Effects of antimicrobial use in agricultural animals on drug-resistant foodborne salmonellosis in humans: A systematic literature review.

Controversy continues concerning antimicrobial use in food animals and its relationship to drug-resistant infections in humans. We systematically reviewed published literature for evidence of a relationship between antimicrobial use in agricultural animals and drug-resistant meat or dairy-borne non-typhoidal salmonellosis in humans. Based on publications from the United States (U.S.), Canada, and Denmark from January 2010 to July 2014, 858 articles received title and abstract review, 104 met study criteria for full article review with 68 retained for which data are presented. Antibiotic exposure in both cattle and humans found an increased likelihood of Salmonella colonization, whereas in chickens, animals not exposed to antibiotics (organic) were more likely to be Salmonella positive and those that had antibiotic exposure were more likely to harbor antimicrobial resistant Salmonella organisms. In swine literature, only tylosin exposure was examined and no correlation was found among exposure, Salmonella colonization, or antimicrobial resistance. No studies that identified farm antimicrobial use also traced antimicrobial-resistant Salmonella from farm to fork.

Effect of Antimicrobial Use in Agricultural Animals on Drug-resistant Foodborne Campylobacteriosis in Humans: A Systematic Literature Review.

Controversy continues concerning antimicrobial use in food animals and its relationship to drug-resistant infections in humans. We systematically reviewed published literature for evidence of a relationship between antimicrobial use in agricultural animals and drug-resistant foodborne campylobacteriosis in humans. Based on publications from the United States (U.S.), Canada and Denmark from 2010 to July 2014, 195 articles were retained for abstract review, 50 met study criteria for full article review with 36 retained for which data are presented. Two publications reported increase in macrolide resistance of Campylobacter coli isolated from feces of swine receiving macrolides in feed, and one of these described similar findings for tetracyclines and fluoroquinolones. A study in growing turkeys demonstrated increased macrolide resistance associated with therapeutic dosing with Tylan® in drinking water. One publication linked tetracycline-resistant C. jejuni clone SA in raw cow's milk to a foodborne outbreak in humans. No studies that identified farm antimicrobial use also traced antimicrobial-resistant Campylobacter from farm to fork. Recent literature confirms that on farm antibiotic selection pressure can increase colonization of animals with drug-resistant Campylobacter spp. but is inadequately detailed to establish a causal relationship between use of antimicrobials in agricultural animals and prevalence of drug-resistant foodborne campylobacteriosis in humans.

The hidden microbiome of hospital infection surveillance testing: biomarkers of health outcomes in MRSA and VRE colonization.

Background: Hospital-acquired infections present a major concern for healthcare systems in the U.S. and worldwide. Drug-resistant infections result in increased costs and prolonged hospital stays. Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) are responsible for many drug-resistant infections in the U.S. We undertook two parallel studies aimed to investigate the differences in the microbial communities of individuals colonized with MRSA (or VRE) as compared to their respective non-colonized counterparts matched for age, sex, race, ethnicity, unit of admission, and diagnostic-related group, when available. Results: The VRE study showed considerably more Enterococcus genus communities in the VRE colonized samples. Our findings for both MRSA and VRE studies suggest a strong association between 16S rRNA gene alpha diversity, beta diversity, and colonization status. When we assessed the colonized microbial communities in isolation, the differences disappeared, suggesting that the colonized microbial communities drove the change. Isolating Staphylococcus, we saw significant differences expressed across colonization in specific sequence variants. Conclusions: The differences seen in the microbial communities from MRSA (or VRE) colonized samples as compared to non-colonized match-pairs are driven by the isolated communities of the Staphylococcus (or Enterococcus) genus, the removal of which results in the disappearance of any differences in the diversity observed across the match-pairs.

Sustained reduction of microbial burden on common hospital surfaces through introduction of copper.

The contribution of environmental surface contamination with pathogenic organisms to the development of health care-associated infections (HAI) has not been well defined. The microbial burden (MB) associated with commonly touched surfaces in intensive care units (ICUs) was determined by sampling six objects in 16 rooms in ICUs in three hospitals over 43 months. At month 23, copper-alloy surfaces, with inherent antimicrobial properties, were installed onto six monitored objects in 8 of 16 rooms, and the effect that this application had on the intrinsic MB present on the six objects was assessed. Census continued in rooms with and without copper for an additional 21 months. In concert with routine infection control practices, the average MB found for the six objects assessed in the clinical environment during the preintervention phase was 28 times higher (6,985 CFU/100 cm(2); n = 3,977 objects sampled) than levels proposed as benign immediately after terminal cleaning (<250 CFU/100 cm(2)). During the intervention phase, the MB was found to be significantly lower for both the control and copper-surfaced objects. Copper was found to cause a significant (83%) reduction in the average MB found on the objects (465 CFU/100 cm(2); n = 2714 objects) compared to the controls (2,674 CFU/100 cm(2); n = 2,831 objects [P < 0.0001]). The introduction of copper surfaces to objects formerly covered with plastic, wood, stainless steel, and other materials found in the patient care environment significantly reduced the overall MB on a continuous basis, thereby providing a potentially safer environment for hospital patients, health care workers (HCWs), and visitors.

Methicillin-resistant Staphylococcus aureus colonization among women admitted for preterm delivery.

OBJECTIVE: Methicillin-resistant Staphylococcus aureus infection is associated with morbidity in the neonatal intensive care unit. The purpose of this study was to determine the relationship between preterm maternal methicillin-resistant S aureus colonization and subsequent colonization and infection in premature neonates. STUDY DESIGN: We conducted a prospective cohort study of 422 women admitted for preterm delivery. Methicillin-resistant S aureus cultures were collected from mothers and their neonates admitted to neonatal intensive care unit. We determined the proportion of women and neonates colonized with methicillin-resistant S aureus and examined possible factors associated with colonization and infection. RESULTS: Fifteen of 422 (3.6%) women were found to be colonized with methicillin-resistant S aureus. Thirteen of 212 (6.1%) neonates admitted to neonatal intensive care unit were methicillin-resistant S aureus colonized and 3 of 13 (23.1%) developed a methicillin-resistant S aureus infection. We identified 1 methicillin-resistant S aureus colonized maternal-neonatal pair. The infant became methicillin-resistant S aureus positive 30 days after admission and did not develop a methicillin-resistant S aureus infection. CONCLUSION: These findings suggest that maternal methicillin-resistant S aureus colonization is not a significant risk factor for vertical transmission of neonatal methicillin-resistant S aureus colonization.

Attributable hospital cost and length of stay associated with health care-associated infections caused by antibiotic-resistant gram-negative bacteria.

Determination of the attributable hospital cost and length of stay (LOS) are of critical importance for patients, providers, and payers who must make rational and informed decisions about patient care and the allocation of resources. The objective of the present study was to determine the additional total hospital cost and LOS attributable to health care-associated infections (HAIs) caused by antibiotic-resistant, gram-negative (GN) pathogens. A single-center, retrospective, observational comparative cohort study was performed. The study involved 662 patients admitted from 2000 to 2008 who developed HAIs caused by one of following pathogens: Acinetobacter spp., Enterobacter spp., Escherichia coli, Klebsiella spp., or Pseudomonas spp. The attributable total hospital cost and LOS for HAIs caused by antibiotic-resistant GN pathogens were determined by comparison with the hospital costs and LOS for a control group with HAIs due to antibiotic-susceptible GN pathogens. Statistical analyses were conducted by using univariate and multivariate analyses. Twenty-nine percent of the HAIs were caused by resistant GN pathogens, and almost 16% involved a multidrug-resistant GN pathogen. The additional total hospital cost and LOS attributable to antibiotic-resistant HAIs caused by GN pathogens were 29.3% (P < 0.0001; 95% confidence interval, 16.23 to 42.35) and 23.8% (P = 0.0003; 95% confidence interval, 11.01 to 36.56) higher than those attributable to HAIs caused by antibiotic-susceptible GN pathogens, respectively. Significant covariates in the multivariate analysis were age >or=12 years, pneumonia, intensive care unit stay, and neutropenia. HAIs caused by antibiotic-resistant GN pathogens were associated with significantly higher total hospital costs and increased LOSs compared to those caused by their susceptible counterparts. This information should be used to assess the potential cost-efficacy of interventions aimed at the prevention of such infections.

Risk Factors for Fungal Prosthetic Joint Infection.

Background: Fungal prosthetic joint infections (PJIs) are rare and often associated with poor outcome; however, risk factors are not well described. Methods: This was a retrospective case control study among all patients with PJIs from 2006-2016 at two major academic centers. Each fungal PJI case was matched 1:1 with a bacterial PJI control by joint (hip, knee, shoulder) and year of diagnosis. We compared demographics, comorbidities, and clinical characteristics between cases and controls using chi square/Fisher's exact or Wilcoxon rank sum test. Independent risk factors were identified with multivariable logistic regression. Results: Forty-one fungal PJIs occurred over the study and 61% were due to Candida albicans. The hip was involved in 51.2% of cases, followed by the knee (46.3%). Compared to bacterial PJI, fungal PJI cases were more likely to have received antibiotics within the previous 3 months (70.7% vs 34%, P=.001), wound drainage lasting >5 days (48% vs 9%, P=.0002), had a lower median CRP (2.95 mg/dl vs 5.99, P=.013) and synovial fluid white blood cell count (13,953 cells/mm3 vs 33,198, P=.007), and a higher proportion of prior two-stage exchanges (82.9% vs 53.6%, P=.008). After controlling for center, prolonged wound drainage (OR, 7.3; 95% CI, 2.02-26.95) and recent antibiotics (OR, 3.4; 95% CI, 1.2-9.3) were significantly associated with fungal PJI. Conclusion: In our study, Candida albicans was the most common species in fungal PJIs and prolonged wound drainage and recent antibiotics were independent risk factors. These clinical characteristics may help providers anticipate fungal PJI and adjust management strategies.

Development of a Sterile Personal Protective Equipment Donning and Doffing Procedure to Protect Surgical Teams from SARS-CoV-2 Exposure during the COVID-19 Pandemic.

Background: The coronavirus disease 2019 (COVID-19) pandemic has become an increasingly challenging problem throughout the world. Because of the numerous potential modes of transmission, surgeons and all procedural staff represent a unique population that requires standardized procedures to protect themselves and their patients. Although several protocols have been implemented during other infectious disease outbreaks, such as Ebola virus, no standardized protocol has been published in regard to the COVID-19 pandemic. Methods: A multidisciplinary team of two surgeons, an anesthesiologist, and an infection preventionist was assembled to create a process with sterile attire adapted from the National Emerging Special Pathogen Training and Education Center (NETEC) donning and doffing process. After editing, a donning procedure and doffing procedure was created and made into checklists. The procedures were simulated in an empty operating room (OR) with simulation of all personnel roles. A "dofficer" role was established to ensure real-time adherence to the procedures. Results: The donning and doffing procedures were printed as one-page documents for easy posting in ORs and procedural areas. Pictures from the simulation were also obtained and made into flow chart-style diagrams that were also posted in the ORs. Conclusions: Coronavirus disease 2019 (COVID-19) is a quickly evolving pandemic that has spread all over the globe. With the rapid increase of infections and the increasing number of severely ill individuals, healthcare providers need easy-to-follow guidelines to keep themselves and patients as safe as possible. The processes for donning and doffing personal protective equipment (PPE) presented here provide an added measure of safety to surgeons and support staff to provide quality surgical care to positive and suspected COVID-19-positive patients.

Potential for the current National Healthcare Safety Network (NHSN) >3 days after admission definition of laboratory-identified, healthcare-facility-onset, Clostridioides difficile infection (HO-CDI) to overestimate rates.

Healthcare-facility-onset C.difficile LabID events are defined as positive stool samples collected >3 days after hospitalization. Using a definition of >72 hours, we found that 84 of 1013 cases (8.3%) identified as C. difficile LabID events were collected between 48 and 72 hours after admission.

Health care-associated bloodstream infections associated with negative- or positive-pressure or displacement mechanical valve needleless connectors.

BACKGROUND: Health care-associated, central venous catheter-related bloodstream infections (HA-BSIs) are a major cause of morbidity and mortality. Needleless connectors (NCs) are an important component of the intravenous system. NCs initially were introduced to reduce health care worker needlestick injuries, yet some of these NCs may increase HA-BSI risk. METHODS: We compared HA-BSI rates on wards or intensive care units (ICUs) at 5 hospitals that had converted from split septum (SS) connectors or needles to mechanical valve needleless connectors (MV-NCs). The hospitals (16 ICUs, 1 entire hospital, and 1 oncology unit; 3 hospitals were located in the United States, and 2 were located in Australia) had conducted HA-BSI surveillance using Centers for Disease Control and Prevention definitions during use of both NCs. HA-BSI rates and prevention practices were compared during the pre-MV period, MV period, and post-MV period. RESULTS: The HA-BSI rate increased in all ICUs and wards when SS-NCs were replaced by MV-NCs. In the 16 ICUs, the HA-BSI rate increased significantly when SS-NCs or needles were replaced by MV-NCs (6.15 vs 9.49 BSIs per 1000 central venous catheter [CVC]-days; relative risk, 1.54; 95% confidence interval, 1.37-1.74; P < .001). The 14 ICUs that switched back to SS-NCs had significant reductions in their BSI rates (9.49 vs 5.77 BSIs per 1000 CVC-days; relative risk, 1.65; 95% confidence interval, 1.38-1.96; p < .001). BSI infection prevention strategies were similar in the pre-MV and MV periods. CONCLUSIONS: We found strong evidence that MV-NCs were associated with increased HA-BSI rates, despite similar BSI surveillance, definitions, and prevention strategies. Hospital personnel should monitor their HA-BSI rates and, if they are elevated, examine the role of newer technologies, such as MV-NCs.

Peripherally inserted central catheter-associated bloodstream infection: Risk factors and the role of antibiotic-impregnated catheters for prevention.

BACKGROUND: Antimicrobial-impregnated (AIP) peripherally inserted central catheters (PICCs) may lower risk of central line-associated bloodstream infection (CLABSI) compared with nonantimicrobial-impregnated (NAIP) catheters. We sought to assess risk factors for CLABSI with a focus on the effect of AIP PICCs. METHODS: CLABSI rate was determined among patients who received PICCs from July 2009 through June 2012 using a retrospective study design. A nested case-control study matched for operators (interventional radiology [IR], infectious diseases [IDs], and the nurse venous access team [VAT]) was conducted to assess risks for PICC CLABSI. RESULTS: Eighty-nine PICC CLABSIs (1.66%) occurred among 5,372 PICC placements a mean of 32 days after placement. Higher infection risk (1.75) was observed for IR-placed PICCs compared with ID-placed PICCs (P = .02). In addition, higher infection risk (4.22) was observed for IR-placed PICCS compared with VAT-placed PICCs (P = .0008). IR-placed NAIP catheters, as indicated by multivariate analysis, revealed a 5.45-fold greater CLABSI risk compared with AIP catheters (P < .0005). Other risk factors included chemotherapy, placement of a tunneled catheter, leukemia, and AIDS. CONCLUSIONS: PICC CLABSIs were highest among patients receiving NAIP catheters in this large study. Highest risk occurred with placement of a tunneled catheter, AIDS, leukemia, and if the indication for PICC was chemotherapy. Our study suggests that the AIP PICC should be considered in all patients receiving PICCs.

Risk of vancomycin-resistant Enterococcus (VRE) bloodstream infection among patients colonized with VRE.

BACKGROUND: Colonization with vancomycin-resistant Enterococcus (VRE) is a risk factor for subsequent VRE bloodstream infection (BSI); however, risk factors for BSI among colonized patients have not been adequately described. We sought to determine the proportion of VRE-colonized patients who subsequently develop VRE BSI and to identify risk factors for VRE BSI among these patients. METHODS: Records of 768 patients colonized with VRE from January 2002 through June 2005 were reviewed. The proportion of patients who developed VRE BSI was calculated, and the characteristics of these patients were compared, in a 2:1 ratio, with those of patients who did not develop VRE BSI. To identify risk factors for VRE BSI and for death, we used univariate logistic regression analysis and then multivariate logistic regression analysis. Using pulsed-field gel electrophoresis (PFGE), we compared the isolate recovered when the patient was colonized and the isolate recovered when the patient developed VRE BSI. RESULTS: Of the 768 patients colonized with VRE, 31 (4.0%) developed VRE BSI. Multivariate analysis identified the following independent risk factors for developing VRE BSI: infection of an additional body site other than blood (adjusted odds ratio [aOR], 3.9; P = .04), admission to the hospital from a long-term care facility (aOR, 12.6; P = .04), and receipt of vancomycin (aOR, 10.6; P = .001). The independent risk factors for death among patients colonized with VRE were immunosuppression (aOR, 12.9; P = .001) and VRE BSI (aOR, 9.1; P = .002). Of the 31 patients who developed VRE BSI, 23 (74%) had a pair of isolates representing VRE colonization and VRE BSI. For 19 (83%) of these 23 patients, the isolate representing BSI was genetically related to the isolate representing VRE colonization: 12 pairs of isolates (52%) had identical banding patterns, 5 had closely related patterns, and 2 had possibly related patterns. CONCLUSION: Of the 768 patients colonized with VRE, 31 (4.0%) usually developed VRE BSI due to a related strain. Independent risk factors for BSI among colonized patients were admission from a long-term care facility, infection of an additional body site, and exposure to vancomycin. Independent risk factors for death were immunosuppression and VRE BSI.

Nosocomial infections due to methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus: relationships with antibiotic use and cost drivers.

BACKGROUND: Increased incidence of nosocomial infections due to methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) has been associated with the use of certain antibiotics and has resulted in increased morbidity, mortality, and costs of care. OBJECTIVE: To describe relationships between vancomycin and linezolid use and incidence of these nosocomial infections over time and to determine factors associated with the increased costs of care (cost drivers) associated with affected patients. METHODS: The association between institution-wide antibiotic use and the rate of nosocomial MRSA and VRE infections was assessed using segmented regression analysis for interrupted time series. The effect that patient characteristics and procedures, as well as certain antibiotic use, had on costs and length of stay of patients with MRSA or VRE nosocomial infection was also assessed and cost drivers for the 2 types of infections were compared. RESULTS: Our analysis included 206 patients who developed MRSA (n = 187) or VRE (n = 19) nosocomial infection. Although small numbers of VRE nosocomial infection may limit generalizations from our results, we found no significant relationship between vancomycin or linezolid use and the rate of either infection. While mean hospital costs were similar, cost drivers varied somewhat between infection types. CONCLUSIONS: The incidence of MRSA or VRE infections does not appear to be related to the use of vancomycin or linezolid. Costs of care are quite high in some affected patients and, while mean total hospital costs are similar, cost drivers appear to differ between the 2 infection types.

Strongyloides hyperinfection: a treatment dilemma.

Strongyloides stercoralis infection is a common cause of abdominal pain and diarrhea worldwide. Usually a chronic and limited disease, it can present a therapeutic dilemma when infection is overwhelming, such as what might occur in an immunosuppressed patient. Here we present a case of strongyloides hyperinfection treated successfully with a veterinary formulation of parenteral ivermectin.

The Influence of Traffic, Area Location, and Other Factors on Operating Room Microbial Load.

OBJECTIVE To determine how the movement of patients, equipment, materials, staff, and door openings within the operating room (OR) affect microbial loads at various locations within the OR. DESIGN Observation and sampling study. SETTING Academic health center, public hospital. METHODS We first analyzed 27 videotaped procedures to determine the areas in the OR with high and low numbers of people in transit. We then placed air samplers and settle plates in representative locations during 21 procedures in 4 different ORs during 2 different seasons of the year to measure microbial load in colony-forming units (CFU). The temperature and humidity, number of door openings, physical movement, and the number of people in the OR were measured for each procedure. Statistical analysis was conducted using hierarchical regression. RESULTS The microbial load was affected by the time of year that the samples were taken. Both microbial load measured by the air samplers and by settle plates in 1 area of the OR was correlated with the physical movement of people in the same area but not with the number of door openings and the number of people in the OR. CONCLUSIONS Movement in the OR is correlated with the microbial load. Establishing operational guidelines or developing OR layouts that focus on minimizing movement by incorporating desirable internal storage points and workstations can potentially reduce microbial load, thereby potentially reducing surgical site infection risk. Infect Control Hosp Epidemiol 2018;39:391-397.

Increased rate of catheter-related bloodstream infection associated with use of a needleless mechanical valve device at a long-term acute care hospital.

OBJECTIVE: To determine whether introduction of a needleless mechanical valve device (NMVD) at a long-term acute care hospital was associated with an increased frequency of catheter-related bloodstream infection (BSI). DESIGN: For patients with a central venous catheter in place, the catheter-related BSI rate during the 24-month period before introduction of the NMVD, a period in which a needleless split-septum device (NSSD) was being used (hereafter, the NSSD period), was compared with the catheter-related BSI rate during the 24-month period after introduction of the NMVD (hereafter, the NMVD period). The microbiological characteristics of catheter-related BSIs during each period were also compared. Comparisons and calculations of relative risks (RRs) with 95% confidence intervals (CIs) were performed using chi (2) analysis. RESULTS: Eighty-six catheter-related BSIs (3.86 infections per 1,000 catheter-days) occurred during the study period. The rate of catheter-related BSI during the NMVD period was significantly higher than that during the NSSD period (5.95 vs 1.79 infections per 1,000 catheter-days; RR, 3.32 [95% CI, 2.88-3.83]; P<.001). A significantly greater percentage of catheter-related BSIs during the NMVD period were caused by gram-negative organisms, compared with the percentage recorded during the NSSD period (39.5% vs 8%; P=.007). Among catheter-related BSIs due to gram-positive organisms, the percentage caused by enterococci was significantly greater during the NMVD period, compared with the NSSD period (54.8% vs 13.6%; P=.004). The catheter-related BSI rate remained high during the NMVD period despite several educational sessions regarding proper use of the NMVD. CONCLUSIONS: An increased catheter-related BSI rate was temporally associated with use of a NMVD at the study hospital, despite several educational sessions regarding proper NMVD use. The current design of the NMVD may be unsafe for use in certain patient populations.

When should contact precautions be discontinued for patients with methicillin-resistant Staphylococcus aureus?

When to discontinue contact precautions for patients with methicillin-resistant Staphylococcus aureus (MRSA) remains unresolved and policies vary between hospitals. We prospectively performed admission active surveillance cultures on patients known to have been MRSA positive for at least 1 year to determine the proportion who remained positive. The proportion of patients with MRSA who remained positive was 19.9%; however, this significantly decreased over time, particularly after 5 years.

Antimicrobial copper alloys decreased bacteria on stethoscope surfaces.

BACKGROUND: Stethoscopes may serve as vehicles for transmission of bacteria among patients. The aim of this study was to assess the efficacy of antimicrobial copper surfaces to reduce the bacterial concentration associated with stethoscope surfaces. METHODS: A structured prospective trial involving 21 health care providers was conducted at a pediatric emergency division (ED) (n = 14) and an adult medical intensive care unit located in tertiary care facilities (n = 7). Four surfaces common to a stethoscope and a facsimile instrument fabricated from U.S. Environmental Protection Agency-registered antimicrobial copper alloys (AMCus) were assessed for total aerobic colony counts (ACCs), methicillin-resistant Staphylococcus aureus, gram-negative bacteria, and vancomycin-resistant enterococci for 90 days. RESULTS: The mean ACCs collectively recovered from all stethoscope surfaces fabricated from the AMCus were found to carry significantly lower concentrations of bacteria (pediatric ED, 11.7 vs 127.1 colony forming units [CFU]/cm2, P < .00001) than their control equivalents. This observation was independent of health care provider or infection control practices. Absence of recovery of bacteria from the AMCu surfaces (66.3%) was significantly higher (P < .00001) than the control surfaces (22.4%). The urethane rim common to the stethoscopes was the most heavily burdened surface; mean concentrations exceeded the health care-associated infection acquisition concentration (5 CFU/cm2) by at least 25×, supporting that the stethoscope warrants consideration in plans mitigating microbial cross-transmission during patient care. CONCLUSIONS: Stethoscope surfaces fabricated with AMCus were consistently found to harbor fewer bacteria.