Effectiveness of mRNA Booster Vaccine Against Coronavirus Disease 2019 Infection and Severe Outcomes Among Persons With and Without Immune Dysfunction: A Retrospective Cohort Study of National Electronic Medical Record Data in the United States.

Background: Real-world evidence of coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) booster effectiveness among patients with immune dysfunction are limited. Methods: We included data from patients in the United States National COVID Cohort Collaborative (N3C) who completed ≥2 doses of mRNA vaccination between 10 December 2020 and 27 May 2022. Immune dysfunction conditions included human immunodeficiency virus infection, solid organ or bone marrow transplant, autoimmune diseases, and cancer. We defined incident COVID-19 BTI as positive results from laboratory tests or diagnostic codes 14 days after at least 2 doses of mRNA vaccination; and severe COVID-19 BTI as hospitalization, invasive cardiopulmonary support, and/or death. We used propensity scores to match boosted versus nonboosted patients and evaluated hazards of incident and severe COVID-19 BTI using Cox regression after matching. Results: Among patients without immune dysfunction, the relative effectiveness of booster (3 doses) after 6 months from the primary (2 doses) vaccination against BTI ranged from 69% to 81% during the Delta-predominant period and from 33% to 39% during the Omicron-predominant period. Relative effectiveness against BTI was lower among patients with immune dysfunction but remained statistically significant in both periods. Boosted patients had lower risk of COVID-19-related hospitalization (hazard ratios [HR] ranged from 0.5 [95% confidence interval {CI}, .48-.53] to 0.63 [95% CI, .56-.70]), invasive cardiopulmonary support, or death (HRs ranged from 0.46 [95% CI, .41-.52] to 0.63 [95% CI, .50-.79]) during both periods. Conclusions: Booster vaccines remain effective against severe COVID-19 BTI throughout the Delta- and Omicron-predominant periods, regardless of patients' immune status.

Surgical Site Infection Prevention Using "Strike Teams": The Experience of an Academic Colorectal Surgical Department.

ABSTRACT: Surgical site infections (SSIs) are healthcare-acquired infections with substantial morbidity. Surgical site infection persist because of low adherence to prevention bundles comprising multiple infection control elements. We propose the "Strike Team" as an implementation strategy to improve adherence and reduce SSI in colorectal surgery. At an academic medical center, a multidisciplinary Strike Team met monthly to review colorectal SSI cases, audit and discuss barriers to adherence to SSI prevention bundle, and propose actionable feedback. The latter was shared with frontline clinicians by the Strike Team's surgical leaders in everyday practice. Colorectal SSI rates and bundle adherence data were disseminated quarterly via the hospital intranet and reviewed with surgeons at departmental meetings. Trends in adherence and SSI rates were analyzed by regression analysis using a time series model. While the Strike Team was active, adherence to antibiotic prophylaxis, maintenance of normoglycemia, and standardized intraoperative skin preparation significantly increased (p < .05). There was a trend toward statistically significant reduction in SSI (p = .07), although it was not maintained once the Strike Team activity was disrupted by the COVID-19 pandemic. Colorectal SSI prevention requires a resource-intensive, multidisciplinary approach with numerous strategies to improve adherence to infection control bundles, as illustrated by our SSI Strike Team experience.

A severe acute respiratory coronavirus virus 2 (SARS-CoV-2) nosocomial cluster with inter-facility spread: Lessons learned.

BACKGROUND: Despite infection control guidance, sporadic nosocomial coronavirus disease 2019 (COVID-19) outbreaks occur. We describe a complex severe acute respiratory coronavirus virus 2 (SARS-CoV-2) cluster with interfacility spread during the SARS-CoV-2 δ (delta) pandemic surge in the Midwest. SETTING: This study was conducted in (1) a hematology-oncology ward in a regional academic medical center and (2) a geographically distant acute rehabilitation hospital. METHODS: We conducted contact tracing for each COVID-19 case to identify healthcare exposures within 14 days prior to diagnosis. Liberal testing was performed for asymptomatic carriage for patients and staff. Whole-genome sequencing was conducted for all available clinical isolates from patients and healthcare workers (HCWs) to identify transmission clusters. RESULTS: In the immunosuppressed ward, 19 cases (4 patients, 15 HCWs) shared a genetically related SARS-CoV-2 isolate. Of these 4 patients, 3 died in the hospital or within 1 week of discharge. The suspected index case was a patient with new dyspnea, diagnosed during preprocedure screening. In the rehabilitation hospital, 20 cases (5 patients and 15 HCWs) positive for COVID-19, of whom 2 patients and 3 HCWs had an isolate genetically related to the above cluster. The suspected index case was a patient from the immune suppressed ward whose positive status was not detected at admission to the rehabilitation facility. Our response to this cluster included the following interventions in both settings: restricting visitors, restricting learners, restricting overflow admissions, enforcing strict compliance with escalated PPE, access to on-site free and frequent testing for staff, and testing all patients prior to hospital discharge and transfer to other facilities. CONCLUSIONS: Stringent infection control measures can prevent nosocomial COVID-19 transmission in healthcare facilities with high-risk patients during pandemic surges. These interventions were successful in ending these outbreaks.

Quality improvement study on the effectiveness of intranasal povidone-iodine decolonization on surgery patients.

Background: Surgical site infection prevention and treatment remains a challenge in healthcare settings globally. The routine use of intranasal mupirocin for decolonization has challenges and preoperative intranasal povidone-iodine decolonization is another option. The purpose of this quality improvement study was to assess if a one-time preoperative intranasal povidone-iodine application could reduce the risk of the likelihood of nasal carriage of Staphylococcus aureus after surgery. Methods: Ambulatory Surgery Center patients were enrolled in an intranasal povidone-iodine decolonization quality improvement study as they reported at the pre-operative holding area. Pre-decolonization intranasal samples were collected, followed by intranasal application of povidone-iodine. Patients waited for a minimum of 20 minutes after application before proceeding with surgery. Nasal samples were again collected after surgery. Each sample was tested for S. aureus colonization using the 16S rRNA-mecA-nuc triplex polymerase chain reaction, standard biochemical tests, and qualitative culturing. Findings: In the 98 patients enrolled, 36% of these patients had intranasal colonization with S. aureus by 16S rRNA-mecA-nuc triplex polymerase chain reaction before surgery. Using a qualitative culture technique, 28% of patients tested positive for S. aureus before surgery and 20% of patients tested positive for S. aureus after surgery (P = 0.039). Conclusion: Intranasal preoperative povidone-iodine is an effective strategy in the decolonization of S. aureus from the nares if properly implemented.

Perturbation of the gut microbiome and association with outcomes following autologous stem cell transplantation in patients with multiple myeloma.

The gut microbiome is an important feature of host immunity with associations to hematologic malignancies and cellular therapy. We evaluated the gut microbiome and dietary intake in patients with multiple myeloma undergoing autologous stem cell transplantation. Thirty patients were enrolled, and samples were collected at four timepoints: pre-transplant, engraftment, day +100 (D + 100), and 9-12 months post-transplant. Microbiome analysis demonstrated a loss of alpha diversity at the engraftment timepoint driven by decreases in Blautia, Ruminococcus, and Faecalibacterium genera and related to intravenous antibiotic exposure. Higher fiber intake was associated with increased relative abundance of Blautia at the pre-transplant timepoint. Lower alpha diversity at engraftment was associated with a partial response to therapy compared with complete response (CR) or very good partial response (VGPR) (CR/VGPR vs. PR, p < 0.05). We conclude that loss of bacterial diversity at engraftment may be associated with impaired response to stem cell transplantation in multiple myeloma.

A quality improvement study on the relationship between intranasal povidone-iodine and anesthesia and the nasal microbiota of surgery patients.

INTRODUCTION: The composition of the nasal microbiota in surgical patients in the context of general anesthesia and nasal povidone-iodine decolonization is unknown. The purpose of this quality improvement study was to determine: (i) if general anesthesia is associated with changes in the nasal microbiota of surgery patients and (ii) if preoperative intranasal povidone-iodine decolonization is associated with changes in the nasal microbiota of surgery patients. MATERIALS AND METHODS: One hundred and fifty-one ambulatory patients presenting for surgery were enrolled in a quality improvement study by convenience sampling. Pre- and post-surgery nasal samples were collected from patients in the no intranasal decolonization group (control group, n = 54). Pre-decolonization nasal samples were collected from the preoperative intranasal povidone-iodine decolonization group (povidone-iodine group, n = 97). Intranasal povidone-iodine was administered immediately prior to surgery and continued for 20 minutes before patients proceeded for surgery. Post-nasal samples were then collected. General anesthesia was administered to both groups. DNA from the samples was extracted for 16S rRNA sequencing on an Illumina MiSeq. RESULTS: In the control group, there was no evidence of change in bacterial diversity between pre- and post-surgery samples. In the povidone-iodine group, nasal bacterial diversity was greater in post-surgery, relative to pre-surgery (Shannon's Diversity Index (P = 0.038), Chao's richness estimate (P = 0.02) and Inverse Simpson index (P = 0.027). Among all the genera, only the relative abundance of the genus Staphylococcus trended towards a decrease in patients after application (FDR adjusted P = 0.06). Abundant genera common to both povidone-iodine and control groups included Staphylococcus, Bradyrhizobium, Corynebacterium, Dolosigranulum, Lactobacillus, and Moraxella. CONCLUSIONS: We found general anesthesia was not associated with changes in the nasal microbiota. Povidone-iodine treatment was associated with nasal microbial diversity and decreased abundance of Staphylococcus. Future studies should examine the nasal microbiota structure and function longitudinally in surgical patients receiving intranasal povidone-iodine.

Efficacy of combinational therapy using blue light and benzoyl peroxide in reducing Cutibacterium acnes bioburden at the deltopectoral interval: a randomized controlled trial.

BACKGROUND: The purpose of this study was to compare the efficacy of blue light therapy (BLT) and 5% topical benzoyl peroxide (BPO) gel in combination with standard chlorhexidine (CHX) preparation in eradicating Cutibacterium acnes at the deltopectoral interval measured by positive, quantitative culture findings. METHODS: Adult male volunteers were randomized to 1 of 3 treatment groups: BPO, BLT, and BPO followed by BLT. Contralateral shoulders served as matched controls. Volunteers randomized to BPO applied the gel for a total of 5 treatments. In the BLT group, a single 23-minute treatment was administered at an estimated irradiance of 40 mW/cm2 (radiant exposure, 55.2 J/cm2). In the BPO-BLT group, volunteers received both treatments as described earlier. After treatment with either BPO, BLT, or both, a single swab culture was taken from the treatment shoulder. Next, control and treatment shoulders were prepared with CHX, and cultures were taken from each shoulder. Cultures were sent for anaerobic quantitative growth analysis with both polymerase chain reaction and Sanger sequencing confirmation of presumptive C acnes colonies. RESULTS: This study enrolled 60 male volunteers, 20 per group, with no loss to follow-up. After treatment but prior to CHX administration, all culture samples in the BPO group and BLT group grew C acnes. Prior to CHX, 16 samples (80%) in the BPO-BLT group grew C acnes. On quantitative analysis, the BPO group and BPO-BLT group had significantly less growth of C acnes compared with the BLT group after treatment but prior to CHX (P < .05 for each). Following CHX administration, the BPO and BPO-BLT groups had significantly fewer positive culture findings (odds ratios of 0.03 and 0.29, respectively) and less quantity of growth compared with their control arms (P < .05). This was not seen in the BLT group. For quantitative between-group analysis, no significant synergistic effects were seen with BPO-BLT compared with BPO alone (P = .688). There was no difference in side effects between groups. CONCLUSION: The combination of topical BPO and CHX was effective at eliminating C acnes in most cases. BLT alone did not demonstrate effective antimicrobial properties against C acnes at the radiant exposure administered in this study. Combining BPO and BLT did not lead to significant synergistic antimicrobial effects. Both BPO and BLT are safe with few, transient side effects reported. More work is needed to determine whether BLT at higher radiant exposures or serial treatment results in bactericidal effects against C acnes in vivo.

Hospital-acquired Legionella pneumonia outbreak at an academic medical center: Lessons learned.

BACKGROUND: An outbreak of Legionella pneumonia occurred at a university hospital using copper-silver ionization for potable water disinfection. We present the epidemiological and laboratory investigation of the outbreak, and associated case-control study. METHODS: Cases were defined by syndrome compatible with Legionella pneumonia with laboratory-confirmed Legionella infection. The water circuit and disinfection system were assessed, and water samples collected for Legionella culture. Whole genome multi-locus sequence typing (wgMLST) was used to compare the genetic similarity of patient and environmental isolates. A case-control study was conducted to identify risk factors for Legionella pneumonia. RESULTS: We identified 13 cases of hospital-acquired Legionella. wgMLST revealed >99.9% shared allele content among strains isolated from clinical and water samples. Smoking (P= .008), steroid use (P= .007), and documented shower during hospitalization (P= .03) were risk factors for Legionella pneumonia on multivariable analysis. Environmental assessment identified modifications to the hospital water system had occurred in the month preceding the outbreak. Multiple mitigation efforts and application of point of use water filters stopped the outbreak. CONCLUSIONS: Potable water system Legionella colonization occurs despite existing copper-silver ionization systems, particularly after structural disruptions. Multidisciplinary collaboration and direct monitoring for Legionella are important for outbreak prevention. Showering is a modifiable risk factor for nosocomial Legionella pneumonia. Shower restriction and point-of-use filters merit consideration during an outbreak.

Gaining momentum in colorectal surgical site infection reduction through a human factors engineering approach.

Surgical site infection (SSI) prevention requires multiple interventions packaged into "bundles." The implementation of all bundle elements is key to the bundle's efficacy. A human-factors engineering approach can be used to identify key barriers and facilitators to implementing elements and develop recommendations for bundle implementation within the clinical work system.

Variability in infection surveillance methods and impact on surgical site infection rates.

BACKGROUND: The impact of variability in infection surveillance methodologies on publicly reported rates of surgical site infection (SSI) is not well defined. METHODS: We performed a cross-sectional study to assess infection preventionists' surveillance practices across acute care US hospitals. We collected self-reported annual facility standardized infection ratios for colon surgery and abdominal hysterectomy as provided by the National Healthcare Safety Network. Trend analysis using Kendall's rank correlation evaluated the association between surveillance rigor and SSI rates. RESULTS: Among 492 participating hospitals, 63%, 15%, 13%, and 8% were community, university-affiliated, critical access, and ambulatory surgical centers, respectively. Most critical access hospitals (82%) and ambulatory surgical centers (98%) reported less than one full time infection preventionists (P ≤ .001). University-affiliated medical centers spent significantly more time and used more data sources for monthly SSI review compared with other hospitals. Critical access hospitals and ambulatory surgical centers were more likely to rely on manual surveillance only (P < .001). The number of different data sources used for SSI surveillance was positively associated with higher SSI rates: (KT 0.14, P = .028 for colon SSI in 2017; KT 0.20, P = .009 for hysterectomy SSI in 2016; KT 0.25, P = .001 for hysterectomy SSI in 2017). CONCLUSIONS: Rigorous SSI surveillance using more data sources for case-finding is more likely to be associated with higher facility SSI rates for colon surgery and abdominal hysterectomy.

Revealing fine-scale spatiotemporal differences in SARS-CoV-2 introduction and spread.

Evidence-based public health approaches that minimize the introduction and spread of new SARS-CoV-2 transmission clusters are urgently needed in the United States and other countries struggling with expanding epidemics. Here we analyze 247 full-genome SARS-CoV-2 sequences from two nearby communities in Wisconsin, USA, and find surprisingly distinct patterns of viral spread. Dane County had the 12th known introduction of SARS-CoV-2 in the United States, but this did not lead to descendant community spread. Instead, the Dane County outbreak was seeded by multiple later introductions, followed by limited community spread. In contrast, relatively few introductions in Milwaukee County led to extensive community spread. We present evidence for reduced viral spread in both counties following the statewide "Safer at Home" order, which went into effect 25 March 2020. Our results suggest patterns of SARS-CoV-2 transmission may vary substantially even in nearby communities. Understanding these local patterns will enable better targeting of public health interventions.

Colorectal bundles for surgical site infection prevention: A systematic review and meta-analysis.

OBJECTIVE: In colorectal surgery, the composition of the most effective bundle for prevention of surgical site infections (SSI) remains uncertain. We performed a meta-analysis to identify bundle interventions most associated with SSI reduction. METHODS: We systematically reviewed 4 databases for studies that assessed bundles with ≥3 elements recommended by clinical practice guidelines for adult colorectal surgery. The main outcome was 30-day postoperative SSI rate (overall, superficial, deep, and/or organ-space). RESULTS: We included 40 studies in the qualitative review, and 35 studies (54,221 patients) in the quantitative review. Only 3 studies were randomized controlled trials. On meta-analyses, bundles were associated with overall SSI reductions of 44% (RR, 0.57; 95% CI, 0.48-0.65); superficial SSI reductions of 44% (RR, 0.56; 95% CI, 0.42-0.75); deep SSI reductions of 33% (RR, 0.67; 95% CI, 0.46-0.98); and organ-space SSI reductions of 37% (RR, 0.63; 95% CI, 0.50-0.81). Bundle composition was heterogeneous. In our meta-regression analysis, bundles containing ≥11 elements, consisting of both standard of care and new interventions, demonstrated the greatest SSI reduction. Separate instrument trays, gloves with and without gown change for wound closure, and standardized postoperative dressing change at 48 hours correlated with the highest reductions in superficial SSIs. Mechanical bowel preparation combined with oral antibiotics, and preoperative chlorhexidine showers correlated with highest organ-space SSI reductions. CONCLUSIONS: Preventive bundles emphasizing guideline-recommended elements from both standard of care as well as new interventions were most effective for SSI reduction following colorectal surgery. High clinical-bundle heterogeneity and low quality for most observational studies significantly limit our conclusion.

Detection and Remediation of Misidentification Errors in Radiology Examination Ordering.

BACKGROUND: Despite progress in patient safety, misidentification errors in radiology such as ordering imaging on the wrong anatomic side persist. If undetected, these errors can cause patient harm for multiple reasons, in addition to producing erroneous electronic health records (EHR) data. OBJECTIVES: We describe the pilot testing of a quality improvement methodology using electronic trigger tools and preimaging checklists to detect "wrong-side" misidentification errors in radiology examination ordering, and to measure staff adherence to departmental policy in error remediation. METHODS: We retrospectively applied and compared two methods for the detection of "wrong-side" misidentification errors among a cohort of all imaging studies ordered during a 1-year period (June 1, 2015-May 31, 2016) at our tertiary care hospital. Our methods included: (1) manual review of internal quality improvement spreadsheet records arising from the prospective performance of preimaging safety checklists, and (2) automated error detection via the development and validation of an electronic trigger tool which identified discrepant side indications within EHR imaging orders. RESULTS: Our combined methods detected misidentification errors in 6.5/1,000 of study cohort imaging orders. Our trigger tool retrospectively identified substantially more misidentification errors than were detected prospectively during preimaging checklist performance, with a high positive predictive value (PPV: 88.4%, 95% confidence interval: 85.4-91.4). However, two third of errors detected during checklist performance were not detected by the trigger tool, and checklist-detected errors were more often appropriately resolved (p < 0.00001, 95% confidence interval: 2.0-6.9; odds ratio: 3.6). CONCLUSION: Our trigger tool enabled the detection of substantially more imaging ordering misidentification errors than preimaging safety checklists alone, with a high PPV. Many errors were only detected by the preimaging checklist; however, suggesting that additional trigger tools may need to be developed and used in conjunction with checklist-based methods to ensure patient safety.

Pre-operative Decolonization as a Strategy to Reduce Surgical Site Infection.

PURPOSE OF REVIEW: To identify the most common strategies currently used for S. aureus decolonization and surgical site infection (SSI) prevention. RECENT FINDINGS: Pre-operative colonization with Staphylococcus aureus increases SSI risk. Screening and decolonization with intra-nasal mupirocin and pre-operative chlorhexidine bathing remains the most common and effective strategy, especially for orthopedic and cardiovascular surgery. Intra-nasal povidone-iodine immediately before surgery appears effective in preliminary studies, is less expensive, and may be easier to implement in the clinical setting. Future well-designed clinical research studies are needed to confirm its effectiveness in SSI prevention. Intra-nasal alcohol-based antisepsis and photodynamic therapy are promising strategies that deserve further study before they can be clinically applied to SSI prevention. Decolonization with intra-nasal mupirocin or povidone-iodine, in addition to pre-operative chlorhexidine bathing, is an important SSI prevention strategy. Future studies should address optimal dosing, timing, and number of applications for each regimen.

Clostridioides difficile Infection in the Stem Cell Transplant and Hematologic Malignancy Population.

Clostridioides difficile infection (CDI) is common in the stem cell transplant (SCT) and hematologic malignancy (HM) population and mostly occurs in the early posttransplant period. Treatment of CDI in SCT/HM is the same as for the general population, with the exception that fecal microbiota transplant (FMT) has not been widely adopted because of safety concerns. Several case reports, small series, and retrospective studies have shown that FMT is effective and safe. A randomized controlled trial of FMT for prophylaxis of CDI in SCT patients is underway. In addition, an abundance of novel therapeutics for CDI is currently in development.

Cefazolin as surgical antimicrobial prophylaxis in hysterectomy: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: Current practice guidelines recommend cefazolin, cefoxitin, cefotetan, or ampicillin-sulbactam as first-line antibiotic prophylaxis in hysterectomy. We undertook this systematic review and meta-analysis of randomized controlled trials (RCTs) to determine whether cefazolin, with limited antianaerobic spectrum, is as effective in preventing surgical site-infection (SSI) as the other first-choice antimicrobials that have more extensive antianaerobic activity. METHODS: We searched PubMed, Scopus, Web of Science, Cochrane Central, and EMBASE for relevant randomized controlled trials (RCT) in any language up to January 23, 2018. We only included trials that measured SSI (our primary outcome) defined as superficial, deep, or organ space. We excluded trials of ß-lactams no longer in clinical use. RESULTS: In terms of SSI incidence, cefazolin use was not inferior to its comparator in 12 of 13 individual RCTs included in the analysis. The meta-analysis summary estimate showed a significantly higher SSI risk with cefazolin versus cefoxitin or cefotetan (risk ratio, 1.7; 95% CI, 1.04-2.77; P = .03). However, most studies included nonstandardized dosing and duration of antimicrobial prophylaxis, had indeterminate or high risk of bias, did not include patients with gynecological malignancies, and/or were older RCTs not reflective of current clinical practices. CONCLUSION: Due to inherent limitations associated with old RCTs with limited relevance to contemporary surgery, an RCT of cefazolin versus regimens with significant antianaerobic spectrum is needed to establish the optimal choice for SSI prevention in hysterectomy.

Kidney transplant recipients with polycystic kidney disease have a lower risk of post-transplant BK infection than those with end-stage renal disease due to other causes.

BACKGROUND: Polyomavirus-associated nephropathy is associated with high risk of kidney allograft loss. Whether the cause of native end-stage renal disease influences the risk of BK infection is unclear. METHODS: A retrospective, single-center study of 2741 adult kidney transplant recipients between 1994 and 2014 was performed. Recipients had end-stage renal disease due to polycystic kidney disease (PKD, n = 549), diabetes mellitus (DM, n = 947), hypertension (HTN, n = 442), or glomerulonephritis (GN, n = 803). RESULTS: A total of 327 recipients (12%) developed post-transplant BK viremia over a median follow-up time of 5 years. The incidence rate of BK viremia was lowest in patients with PKD (1.46 per 100 person-years) compared to other causes of ESRD (DM = 2.06, HTN = 2.65, and GN = 2.01 per 100 person-years). A diagnosis of PKD was associated with a lower risk of post-transplant BK viremia (adjusted HR (95% CI) = 0.67 (0.48-0.95), P = 0.02). BK nephropathy was significantly less common in patients with PKD (0.21 per 100 person-years) compared to those with HTN (0.80 per 100 person-years, P ≤ 0.001). Among patients with PKD, the risk of BK viremia was lower in patients with nephrectomy, compared to those without nephrectomy (adjusted HR (95% CI) = 0.42 (0.19-0.92), P < 0.05). CONCLUSION: ESRD due to PKD is associated with a lower risk of post-transplant BK infection. The renal tubular epithelial cells in PKD are unique; they are in a proliferative but non-differentiated state. Whether this characteristic of renal tubular epithelial cells alters the BK viral reservoir or replication in PKD patients warrants further study.

Heavy metal exposure and nasal Staphylococcus aureus colonization: analysis of the National Health and Nutrition Examination Survey (NHANES).

BACKGROUND: Heavy metals including lead and cadmium can disrupt the immune system and the human microbiota. and are increasingly of concern with respect to the propogation of antibiotic-resistence. Infection by methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of global morbidity and mortality. Heavy metal exposure may be associated with increased MRSA colonization and infection, and a decrease in methicillin-susceptible Staphylococcus aureus (MSSA) through co-selection mechanisms and natural selection of antibiotic resistance in the presence of heavy metals. This study examines the association between blood lead (Pb) and cadmium (Cd) level, and MRSA and MSSA nasal colonization. METHODS: All data used for this analysis came from the 2001-2004 National Health and Nutrition Examination Survey (NHANES). The analytical sample consisted of 18,626 participants aged 1 year and older. Multivariate logistic regression, including adjustment for demographic and dietary factors, was used to analyze the association between blood Pb and Cd, and nasal colonization by MRSA and MSSA. RESULTS: Prevalence of MRSA and MSSA carriage were 1.2%, and 29.3% respectively. MRSA was highest in women, individuals age 70 and older, who self-identified as black, had only a high school diploma, lived below 200% of the Federal Poverty Level, and had a history of smoking. While not significantly different from those colonized with MSSA, geometric mean blood Pb (1.74 µg/dL) and blood Cd (0.31 µg/L) were highest in those colonized with MRSA. Associations with MRSA colonization appeared to increase in a dose-dependent manner with increasing quartile of blood Pb level. Blood Cd level in the fourth quartile was also significantly associated with lower odds of MRSA colonization. Both metals were associated with lower odds of MSSA colonization. CONCLUSIONS: Both MRSA and MSSA results suggest that general population levels of blood Pb but not Cd are associated with differences in nasal carriage of S. aureus. While further research is needed, reduction in heavy metal exposures such as lead, concurrently with maintaining a healthy microbiota may be two modifiable options to consider in the fight against antibiotic-resistance.

Reducing unnecessary culturing: a systems approach to evaluating urine culture ordering and collection practices among nurses in two acute care settings.

Background: Inappropriate ordering and acquisition of urine cultures leads to unnecessary treatment of asymptomatic bacteriuria (ASB). Treatment of ASB contributes to antimicrobial resistance particularly among hospital-acquired organisms. Our objective was to investigate urine culture ordering and collection practices among nurses to identify key system-level and human factor barriers and facilitators that affect optimal ordering and collection practices. Methods: We conducted two focus groups, one with ED nurses and the other with ICU nurses. Questions were developed using the Systems Engineering Initiative for Patient Safety (SEIPS) framework. We used iterative categorization (directed content analysis followed by summative content analysis) to code and analyze the data both deductively (using SEIPS domains) and inductively (emerging themes). Results: Factors affecting optimal urine ordering and collection included barriers at the person, process, and task levels. For ED nurses, barriers included patient factors, physician communication, reflex culture protocols, the electronic health record, urinary symptoms, and ED throughput. For ICU nurses, barriers included physician notification of urinalysis results, personal protective equipment, collection technique, patient body habitus, and Foley catheter issues. Conclusions: We identified multiple potential process barriers to nurse adherence with evidence-based recommendations for ordering and collecting urine cultures in the ICU and ED. A systems approach to identifying barriers and facilitators can be useful to design interventions for improving urine ordering and collection practices.