Comparison of PCR/electron spray ionization-time-of-flight-mass spectrometry versus traditional clinical microbiology for active surveillance of organisms contaminating high-use surfaces in a burn intensive care unit, an orthopedic ward and healthcare workers.

BACKGROUND: Understanding nosocomial pathogen transmission is restricted by culture limitations. Novel platforms, such as PCR-based electron spray ionization-time-of-flight-mass spectrometry (ESI-TOF-MS), may be useful as investigational tools. METHODS: Traditional clinical microbiology (TCM) and PCR/ESI-TOF-MS were used to recover and detect microorganisms from the hands and personal protective equipment of 10 burn intensive care unit (ICU) healthcare workers providing clinical care at a tertiary care military referral hospital. High-use environmental surfaces were assessed in 9 burn ICU and 10 orthopedic patient rooms. Clinical cultures during the study period were reviewed for pathogen comparison with investigational molecular diagnostic methods. RESULTS: From 158 samples, 142 organisms were identified by TCM and 718 by PCR/ESI-TOF-MS. The molecular diagnostic method detected more organisms (4.5 ± 2.1 vs. 0.9 ± 0.8, p < 0.01) from 99% vs. 67% of samples (p < 0.01). TCM detected S. aureus in 13 samples vs. 21 by PCR/ESI-TOF-MS. Gram-negative organisms were less commonly identified than gram-positive by both methods; especially by TCM. Among all detected bacterial species, similar percentages were typical nosocomial pathogens (18-19%) for TCM vs. PCR/ESI-TOF-MS. PCR/ESI-TOF-MS also detected mecA in 112 samples, vanA in 13, and KPC-3 in 2. MecA was associated (p < 0.01) with codetection of coagulase negative staphylococci but not S. aureus. No vanA was codetected with enterococci; one KPC-3 was detected without Klebsiella spp. CONCLUSIONS: In this pilot study, PCR/ESI-TOF-MS detected more organisms, especially gram-negatives, compared to TCM, but the current assay format is limited by the number of antibiotic resistance determinants it covers. Further large-scale assessments of PCR/ESI-TOF-MS for hospital surveillance are warranted.

Infection prevention and control in deployed military medical treatment facilities.

Infections have complicated the care of combat casualties throughout history and were at one time considered part of the natural history of combat trauma. Personnel who survived to reach medical care were expected to develop and possibly succumb to infections during their care in military hospitals. Initial care of war wounds continues to focus on rapid surgical care with debridement and irrigation, aimed at preventing local infection and sepsis with bacteria from the environment (e.g., clostridial gangrene) or the casualty's own flora. Over the past 150 years, with the revelation that pathogens can be spread from patient to patient and from healthcare providers to patients (including via unwashed hands of healthcare workers, the hospital environment and fomites), a focus on infection prevention and control aimed at decreasing transmission of pathogens and prevention of these infections has developed. Infections associated with combat-related injuries in the recent operations in Iraq and Afghanistan have predominantly been secondary to multidrug-resistant pathogens, likely acquired within the military healthcare system. These healthcare-associated infections seem to originate throughout the system, from deployed medical treatment facilities through the chain of care outside of the combat zone. Emphasis on infection prevention and control, including hand hygiene, isolation, cohorting, and antibiotic control measures, in deployed medical treatment facilities is essential to reducing these healthcare-associated infections. This review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Multidrug-resistant bacterial colonization of combat-injured personnel at admission to medical centers after evacuation from Afghanistan and Iraq.

BACKGROUND: Multidrug-resistant organism (MDRO) infections, including those secondary to Acinetobacter (ACB) and extended spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae (Escherichia coli and Klebsiella species) have complicated the care of combat-injured personnel during Operations Iraqi Freedom and Enduring Freedom. Data suggest that the source of these bacterial infections includes nosocomial transmission in both deployed hospitals and receiving military medical centers (MEDCENs). Admission screening for MDRO colonization has been established to monitor this problem and effectiveness of responses to it. METHODS: Admission colonization screening of injured personnel began in 2003 at the three US-based MEDCENs receiving the majority of combat-injured personnel. This was extended to Landstuhl Regional Medical Center (LRMC; Germany) in 2005. Focused on ACB initially, screening was expanded to include all MDROs in 2009 with a standardized screening strategy at LRMC and US-based MEDCENs for patients evacuated from the combat zone. RESULTS: Eighteen thousand five hundred sixty of 21,272 patients admitted to the 4 MEDCENs in calendar years 2005 to 2009 were screened for MDRO colonization. Average admission ACB colonization rates at the US-based MEDCENs declined during this 5-year period from 21% (2005) to 4% (2009); as did rates at LRMC (7-1%). In the first year of screening for all MDROs, 6% (171 of 2,989) of patients were found colonized at admission, only 29% (50) with ACB. Fifty-seven percent of patients (98) were colonized with ESBL-producing E. coli and 11% (18) with ESBL-producing Klebsiella species. CONCLUSIONS: Although colonization with ACB declined during the past 5 years, there seems to be replacement of this pathogen with ESBL-producing Enterobacteriaceae.

Executive summary: Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society.

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society.

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications, and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Response to infection control challenges in the deployed setting: Operations Iraqi and Enduring Freedom.

BACKGROUND: Infections caused by multidrug-resistant organisms (MDROs), including Acinetobacter, have complicated the care of military personnel injured in Operations Iraqi and Enduring Freedom. Cumulative data suggest that nosocomial transmission of MDROs in deployed medical treatment facilities (MTFs) has contributed to these infections. A 2008 review of deployed MTFs identified multiple factors impeding the performance of infection prevention and control (IC) practices. In response, efforts to emphasize IC basics, improve expertise, and better track MDRO colonization were pursued. METHODS: Efforts to increase awareness and enhance IC in deployed MTFs were focused on educating leaders and deploying personnel, producing deployed IC resources, and standardizing level IV and V admission screening for MDRO colonization. A repeat mission in 2009 reviewed interval progress. RESULTS: Increased awareness and the need for emphasis on basic IC practice, including hand hygiene, use of transmission-based (isolation) precautions, and cohorting of patients, were imparted to leaders and deploying personnel through briefings, presentations, and an All Army Activities message. Enhancement of IC expertise was implemented through increased standardization of IC practice, establishment of a predeployment IC short course, an IC teleconsultation service, and dedicated Internet resources. Standardization of admission colonization screening of personnel evacuated from the combat theater was established to better define and respond to the MDRO problem. A repeat review of the deployed MTFs found overall improvement in IC practice, including clear command emphasis in the Iraqi theater of operations. CONCLUSIONS: Maintaining a strong IC effort in the deployed setting, even in a stabilized operational environment, is difficult. Use of innovative strategies to enhance expertise and practice were implemented to reduce MDRO infections.

Development of a deployment infection control course.

Since the beginning of military operations in Iraq and Afghanistan, multidrug-resistant bacteria have been noted to be infecting and colonizing combat casualties. Studies suggest the primary source of these bacteria is nosocomial transmission. A focus area for improvement has been to enhance infection control (IC) at hospitals in the combat theater. A 5-day IC course was developed and implemented to provide just-in-time training to those personnel who have been identified to lead IC efforts while deployed. Twenty-nine students have attended the first 6 offerings of this course. A pre- and post-course test showed an average 21% improvement in knowledge. A follow-up questionnaire provided to those students who deployed found the course had enhanced performance of their IC duties. We describe the deployment-unique training developed to provide basic IC, emphasizing the unique challenges found in the combat setting.

Infection control challenges in deployed US military treatment facilities.

BACKGROUND: Personnel sustaining combat-related injuries in current overseas conflicts continue to have their care complicated by infections caused by multidrug-resistant organisms, including Acinetobacter, Klebsiella, and Pseudomonas. Although presumed to be due to multiple factors both within and outside of the combat theater, concern has been raised about the difficulties in establishing and maintaining standard infection control (IC) practices in deployed medical treatment facilities and in the evacuation of the injured back to the United States. METHODS: Level III facilities (hospitals capable of holding patients >72 hours) in Iraq and Afghanistan and the evacuation system from Iraq to the continental US were reviewed by an expert IC-infectious disease team. RESULTS: All reviewed facilities had established IC programs, but these were staffed by personnel with limited IC experience, often without perceived adequate time dedicated to perform their duties, and without uniform levels of command emphasis or support. Proper hand hygiene between patients was not always ideal. Isolation and cohorting of patients to decrease multidrug-resistant organism colonization and infection varied among facilities. Review of standard operating procedures found variability among institutions and in quality of these documents. Application of US national and theater-specific guidelines and of antimicrobial control measures also varied among facilities. CONCLUSIONS: Effective IC practices are often difficult to maintain in modern US hospitals. In the deployed setting, with ever-changing personnel in a less than optimal practice environment, IC is even more challenging. Standardization of practice with emphasis on the basics of IC practice (e.g., hand hygiene and isolation procedures) needs to be emplaced and maintained in the deployed setting.

Recovery of multidrug-resistant bacteria from combat personnel evacuated from Iraq and Afghanistan at a single military treatment facility.

U.S. combat casualties from Iraq and Afghanistan continue to develop infections with multidrug-resistant (MDR) bacteria. This study assesses the infection control database and clinical microbiology antibiograms at a single site from 2005 to 2007, a period when all Operation Iraqi Freedom (OIF)/Operation Enduring Freedom (OEF) casualties admitted to the facility underwent initial isolation and screening for MDR pathogens. During this 3-year period, there were 2,242 OIF/OEF admissions: 560 in 2005, 724 in 2006, and 958 in 2007. The most commonly recovered pathogens from OIF/OEF admission screening cultures were methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae and Acinetobacter. The yearly nosocomial infection rate of these three pathogens among OIF/OEF admissions ranged between 2 and 4%. There were remarkable changes in resistance profiles for Acinetobacter, K. pneumoniae, and S. aureus over time. Despite aggressive infection control procedures, there is continued nosocomial transmission within the facility and increasing antimicrobial resistance in some pathogens. Novel techniques are needed to control the impact of MDR bacteria in medical facilities.

Guidelines for the prevention of infection after combat-related injuries.

Management of combat-related trauma is derived from skills and data collected in past conflicts and civilian trauma, and from information and experience obtained during ongoing conflicts. The best methods to prevent infections associated with injuries observed in military combat are not fully established. Current methods to prevent infections in these types of injuries are derived primarily from controlled trials of elective surgery and civilian trauma as well as retrospective studies of civilian and military trauma interventions. The following guidelines integrate available evidence and expert opinion, from within and outside of the US military medical community, to provide guidance to US military health care providers (deployed and in permanent medical treatment facilities) in the diagnosis, treatment, and prevention of infections in those individuals wounded in combat. These guidelines may be applicable to noncombat traumatic injuries under certain circumstances. Early wound cleansing and surgical debridement, antibiotics, bony stabilization, and maintenance of infection control measures are the essential components to diminish or prevent these infections. Future research should be directed at ideal treatment strategies for prevention of combat-related injury infections, including investigation of unique infection control techniques, more rapid diagnostic strategies for infection, and better defining the role of antimicrobial agents, including the appropriate spectrum of activity and duration.

Infection Prevention in Combat-Related Injuries.

Wound infections play an important role in the morbidity and mortality of service members injured in combat. The exigent and often long road to recovery can be complicated by healthcare-associated infections caused by multidrug-resistant organisms. The outcome is not only financially taxing but also can be life threatening. This Clinical Practice Guideline (CPG) will provide the reader with a brief overview of this topic, easy and equitable strategies to implement, and significantly reduce the exposure and possible contamination and spread of life threatening organisms in combat wounds. The table and guidance will provide easy step-wise approach in management of different challenging scenarios to help control spread of infection down range and at every level of medical treatment facility involved in patient transport to the ultimate institution.

Methicillin-resistant Staphylococcus aureus (MRSA) nares colonization at hospital admission and its effect on subsequent MRSA infection.

BACKGROUND: Asymptomatic colonization with methicillin-resistant Staphylococcus aureus (MRSA) has been described as a risk factor for subsequent MRSA infection. MRSA is an important nosocomial pathogen but has currently been reported in patients without typical risk factors for nosocomial acquisition. This study was designed to evaluate the impact of asymptomatic nares MRSA colonization on the development of subsequent MRSA infection. The incidence of MRSA infection was examined in patients with and patients without MRSA or methicillin-susceptible S. aureus (MSSA) colonization at admission to the hospital and in those who developed colonization during hospitalization. METHODS: Patients admitted to 5 representative hospital units were prospectively evaluated. Nares samples were obtained for culture at admission and during hospitalization. Laboratory culture results were monitored to identify all MRSA infections that occurred during the study period and 1 year thereafter. RESULTS: Of the 758 patients who had cultures of nares samples performed at admission, 3.4% were colonized with MRSA, and 21% were colonized with MSSA. A total of 19% of patients with MRSA colonization at admission and 25% who acquired MRSA colonization during hospitalization developed infection with MRSA, compared with 1.5% and 2.0% of patients colonized with MSSA (P<.01) and uncolonized (P<.01), respectively, at admission. MRSA colonization at admission increased the risk of subsequent MRSA infection, compared with MSSA colonization (relative risk [RR], 13; 95% confidence interval [CI], 2.7-64) or no staphylococcal colonization (RR, 9.5; 95% CI, 3.6-25) at admission. Acquisition of MRSA colonization also increased the risk for subsequent MRSA infection, compared with no acquisition (RR, 12; 95% CI, 4.0-38). CONCLUSION: MRSA colonization of nares, either present at admission to the hospital or acquired during hospitalization, increases the risk for MRSA infection. Identifying MRSA colonization at admission could target a high-risk population that may benefit from interventions to decrease the risk for subsequent MRSA infection.

Frequency of vaccinia virus isolation on semipermeable versus nonocclusive dressings covering smallpox vaccination sites in hospital personnel.

BACKGROUND: The Centers for Disease Control and Prevention recommends a semipermeable occlusive dressing for hospital workers who receive smallpox vaccination. OBJECTIVE: The study was designed to determine the frequency of vaccinia virus isolation from the outer surface of semipermeable dressings and to compare the prevalence of vaccinia virus on the outer surface of semipermeable dressings with its prevalence on the outer surface of nonocclusive dressings. METHODS: A prospective, observational study was conducted on hospital employees who received smallpox vaccination at a military academic medical center. Subjects were instructed to wear a semipermeable dressing if they had direct patient contact. Employees without direct patient care had the option of wearing a semipermeable dressing or a nonocclusive dressing. Prior to a programmed dressing change, the outer surface of the bandage site was swabbed and cultured for virus. Samples were considered positive when cytopathic effects were observed, with results confirmed as vaccinia by polymerase chain reaction. RESULTS: A total of 212 cultures were obtained from 93 subjects. All cultures directly obtained from active lesions were positive (13/13). Positive cultures were obtained from 7% (10/135) of the semipermeable dressings and 23% (15/64) of the nonocclusive dressings (P <.05). Ten percent (8/79) of the semipermeable dressings with purulent exudate observed underneath the bandage were culture positive, compared with 4% (2/56) of semipermeable dressings with no purulent exudate observed underneath the bandage (P=.19). CONCLUSIONS: Compared with nonocclusive dressings, the semipermeable dressing reduced, but did not eliminate, the frequency with which vaccinia virus was cultured from the surface of the dressing. Virus was present, but only rarely, on the dressing surface in the absence of purulent exudate under the semipermeable dressings.

The effect of semipermeable dressings on smallpox vaccine site evolution.

BACKGROUND: Many hospital systems in the United States are contemplating the implementation of a smallpox vaccination program. The Centers for Disease Control and Prevention and other organizations recommend use of occlusive dressings over the vaccination site of health care workers in contact with patients. Minimal data are available on the impact of an occlusive dressing on the evolution of the vaccinia inoculation site. METHODS: We conducted a prospective observational study in which subjects were instructed to cover their vaccination site with either a semipermeable dressing over gauze or gauze alone. We recorded the duration of semipermeable dressing use and parameters pertaining to vaccination site evolution, to include time until scab separation. RESULTS: The increased use of a semipermeable dressing is associated with increased time until scab separation (n = 41, r =.48, P =.001 by regression analysis). This analysis predicts a 9-day difference in time until scab separation between patients that wore semipermeable dressings 100% of the time versus not at all. No significant correlation was observed between semipermeable dressing use and size of maximum erythema, time until maximum erythema, size of erythema on day 6 or 8, nor time until pustule formation. CONCLUSION: Semipermeable dressing use appears to prolong the time until scab separation and possibly the duration of infectivity and risk of secondary transmission. Health care organizations may wish to consider this information when instituting a smallpox vaccination program.

Evaluation of potential environmental contamination sources for the presence of multidrug-resistant bacteria linked to wound infections in combat casualties.

OBJECTIVE: To determine whether multidrug-resistant (MDR) gram-negative organisms are present in Afghanistan or Iraq soil samples, contaminate standard deployed hospital or modular operating rooms (ORs), or aerosolize during surgical procedures. DESIGN: Active surveillance. SETTING: US military hospitals in the United States, Afghanistan, and Iraq. METHODS: Soil samples were collected from sites throughout Afghanistan and Iraq and analyzed for presence of MDR bacteria. Environmental sampling of selected newly established modular and deployed OR high-touch surfaces and equipment was performed to determine the presence of bacterial contamination. Gram-negative bacteria aerosolization during OR surgical procedures was determined by microbiological analysis of settle plate growth. RESULTS: Subsurface soil sample isolates recovered in Afghanistan and Iraq included various pansusceptible members of Enterobacteriaceae, Vibrio species, Pseudomonas species, Acinetobacter lwoffii, and coagulase-negative Staphylococcus (CNS). OR contamination studies in Afghanistan revealed 1 surface with a Micrococcus luteus. Newly established US-based modular ORs and the colocated fixed-facility ORs revealed no gram-negative bacterial contamination prior to the opening of the modular OR and 5 weeks later. Bacterial aerosolization during surgery in a deployed fixed hospital revealed a mean gram-negative bacteria colony count of 12.8 colony-forming units (CFU)/dm(2)/h (standard deviation [SD], 17.0) during surgeries and 6.5 CFU/dm(2)/h (SD, 7.5; [Formula: see text]) when the OR was not in use. CONCLUSION: This study demonstrates no significant gram-negative bacilli colonization of modular and fixed-facility ORs or dirt and no significant aerosolization of these bacilli during surgical procedures. These results lend additional support to the role of nosocomial transmission of MDR pathogens or the colonization of the patient themselves prior to injury.