Sustained reduction in antimicrobial use and decrease in methicillin-resistant Staphylococcus aureus and Clostridium difficile infections following implementation of an electronic medical record at a tertiary-care teaching hospital

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen of hospital infection with multi-drug resistant characteristics. Its spread and epidemic pose great challenges to nosocomial infection control. This study was aimed to identify risk factors for hospital-acquired MRSA (HA-MRSA) infections and investigate its clinical outcome, developing infection control strategies and improving patient outcomes.MethodsA retrospective case-case-control study was conducted to compare patients in Southwest Hospital, Chongqing, People's Republic of China from January 2018 to December 2018 with control patients. In this study, 251 patients with MRSA nosocomial infection, 339 patients with methicillin-sensitive Staphylococcus aureus strains (MSSA) nosocomial infection, and 300 patients with non-Staphylococcus aureus infection were included.ResultsMultivariate analysis showed that presence of central venous catheters (odds ratio [OR], 1.932; 95% confidence interval [CI], 1.074–3.477; P=0.028), sputum suction (OR, 2.887; 95% CI, 1.591–5.240; p<0.001), and total hospital stays more than 30 days (OR, 3.067; 95% CI, 2.063–4.559; P<0.001) were independent risk factors for HA-MRSA. Renal insufficiency (OR, 2.744; 95% CI, 1.089–6.914; P=0.032) and receipt of immunosuppressors (OR, 3.140; 95% CI, 1.284–7.678; P=0.012) were independent predictors of poor prognosis of MRSA nosocomial infection. Moreover, empirical use of antibiotics (OR, 0.514; 95% CI, 0.282–0.935; P=0.029) was a protective factor for poor prognosis of MRSA nosocomial infection. In-hospital mortality in the MRSA group was not statistically significant compared with the other two groups; however, the rate of poor prognosis in the MRSA group was higher than that of the MSSA group (27.5% vs 17.1%, χ2=9.200, P=0.002) and the control group (27.5% vs 16.0%, χ2=19.190, P=0.001).ConclusionOur results have shown presence of central venous catheters, sputum suction, and total hospital stays more than 30 days were associated with nosocomial MRSA infection. Patients with renal insufficiency and immunosuppressive therapy were more likely to cause poor prognosis with MRSA infection, and the empirical use of antibiotics can effectively reduce the adverse clinical outcomes caused by MRSA infection. Based on above findings, strategies to control MRSA infection should emphasize more attention to these patients and appropriate empirical use of antibiotics.

This book is an extensively researched and detailed review of methicillin-resistant Staphylococcus aureus (MRSA) by Maryn McKenna, a journalist and the former Centers for Disease Control and Prevention beat reporter for the Atlanta Journal Constitution. Although McKenna has a background in science reporting, she infused this work with drama, an approach that will draw in some readers but be off-putting to others. To the reader familiar with MRSA, the use of hyperbole coupled with factual inaccuracies leaves one wondering where truth stops and fiction begins. These shortcomings may keep this work off scholarly reading lists. Most chapters include case presentations that emphasize the emotional toll wrought by MRSA infections. The cases effectively introduce topics such as MRSA in athletes and other risk groups, MRSA in animals, and postinfluenza MRSA pneumonia. The chapter on infections caused by the 80/81 strain of S. aureus in the 1950s is particularly useful because it demonstrates parallels between the 1950s epidemic and the USA300 clone of MRSA today. However, McKenna infers that the 80/81 strain disappearance was caused by use of antistaphylococcal drugs and not natural events. Although 80/81 did disappear after the introduction of methicillin, the cause of the strain’s disappearance is largely unknown. The community-onset MRSA epidemic of the past decade is not presented with a clear timeline. As a result, the reader is unclear if the incidence of disease is still increasing, has leveled, or is decreasing and could further parallel incidence of the 80/81 strain. The chapter on healthcare-associated infections is MRSA centric and misses excellent opportunities to frame these infections and problems such as antimicrobial drug resistance and overuse in a broader context. The challenges of MRSA prevention are not balanced with other infection prevention priorities such as control of multidrug-resistant gram-negative pathogens and Clostridium difficile. Active surveillance to identify MRSA carriers is emphasized more than hand hygiene. Legislation mandating MRSA screening is discussed without explaining why major infection prevention organizations believe such legislation is unwise. Some of the physicians, researchers, and other heroes in the MRSA story are appropriately praised. Failings of physicians and the healthcare establishments are deservedly criticized. However, there is no call to arms over some of the most egregious medical failures, such as poor hand hygiene compliance and unwise antimicrobial drug use. The reader is left frustrated about the inability of the medical establishment to control MRSA. The book attempts to appeal to a broad audience, and although McKenna uses a lot of medical jargon, she effectively explains concepts such as antimicrobial drug mechanisms and molecular typing. Her style and the human interest stories will appeal to a lay audience, particularly consumer advocates. The historical background and scientific detail may appeal to healthcare professionals interested in infectious diseases or public health. However, the main goal of the book appears to be to scare the reader about the “Superbug.” In this regard, McKenna succeeds.

BACKGROUND AND OBJECTIVES:Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. The aim of the present study was to assess the burden of MRSA nosocomial infection, its association with factors of interest, and its antimicrobial susceptibility.METHODS:This was a retrospective analysis of a database of all S aureus that were cultured from patients admitted to the different wards of Hospital Universiti Sains Malaysia (HUSM) over a period of 6 years.RESULTS:The MRSA infections rate was 10.0 per 1000 hospital admissions. The incidence density rate of MRSA infections during the study period was 1.8 per 1000 patient-days, with annual rates ranging from 0.95 to 3.47 per 1000 patient-days. Duration of hospitalization, previous antibiotic use, and bedside invasive procedures were significantly higher among MRSA than methicillin-sensitive S aureus patients (P>.05). The highest number of MRSA infections were found in orthopedic wards (25.3%), followed by surgical wards (18.2%) and intensive care units (ICUs) (16.4%). All MRSA isolates were resistant to erythromycin (98.0%), co-trimoxazole (94.0%) and gentamicin (92.0%). Clindamycin was the best antibiotic with only 6% resistance. All MRSA isolates were sensitive to vancomycin.CONCLUSION:The rate of nosocomial MRSA infection per 1000 admissions was higher than that in other studies. The three factors associated most significantly with acquired MRSA infections included duration of hospitalization, antibiotic use, and bedside invasive procedures. This study confirmed that vancomycin-resistant S aureus has not yet been established in HUSM.

Background: Inappropriate broad-spectrum antibiotic use targeting methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa can result in increased adverse events, antibiotic resistance, and Clostridioides difficile infection. In 2019, revised ATS/IDSA community-acquired pneumonia (CAP) guidelines removed healthcare-associated pneumonia (HCAP) as a clinical entity and modified patient factors warranting empiric broad-spectrum antibiotic (BSA) use. As a result, most patients hospitalized with CAP should receive empiric antibiotics targeting standard CAP pathogens. Based on revised guidelines, we evaluated predictors and outcomes associated with inappropriate BSA use among hospitalized patients with CAP. Methods: Between November 2019 and July 2022, trained abstractors collected data on non-ICU adult medical patients admitted with CAP at 67 Michigan hospitals who received either an inappropriate empiric BSA on hospital day 1 or 2 or a standard CAP regimen. Inappropriate empiric BSA use was defined as use of an anti-MRSA or anti-pseudomonal antibiotic in a patient eligible for standard CAP coverage per IDSA guidelines. Patients with immune compromise, moderate or severe chronic obstructive pulmonary disease (COPD), pulmonary complication, or guideline-concordant treatment with BSA were excluded. Data collected included comorbidities, antibiotic use and hospitalizations in the preceding 90 days, cultures in the preceding year, signs or symptoms of pneumonia, hospital characteristics, and 30-day postdischarge patient outcomes. Data were collected through chart review and patient phone calls. Predictors of inappropriate empiric BSA were evaluated using logistic general estimating equation (GEE) models, accounting for hospital-level clustering. We assessed the effect of inappropriate empiric BSA (vs standard CAP therapy) on 30-day patient outcomes using logistic GEE models controlling for predictors associated with the outcome and probability of treatment. Results: Of 8,286 included patients with CAP, 2,215 (26.7%) were empirically treated with inappropriate BSA. The median BSA treatment was 3 days (IQR, 2.5). After adjustments, factors associated with inappropriate empiric BSA treatment included hospitalization or treatment with high-risk antibiotics in preceding 90 days, transfer from a postacute care facility, hemodialysis, support with ≥3 L supplemental oxygen, severe sepsis, leukocytosis, and higher pneumonia severity index (Fig. 1). After adjustments, patients with inappropriate empiric BSA treatment had higher readmissions 30 days after discharge, more transfers to the intensive care unit, more antibiotic-associated adverse events, and longer hospitalizations (Fig. 2). Conclusions: Patients hospitalized with CAP often received inappropriate BSA as empiric coverage, and this inappropriate antibiotic selection was associated with worse patient outcomes. To improve patient outcomes, stewardship efforts should focus on reducing inappropriate BSA use in patients hospitalized for CAP with historic HCAP risk factors or severe CAP without other guideline-directed indications for BSA.Financial support. H.M.S. initiative is underwritten by Blue Cross and Blue Shield of Michigan.Disclosures: None

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has posed a challenge in the treatment of neurosurgical patients. The authors investigated the impact of MRSA colonization and infection in the neurosurgical population at a community-based, tertiary care referral center. Hospitalized patients under the care of the Kaiser Permanente inpatient neurosurgery service were prospectively entered into a database. In Phase I of the study, 492 consecutive patients were followed. Per hospital policy, the 260 patients from this group who were admitted to the intensive care unit (ICU) underwent screening for MRSA based on nasal swab cultures and a review of their medical history for prior MRSA infections. These patients were designated as either MRSA positive (17 patients, 6.5% of screened patients) or MRSA negative (243 patients). The 232 patients admitted to non-ICU nursing units did not undergo MRSA screening and were designated as unscreened. In Phase II of the study, the authors reviewed 1005 neurosurgical admissions and completed a detailed chart review in 62 MRSA-positive patients (6.2%). Eleven patients received nonoperative treatment. Five patients presented with community-acquired neurosurgical infections, and the causative organism was MRSA in 3 cases. Forty-six patients underwent 55 procedures, and the authors reviewed their perioperative management. In Phase I of the study, the authors found that for the MRSA-positive, MRSA-negative, and unscreened groups, the rates of postoperative neurosurgical wound infections caused by all pathogens were 23.5, 4.1, and 1.3%, respectively. For MRSA wound infections, the rates were 23.5, 0.8, and 0%, respectively. In Phase II, patients with MRSA were noted to have the following clinical features: male sex in 63%, a malignancy in 39.1%, diabetes in 34.8%, prior MRSA infection in 21.7%, immunosuppressed state in 17.4%, and a traumatic injury in 15.2%. The rate of postoperative neurosurgical wound infection in patients who received MRSA-specific prophylactic antibiotic therapy (usually vancomycin) was 7.4% (27 procedures) compared with 32.1% (28 procedures) in patients who received the standard treatment (usually cefazolin) (p = 0.04). Wound care for ICU patients was standardized for postoperative Days 0-7 with chlorhexidine cleaning at bandage changes at 3-day intervals. Wound cultures from neurosurgical site infections in patients with prior MRSA colonization or infection grew MRSA in 7 of 11 patients. Neurosurgical patients identified with MRSA colonization or a prior history of MRSA infections benefit from specific perioperative care, including prophylactic antibiotics active against MRSA (such as vancomycin) and postoperative wound care with coverings and chlorhexidine antisepsis to reduce MRSA wound colonization.

Methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) are problematic for incarcerated adolescents but have not been previously researched. This was a 2-year prospective study of all New South Wales Juvenile Custodial Centres involving incarcerated youth aged 12-20 years. The main outcomes measured were MRSA SSTIs, MRSA molecular subtypes and associations with MRSA infection. Variables included age, gender, SSTI site and type, Indigenous status, incarceration time, lifetime incarcerations, intravenous drug use, overweight/obesity, recent antibiotic use and health centre presentations. From February 2013 to January 2015, there were 77 SSTIs (92.2% male, 59.2% Indigenous, mean age 16.9 years). The majority (77.9%) were collections, mostly on the lower limb (44.2%), and 33 (42.9%) isolates were MRSA; 94% were Panton-Valentine leukocidin positive. This represents 11 SSTIs per 1000 custodial admissions, and 4.7 MRSA SSTIs per 1000 custodial admissions. Independent associations with MRSA SSTI (vs. non-MRSA SSTI) were Indigenous status (adjusted odds ratio (AOR) 5.92, P < 0.001), presenting with a collection (AOR 18.29, P < 0.001) and recent antibiotic use (AOR 3.62, P < 0.05). Incarcerated Australian youth have high rates of MRSA SSTIs, comparable to rates in US adult inmates, but with different molecular subtypes. At particular risk of MRSA infection are Indigenous youth, those with recent antibiotic use and those presenting with a collection. Many MRSA infections present at custodial admission, making surveillance and containment important, along with avoidance of unnecessary antibiotics and hand hygiene. Panton-Valentine leukocidin-positive MRSA predominates and is known for causing flu-associated necrotising pneumonia. Albeit a rare outcome, the seasonal influenza vaccination should be mandatory for youth in custody and custodial staff.

To describe the relative contribution of and risk factors for both community-acquired and nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections. Retrospective cohort study. 270-bed, tertiary-care children's hospital. All MRSA-infected children from whom MRSA was recovered between October 1, 1999, and September 30, 2001. Demographic, clinical, and risk factor data were abstracted from medical records. Categorical variables were analyzed using the chi-square or Fisher's exact test and continuous variables were analyzed using the Mann-Whitney test. Of the 62 patients with new MRSA infection, 37 had community-acquired MRSA and 25 had nosocomial MRSA. Most community-acquired MRSA infections were of the skin and soft tissue, the middle ear, and the lower respiratory tract. Nosocomial MRSA infections occurred in the lower respiratory tract, the skin and soft tissue, and the blood. Risk factors for infection, including underlying medical illness, prior hospitalization, and prior surgery, were similar for patients with community-acquired MRSA and nosocomial MRSA. History of central venous catheterization and previous endotracheal intubation was more common in patients with nosocomial MRSA. Only 3 patients with community-acquired MRSA had no identifiable risk factor other than recent antibiotic use. Resistance for clindamycin, erythromycin, and levofloxacin was similar between strains of community-acquired MRSA and nosocomial MRSA. Similarities in patient risk factors and resistance patterns of isolates of both community-acquired and nosocomial MRSA suggest healthcare acquisition of most MRSA. Thus, classifying MRSA as either community acquired or nosocomial underestimates the amount of healthcare-associated MRSA.

Utilization of a Clostridioides Difficile Testing Algorithm to Promote Evidence-based Laboratory Testing

Evaluation of contact precautions for methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus

Importance: Despite recommendations not to routinely use probiotics for primary prevention of Clostridium difficile infection (CDI) from Updated Practice Guidelines for CDI in 2010 by the Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America, the use of probiotics remains common among prescribers and patients. To our knowledge, there has been no analysis conducted to evaluate the impact of probiotics on the primary prevention of CDI among patients receiving antibiotics known to be associated with an increased risk of CDI. Objective: To determine whether patients who receive “high-risk” antibiotics along with probiotics are at a decreased risk of developing CDI. Design, setting, and participants: This was a retrospective cohort study including adult patients admitted to Yale New Haven Hospital, Saint Raphael Campus, between July 1, 2010 and December 31, 2010. Patients were excluded if they did not receive high-risk antibiotic(s) for more than 5 days nor had a history of CDI. Interventions: Eligible patients were then analyzed based on whether they had received concomitant use of probiotics or antibiotics alone. Main outcome(s) and measure(s): The primary outcome of the study was the development of CDI within 90 days of high-risk antibiotic use. Results: A total of 389 patients were included in the study. CDI occurred in 8.4% (12/143) of patients who received concomitant probiotics as opposed to 3.3% (8/246) that had CDI and received antibiotics alone with relative risk (RR) of 2.58 (95% CI: 1.08, 6.16; p=0.033). A chi-square analysis identified statistically significant differences in age (p<0.0001) and proton-pump inhibitor (PPI) utilization (p=0.0088), but the imbalance between patients with and without probiotics was removed after adjusting for the propensity score (p=0.1141). Conclusion and relevance: We found that use of antibiotics along with probiotics had a significantly higher incidence of CDI than those who did not receive probiotics. Our findings based on adjusted odds ratio do not support the recommendation of the routine use of probiotics for the prevention of CDI. Other strategies such as eliminating the unnecessary use of PPI should be applied to prevent CDI.

Methicillin-resistant Staphylococcus aureus nasal carriage and infections in CAPD

Suspected horse-to-human transmission of MRSA ST398.

Patients with inflammatory bowel disease (IBD) have a higher incidence of Clostridioides difficile infection (CDI). Previous studies have demonstrated negative clinical outcomes in IBD patients with CDI compared to patients without CDI. The clinical presentation of CDI is indistinguishable from IBD exacerbation, thus posing a frequent clinical dilemma on the role of Clostridioides infection in the testing, diagnosis, and treatment of these patients. To compare clinical outcomes of CDI in patients with IBD to those without IBD. Retrospective cohort of adult patients admitted to Rabin Medical Center Israel between the years 2014 and 2020 with a concurrent diagnosis of IBD and CDI. Matching 1:2 was performed between the IBD patients and the non-IBD population with respect to age and sex. Sixty-seven patients with IBD and 134 patients without IBD were included in the study. The groups' median age was 40.6 (interquartile range [IQR] of 29.8-68.9), with 45.8% male and 54.2% female. The non-IBD group had a higher Charlson score with 2 (IQR 0; 5) versus 0 (IQR 0; 4) in the IBD group (P value <.01). Patients with IBD had more exposure to systemic antibiotics, 71.1% versus 26.3% (P value <.01). In a multivariable analysis we found no difference in 90-day mortality and rate of relapse between the 2 study groups with an odds ratio of 1.709 (95% confidence interval 0.321-9.905) and odds ratio of 0.209 (95% confidence interval 0.055-1.513) respectively. In our cohort patients with IBD who present with diarrhea and concomitant CDI have similar rates of relapse and mortality compared with patients without IBD.

Background: Some hospitals continue to struggle with nosocomial transmission of Clostridioides difficile infection (CDI) and methicillin-resistant Staphylococcus aureus (MRSA) despite years of infection control efforts. We investigated the relationship between unit infrastructural–organizational risk factors and nosocomial transmission of CDI and MRSA. Methods: This retrospective observational study included 100 eligible acute-care inpatient units from 12 hospitals in British Columbia, Canada, from April 1, 2020, to September 16, 2021. The outcome variables included whether a unit was on the CDI or MRSA vulnerable unit list (ie, defined as having ≥5 CDI cases or ≥6 MRSA cases being attributed to the unit in the last 6 fiscal periods), the average CDI/MRSA rate, as well as the average CDI/MRSA standardized infection ratio (SIR). Independent variables included, but were not limited to, infection control factors (eg hand hygiene rate), infrastructural factors (eg, unit age, total beds on unit), and organizational factors (eg, hallway bed utilization, nursing overtime). Multivariable regression was performed to identify statistically significant risk factors using SAS, R Studio, and Stata software. Results: For CDI, older units were associated with higher odds of being on the CDI vulnerable unit list (aOR, 1.086; 95% CI, 1.024–1.175), higher CDI rate (adjusted relative risk [aRR], 0.012; 95% CI, 0.004–0.020), and higher CDI SIR (aRR, 0.011; 95% CI, 0.003–0.020). Larger unit size was associated with higher odds of being on the CDI vulnerable unit list (aOR, 1.210; 95% CI, 1.095–1.400) and higher CDI SIR (aRR, 0.013; 95% CI, 0.001–0.026). For MRSA, an increase in hand hygiene rate was associated with lower odds of being on the MRSA vulnerable unit list (aOR, 0.71; 95% CI, 0.53–0.897), lower MRSA rate (aRR, −0.035; 95% CI, −0.063 to −0.008), and lower MRSA SIR (aRR, −0.039; 95% CI, −0.069 to −0.008). Higher MRSA bioburden was associated with higher odds of being on the MRSA vulnerable unit list (aOR, &gt;999; 95% CI, &gt;999 to &gt;999), higher MRSA rate (aRR, 9.008; 95% CI, 5.586–12.429), and higher MRSA SIR (aRR, 4.964; 95% CI, 1.971–7.958). Additionally, higher MRSA rates were associated increased utilization of hallway beds (aRR, 0.680; 95% CI, 0.094–1.267), increased nursing overtime rate (aRR, 5.018; 95% CI, 1.210–8.826), and not having a clean supply room with the door consistently closed (aRR, −0.283; 95% CI, −0.536 to −0.03). Conclusions: Several infrastructural and organizational factors were associated with nosocomial transmissions of CDI and MRSA. Further research is needed to investigate the mechanisms by which these factors are associated.Disclosures: None

Traditionally, methicillin-resistant Staphylococcus aureus (MRSA) has been seen as an infection control problem in healthcare communities. It is now clear that antibiotic use is also an important factor in the control of MRSA, both in the treatment of infection and also, paradoxically perhaps, as a cause of the MRSA problem, in the same way that antibiotic use causes Clostridium difficile disease. At both levels, major improvements in the quality of our antibiotic use are required, particularly antibiotic stewardship to reduce the selection, maintenance and transmission of MRSA strains. In addition, new agents are required to reduce our reliance on glycopeptides for the treatment of serious MRSA infections. Daptomycin has great promise in this regard as its rapid bactericidal activity makes it particularly suitable for the treatment of bacteraemia and endocarditis.