Society for Health Care Epidemiology guidelines recommend decreasing the use of fluoroquinolone antibiotics in institutions where methicillin-resistant Staphylococcus aureus (MRSA) is endemic. We evaluated whether an intervention to limit fluoroquinolone use was associated with a lower rate of nosocomial MRSA infection and summarized changes in antibiotic use, changes in other variables potentially correlated with a lower rate of MRSA infection, and rates of nosocomial infections due to other pathogens.

Single-center quasi-experimental design. A time series of nosocomial MRSA infections was measured at monthly intervals from July 2001 through June of 2004; there were 80 MRSA infections recorded. Segmented regression analysis (ie, quasi-Poisson generalized linear models) was used to evaluate variables possibly associated with the nosocomial MRSA infection rate.

An 87-bed Veterans Affairs teaching hospital with an extended-care facility.

A physician-directed computer-generated intervention designed to limit the use of fluoroquinolone antibiotics was initiated, and institutional changes in antibiotic use and nosocomial MRSA infection rates were tracked.

After the intervention, fluoroquinolone use decreased by approximately 34%, and levofloxacin use decreased by approximately 50%. Decreased fluoroquinolone use was offset by increased cephalosporin, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole use. The nosocomial MRSA infection rate decreased from 1.37 to 0.63 episodes per 1,000 patient-days after the study intervention (P = .02). Coagulase-negative Staphylococcus and Enterococcus infection rates also decreased. However, the rate of infection with gram-negative organisms increased. The rate of MRSA infection was positively correlated with levofloxacin use (P = .01) and azithromycin use (P = .08), whereas it was negatively correlated with summer season (P = .05). In a subsequent model, the rate of MRSA infection was negatively correlated with the study intervention (P = .04).

Reduction in the institutional use of fluoroquinolones may be associated with a lower nosocomial MRSA infection rate.

Hand hygiene and environmental cleaning are essential infection prevention strategies, but the relative impact of each is unknown. This information is important in assessing resource allocation.

We developed an agent-based model of patient-to-patient transmission—via the hands of transiently colonized healthcare workers and incompletely terminally cleaned rooms—in a 20-patient intensive care unit. Nurses and physicians were modeled and had distinct hand hygiene compliance levels on entry and exit to patient rooms. We simulated the transmission of Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci for 1 year using data from the literature and observed data to inform model input parameters.

We simulated 175 parameter-based scenarios and compared the effects of hand hygiene and environmental cleaning on rates of multidrug-resistant organism acquisition. For all organisms, increases in hand hygiene compliance outperformed equal increases in thoroughness of terminal cleaning. From baseline, a 2∶1 improvement in terminal cleaning compared with hand hygiene was required to match an equal reduction in acquisition rates (eg, a 20% improvement in terminal cleaning was required to match the reduction in acquisition due to a 10% improvement in hand hygiene compliance).

Hand hygiene should remain a priority for infection control programs, but environmental cleaning can have significant benefit for hospitals or individual hospital units that have either high hand hygiene compliance levels or low terminal cleaning thoroughness.

Infect Control Hosp Epidemiol 2014;35(9):1156-1162

Laminar airflow (LAF) systems are widely used, at least in orthopedic surgery. However, there is still controversial discussion about the influence of LAF on surgical site infection (SSI) rates. The size of the LAF ceiling is also often a question of debate. Our objective is to determine the effect of this technique under conditions of actual rather than ideal use.

Cohort study using multivariate analysis with generalized estimating equations method.

Data for hip and knee prosthesis procedures from hospitals participating in the German national nosocomial infection surveillance system (KISS) from July 2004 to June 2009 were used for analysis.

A total of 33,463 elective hip prosthesis procedures due to arthrosis (HIP-A) from 48 hospitals, 7,749 urgent hip prosthesis procedures due to fracture (HIP-F) from 41 hospitals, and 20,554 knee prosthesis (KPRO) procedures from 38 hospitals were included.

The data were analyzed for hospitals with and without LAF in the operating rooms and by the size of the LAF ceiling. The endpoints were severe SSI rates.

The overall severe SSI rate was 0.74 per 100 procedures for HIP-A, 2.39 for HIP-F, and 0.63 for KPRO. For all 3 prosthesis types, neither LAF nor the size of the LAF ceiling was associated with lower infection risk.

The data demonstrate consistency and reproducibility with the results from earlier registry studies. Neither LAF nor ceiling size had an impact on severe SSI rates.

To evaluate educational level as a contributing factor in handwashing compliance.

Observation of hand washing opportunities was performed for approximately 12 weeks before an announced Joint Commission on Accreditation of Healthcare Organizations (JCAHO) visit and for approximately 10 weeks after the visit. Trained observers recorded the date, time, and location of the observation; the type of healthcare worker or hospital employee observed; and the type of hand hygiene opportunity observed.

University of Toledo Medical Center, a 319-bed teaching hospital.

A total of 2,373 observations were performed. The rate of hand washing compliance among nurses was 91.3% overall. Medical attending physicians had the lowest observed rate of compliance (72.4%; P < .001). Nurses showed statistically significant improvement in their rate of hand hygiene compliance after the JCAHO visit (P = .001), but no improvement was seen for attending physicians (P = .117). The compliance rate in the surgical intensive care unit was more than 90%, greater than that in other hospital units (P = .001). Statistically, the compliance rate was better during the first part of the week (Monday, Tuesday, and Wednesday) than during the latter part of the week (Thursday and Friday) (P = .002), and the compliance rate was better during the 3 PM-1 1 PM shift, compared with the 7 AM-3 PM shift (P < .001). When evaluated by logistic regression analysis, non-physician healthcare worker status and observation after the JCAHO accreditation visit were associated with an increased rate of hand hygiene compliance.

An inverse correlation existed between the level of professional educational and the rate of compliance. Future research initiatives may need to address the different motivating factors for hand hygiene among nurses and physicians to increase compliance.

Transmission of pathogens within the hospital environment remains a hazard for hospitalized patients. Healthcare personnel clothing and devices carried by them may harbor pathogens and contribute to the risk of pathogen transmission.

To examine bacterial contamination of healthcare personnel attire and commonly used devices.

Systematic review.

Of 1,175 studies screened, 72 individual studies assessed contamination of a variety of items, including white coats, neckties, stethoscopes, and mobile electronic devices, with varied pathogens including Staphylococcus aureus, including methicillin-resistant S. aureus, gram-negative rods, and enterococci. Contamination rates varied significantly across studies and by device but in general ranged from 0 to 32% for methicillin-resistant S. aureus and gram-negative rods. Enterococcus was a less common contaminant. Few studies explicitly evaluated for the presence of Clostridium difficile. Sampling and microbiologic techniques varied significantly across studies. Four studies evaluated for possible connection between healthcare personnel contaminants and clinical isolates with no unequivocally direct link identified.

Further studies to explore the relationship between healthcare personnel attire and devices and clinical infection are needed.

Infect Control Hosp Epidemiol 2016;1–7

The incidence of surgical site infection (SSI) after hysterectomy ranges widely from 2% to 21%. A specific risk stratification index could help to predict more accurately the risk of incisional SSI following abdominal hysterectomy and would help determine the reasons for the wide range of reported SSI rates in individual studies. To increase our understanding of the risk factors needed to build a specific risk stratification index, we performed a retrospective multihospital analysis of risk factors for SSI after abdominal hysterectomy.

Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from July 1, 2003, to June 30, 2005, at 4 institutions. SSIs were defined by using Centers for Disease Control and Prevention/National Nosocomial Infections Surveillance criteria. Independent risk factors for abdominal hysterectomy were identified by using logistic regression.

There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSIs after abdominal hysterectomy and 14 organ-space SSIs after vaginal hysterectomy. Because risk factors for organ-space SSI were different according to univariate analysis, we focused further analyses on incisional SSI after abdominal hysterectomy. The maximum serum glucose level within 5 days after operation was highest in patients with deep incisional SSI, lower in patients with superficial incisional SSI, and lowest in uninfected patients (median, 189, 156, and 141 mg/dL, respectively; P = .005). Independent risk factors for incisional SSI included blood transfusion (odds ratio [OR], 2.4) and morbid obesity (body mass index [BMI], >35; OR, 5.7). Duration of operation greater than the 75th percentile (OR, 1.7), obesity (BMI, 30–35; OR, 3.0), and lack of private health insurance (OR, 1.7) were marginally associated with increased odds of SSI.

Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer duration of operation and lack of private health insurance were marginally associated with SSI.

To evaluate whether hospital-acquired catheter-associated urinary tract infections (CA-UTIs) are accurately documented in discharge records with the use of International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes so that nonpayment is triggered, as mandated by the Centers for Medicare and Medicaid Services (CMS) Hospital-Acquired Conditions Initiative.

We conducted a retrospective medical record review of 80 randomly selected adult discharges from May 2006 through September 2007 from the University of Michigan Health System (UMHS) with secondary-diagnosis urinary tract infections (UTIs). One physician-abstractor reviewed each record to categorize UTIs as catheter associated and/or hospital acquired; these results (considered “gold standard”) were compared with diagnosis codes assigned by hospital coders. Annual use of the catheter association code (996.64) by UMHS coders was compared with state and US rates by using Healthcare Cost and Utilization Project data.

Patient mean age was 58 years; 56 (70%) were women; median length of hospital stay was 6 days; 50 patients (62%) used urinary catheters during hospitalization. Hospital coders had listed 20 secondary-diagnosis UTIs (25%) as hospital acquired, whereas physician-abstractors indicated that 37 (46%) were hospital acquired. Hospital coders had identified no CA-UTIs (code 996.64 was never used), whereas physician-abstractors identified 36 CA-UTIs (45%; 28 hospital acquired and 8 present on admission). Catheter use often was evident only from nursing notes, which, unlike physician notes, cannot be used by coders to assign discharge codes. State and US annual rates of 996.64 coding (~1% of secondary-diagnosis UTIs) were similar to those at UMHS.

Hospital coders rarely use the catheter association code needed to identify CA-UTI among secondary-diagnosis UTIs. Coders often listed a UTI as present on admission, although the medical record indicated that it was hospital acquired. Because coding of hospital-acquired CA-UTI seems to be fraught with error, nonpayment according to CMS policy may not reliably occur.

To determine the incidence of central venous catheter (CVC)-associated bloodstream infection (CA-BSI) among patients admitted to general medical wards outside the intensive care unit (ICU).

Prospective cohort study performed over a 13-month period, from April 1, 2002, through April 30, 2003.

Four selected general medical wards at Barnes-Jewish Hospital, a 1,250-bed teaching hospital in Saint Louis, Missouri.

All patients admitted to 4 general medical wards.

A total of 7,337 catheter-days were observed during 33,174 patient-days. The device utilization ratio (defined as the number of catheter-days divided by the number of patient-days) was 0.22 overall and was similar among the 4 wards (0.21, 0.25, 0.19, and 0.24). Forty-two episodes of CA-BSI were identified (rate, 5.7 infections per 1,000 catheter-days). Twenty-four (57%) of the 42 cases of CA-BSI were caused by gram-positive bacteria: 10 isolates (24%) were coagulase-negative staphylococci, 10 (24%) were Enterococcus species, and 3 (7%) were Staphylococcus aureus. Gram-negative bacteria caused 7 infections (17%). Five CA-BSIs (12%) were caused by Candida albicans, and 5 infections (12%) had a polymicrobial etiology. Thirty-five patients (83%) with CA-BSI had nontunneled CVCs in place.

Non-ICU medical wards in the study hospital had device utilization rates that were considerably lower than those of medical ICUs, but CA-BSI rates were similar to CA-BSI rates in medical ICUs in the United States. Studies of catheter utilization and on CVC insertion and care should be performed on medical wards. CA-BSI prevention strategies that have been used in ICUs should be studied on medical wards.

To evaluate the long-term efficacy of urinary Foley catheters (latex and silicone) impregnated with (1) chlorhexidine and silver sulfadiazine (CXS) and (2) chlorhexidine, silver sulfadiazine, and triclosan (CXST) in inhibiting extra-luminal bacterial adherence and to compare their efficacy with that of silver hydrogel latex (SH) and nitrofurazone-treated silicone (NF) catheters.

The antimicrobial spectrum of these catheters was evaluated using a zone of inhibition assay. A novel in vitro urinary tract model was developed to study the potential in vivo efficacy of antimicrobial catheters in preventing extraluminal bacterial colonization. The “meatus” was inoculated daily with Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans. The “bladder” portion of the model was cultured daily to determine bacterial growth.

Both CXS and CXST catheters had a broader antimicrobial spectrum than SH and NF catheters. In the in vitro model, CXST latex and silicone catheters exhibited significantly better efficacy (3 to 25 days) against uropathogens, compared with CXS (1 to 14 days) and control (0 to 5 days) catheters (P = .01). CXST latex catheters exhibited significantly longer protection against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa, compared with SH catheters (P = .01). CXST silicone catheters resisted colonization with Staphylococcus aureus and Staphylococcus epidermidis for a significantly longer period (23 to 24 days) than did NF catheters (9 to 11 days) (P = .01).

Catheters impregnated with synergistic combinations of chlorhexidine, silver sulfadiazine, and triclosan exhibited broad-spectrum, long-term resistance against microbial colonization on their outer surfaces (Infect Control Hosp Epidemiol 2003;24:506-513)

The prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains causing bloodstream infection (BSI) has not been studied in Korea.

We sought to determine the prevalence of CA-MRSA strains among isolates recovered from patients with MRSA BSIs and to explore epidemiological changes in Korea. We also sought to evaluate clinical characteristics relevant to the development of healthcare-associated BSIs.

We prospectively collected consecutive MRSA isolates from patients with BSI at 4 hospitals from July 1 through November 30, 2007, and we also included MRSA isolates recovered from culture of blood samples collected during a previous year (October 1, 2004 through September 30, 2005) at a different hospital. Molecular typing studies were performed, including pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, Staphylococcus protein A (spa) typing, and staphylococcal cassette chromosome mec (SCCmec) typing. We compared the clinical characteristics and outcomes of patients with healthcare-associated BSI due to CA-MRSA strains with those of patients with healthcare-associated BSI due to healthcare-associated MRSA (HA-MRSA) strains.

There were 76 cases of MRSA BSI, of which 4 (5.3%) were community-associated and 72 (94.7%) were healthcare-associated. Among the 72 HA-MRSA BSIs, 18 (25%) were community onset, and 54 (75%) were hospital onset. PFGE type D-ST72–spa B-SCCmec type IVA MRSA, the predominant genotype of CA-MRSA in Korea, accounted for 19 (25%) of all 76 MRSA BSIs, including 17 (23.6%) of 72 HA-MRSA BSIs and 11 (20.8%) of 53 hospital-onset HA-MRSA BSIs. Patients with healthcare-associated BSIs due to CA-MRSA strains carrying SCCmec type IVA tended to have fewer healthcare-associated risk factors, compared with patients with healthcare-associated BSIs due to HA-MRSA strains carrying other SCCmec types. The presence of a central venous catheter or other invasive device was the only independent factor differentiating patients infected with hospital-associated genotype strains from patients infected with other strains. Clinical outcomes were similar between both groups.

CA-MRSA strains are emerging as a major cause of BSI in healthcare settings in Korea. This changing epidemiology of MRSA poses a challenge to public health and infection control in hospital settings.

A systematic literature review was performed to assess the impact of surgical-staff behaviors on the risk of surgical site infections. Published data are limited, heterogeneous, and weakened by several methodological flaws, underlying the need for more studies with accurate tools.

To assess the current literature regarding the impact of surgical-staff behaviors on the risk of surgical-site infection (SSI).

Systematic literature review.

We searched the Medline, EMBASE, Ovid, Web of Science, and Cochrane databases for original articles about the impact of intraoperative behaviors on the risk of SSI published in English before September 2013.

We retrieved 27 original articles reporting data on number of people in the operating room (n=14), door openings (n=14; number [n=6], frequency [n=7], reasons [n=4], or duration [n=3]), surgical-team discipline (evidence of distraction; n=4), compliance with traffic measures (n=6), or simulated behaviors (n=3). Most (59%) articles were published in 2009–2013. End points were the 30-day SSI rate (n=8), air-particle count (n=2), or microbiological air counts (n=6); 11 studies were only descriptive. Number of people in the operating room and SSI rate or airborne contaminants (particle/bacteria) were correlated in 2 studies. Door openings and airborne bacteria counts were correlated in 2 observational studies and 1 experimental study. Two cohort studies showed a significant association between surgeon interruptions/distraction or noise and SSI rate. The level of evidence was low in all studies.

Published data about the impact of operating-room behaviors on the risk of infection are limited and heterogeneous. All studies exhibit major methodological flaws. More studies with accurate tools should be performed to address the influence of operating room behaviors on the infectious risk.

Infect Control Hosp Epidemiol 2015;36(1): 93–106

To review the evidence regarding the effects of interventions to improve hospital design and construction on the occurrence of nosocomial infections.

Systematic review of experimental and non-experimental, architectural intervention studies in intensive care units (ICUs), surgical departments, isolation units, and hospitals in general. The studies dated from 1975, and were in English, French, German, Italian, and Spanish. Regardless of format, the studies were identified through seven medical databases, reference lists, and expert consultation.

One hundred seventy-eight scientific articles were identified; however, none of these described a meta-analy-sis, systematic review, or randomized, controlled trial. Most of the articles were categorized at the lowest level of evidence (expert judgment or consensus statements). Only 17 described completed concurrent or historical cohort studies matching the inclusion criteria (ICUs, 9; surgical departments, 4; isolation units, 2; hospitals in generai, 2). The interventions generally included a move to other premises or renovation. However, in many studies, the staff-to-patient ratio was also improved. Some studies showed lower infection rates after intervention, but this finding cannot be generalized because of confounding and fre-quently small study populations.

The lack of stringent evidence linking hospital design and construction with the prevention of nosocomial infection is partly attributable to the multifactorial nature of these infections, and some improvement will be seen if basic conditions such as the availability of sufficient space, isolation capac-ity, and facilities for handwashing are met. However, to our knowledge, other factors, especially the improper hand hygiene of medical staff, have greater impact.

Hospitalized premature infants are particularly vulnerable to morbidity and mortality from pertussis. Effective prevention and investigative and control measures are not well described.

To identify the source of nosocomial pertussis in a 2-month-old premature infant in a neonatal intermediate care nursery (ICN) and to critically review the investigation and outbreak control measures.

An ICN and a neonatal intensive care unit.

We queried healthcare workers (HCWs) and family members about cough illness and contacted potentially exposed patients to determine whether they had symptoms of pertussis. Culture and polymerase chain reaction (PCR) testing for Bordetella pertussis were performed by the hospital laboratory with specimens collected from symptomatic patients and HCWs. Levels of pertussis toxin immunoglobulin G antibodies were measured in HCWs with cough of at least 14 days' duration at a public health laboratory. Extensive control measures were instituted.

Four ICN HCWs met the clinical case definition for presence of pertussis. Serologic test results were positive for 3 of the HCWs. The primary case patient was a 36-year-old HCW with a cough illness of 3-weeks' duration that was accompanied by paroxysms, whoop, posttussive emesis, and pneumothorax. Among the 4 affected HCWs, the duration of cough illness prior to identification of the infant index patient ranged from 11 to 25 days. Outbreak control measures included isolation of the infant case patient, furlough and treatment of symptomatic HCWs, administration of chemoprophylaxis to contacts, and surveillance for additional cases. Seventy-two infant patients and 72 HCWs were exposed and were given antibiotic prophylaxis. One additional case of pertussis, confirmed by PCR and culture, occurred in a resident physician who declined prophylaxis; she had cared for the index patient but had no contact with symptomatic HCWs.

HCWs or patients may serve as the source of pertussis in nosocomial outbreaks, which can result in substantial morbidity and outlay of resources for control measures. Our review suggested that a diagnosis of pertussis should be an early consideration for HCWs with cough illness. Targeted pertussis immunization of HCWs, employee health policies that provide for testing and furlough of HCWs with prolonged cough, and monitoring of HCWs for compliance with infection control measures could reduce the morbidity and costs associated with pertussis outbreaks. These measures will require evaluation of their effectiveness.

To identify environmentally safe, rapidly acting agents for killing spores of Clostridium difficile in the hospital environment.

Three classic disinfectants (2% glutaraldehyde, 1.6% peracetyl ions, and 70% isopropanol) and acidified nitrite were compared for activity against C. difficile spores. Four strains of C. difficile belonging to different serogroups were tested using a dilution–neutralization method according to preliminary European Standard prEN 14347. For peracetyl ions and acidified nitrite, the subjective cleaning effect and the sporicidal activity was also tested in the presence of organic load.

Peracetyl ions were highly sporicidal and yielded a minimum 4 log10 reduction of germinating spores already at short exposure times, independent of organic load conditions. Isopropanol 70% showed low or no inactivation at all exposure times, whereas glutaraldehyde and acidified nitrite each resulted in an increasing inactivation factor (IF) over time, from an IF greater than 1.4 at 5 minutes of exposure time to greater than 4.1 at 30 minutes. Soiling conditions did not influence the effect of acidified nitrite. There was no difference in the IF among the 4 strains tested for any of the investigated agents. Acidified nitrite demonstrated a good subjective cleaning effect and peracetyl ions demonstrated a satisfactory effect.

Cidal activity was shown against C. difficile spores by glutaraldehyde, peracetyl ions, and acidified nitrite. As acidified nitrite and peracetyl ions are considered to be environmentally safe chemicals, these agents seem well suited for the disinfection of C. difficile spores in the hospital environment.

To evaluate (1) the framework of the 12 Steps to Prevent Antimicrobial Resistance Among Hospitalized Adults that is part of the Centers for Disease Control and Prevention (CDC) Campaign to Prevent Antimicrobial Resistance in Healthcare Settings, with regard to steps addressing antimicrobial use; and (2) methods of feedback to clinicians regarding antimicrobial use after postprescription review.

Prospective intervention to identify and modify inappropriate antimicrobial therapy.

A 1,000-bed, tertiary care teaching hospital.

Inpatients in selected medicine and surgery units receiving broad-spectrum antimicrobials for 48-72 hours.

We created a computer-based clinical-event detection system that automatically identified inpatients taking broad-spectrum and “reserve” antimicrobials for 48-72 hours. Although prior approval was required for initial administration of broad-spectrum and reserve antimicrobials, once approval was obtained, therapy with the antimicrobials could be continued indefinitely at the discretion of the treating clinician. Therapy that was ongoing at 48-72 hours was reviewed by an infectious diseases pharmacist or physician, and when indicated feedback was provided to clinicians to modify or discontinue therapy. Feedback was provided via a direct telephone call, a note on the front of the medical record, or text message sent to the clinician's pager. The acceptance rate of feedback was recorded and recommendations were categorized according to the 12 steps recommended by the CDC.

Interventions were recommended for 334 (30%) of 1,104 courses of antimicrobial therapy reviewed. A total of 87% of interventions fit into one of the CDC's 12 steps of prevention: 39% into step 3 (“target the pathogen”), 1% into step 4 (“access experts”), 3% into steps 7 and 8 (“treat infection, not colonization or contamination”), 18% into step 9 (“say ‘no’ to vancomycin”), and 26% into step 10 (“stop treatment when no infection”). The rate of compliance with recommendations to improve antimicrobial use was 72%. No differences in compliance were seen with the different methods of feedback.

Nearly one-third of antimicrobial courses did not follow the CDC's recommended 12 steps for prevention of antimicrobial resistance. Clinicians demonstrated high compliance with following suggestions made after postprescription review, suggesting that it is a useful approach to decreasing and improving antimicrobial use among inpatients.