Differences in microorganisms causing infection after cranial and spinal surgeries.

OBJECTIVE: The primary aim of this retrospective study was to assess differences in the pathogens causing surgical site infections (SSIs) following craniectomies/craniotomies and open spinal surgery. The secondary aim was to assess differences in rates of SSI among these operative procedures. METHODS: ANOVA tests with Bonferroni correction and incidence risk ratios (RRs) were used to identify differences in pathogens by surgical site and procedure using retrospective, de-identified records of 19,993 postneurosurgical patients treated between 2007 and 2020. RESULTS: The overall infection rates for craniotomy/craniectomy, laminectomy, and fusion were 2.1%, 1.1%, and 1.5%, respectively, and overall infection rates for cervical, thoracic, and lumbar spine surgery were 0.3%, 1.6%, and 1.9%, respectively. Craniotomy/craniectomy was more likely to result in an SSI than spine surgery (RR 1.8, 95% CI 1.4-2.2, p < 0.0001). Cutibacterium acnes (RR 24.2, 95% CI 7.3-80.0, p < 0.0001); coagulase-negative staphylococci (CoNS) (methicillin-susceptible CoNS: RR 2.9, 95% CI 1.6-5.4, p = 0.0006; methicillin-resistant CoNS: RR 5.6, 95% CI 1.4-22.3, p = 0.02); Klebsiella aerogenes (RR 6.5, 95% CI 1.7-25.1, p = 0.0003); Serratia marcescens (RR 2.4, 95% CI 1.1-7.1, p = 0.01); Enterobacter cloacae (RR 3.1, 95% CI 1.2-8.1, p = 0.02); and Candida albicans (RR 3.9, 95% CI 1.2-12.3, p = 0.02) were more commonly associated with craniotomy/craniectomy cases than fusion or laminectomy SSIs. Pseudomonas aeruginosa was more commonly associated with fusion SSIs than craniotomy SSIs (RR 4.4, 95% CI 1.3-14.8, p = 0.02), whereas Escherichia coli was nonsignificantly associated with fusion SSIs compared to craniotomy SSIs (RR 4.1, 95% CI 0.9-18.1, p = 0.06). Infections with E. coli and P. aeruginosa occurred primarily in the lumbar spine (p = 0.0003 and p = 0.0001, respectively). CONCLUSIONS: SSIs due to typical gastrointestinal or genitourinary gram-negative bacteria occur most commonly following lumbar surgery, particularly fusion, and are likely to be due to contamination of the surgical bed with microbial flora in the perianal area and genitourinary tract. Cutibacterium acnes in the skin flora of the head and neck increases risk of infection due to this microbe following surgical interventions in these body sites. The types of gram-negative bacteria associated with craniotomy/craniectomy SSIs suggest potential environmental sources of these pathogens. Based on the authors' findings, neurosurgeons should consider using a two-step skin preparation with benzoyl peroxide, in addition to a standard antiseptic such as alcoholic chlorhexidine for cranial, cervical, and upper thoracic surgeries. Additionally, broader gram-negative bacterial coverage, such as use of a third-generation cephalosporin, should be considered for lumbar/lumbosacral fusion surgical antibiotic prophylaxis.

Alpha Defensin-1 Biomarker Outperforms Culture in Diagnosing Breast Implant-Related Infection: Results from a Multicenter Prospective Study.

BACKGROUND: Prompt diagnosis of breast implant infection is critical to reducing morbidity. A high incidence of false-negative microbial culture mandates superior testing modalities. Alpha defensin-1 (AD-1), an infection biomarker, has outperformed culture in diagnosing periprosthetic joint infection with sensitivity/specificity of 97%. After previously demonstrating its feasibility in breast implant-related infection (BIRI), this case-control study compares the accuracy of AD-1 to microbial culture in suspected BIRI. METHODS: An institutional review board-approved, prospective, multicenter study was conducted of adults with prior breast implant reconstruction undergoing surgery for suspected infection (cases) or prosthetic exchange/revision (controls). Demographics, perioperative characteristics, antibiotic exposure, and implant pocket fluid were collected. Fluid samples underwent microbial culture, AD-1 assay, and adjunctive markers (C-reactive protein, lactate, cell differential); diagnostic performance was assessed by means of sensitivity, specificity, and accuracy from receiver operating characteristic curve analysis, with values of P < 0.05 considered significant. RESULTS: Fifty-three implant pocket samples were included (cases, n = 20; controls, n = 33). All 20 patients with suspected BIRI exhibited cellulitis, 65% had abnormal drainage, and 55% were febrile. All suspected BIRIs were AD-1 positive (sensitivity, 100%). Microbial culture failed to grow any microorganisms in four BIRIs (sensitivity, 80%; P = 0.046); Gram stain was least accurate (sensitivity, 25%; P < 0.001). All tests demonstrated 100% specificity. Receiver operating characteristic curve analyses yielded the following areas under the curve: AD-1, 1.0; microbial culture, 0.90 ( P = 0.029); and Gram stain, 0.62 ( P < 0.001). Adjunctive markers were significantly higher among infections versus controls ( P < 0.001). CONCLUSIONS: Study findings confirm the accuracy of AD-1 in diagnosing BIRI and indicate superiority to microbial culture. Although further study is warranted, AD-1 may facilitate perioperative decision-making in BIRI management in a resource-efficient manner. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, II.

Risk factors and outcomes associated with external ventricular drain infections.

BACKGROUND: Insertion of an external ventricular drain (EVD) is a common neurosurgical procedure which may lead to serious complications including infection. Some risk factors associated with EVD infection are well established. Others remain less certain, including specific indications for placement, prior neurosurgery, and prior EVD placement. OBJECTIVE: To identify risk factors for EVD infections. METHODS: We reviewed all EVD insertions at our institution from March 2015 through May 2019 following implementation of a standardized infection control protocol for EVD insertion and maintenance. Cox regression was used to identify risk factors for EVD infections. RESULTS: 479 EVDs placed in 409 patients met inclusion criteria, and 9 culture-positive infections were observed during the study period. The risk of infection within 30 days of EVD placement was 2.2% (2.3 infections/1,000 EVD days). Coagulase-negative staphylococci were identified in 6 of the 9 EVD infections). EVD infection led to prolonged length of stay post-EVD-placement (23 days vs 16 days; P = .045). Cox regression demonstrated increased infection risk in patients with prior brain surgery associated with cerebrospinal fluid (CSF) diversion (HR, 8.08; 95% CI, 1.7-39.4; P = .010), CSF leak around the catheter (HR, 21.0; 95% CI, 7.0-145.1; P = .0007), and insertion site dehiscence (HR, 7.53; 95% CI, 1.04-37.1; P = .0407). Duration of EVD use >7 days was not associated with infection risk (HR, 0.62; 95% CI, 0.07-5.45; P = .669). CONCLUSION: Risk factors associated with EVD infection include prior brain surgery, CSF leak, and insertion site dehiscence. We found no significant association between infection risk and duration of EVD placement.

Prevention of hospital-acquired respiratory viral infections: Assessment of a multimodal intervention program.

A multimodal program focused on preventing nosocomial respiratory viral infections. Definite cases per 1,000 discharges increased 1.3-fold in hospital units screening visitors for respiratory viral symptoms during the 2017-2018 respiratory virus season but not during the 2016-2017 season. Definite cases per 1,000 discharges increased 3.1-fold in hospital units that did not screen visitors either season.

Antimicrobial Efficacy and Safety of a Novel Gas Plasma-Activated Catheter Lock Solution.

Antimicrobial lock solutions are important for prevention of microbial colonization and infection of long-term central venous catheters. We investigated the efficacy and safety of a novel antibiotic-free lock solution formed from gas plasma-activated disinfectant (PAD). Using a luminal biofilm model, viable cells of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Candida albicans in mature biofilms were reduced by 6 to 8 orders of magnitude with a PAD lock for 60 min. Subsequent 24-h incubation of PAD-treated samples resulted in no detectable regrowth of viable bacteria or fungi. As a comparison, the use of a minocycline-EDTA-ethanol lock solution for 60 min led to regrowth of bacteria and fungi, up to 107 to 109 CFU/ml, in 24 h. The PAD lock solution had minimal impact on human umbilical vein endothelial cell viability, whereas the minocycline-EDTA-ethanol solution elicited cell death in nearly half of human endothelial cells. Additionally, PAD treatment caused little topological change to catheter materials. In conclusion, PAD represents a novel antibiotic-free, noncytotoxic lock solution that elicits rapid and broad-spectrum eradication of biofilm-laden microbes and shows promise for the prevention and treatment of intravascular catheter infections.

Antimicrobial lock solutions as a method to prevent central line-associated bloodstream infections: a meta-analysis of randomized controlled trials.

BACKGROUND: Antimicrobial lock solutions may be an effective strategy to prevent catheter-associated infections. However, there remains concern about their efficacy and safety. METHODS: To investigate the efficacy of antimicrobial lock therapy to prevent central line-associated bloodstream infections (CLABSIs), we performed a systematic search of PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov, from the earliest date up to 31 December 2013. Studies were eligible if they were randomized controlled trials comparing antimicrobial lock solutions to heparin and if they provided an appropriate definition of infection. RESULTS: The 23 included studies reported data on 2896 patients, who were predominantly adult patients undergoing hemodialysis (16/23 studies), but also adult and pediatric oncology patients, critically ill neonates, and patients receiving total parenteral nutrition. The use of antimicrobial lock solutions led to a 69% reduction in CLABSI rate (relative risk [RR], 0.31; 95% confidence interval [CI], .24-.40) and a 32% reduction in the rate of exit site infections (RR, 0.68; 95% CI, .49-.95) compared with heparin, without significantly affecting catheter failure due to noninfectious complications (RR, 0.83; 95% CI, .65-1.06). All-cause mortality was not different between the groups (RR, 0.84; 95% CI .64-1.12). Neither the type of antimicrobial solution nor the population studied, affected the relative reduction in CLABSIs, which also remained significant among studies reporting baseline infection rates of <1.15 per 1000 catheter-days, and studies providing data for catheter-related bloodstream infections. Publication and selective reporting bias are a concern in our study and should be acknowledged. CONCLUSIONS: Antimicrobial lock solutions are effective in reducing risk of CLABSI, and this effect appears to be additive to traditional prevention measures.

Comparison of ML8-X10 (a prototype oil-in-water micro-emulsion based on a novel free fatty acid), taurolidine/citrate/heparin and vancomycin/heparin antimicrobial lock solutions in the eradication of biofilm-producing staphylococci from central venous catheters.

OBJECTIVES: Antimicrobial lock solutions are used for prevention and management of catheter-related bloodstream infections. ML8-X10 (a prototype oil-in-water micro-emulsion based on a novel free fatty acid), vancomycin/heparin and taurolidine/citrate/heparin (Taurolock™-Hep500) lock solutions were tested against biofilm-forming Staphylococcus epidermidis and methicillin-susceptible Staphylococcus aureus. METHODS: MICs were tested in neutral broth (pH ~7) and acidified broth (pH 5). In an established in vitro central venous catheter (CVC) lock model, solutions were introduced after 24 h of bacterial growth in a CVC incubated at 37°C. After an additional 8, 24 or 72 h of incubation, saline flush and cut catheter segments were processed for bacterial quantification. The cfu/mL at 0 h was subtracted from cfu/mL at the different timepoints. RESULTS: The activities of ML8-X10 and taurolidine solutions were enhanced at lower pH (P < 0.05). Against S. epidermidis, ML8-X10 solution demonstrated less activity than taurolidine at 8 h (P < 0.001), but was not significantly different from vancomycin. At 24 h, ML8-X10 solution demonstrated significantly less activity than taurolidine (P < 0.001), but was significantly more active than vancomycin (P < 0.001). Against S. aureus, ML8-X10 solution was less active than taurolidine at 8 and 24 h (P < 0.001 for both), but was similar to vancomycin. At 72 h, all lock solutions reduced colony counts to levels that approached or reached the limit of detection against both strains. CONCLUSIONS: In our in vitro catheter lock model, the novel free fatty acid emulsion demonstrated activity against biofilm-forming staphylococci similar to or greater than that of vancomycin lock solution. Taurolidine was the most active lock solution at 8 and 24 h, with all lock solutions tested demonstrating high activity at 72 h.

Severe group a streptococcus surgical site infection after thyroid lobectomy.

BACKGROUND: Thyroidectomy is rarely complicated by a surgical site infection (SSI). Despite its low incidence, post-thyroidectomy SSI is especially concerning because of its proximity to vital head and neck structures and the very real potential for airway compromise and death. Severe SSIs frequently are caused by Group A Streptococcus (GAS) because of its potential for developing into necrotizing fascitis. No description of the surgical approach to a necrotizing soft-tissue infection after thyroid resection is available in the current literature. METHODS: Case report and review of the pertinent English-language literature. RESULTS: A 47-year-old male underwent a right thyroid lobectomy and isthmusectomy for a follicular neoplasm. On post-operative day 2, the patient presented to the emergency department with persistent pain, rapid onset of swelling, and airway compromise shown on computed tomography scan. Emergency incision and drainage revealed a severe soft tissue infection. Because of subsequent worsening erythema and soft-tissue swelling, the patient had to be re-explored. The infection, later identified as caused by GAS, might have been transmitted from the patient's daughter. CONCLUSION: To our knowledge, this is the first case reported of exposure to a family member with GAS pharyngitis. Successful treatment requires an appropriately high level of suspicion followed by emergent operative debridement and systemic antibiotics.

Infection prevention and control during prolonged human space travel.

Prolonged human spaceflight to another planet or an asteroid will introduce unique challenges of mitigating the risk of infection. During space travel, exposure to microgravity, radiation, and stress alter human immunoregulatory responses, which can in turn impact an astronaut's ability to prevent acquisition of infectious agents or reactivation of latent infection. In addition, microgravity affects virulence, growth kinetics, and biofilm formation of potential microbial pathogens. These interactions occur in a confined space in microgravity, providing ample opportunity for heavy microbial contamination of the environment. In addition, there is the persistence of aerosolized, microbe-containing particles. Any mission involving prolonged human spaceflight must be carefully planned to minimize vulnerabilities and maximize the likelihood of success.

Defining bloodstream infections related to central venous catheters in patients with cancer: a systematic review.

The objective of this review was to determine whether consistent definitions were used in published studies of bloodstream infections due to central venous catheters in patients with cancer (ie, catheter-related or catheter-associated bloodstream infections). Review of 191 studies reporting catheter-related or catheter-associated bloodstream infections in patients with cancer revealed a lack of uniformity in these definitions. We grouped definitions by type, with 39 articles failing to cite or report a definition. Definitions included those of the Centers for Disease Control and Prevention (n = 39) and the Infectious Diseases Society of America (n = 18). The criteria included in the definitions in studies were also tabulated. Clinical manifestations were frequently included. Definitions used have been highly variable; comparability of risk factors, incidence, management, and outcomes of such infections is difficult to achieve across studies. Future research should focus on development of a common definition of catheter-related and catheter-associated bloodstream infections for both adults and children with cancer.

Distinguishing characteristics between pandemic 2009-2010 influenza A (H1N1) and other viruses in patients hospitalized with respiratory illness.

BACKGROUND: Differences in clinical presentation and outcomes among patients infected with pandemic 2009 influenza A H1N1 (pH1N1) compared to other respiratory viruses have not been fully elucidated. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective study was performed of all hospitalized patients at the peak of the pH1N1 season in whom a single respiratory virus was detected by a molecular assay targeting 18 viruses/subtypes (RVP, Luminex xTAG). Fifty-two percent (615/1192) of patients from October, 2009 to December, 2009 had a single respiratory virus (291 pH1N1; 207 rhinovirus; 45 RSV A/B; 37 parainfluenza; 27 adenovirus; 6 coronavirus; and 2 metapneumovirus). No seasonal influenza A or B was detected. Individuals with pH1N1, compared to other viruses, were more likely to present with fever (92% & 70%), cough (92% & 86%), sore throat (32% & 16%), nausea (31% & 8%), vomiting (39% & 30%), abdominal pain (14% & 7%), and a lower white blood count (8,500/L & 13,600/L, all p-values<0.05). In patients with cough and gastrointestinal complaints, the presence of subjective fever/chills independently raised the likelihood of pH1N1 (OR 10). Fifty-five percent (336/615) of our cohort received antibacterial agents, 63% (385/615) received oseltamivir, and 41% (252/615) received steroids. The mortality rate of our cohort was 1% (7/615) and was higher in individuals with pH1N1 compared to other viruses (2.1% & 0.3%, respectively; p = 0.04). CONCLUSIONS/SIGNIFICANCE: During the peak pandemic 2009-2010 influenza season in Rhode Island, nearly half of patients admitted with influenza-like symptoms had respiratory viruses other than influenza A. A high proportion of patients were treated with antibiotics and pH1N1 infection had higher mortality compared to other respiratory viruses.

Methicillin-resistant Staphylococcus aureus colonization of house officers.

We performed a prospective prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage in the nares of 50 medical and 50 surgical house officers. None of the 50 internal medicine house officers and 5 of the 50 general surgery house officers had MRSA nares colonization (P = .03). None of the MRSA isolates recovered from the surgical house officers were identical.

Microbial colonization of tourniquets used in orthopedic surgery.

This study analyzed tourniquets used for orthopedic surgery in our hospital to determine the frequency and type of microbial contamination. Group A tourniquets were from our main operating room, Group B tourniquets were from our ambulatory surgicenter, Group C tourniquets were unused, prepackaged, sterile tourniquets from our main operating room, and Group D tourniquets were sterilely packed tourniquets from our ambulatory surgicenter. Tourniquets from Groups A, B, C, and D had 100%, 40%, 0%, and 0% microbial growth, respectively. For Group A tourniquets, coagulase-negative staphylococci, Bacillus, and Staphylococcus aureus were present in 100%, 60%, and 20% of tourniquets, respectively. Twenty percent were contaminated either with Streptococcus sanguis, Aerococcus viridans, or Cornyebacterium species. Coagulase-negative staphylococci and Bacillus were present in 40% and 30% of Group B tourniquets, respectively. Tourniquet contamination may be a risk factor for the development of surgical site infection in orthopedic surgery.

Pseudomonas surgical-site infections linked to a healthcare worker with onychomycosis.

OBJECTIVE: To determine the etiology of Pseudomonas aeruginosa surgical-site infections following cardiac surgery. SETTING: University teaching hospital. PATIENTS: Those with wound cultures that grew P. aeruginosa after cardiac surgery performed from 1999 to 2001. METHODS: Medical records and operating room (OR) records of patients with P. aeruginosa cardiac surgical-site infections from 1999 to 2001 were reviewed. Healthcare workers involved with two or more cases were interviewed and examined. Specimens for environmental cultures were obtained from the ORs and cardiac surgical equipment. Cardiac surgery cases were observed and postoperative care and the cleaning of surgical instruments were investigated. OR air handling system records during the epidemic period were reviewed. Molecular fingerprinting of available P. aeruginosa isolates from infected patients and a healthcare worker was done. RESULTS: There were five P. aeruginosa cardiac surgical-site infections from January to August 2001, compared with no such infections from 1999 to 2000. All were adult patients. One cardiac surgeon with onychomycosis operated on all five cases. He did not routinely double glove. The involved fingernail grew P. aeruginosa. Three P. aeruginosa patient isolates were available for pulsed-field gel electrophoresis; two were identical to the isolate from the involved surgeon's onychomycotic nail. No environmental OR cultures grew P. aeruginosa. The surgeon's culture-positive nail was completely removed. There have been no P. aeruginosa surgical-site infections among cardiac surgery patients since this intervention. CONCLUSION: At least two cases of a cluster of P. aeruginosa surgical-site infections resulted from colonization of a cardiac surgeon's onychomycotic nail.

Guidelines for the prevention of intravascular catheter-related infections. The Hospital Infection Control Practices Advisory Committee, Center for Disease Control and Prevention, U.S.

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996. These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Guidelines for the prevention of intravascular catheter-related infections. Centers for Disease Control and Prevention.

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery anesthesiology interventional radiology pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology ofAmerica (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996 These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e., education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.