The Centers for Disease Control and Prevention implemented new surveillance definitions for ventilator-associated events (VAEs) in January 2013. We describe the epidemiology, attributable morbidity, and attributable mortality of VAEs.

Retrospective cohort study.

Academic tertiary care center.

All patients initiated on mechanical ventilation between January 1, 2006, and December 31, 2011.

We calculated and compared VAE hazard ratios, antibiotic exposures, microbiology, attributable morbidity, and attributable mortality for all VAE tiers.

Among 20,356 episodes of mechanical ventilation, there were 1,141 (5.6%) ventilator-associated condition (VAC) events, 431 (2.1%) infection-related ventilator-associated complications (IVACs), 139 (0.7%) possible pneumonias, and 127 (0.6%) probable pneumonias. VAC hazard rates were highest in medical, surgical, and thoracic units and lowest in cardiac and neuroscience units. The median number of days to VAC onset was 6 (interquartile range, 4–11). The proportion of IVACs to VACs ranged from 29% in medical units to 42% in surgical units. Patients with probable pneumonia were more likely to be prescribed nafcillin, ceftazidime, and fluroquinolones compared with patients with possible pneumonia or IVAC-alone. The most frequendy isolated organisms were Staphylococcus aureus (29%), Pseudomonas aeruginosa (14%), and Enterobacter species (7.9%). Compared with matched controls, VAEs were associated with more days to extubation (relative rate, 3.12 [95% confidence interval (CI), 2.96–3.29]), more days to hospital discharge (relative rate, 1.46 [95% CI, 1.37–1.55]), and higher hospital mortality risk (odds ratio, 1.98 [95% CI, 1.60–2.44]).

VAEs are common and morbid. Prevention strategies targeting VAEs are needed.

Determine whether daily bathing with chlorhexidine-based soap decreased methicillin-resistant Staphylococcus aureus (MRSA) transmission and intensive care unit (ICU)-acquired S. aureus infection among ICU patients.

Prospective pre-post-intervention study with control unit.

A 1,250-bed tertiary care teaching hospital.

Medical and surgical ICU patients.

Active surveillance for MRSA colonization was performed in both ICUs. In June 2005, a chlorhexidine bathing protocol was implemented in the surgical ICU. Changes in S. aureus transmission and infection rate before and after implementation were analyzed using time-series methodology.

The intervention unit had a 20.68% decrease in MRSA acquisition after institution of the bathing protocol (12.64 cases per 1,000 patient-days at risk before the intervention vs 10.03 cases per 1,000 patient-days at risk after the intervention; β, −2.62 [95% confidence interval (CI), −5.19 to −0.04]; P = .046). There was no significant change in MRSA acquisition in the control ICU during the study period (10.97 cases per 1,000 patient-days at risk before June 2005 vs 11.33 cases per 1,000 patient-days at risk after June 2005; β, −11.10 [95% CI, −37.40 to 15.19]; P = .40). There was a 20.77% decrease in all S. aureus (including MRSA) acquisition in the intervention ICU from 2002 through 2007 (19.73 cases per 1,000 patient-days at risk before the intervention to 15.63 cases per 1,000 patient-days at risk after the intervention [95% CI, −7.25 to −0.95]; P = .012)]. The incidence of ICU-acquired MRSA infections decreased by 41.37% in the intervention ICU (1.96 infections per 1,000 patient-days at risk before the intervention vs 1.15 infections per 1,000 patient-days at risk after the intervention; P = .001).

Institution of daily chlorhexidine bathing in an ICU resulted in a decrease in the transmission of S. aureus, including MRSA. These data support the use of routine daily chlorhexidine baths to decrease rates of S. aureus transmission and infection.

The Centers for Medicare and Medicaid Services (CMS) implemented a policy in October 2008 to eliminate additional Medicare payment for mediastinitis following coronary artery bypass graft (CABG) surgery.

To evaluate the impact of this policy on mediastinitis rates, using Medicare claims and National Healthcare Safety Network (NHSN) prospective surveillance data.

We used an interrupted time series design to compare mediastinitis rates before and after the policy, adjusted for secular trends. Billing rates came from Medicare inpatient claims following 638,761 CABG procedures in 1,234 US hospitals (January 2006-September 2010). Prospective surveillance rates came from 151 NHSN hospitals in 29 states performing 94,739 CABG procedures (January 2007-September 2010). Logistic regression mixed-effects models estimated trends for mediastinitis rates.

We found a sudden drop in coding for index admission mediastinitis at the time of policy implementation (odds ratio, 0.36 [95% confidence interval (CI), 0.23-0.57]) and a decreasing trend in coding for index admission mediastinitis in the postintervention period compared with the preintervention period (ratio of slopes, 0.83 [95% CI, 0.74-0.95]). However, we saw no impact of the policy on infection rates as measured using NHSN data. Our results were not affected by changes in patient risk over time, heterogeneity in hospital demographics, or timing of hospital participation in NHSN.

The CMS policy of withholding additional Medicare payment for mediastinitis on the basis of claims-based evidence of infection was associated with changes in coding for infections but not with changes in actual infection rates during the first 2 years after policy implementation.

Studies conducted in Europe have observed resistance to trace metals such as zinc chloride and copper sulfate in livestock-associated Staphylococcus aureus. This study was conducted to determine the prevalence of zinc and cadmium resistance in S. aureus isolated in the United States.

Cross-sectional study of convenience sample of S. aureus isolates.

Three hundred forty-nine S. aureus isolates, including methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) obtained from human, swine, and retail meat were included in the sample set.

Polymerase chain reaction was used to test for the presence of genes for zinc and cadmium resistance (czrC), methicillin resistance (mecA), and staphylococcal complement inhibitor (scn). Antibiotic susceptibility of isolates was tested using the broth microdilution method. Data were analyzed using the multivariable logistic regression method.

Twenty-nine percent (102/349) of S. aureus isolates were czrC positive. MRSA isolates were more likely to be czrC positive compared to MSSA (MRSA czrC positive: 12/61, 19.6%; MSSA czrC positive: 12/183, 6.6%). After adjustment for oxacillin and clindamycin susceptibility in analysis, multidrug-resistant S. aureus was observed to have low odds of being czrC positive (P = .03). The odds of being czrC positive were observed to be significantly high in tetracycline-resistant S. aureus isolated from noninfection samples (P = .009) and swine (P < .0001).

Resistance to zinc and cadmium was observed to be associated with MRSA, a finding consistently observed in European studies. Prolonged exposure to zinc in livestock feeds and fertilizers could propagate resistance to the metal ion, thereby hindering use of zinc-based topical agents in treating S. aureus infections.

To evaluate whether an ecologic inverse association exists between methicillin-susceptible Staphylococcus aureus (MSSA) prevalence and methicillin-resistant S. aureus (MRSA) prevalence in nursing homes.

We conducted a secondary analysis of a prospective cross-sectional study of S. aureus prevalence in 26 nursing homes across Orange County, California, from 2008–2011. Admission prevalence was assessed using bilateral nares swabs collected from all new residents within 3 days of admission until 100 swabs were obtained. Point prevalence was assessed from a representative sample of 100 residents. Swab samples were plated on 5% sheep blood agar and Spectra MRSA chromogenic agar. If MRSA was detected, no further tests were performed. If MRSA was not detected, blood agar was evaluated for MSSA growth. We evaluated the association between MRSA and MSSA admission and point prevalence using correlation and linear regression testing.

We collected 3,806 total swabs. MRSA and MSSA admission prevalence were not correlated (r = −0.40, P = .09). However, MRSA and MSSA point prevalence were negatively correlated regardless of whether MSSA prevalence was measured among all residents sampled (r = −0.67, P = .0002) or among those who did not harbor MRSA (r = −0.41, P = .04). This effect persisted in regression models adjusted for the percentage of residents with diabetes (β = −0.73, P = .04), skin lesions (β = −1.17, P = .002), or invasive devices (β = −1.4, P = .0006).

The inverse association between MRSA and MSSA point prevalence and minimal association on admission prevalence suggest MSSA carriage may protect against MRSA acquisition in nursing homes. The minimal association on admission prevalence further suggests competition may occur during nursing home stays.

Infect Control Hosp Epidemiol 2014;35(10):1257–1262

Patients in the neonatal intensive care unit (NICU) are at high risk for healthcare-associated infections. Variability in reported infection rates among NICUs exists, possibly related to differences in prevention strategies. A better understanding of current prevention practices may help identify prevention gaps and areas for further research.

We surveyed infection control staff in NICUs reporting to the National Healthcare Safety Network (NHSN) to assess strategies used to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and central line–associated bloodstream infections in NICUs.

Staff from 162 of 342 NICUs responded (response rate, 47.3%). Most (92.3%) NICUs use central line insertion and maintenance bundles, but maintenance practices varied, including agents used for antisepsis and frequency of dressing changes. Forty-two percent reported routine screening for MRSA colonization upon admission for all patients. Chlorhexidine gluconate (CHG) use for central line care for at least 1 indication (central line insertion, dressing changes, or port/cap antisepsis) was reported in 82 NICUs (51.3%). Among sixty-five NICUs responding to questions on CHG use restrictions, 46.2% reported no restrictions.

Our survey illustrated heterogeneity of CLABSI and MRSA prevention practices and underscores the need for further research to define optimal strategies and evidence-based prevention recommendations for neonates.

Infect Control Hosp Epidemiol 2014;35(9):1126-1132

To assess definitions, experience, and infection control practices for multidrug-resistant gram-negative bacteria (MDR-GNB), including Enterobacteriaceae, Acinetobacter, and Pseudomonas species, in acute care hospitals.

Cross-sectional survey.

US and international members of the Society for Healthcare Epidemiology of America (SHEA) Research Network.

Online survey that included definitions, infection control procedures, and microbiology capability related to MDR-GNB and other MDR bacteria.

From November 2012 through February 2013, 66 of 170 SHEA Research Network members responded (39% response rate), representing 26 states and 15 countries. More than 80% of facilities reported experience with each MDR-GNB isolate, and 78% had encountered GNB resistant to all antibiotics except colistin (62% Acinetobacter, 59% Pseudomonas, and 52% Enterobacteriaceae species). Participants varied regarding their definitions of “multidrug resistant,” with 14 unique definitions for Acinetobacter, 18 for Pseudomonas, and 22 for Enterobacteriaceae species. Substantial variation also existed in isolation practices. Although isolation was commonly used for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and carbapenem-resistant Enterobacteriaceae (CRE), approximately 20% of facilities did not isolate for MDR Pseudomonas or Acinetobacter. The majority of those that isolated MDR organisms also removed isolation using a wide variety of criteria.

Facilities vary significantly in their approach to preventing MDR-GNB transmission. Although practices for MRSA and VRE are relatively standardized, emerging pathogens CRE and other MDR-GNB have highly varied definitions and management. This confusion makes communication difficult, and varied use of isolation may contribute to emergence of these organisms. Public health agencies need to promote standard definitions and management to enable broader initiatives to limit emergence of MDR-GNB.

To build and to begin evaluating a regional automated system to notify infection preventionists (IPs) when a patient with a history of gram-negative rod multidrug-resistant organism (GNRMDRO) is admitted to an emergency department (ED) or inpatient setting.

Observational, retrospective study.

Twenty-seven hospitals, mostly in the Indianapolis metropolitan area, in a health information exchange (HIE).

During testing of the new system: 80,180 patients with microbiology cultures between October 1, 2013, and December 31, 2013; 573 had a GNRMDRO.

A Health Level Seven (HL7) data feed from the HIE was obtained, corrected, enhanced, and used for decision support (secure e-mail notification to the IPs). Retrospective analysis of patients with microbiology data (October 1, 2013, through December 31, 2013) and subsequent healthcare encounters (through February 6, 2014).

The 573 patients (median age, 66 years; 68% women) had extended-spectrum β-lactamase-producing Enterobacteriaceae (78%), carbapenem-resistant Enterobacteriaceae (7%), Pseudomonas aeruginosa (9%), Acinetobacter baumannii (3%), or other GNR (3%). Body sources were urine (68%), sputum/trachea/bronchoalveolar lavage (13%), wound/skin (6%), blood (6%), or other/unidentified (7%). Between October 1, 2013, and February 6, 2014, 252 (44%) of 573 had an ED or inpatient encounter after the GNRMDRO culture, 47 (19% of 252) at an institution different from where the culture was drawn. During the first 7 weeks of actual alerts (January 29, 2014, through March 19, 2014), alerts were generated regarding 67 patients (19 of 67 admitted elsewhere from where the culture was drawn).

It proved challenging but ultimately feasible to create a regional microbiology-based alert system. Even in a few months, we observed substantial crossover between institutions. This system, if it contributes to timely isolation, may help reduce the spread of GNRMDROs.

To determine the association between state legal mandates for data submission of central line–associated bloodstream infections (CLABSIs) in neonatal intensive care units (NICUs) with process and outcome measures.

Cross-sectional study.

Participants. National sample of level II/III and III NICUs participating in National Healthcare Safety Network (NHSN) surveillance.

State mandates for data submission of CLABSIs in NICUs in place by 2011 were compiled and verified with state healthcare-associated infection coordinators. A web-based survey of infection control departments in October 2011 assessed CLABSI prevention practices, ie, compliance with checklist/bundle components (process measures) in ICUs including NICUs. Corresponding 2011 NHSN NICU CLABSI rates (outcome measures) were used to calculate standardized infection ratios (SIRs). Association between mandates and process and outcome measures was assessed by multivariable logistic regression.

Among 190 study NICUs, 107 (56.3%) were located in states with mandates, with mandates in place >3 years in 52 (49%). More NICUs in states with mandates reported ≥95% compliance to at least 1 CLABSI prevention practice (52.3%–66.4%) than NICUs in states without mandates (28.9%–48.2%). Mandates were predictors of ≥95% compliance with all practices (odds ratio, 2.8; 95% confidence interval, 1.4–6.1). NICUs in states with mandates reported lower mean CLABSI rates in the ≤750-g birth weight group (2.4 vs 5.7 CLABSIs/1,000 central line–days) but not in others. Mandates were not associated with SIR <1.

State mandates for NICU CLABSI data submission were significantly associated with ≥95% compliance with CLABSI prevention practices, which declined with the duration of mandate but not with lower CLABSI rates.

Infect Control Hosp Epidemiol 2014;35(9):1133-1139

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been found to be epidemiologically and microbiologically distinct from healthcare-associated MRSA. Most CA-MRSA infections are not invasive; however, fatal outcomes have been reported among healthy people with CA-MRSA invasive infections. Epidemiological studies have attributed a major burden of CA-MRSA infections in the United States to the predominant clone USA300. We investigated the association between USA300 invasive infections and mortality by conducting a systematic review and meta-analysis of studies that reported mortality rates associated with USA300 strains.

We searched PubMed, bibliographies of other publications, and gray literature between January 2001 and December 2013. Observational studies of patients with an invasive MRSA infection were included. The exposure of interest was presence of USA300 invasive infection. Studies were included only if they provided MRSA PFGE types and if corresponding mortality data were the measured outcome. We pooled crude odds ratios (cORs) using a random-effects model. Woolf test of homogeneity and Q and I2 statistics were assessed.

Of 574 articles identified by the search strategy, 8 met the inclusion criteria. Risk of mortality was significantly lower among patients with USA300 MRSA infections (pooled cOR, 0.63 [95% confidence interval (CI)], 0.49–0.81). There was a moderate degree of heterogeneity among study results (P = .29; I2 = 18%). Results were observed to be heterogeneous due to study design, quality of studies, and definition of mortality.

MRSA invasive infection with USA300 does not appear to be associated with higher mortality compared with infections due to non-USA300 strains. Nevertheless, larger well-designed studies are warranted to further evaluate this association.

To analyze trends in the incidence and pathogen distribution of healthcare-associated bloodstream infections (HABSIs) over a 20-year period (1992–2011).

Historical cohort study.

Thirty-two-bed neonatal intensive care unit (NICU) in a tertiary referral hospital.

Neonates with HABSIs defined according to the criteria of the National Institute of Child Health and Development (NICHD).

A hospital-based ongoing surveillance program was used to identify HABSI cases in neonates. A distinction between definite or possible HABSI was made according to the NICHD criteria. Incidence, incidence densities (HABSIs per 1,000 hospital-days and HABSIs per 1,000 total parenteral nutrition–days), and case fatality rate were calculated. Logistic regression analysis was used to find time trends. Four periods of 5 years were considered when executing variance analysis.

In total, 682 episodes of HABSIs occurred on 9,934 admissions (6.9%). The median total incidence density rate was 3.1 (interquartile range, 2.2–3.9). A significant increasing time trend in incidence density was observed for the period 1995–2011 (P < .003). A significant decrease in the case fatality rate was found in the last 5-year period (P < .001). No neonate died following possible HABSIs, whereas the case fatality rate among neonates with definite HABSIs was 9.7%. Most HABSIs were caused by coagulase-negative staphylococci (n = 414 [60.7%]). A significant increase in Staphylococcus aureus HABSI was observed in the last 10-year period (P < .001).

An increase in incidence density rate occurred, while the case fatality rate dropped. Better perinatal care could be responsible for the latter. A decrease in days before infection and a high incidence of coagulase-negative Staphylococcus HABSIs indicate the need for vigorous application of evidence-based prevention initiatives, in particular for catheter care.

To determine whether well-child visits are a risk factor for subsequent influenza-like illness (ILI) visits within a child's family. DESIGN. Retrospective cohort.

Using data from the Medical Expenditure Panel Survey from the years 1996-2008, we identified 84,595 families. For each family, we determined those weeks in which a well-child visit or an ILI visit occurred. We identified 23,776 well-child-visit weeks and 97,250 ILI-visit weeks. We fitted a logistic regression model, where the binary dependent variable indicated an ILI clinic visit in a particular week. Independent variables included binary indicators to denote a well-child visit in the concurrent week or one of the previous 2 weeks, the occurrence of the ILI visit during the influenza season, and the presence of children in the family in each of the age groups 0–3, 4–7, and 8–17 years. Socioeconomic variables were also included. We also estimated the overall cost of well-child-exam-related ILI using data from 2008.

We found that an ILI office visit by a family member was positively associated with a well-child visit in the same or one of the previous 2 weeks (odds ratio, 1.54). This additional risk translates to potentially 778,974 excess cases of ILI per year in the United States, with a cost of $500 million annually.

Our results should encourage ambulatory clinics to strictly enforce infection control recommendations. In addition, clinics could consider time-shifting of well-child visits so as not to coincide with the peak of the influenza season.

To establish the source and contamination routes resulting in positive clinical and surveillance microbiological cultures with carbapenem-resistant, GIM-1 metallo-β-lactamase–positive Acinetobacter pitii and Acinetobacter radioresistens from 21 patients in 8 departments

Retrospective, descriptive study.

A 1,300-bed tertiary care academic medical facility consisting of 90 buildings linked by a pneumatic transport system (PTS).

Microbiological workup of the cluster strains included matrix-assisted laser desorption/ionization time-of-flight species identification, phenotypic carbapenemase tests, polymerase chain reaction–based genotyping of carbapenemase, and pulsed-field gel electrophoresis. Outbreak management procedures were employed according to institutional regulations.

The rarity of GIM-1 Acinetobacter species in the hospital and region, the lack of epidemiological links between patients, and the fact that in some patients the apparent colonization was clearly nonnosocomial prompted the suspicion of a pseudo-outbreak. Numerous environmental cultures were positive for GIM-1-positive Acinetobacter (including archived sample requisition forms, PTS capsules, cultures from line-diverter and dispenser stations, and sterilized transport capsules following PTS delivery). Moreover, it was observed that condensation fluid from subterranean PTS tubing resulted in water entry in PTS capsules, possibly conferring specimen contamination. After extensive system disinfection, environmental surveys of the PTS were negative, and no further positive patient specimens were encountered.

This is the first report of a PTS-associated pseudo-outbreak. The large number of falsely positive patient-related specimens in conjunction with the potential hazard of airborne and contact spread of multidrug-resistant microorganisms (in this case, GIM-1 carbapenem-resistant Acinetobacter species) underscores the need for implementation of infection control–based monitoring and operating procedures in a hospital PTS.

To identify differences in organizational culture and better understand motivators to implementation of abundle intervention to control Klebsiella pneumoniae carbapenemase–producing Enterobacteriaceae (KPC).

Mixed-methods study.

Four long-term acute care hospitals (LTACHs) in Chicago.

LTACH staff across 3 strata of employees (administration, midlevel management, and frontline clinical workers).

Qualitative interviews or focus groups and completion of a quantitative questionnaire.

Eighty employees (frontline, 72.5%; midlevel, 17.5%; administration, 10%) completed surveys and participated in qualitative discussions in August 2012. Although 82.3% of respondents felt that quality improvement was a priority at their LTACH, there were statistically significant differences in organizational culture between staff strata, with administrative-level having higher organizational culture scores (ie, more favorable responses) than midlevel or frontline staff. When asked to rank the success of the KPC control program, mean response was 8.0 (95% confidence interval, 7.6–8.5), indicating a high level of agreement with the perception that the program was a success. Patient safety and personal safety were reported most often as personal motivators for intervention adherence. The most convergent theme related to prevention across groups was that proper hand hygiene is vital to prevention of KPC transmission.

Despite differences in organizational culture across 3 strata of LTACH employees, the high degree of convergence in motivation, understanding, and beliefs related to implementation of a KPC control bundle suggests that all levels of staff may be able to align perspectives when faced with a key infection control problem and quality improvement initiative.

States have established public reporting of hospital-associated (HA) infections—including those of methicillin-resistant Staphylococcus aureus (MRSA)—but do not account for hospital case mix or postdischarge events

Identify facility-level characteristics associated with HA-MRSA infection admissions and create adjusted hospital rankings.

A retrospective cohort study of 2009–2010 California acute care hospitals. We defined HA-MRSA admissions as involving MRSA pneumonia or septicemia events arising during hospitalization or within 30 days after discharge. We used mandatory hospitalization and US Census data sets to generate hospital population characteristics by summarizing across admissions. Facility-level factors associated with hospitals’ proportions of HA-MRSA infection admissions were identified using generalized linear models. Using state methodology, hospitals were categorized into 3 tiers of HA-MRSA infection prevention performance, using raw and adjusted values.

Among 323 hospitals, a median of 16 HA-MRSA infections (range, 0–102) per 10,000 admissions was found. Hospitals serving a greater proportion of patients who had serious comorbidities, were from low-education zip codes, and were discharged to locations other than home were associated with higher HA-MRSA infection risk. Total concordance between all raw and adjusted hospital rankings was 0.45 (95% confidence interval, 0.40–0.51). Among 53 community hospitals in the poor-performance category, more than 20% moved into the average-performance category after adjustment. Similarly, among 71 hospitals in the superior-performance category, half moved into the average-performance category after adjustment.

When adjusting for nonmodifiable facility characteristics and case mix, hospital rankings based on HA-MRSA infections substantially changed. Quality indicators for hospitals require adequate adjustment for patient population characteristics for valid interhospital performance comparisons.

Infect Control Hosp Epidemiol 2014;35(10):1263–1270

Central line–associated bloodstream infection (BSI) rates are a key quality metric for comparing hospital quality and safety. Traditional BSI surveillance may be limited by interrater variability. We assessed whether a computer-automated method of central line–associated BSI detection can improve the validity of surveillance.

Retrospective cohort study.

Eight medical and surgical intensive care units (ICUs) in 4 academic medical centers.

Traditional surveillance (by hospital staff) and computer algorithm surveillance were each compared against a retrospective audit review using a random sample of blood culture episodes during the period 2004–2007 from which an organism was recovered. Episode-level agreement with audit review was measured with κ statistics, and differences were assessed using the test of equal κ coefficients. Linear regression was used to assess the relationship between surveillance performance (κ) and surveillance-reported BSI rates (BSIs per 1,000 central line–days).

We evaluated 664 blood culture episodes. Agreement with audit review was significantly lower for traditional surveillance (κ [95% confidence interval (CI)] = 0.44 [0.37–0.51]) than computer algorithm surveillance (κ [95% CI] [0.52–0.64]; P = .001). Agreement between traditional surveillance and audit review was heterogeneous across ICUs (P = .001); furthermore, traditional surveillance performed worse among ICUs reporting lower (better) BSI rates (P = .001). In contrast, computer algorithm performance was consistent across ICUs and across the range of computer-reported central line–associated BSI rates.

Compared with traditional surveillance of bloodstream infections, computer automated surveillance improves accuracy and reliability, making interfacility performance comparisons more valid.

Infect Control Hosp Epidemiol 2014;35(12):1483–1490

Surgical site infection (SSI) after total hip and knee arthroplasty is a common postoperative complication. We sought to determine readmission rates and costs for total hip and knee arthroplasty complicated by SSI.

The Thomson Reuters MarketScan database was searched for patients who underwent knee or hip arthroplasty in 2007. From these data, patients who received a diagnosis of SSI and were readmitted after diagnosis were identified.

A population of 31 to 45 million individuals receiving insurance coverage. Patients who underwent knee or hip arthroplasty who experienced a hospitalization for SSI in the year after surgery were analyzed.

Total readmission rates and costs per readmission at 30, 60, and 90 days and 1 year after diagnosis of SSI.

Of the 76,289 case patients with hip or knee replacement in 2007, 1,026 (1.3%) had a hospitalization for SSI within the year after surgery. Among these patients, 310 (30.2%) were subsequently rehospitalized in the year after initial hospitalization specifically due to SSI-related issues. These rehospitalizations were associated with a mean hospital stay of 7.4 ± 11.4 days and a median cost of $20,001 (interquartile range [IQR], $14,057-$30,551). A total of 517 subjects had a subsequent “all-cause” hospitalization during the year after SSI. These rehospitalizations were associated with a mean hospital stay of 6.4 ± 10.4 days and a median cost of $19,870 (IQR, $13,913-$29,728).

Readmissions during the year after SSI diagnosis accounted for 1,072 hospital admissions and cost over $25.5 million. These readmissions are costly and might be a future target for decreased reimbursement.

Treatment of Staphylococcus aureus colonization before surgery reduces risk of surgical site infection (SSI). The regimen of nasal mupirocin ointment and topical chlorhexidine gluconate is effective, but cost and patient compliance may be a barrier. Nasal povidone-iodine solution may provide an alternative to mupirocin.

We conducted an investigator-initiated, open-label, randomized trial comparing SSI after arthroplasty or spine fusion in patients receiving topical chlorhexidine wipes in combination with either twice daily application of nasal mupirocin ointment during the 5 days before surgery or 2 applications of povidone-iodine solution into each nostril within 2 hours of surgical incision. The primary study end point was deep SSI within the 3 months after surgery.

In the modified intent-to-treat analysis, a deep SSI developed after 14 of 855 surgical procedures in the mupirocin group and 6 of 842 surgical procedures in the povidone-iodine group (P = .1); S. aureus deep SSI developed after 5 surgical procedures in the mupirocin group and 1 surgical procedure in the povidone-iodine group (P = .2). In the per protocol analysis, S. aureus deep SSI developed in 5 of 763 surgical procedures in the mupirocin group and 0 of 776 surgical procedures in the povidone-iodine group (P = .03).

Nasal povidone-iodine may be considered as an alternative to mupirocin in a multifaceted approach to reduce SSI.

ClinicalTrials.gov identifier: NCT01313182.