FST outlier analysis. These included known adaptive CNVs containing rh2b and pfmdr1, and several other CNVs (e.g., DNA helicase and three conserved proteins) that require further investigation. Our data are consistent with a significant impact of genetic structure on CNV burden in an important human pathogen.

Artemisinin-resistant Plasmodium falciparum clinical isolates can infect diverse mosquito vectors of Southeast Asia and Africa.

Artemisinin-resistant Plasmodium falciparum parasites are rapidly spreading in Southeast Asia, yet nothing is known about their transmission. This knowledge gap and the possibility that these parasites will spread to Africa endanger global efforts to eliminate malaria. Here we produce gametocytes from parasite clinical isolates that displayed artemisinin resistance in patients and in vitro, and use them to infect native and non-native mosquito vectors. We show that contemporary artemisinin-resistant isolates from Cambodia develop and produce sporozoites in two Southeast Asian vectors, Anopheles dirus and Anopheles minimus, and the major African vector, Anopheles coluzzii (formerly Anopheles gambiae M). The ability of artemisinin-resistant parasites to infect such highly diverse Anopheles species, combined with their higher gametocyte prevalence in patients, may explain the rapid expansion of these parasites in Cambodia and neighbouring countries, and further compromise efforts to prevent their global spread.

Sensitivity of surveillance testing for multidrug-resistant Gram-negative bacteria in the intensive care unit.

We tested intensive care unit patients for colonization with multidrug-resistant Gram-negative bacilli (MDR GNB) and compared the results with those of concurrent clinical cultures. The sensitivity of the surveillance test for detecting MDR GNB was 58.8% (95% confidence interval, 48.6 to 68.5%). Among 133 patients with positive surveillance tests, 61% had no prior clinical culture with MDR GNB.

A microarray platform and novel SNP calling algorithm to evaluate Plasmodium falciparum field samples of low DNA quantity.

BACKGROUND: Analysis of single nucleotide polymorphisms (SNPs) derived from whole-genome studies allows for rapid evaluation of genome-wide diversity, and genomic epidemiology studies of Plasmodium falciparum provide insights into parasite population structure, gene flow, drug resistance and vaccine development. In areas with adequate cold chain facilities, large volumes of leukocyte-depleted patient blood can be frozen for use in parasite genomic analyses. In more remote endemic areas smaller volumes of infected blood are taken by finger prick, and dried and stored on filter paper. These dried blood spots do not generally yield enough concentrated parasite DNA for whole-genome sequencing. RESULTS: A DNA microarray was designed for use on field samples to type a genome-wide set of SNPs which prior sequencing had shown to be variable in Africa, Southeast Asia, and Papua New Guinea. An algorithm was designed to call SNPs in samples with low parasite DNA. With this new algorithm SNP-calling accuracy of 98% was measured by hybridizing purified DNA from malaria lab strains and comparing calls with SNPs called from full genome sequences. An average accuracy of >98% was likewise obtained for DNA extracted from malaria field samples collected in studies in Southeast Asia, with an average call rate of > 82%. CONCLUSION: This new high-density microarray provided high quality SNP calls from a wide range of parasite DNA quantities, and represents a robust tool for genome-wide analysis of malaria parasites in diverse settings.

Nontuberculous mycobacterial infection after fractionated CO(2) laser resurfacing.

Nontuberculous mycobacteria are increasingly associated with cutaneous infections after cosmetic procedures. Fractionated CO2 resurfacing, a widely used technique for photorejuvenation, has been associated with a more favorable side effect profile than alternative procedures. We describe 2 cases of nontuberculous mycobacterial infection after treatment with a fractionated CO2 laser at a private clinic. Densely distributed erythematous papules and pustules developed within the treated area within 2 weeks of the laser procedure. Diagnosis was confirmed by histologic analysis and culture. Both infections responded to a 4-month course of a multidrug regimen. An environmental investigation of the clinic was performed, but no source of infection was found. The case isolates differed from each other and from isolates obtained from the clinic, suggesting that the infection was acquired by postprocedure exposure. Papules and pustules after fractionated CO2 resurfacing should raise the suspicion of nontuberculous mycobacterial infection.

Central line-associated infections as defined by the Centers for Medicare and Medicaid Services' Hospital-acquired condition versus standard infection control surveillance: why hospital compare seems conflicted.

OBJECTIVE: To evaluate the concordance of case-finding methods for central line-associated infection as defined by Centers for Medicare and Medicaid Services (CMS) hospital-acquired condition (HAC) compared with traditional infection control (IC) methods. SETTING: One tertiary care and 2 community hospitals in North Carolina. PATIENTS: Adult and pediatric hospitalized patients determined to have central line infection by either case-finding method. METHODS: We performed a retrospective comparative analysis of infection detected using HAC versus standard IC central line-associated bloodstream infection surveillance from October 1, 2007, through December 31, 2009. One billing and 2 IC databases were queried and matched to determine the number and concordance of cases identified by each method. Manual review of 25 cases from each discordant category was performed. Sensitivity and positive predictive value (PPV) were calculated using IC as criterion standard. RESULTS: A total of 1,505 cases were identified: 844 by International Classification of Diseases, Ninth Revision (ICD-9), and 798 by IC. A total of 204 cases (24%) identified by ICD-9 were deemed not present at hospital admission by coders. Only 112 cases (13%) were concordant. HAC sensitivity was 14% and PPV was 55% compared with IC. Concordance was low regardless of hospital type. Primary reasons for discordance included differences in surveillance and clinical definitions, clinical uncertainty, and poor documentation. CONCLUSIONS: The case-finding method used by CMS HAC and the methods used for traditional IC surveillance frequently do not agree. This can lead to conflicting results when these 2 measures are used as hospital quality metrics.

Observing and improving hand hygiene compliance: implementation and refinement of an electronic-assisted direct-observer hand hygiene audit program.

We implemented a direct-observer hand hygiene audit program that used trained observers, wireless data entry devices, and an intranet portal. We improved the reliability and utility of the data by standardizing audit processes, regularly retraining auditors, developing an audit guidance tool, and reporting weighted composite hand hygiene compliance scores.

"What the eyes don't see, the heart doesn't grieve over": epidemiology and risk factors for bloodstream infections following cardiac catheterization.

No standard definition exists for surveillance and characterization of the epidemiology of bloodstream infections (BSIs) after cardiac catheterization (CC) procedures. We proposed a novel case definition and determined the epidemiology and risk factors of BSIs after CC procedure using this new definition.

Ability of an antibiogram to predict Pseudomonas aeruginosa susceptibility to targeted antimicrobials based on hospital day of isolation.

OBJECTIVE: To determine the utility of an antibiogram in predicting the susceptibility of Pseudomonas aeruginosa isolates to targeted antimicrobial agents based on the day of hospitalization the specimen was collected. DESIGN: Single-center retrospective cohort study. SETTING: A 750-bed tertiary care medical center. PATIENTS AND METHODS: Isolates from consecutive patients with at least 1 clinical culture positive for P. aeruginosa from January 1, 2000, to June 30, 2007, were included. A study antibiogram was created by determining the overall percentages of P. aeruginosa isolates susceptible to amikacin, ceftazidime, ciprofloxacin, gentamicin, imipenem-cilastin, piperacillin-tazobactam, and tobramycin during the study period. Individual logistic regression models were created to determine the day of infection after which the study antibiogram no longer predicted susceptibility to each antibiotic. RESULTS: A total of 3,393 isolates were included. The antibiogram became unreliable as a predictor of susceptibility to ceftazidime, imipenem-cilastin, piperacillin-tazobactam, and tobramycin after day 10 and ciprofloxacin after day 15 but longer for gentamicin (day 21) and amikacin (day 28). Time to unreliability of the antibiogram varied for antibiotics based on location of isolation. For example, the time to unreliability of the antibiogram for ceftazidime was 5 days (95% confidence interval [CI], <1-8) in the intensive care unit (ICU) and 12 days (95% CI, 7-21) in non-ICU hospital wards (P = .003). CONCLUSIONS: The ability of the antibiogram to predict susceptibility of P. aeruginosa decreases as duration of hospitalization increases.

A major genome region underlying artemisinin resistance in malaria.

Evolving resistance to artemisinin-based compounds threatens to derail attempts to control malaria. Resistance has been confirmed in western Cambodia and has recently emerged in western Thailand, but is absent from neighboring Laos. Artemisinin resistance results in reduced parasite clearance rates (CRs) after treatment. We used a two-phase strategy to identify genome region(s) underlying this ongoing selective event. Geographical differentiation and haplotype structure at 6969 polymorphic single-nucleotide polymorphisms (SNPs) in 91 parasites from Cambodia, Thailand, and Laos identified 33 genome regions under strong selection. We screened SNPs and microsatellites within these regions in 715 parasites from Thailand, identifying a selective sweep on chromosome 13 that shows strong association (P = 10(-6) to 10(-12)) with slow CRs, illustrating the efficacy of targeted association for identifying the genetic basis of adaptive traits.

The impact of depth of infection and postdischarge surveillance on rate of surgical-site infections in a network of community hospitals.

OBJECTIVE: To describe the epidemiology of surgical-site infections (SSIs) in community hospitals and to explore the impact of depth of SSI, healthcare location at the time of diagnosis, and variations in surveillance practices on the overall rate of SSI. DESIGN: Retrospective cohort study. SETTING: Thirty-seven community hospitals in the southeastern United States. PATIENTS: Consecutive sample of patients undergoing surgical procedures between July 1, 2007, and December 31, 2008. METHODS: ANOVA was used to compare rates of SSIs, and the F test was used to compare the distribution of rates of SSIs. Wilcoxon Signed Rank test [corrected] was used to test for differences in performance rankings of hospitals. RESULTS: Following 177,706 surgical procedures, 1,919 SSIs were identified (incidence, 1.08 per 100 procedures). Sixty-four percent (1,223 of 1,919) of these were identified as complex SSIs; 87% of the complex SSIs were diagnosed in inpatient settings. The median proportion of superficial-incisional SSIs was 37% (interquartile range, 29.6%-49.5%). Postdischarge SSI surveillance was variable, with 58% of responding hospitals using surgeon letters. As reporting focus was narrowed from all SSIs to complex SSIs (incidence, 0.69 per 100 procedures) and, finally, to complex SSIs diagnosed in the inpatient setting (incidence, 0.51 per 100 procedures), variance in rates changed significantly ([Formula: see text]). Performance ranking of individual hospitals, based on rates of SSIs, differed significantly, depending on the reporting method utilized ([Formula: see text]). CONCLUSIONS: Inconsistent reporting methods focused on variable depths of infection and healthcare location at time of diagnosis significantly impact rates of SSI, distribution of rates of SSI, and hospital comparative-performance rankings. We believe that public reporting of SSI rates should be limited to complex SSIs diagnosed in the inpatient setting.

COOH-terminal truncation of flightin decreases myofilament lattice organization, cross-bridge binding, and power output in Drosophila indirect flight muscle.

The indirect flight muscle (IFM) of insects is characterized by a near crystalline myofilament lattice structure that likely evolved to achieve high power output. In Drosophila IFM, the myosin rod binding protein flightin plays a crucial role in thick filament organization and sarcomere integrity. Here we investigate the extent to which the COOH terminus of flightin contributes to IFM structure and mechanical performance using transgenic Drosophila expressing a truncated flightin lacking the 44 COOH-terminal amino acids (fln(ΔC44)). Electron microscopy and X-ray diffraction measurements show decreased myofilament lattice order in the fln(ΔC44) line compared with control, a transgenic flightin-null rescued line (fln(+)). fln(ΔC44) fibers produced roughly 1/3 the oscillatory work and power of fln(+), with reduced frequencies of maximum work (123 Hz vs. 154 Hz) and power (139 Hz vs. 187 Hz) output, indicating slower myosin cycling kinetics. These reductions in work and power stem from a slower rate of cross-bridge recruitment and decreased cross-bridge binding in fln(ΔC44) fibers, although the mean duration of cross-bridge attachment was not different between both lines. The decreases in lattice order and myosin kinetics resulted in fln(ΔC44) flies being unable to beat their wings. These results indicate that the COOH terminus of flightin is necessary for normal myofilament lattice organization, thereby facilitating the cross-bridge binding required to achieve high power output for flight.

An optimized microarray platform for assaying genomic variation in Plasmodium falciparum field populations.

We present an optimized probe design for copy number variation (CNV) and SNP genotyping in the Plasmodium falciparum genome. We demonstrate that variable length and isothermal probes are superior to static length probes. We show that sample preparation and hybridization conditions mitigate the effects of host DNA contamination in field samples. The microarray and workflow presented can be used to identify CNVs and SNPs with 95% accuracy in a single hybridization, in field samples containing up to 92% human DNA contamination.

The network approach for prevention of healthcare-associated infections: long-term effect of participation in the Duke Infection Control Outreach Network.

OBJECTIVE: To describe the rates of several key outcomes and healthcare-associated infections (HAIs) among hospitals that participated in the Duke Infection Control Outreach Network (DICON). DESIGN AND SETTING: Prospective, observational cohort study of patients admitted to 24 community hospitals from 2003 through 2009. METHODS: The following data were collected and analyzed: incidence of central line-associated bloodstream infections (CLABSIs), ventilator-associated pneumonia (VAP), catheter-associated urinary tract infections (CAUTIs), and HAIs caused by methicillin-resistant Staphylococcus aureus (MRSA); employee exposures to bloodborne pathogens (EBBPs); physician EBBPs; patient-days; central line-days; ventilator-days; and urinary catheter-days. Poisson regression was used to determine whether incidence rates of these HAIs and exposures changed during the first 5 and 7 years of participation in DICON; nonrandom clustering of each outcome was controlled for. Cost saved and lives saved were calculated on the basis of published estimates. RESULTS: In total, we analyzed 6.5 million patient-days, 4,783 EBPPs, 2,948 HAIs due to MRSA, and 2,076 device-related infections. Rates of employee EBBPs, HAIs due to MRSA, and device-related infections decreased significantly during the first 5 years of participation in DICON (P< .05 for all models; average decrease was approximately 50%); in contrast, physician EBBPs remained unchanged. In aggregate, 210 CLABSIs, 312 cases of VAP, 332 CAUTIs, 1,042 HAIs due to MRSA, and 1,016 employee EBBPs were prevented. Each hospital saved approximately $100,000 per year of participation, and collectively the hospitals may have prevented 52-105 deaths from CLABSI or VAP. The 7-year analysis demonstrated that these trends continued with further participation. CONCLUSIONS: Hospitals with long-term participation in an infection control network decreased rates of significant HAIs by approximately 50%, decreased costs, and saved lives.

Comparison of the burdens of hospital-onset, healthcare facility-associated Clostridium difficile Infection and of healthcare-associated infection due to methicillin-resistant Staphylococcus aureus in community hospitals.

We sought to determine the burden of nosocomial Clostridium difficile infection in comparison to other healthcare-associated infections (HAIs) in community hospitals participating in an infection control network. Our data suggest that C. difficile has replaced MRSA as the most common etiology of HAI in community hospitals in the southeastern United States.

A case-control study of community-associated Clostridium difficile infection: no role for proton pump inhibitors.

BACKGROUND: The epidemiology of community-associated Clostridium difficile infection is not well known. We performed a multicenter, case-control study to further describe community-associated C. difficile infection and assess novel risk factors. METHODS: We conducted this study at 5 sites from October 2006 through November 2007. Community-associated C. difficile infection included individuals with diarrhea, a positive C. difficile toxin, and no recent (12 weeks) discharge from a health care facility. We selected controls from the same clinics attended by cases. We collected clinical and exposure data at the time of illness and cultured residual stool samples and performed ribotyping. RESULTS: Of 1041 adult C. difficile infections, 162 (15.5%) met criteria for community-associated: 66 case and 114 control patients were enrolled. Case patients were relatively young (median 64 years), female (56%), and frequently required hospitalization (38%). Antimicrobials, malignancy, exposure to high-risk persons, and remote health care exposure were independently associated with community-associated C. difficile infection. In 40% of cases, we could not confirm recent antibiotic exposure. Stomach-acid suppressants were not associated with community-associated infection, and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors appeared protective. Prevalence of the hypervirulent NAP-1/027 strain was infrequent (17%). CONCLUSIONS: Community-associated C. difficile infection resulted in a substantial health care burden. Antimicrobials are a significant risk factor for community-associated infection. However, other unique factors also may contribute, including person-to-person transmission, remote health care exposures, and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors. A role for stomach-acid suppressants in community-associated C. difficile infection is not supported.