Independent risk factors for surgical site infection (SSI) after cesarean section have not been well documented, despite the large number of cesarean sections performed and the relatively common occurrence of SSI.

To determine independent risk factors for SSI after low transverse cesarean section.

Retrospective case-control study.

Barnes-Jewish Hospital, a 1,250-bed tertiary care hospital.

A total of 1,605 women who underwent low transverse cesarean section during the period from July 1999 to June 2001.

Using the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for SSI or wound complication and/or data on antibiotic use during the surgical hospitalization or at readmission to the hospital or emergency department, we identified potential cases of SSI in a cohort of patients who underwent a low transverse cesarean section. Cases of SSI were verified by chart review using the definitions from the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance System. Control patients without SSI or endomyometritis were randomly selected from the population of patients who underwent cesarean section. Independent risk factors for SSI were determined by logistic regression.

SSIs were identified in 81 (5.0%) of 1,605 women who underwent low transverse cesarean section. Independent risk factors for SSI included development of subcutaneous hematoma after the procedure (adjusted odds ratio [aOR], 11.6 [95% confidence interval {CI}, 4.1–33.2]), operation performed by the university teaching service (aOR, 2.7 [95% CI, 1.4–5.2]), and a higher body mass index at admission (aOR, 1.1 [95% CI, 1.0–1.1]). Cephalosporin therapy before or after the operation was associated with a significantly lower risk of SSI (aOR, 0.2 [95% CI, 0.1–0.5]). Use of staples for skin closure was associated with a marginally increased risk of SSI.

These independent risk factors should be incorporated into approaches for the prevention and surveillance of SSI after surgery.

To assess the feasibility and effectiveness of the World Health Organization hand hygiene improvement strategy in a low-income African country.

A before-and-after study from December 2006 through June 2008, with a 6-month baseline evaluation period and a follow-up period of 8 months from the beginning of the intervention.

University Hospital, Bamako, Mali.

TWO hundred twenty-four healthcare workers.

The intervention consisted of introducing a locally produced, alcohol-based handrub; monitoring hand hygiene compliance; providing performance feedback; educating staff; posting reminders in the workplace; and promoting an institutional safety climate according to the World Health Organization multimodal hand hygiene improvement strategy. Hand hygiene infrastructure, compliance, healthcare workers' knowledge and perceptions, and handrub consumption were evaluated at baseline and at follow-up.

Severe deficiencies in the infrastructure for hand hygiene were identified before the intervention. Local handrub production and quality control proved to be feasible, affordable, and satisfactory. At follow-up, handrubbing was the quasi-exclusive hand hygiene technique (93.3%). Compliance increased from 8.0% at baseline to 21.8% at follow-up (P < .001). Improvement was observed across all professional categories and medical specialities and was independently associated with the intervention (odds ratio, 2.50; 95% confidence interval, 1.8-3.5). Knowledge enhanced significantly (P < .05), and perception surveys showed a high appreciation of each strategy component by staff.

Multimodal hand hygiene promotion is feasible and effective in a low-income country. Access to handrub was critical for its success. These findings motivated the government of Mali to expand the intervention nationwide. This experience represents a significant advancement for patient safety in developing countries.

To compare a hydrogen peroxide dry-mist system and a 0.5% hypochlorite solution with respect to their ability to disinfect Clostridium difficile-contaminated surfaces in vitro and in situ.

Prospective, randomized, before-after trial.

Two French hospitals affected by C. difficile.

In situ efficacy of disinfectants was assessed in rooms that had housed patients with C. difficile infection. A prospective study was performed at 2 hospitals that involved randomization of disinfection processes. When a patient with C. difficile infection was discharged, environmental contamination in the patient's room was evaluated before and after disinfection. Environmental surfaces were sampled for C. difficile by use of moistened swabs; swab samples were cultured on selective plates and in broth. Both disinfectants were tested in vitro with a spore-carrier test; in this test, 2 types of material, vinyl polychloride (representative of the room's floor) and laminate (representative of the room's furniture), were experimentally contaminated with spores from 3 C. difficile strains, including the epidemic clone ribotype 027-North American pulsed-field gel electrophoresis type 1.

There were 748 surface samples collected (360 from rooms treated with hydrogen peroxide and 388 from rooms treated with hypochlorite). Before disinfection, 46 (24%) of 194 samples obtained in the rooms randomized to hypochlorite treatment and 34 (19%) of 180 samples obtained in the rooms randomized to hydrogen peroxide treatment showed environmental contamination. After disinfection, 23 (12%) of 194 samples from hypochlorite-treated rooms and 4 (2%) of 180 samples from hydrogen peroxide treated rooms showed environmental contamination, a decrease in contamination of 50% after hypochlorite decontamination and 91% after hydrogen peroxide decontamination (P < .005). The in vitro activity of 0.5% hypochlorite was time dependent. The mean (±SD) reduction in initial log10 bacterial count was 4.32 ± 0.35 log10 colony-forming units after 10 minutes of exposure to hypochlorite and 4.18 ± 0.8 logl0 colony-forming units after 1 cycle of hydrogen peroxide decontamination.

In situ experiments indicate that the hydrogen peroxide dry-mist disinfection system is significantly more effective than 0.5% sodium hypochlorite solution at eradicating С difficile spores and might represent a new alternative for disinfecting the rooms of patients with C. difficile infection.

To assess the rate of and the risk factors for the detection of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) on the protective gowns and gloves of healthcare workers (HCWs).

We observed the interactions between HCWs and patients during routine clinical activities in a 29-bed medical intensive care unit at the University of Maryland Medical Center, an urban tertiary care academic hospital. Samples for culture were obtained from HCWs' hands prior to their entering a patient's room, from HCWs' disposable gowns and gloves after they completed patient care activities, and from HCWs' hands immediately after they removed their protective gowns and gloves.

Of 137 HCWs caring for patients colonized or infected with MRSA and/or VRE, 24 (17.5%; 95% confidence interval, 11.6%–24.4%) acquired the organism on their gloves, gown, or both. HCW contact with the endotracheal tube or tracheostomy site of a patient (P < .05), HCW contact with the head and/or neck of a patient (P < .05), and HCW presence in the room of a patient with a percutaneous endoscopic gastrostomy and/or jejunostomy tube (P < .05) were associated with an increased risk of acquiring these organisms.

The gloves and gowns of HCWs frequently become contaminated with MRSA and VRE during the routine care of patients, and particularly during care of the patient's respiratory tract and any associated indwelling devices. As part of a larger infection control strategy, including high-compliance hand disinfection, they likely provide a useful barrier to transmitting antibiotic-resistant organisms among patients in an inpatient setting.

To determine risk factors for bloodstream infections (BSIs) caused by Klebsiella pneumoniae producing metallo-β-lactamases (MBLs) or K. pneumoniae carbapenemases (KPCs), as well as risk factors for mortality associated with carbapenem-resistant K. pneumoniae, among intensive care unit (ICU) patients.

Two case-control studies were conducted in a patient cohort with K. pneumoniae BSIs in an 8-bed ICU in a Greek hospital from January 1, 2007, through December 31, 2008. In study 1, patients with K. pneumoniae BSIs were allocated among 3 groups according to isolate susceptibility profile: (1) carbapenem-susceptible insolates (control group), (2) MBL-producing isolates, or (3) KPC-producing isolates. The MBL and KPC groups were compared with the control group to identify risk factors for development of K. pneumoniae BSI. In study 2, patients with K. pneumoniae BSIs who died were compared with survivors to identify risk factors for mortality.

Fifty-nine patients had K. pneumoniae BSIs (22 with carbapenem-susceptible isolates, 18 with MBL-producing isolates, and 19 with KPC-producing isolates). All KPC-producing isolates carried the blaKPC-2 gene, and 17 of 18 MBL-producing isolates carried blaVIM-1 Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.13 [95% confidence interval, 1.03–1.25]; P = .02) was independently associated with KPC-producing K. pneumoniae BSIs. Nine (41%) of 22 control patients, 8 (44%) of 18 MBL group patients, and 13 (68%) of 19 KPC group patients died in the ICU. Nine (41%) of 22 control patients, 10 (56%) of 18 MBL group patients, and 15 (79%) of 19 KPC group patients died in the hospital. Isolation of KPC-producing K. pneumoniae was an independent predictor of ICU death (P = .04) and in-hospital death (P = .03) but not infection-attributable death.

BSIs due to KPC-producing K. pneumoniae resulted in significantly increased mortality. The accurate and rapid detection of these pathogens is necessary for therapeutic considerations and for the implementation of infection control measures to contain them.

The recent emergence of carbapenem resistance among Enterobacteriaceae is a major threat for hospitalized patients, and effective strategies are needed.

To assess the effect of an intensified intervention, which included active surveillance, on the incidence of infection with carbapenem-resistant Klebsiella pneumoniae.

Sheba Medical Center, a 1,600-bed tertiary care teaching hospital in Tel Hashomer, Israel.

Quasi-experimental study.

The medical records of all the patients who acquired a carbapenem-resistant K. pneumoniae infection during 2006 were reviewed. An intensified intervention was initiated in May 2007. In addition to contact precautions, active surveillance was initiated in high-risk units. The incidence of clinical carbapenem-resistant K. pneumoniae infection over time was measured, and interrupted time-series analysis was performed.

The incidence of clinical carbapenem-resistant K. pneumoniae infection increased 6.42-fold from the first quarter of 2006 up to the initiation of the intervention. In 2006, of the 120 patients whose clinical microbiologic culture results were positive for carbapenem-resistant K. pneumoniae, 67 (56%) developed a nosocomial infection. During the intervention period, the rate of carbapenem-resistant K. pneumoniae rectal colonization was 9%. Of the 390 patients with carbapenem-resistant K. pneumoniae colonization or infection, 204 (52%) were identified by screening cultures. There were a total of 12,391 days of contact precautions, and of these, 4,713 (38%) were added as a result of active surveillance. After initiation of infection control measures, we observed a significant decrease in the incidence of carbapenem-resistant K. pneumoniae infection.

The use of active surveillance and contact precautions, as part of a multifactorial intervention, may be an effective strategy to decrease rates of nosocomial transmission of carbapenem-resistant K. pneumoniae colonization or infection.

To determine the cost-effectiveness of a policy of screening high-risk patients for methicillin-resistant Staphylococcus aureus (MRSA) colonization on admission to hospital.

980-bed university-affiliated tertiary-care hospital.

Between June 1996 and May 1997, patients directly transferred from another hospital or nursing home, or who had been hospitalized in the previous 3 months, were screened for MRSA within 72 hours of hospital admission.

Nasal, perineal, and wound swabs were obtained for MRSA screening using standard laboratory methods. Laboratory and nursing costs associated with screening patients for MRSA on admission to hospital were calculated. The costs associated with the implementation of recommended infection control measures for patients with MRSA also were determined.

3,673 specimens were obtained from 1,743 patients. MRSA was found on admission in 23 patients (1.3%), representing 36% of the 64 patients with MRSA identified in the hospital during the year. MRSA-colonized patients were more likely to have been transferred from a nursing home (odds ratio [OR], 6.4; P=.04) or to have had a previous history of MRSA colonization (OR, 13.1; P=.05). Laboratory and nursing costs were found to be $8.34 per specimen, for a total cost of $30,632 during the year. The average cost of implementing recommended infection control measures for patients colonized with MRSA was approximately $5,235 per patient.

If early identification of MRSA in colonized patients prevents nosocomial transmission of the organism to as few as six new patients, the screening program would save money.

Prior data suggest that vancomycin-resistant Enterococcus (VRE) bacteremia is associated with worse outcomes than vancomycin-sensitive Enterococcus (VSE) bacteremia. However, many studies evaluating such outcomes were conducted prior to the availability of effective VRE therapies.

To systematically review VRE and VSE bacteremia outcomes among hospital patients in the era of effective VRE therapy.

Electronic databases and grey literature published between January 1997 and December 2014 were searched to identify all primary research studies comparing outcomes of VRE and VSE bacteremias among hospital patients, following the availability of effective VRE therapies. The primary outcome was all-cause, in-hospital mortality, while total hospital length of stay (LOS) was a secondary outcome. All meta-analyses were conducted in Review Manager 5.3 using random-effects, inverse variance modeling.

Among all the studies reviewed, 12 cohort studies and 1 case control study met inclusion criteria. Similar study designs were combined in meta-analyses for mortality and LOS. VRE bacteremia was associated with increased mortality compared with VSE bacteremia among cohort studies (odds ratio [OR], 1.80; 95% confidence interval [CI], 1.38–2.35; I2=0%; n=11); the case-control study estimate was similar, but not significant (OR, 1.93; 95% CI, 0.97–3.82). LOS was greater for VRE bacteremia patients than for VSE bacteremia patients (mean difference, 5.01 days; 95% CI, 0.58–9.44]; I2=0%; n=5).

Despite the availability of effective VRE therapy, VRE bacteremia remains associated with an increased risk of in-hospital mortality and LOS when compared to VSE bacteremia.

Infect. Control Hosp. Epidemiol. 2015;37(1):26–35

To assess the healthcare burden, morbidity, and mortality of nosocomial Clostridium difficile-associated diarrhea (N-CDAD) in Canadian hospitals.

Laboratory-based prevalence study.

Nineteen acute-care Canadian hospitals belonging to the Canadian Hospital Epidemiology Committee surveillance program.

Hospitalized patients in the participating centers.

Laboratory-based surveillance was conducted for C. difficile toxin in stool among 19 Canadian hospitals from January to April 1997, for 6 continuous weeks or until 200 consecutive diarrhea stool samples had been tested at each site. Patients with N-CDAD had to fulfill the case definition. Data collected for each case included patient demographics, length of stay, extent of diarrhea, complications of CDAD, CDAD-related medical interventions, patient outcome, and details of death.

We found that 371 (18%) of 2,062 tested patients had stools with positive results for C. difficile toxin, of whom 269 (13%) met the case definition for nosocomial CDAD. Of these, 250 patients (93%) had CDAD during their hospitalization, and 19 (7%) were readmitted because of CDAD (average readmission stay, 13.6 days). Forty-one patients (15.2%) died, of whom 4 (1.5% of the total) were considered to have died directly or indirectly of N-CDAD. The following N-CDAD-related morbidity was noted: dehydration, 3%; hypokalemia, 2%; gastrointestinal hemorrhage requiring transfusion, 1%; bowel perforation, 0.4%; and secondary sepsis, 0.4%. The cost of N-CDAD readmissions alone was estimated to be a minimum of $128,200 (Canadian dollars) per year per facility.

N-CDAD is a common and serious nosocomial infectious complication in Canada, is associated with substantial morbidity and mortality, and imposes an important financial burden on healthcare institutions.

From April to June 2001, an outbreak of extended-spectrum beta-lactamase (ESBL)–producing Klebsiella pneumoniae infections was investigated in our neonatal intensive care unit.

Cultures of the gastrointestinal tracts of patients, the hands of healthcare workers (HCWs), and the environment were performed to detect potential reservoirs for ESBL-producing K. pneumoniae. Strains of K. pneumoniae were typed by pulsed-field gel electrophoresis using Xbal. A case–control study was performed to determine risk factors for acquisition of the outbreak clone (clone A); cases were infants infected or colonized with clone A and controls (3 per case) were infants with negative surveillance cultures.

During the study period, 19 case-infants, of whom 13 were detected by surveillance cultures, harbored clone A. The overall attack rate for the outbreak strain was 45%; 9 of 19 infants presented with invasive disease (n = 6) or developed invasive disease (n = 3) after colonization was detected. Clone A was found on the hands of 2 HCWs, 1 of whom wore artificial nails, and on the designated stethoscope of a case-infant. Multiple logistic regression analysis revealed that length of stay per day (odds ratio [OR], 1.05; 95% confidence interval [CI95], 1.02 to 1.09) and exposure to the HCW wearing artificial fingernails (OR, 7.87; CI95, 1.75 to 35.36) were associated with infection or colonization with clone A.

Short, well-groomed, natural nails should be mandatory for HCWs with direct patient contact.

To examine the association between working conditions and needlestick injury among registered nurses. We also describe needle use and needlestick injuries according to nursing position, workplace, and specialty.

Three-wave longitudinal survey conducted between November 2002 and April 2004.

A probability sample of 2,624 actively licensed registered nurses from 2 states in the United States. Follow-up rates for waves 2 and 3 were 85% and 86%, respectively. Respondents who had worked as a nurse during the past year (n = 2,273) prior to wave 1 were included in this analysis.

Of the nurses, 15.6% reported a history of needlestick injury in the year before wave 1, and the cumulative incidence by wave 3 was 16.3%. The estimated number of needles used per day was significantly related to the odds of sustaining a needlestick injury. Hours worked per day, weekends worked per month, working other than day shifts, and working 13 or more hours per day at least once a week were each significantly associated with needlestick injuries. A factor combining these variables was significantly associated with needlestick injuries even after adjustment for job demands, although this association was somewhat explained by physical job demands.

Despite advances in protecting workers from needlestick injuries, extended work schedules and their concomitant physical demands are still contributing to the occurrence of injuries and illnesses to nurses. Such working conditions, if modified, could lead to further reductions in needlestick injuries.

To investigate an increase in reports of legionnaires' disease by multiple hospitals in San Antonio, Texas, and to study risk factors for nosocomial transmission of legionnaires' disease and determinants for Legionella colonization of hospital hot-water systems.

The 16 largest hospitals in the cities of San Antonio, Temple, and Austin, Texas.

Review of laboratory databases to identify patients with legionnaires' disease in the 3 years prior to the investigation and to determine the number of diagnostic tests for Legionella performed; measurement of hot-water temperature and chlorine concentration and culture of potable water for Legionella. Exact univariate calculations, Poisson regression, and linear regression were used to determine factors associated with water-system colonization and transmission of Legionella.

Twelve cases of nosocomial legionnaires' disease were identified; eight of these occurred in 1996. The rise in cases occurred shortly after physicians started requesting Legionella urinary antigen tests. Hospitals that frequently used Legionella urinary antigen tests tended to detect more cases of legionnaires' disease. Legionella was isolated from the water systems of 11 of 12 hospitals in San Antonio; the 12th had just experienced an outbreak of legionnaires' disease and had implemented control measures. Nosocomial legionellosis cases probably occurred in 5 hospitals. The number of nosocomial legionnaires' disease cases in each hospital correlated better with the proportion of water-system sites that tested positive for Legionella (P=.07) than with the concentration of Legionella bacteria in water samples (P=.23). Hospitals in municipalities where the water treatment plant used monochloramine as a residual disinfectant (n=4) and the hospital that had implemented control measures were Legionella-free. The hot-water systems of all other hospitals (n=11) were colonized with Legionella. These were all supplied with municipal drinking water that contained free chlorine as a residual disinfectant. In these contaminated hospitals, the proportion of sites testing positive was inversely correlated with free residual chlorine concentration (P=.01). In all hospitals, hot-water temperatures were too low to inhibit Legionella growth.

The increase in reporting of nosocomial legionnaires' disease was attributable to increased use of urinary antigen tests; prior cases may have gone unrecognized. Risk of legionnaires' disease in hospital patients was better predicted by the proportion of water-system sites testing positive for Legionella than by the measured concentration of Legionella bacteria. Use of monochloramine by municipalities for residual drinking water disinfection may help prevent legionnaires' disease.

To determine the effect of a bundle of infection control interventions on the horizontal transmission of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae during an outbreak.

Quasi-experimental study.

Long-term acute care hospital.

On July 23,2008, a bundled intervention was implemented: daily 2% Chlorhexidine gluconate baths for patients, enhanced environmental cleaning, surveillance cultures at admission, serial point prevalence surveillance (PPS), isolation precautions, and training of personnel. Baseline PPS was performed before the intervention was implemented. Any gram-negative rod isolate suspected of KPC production underwent a modified Hodge test and, if results were positive, confirmatory polymerase chain reaction testing. Clinical cases were defined to occur for patients whose samples yielded KPC-positive gram-negative rods in clinical cultures.

Baseline PPS performed on June 17, 2008, showed a prevalence of colonization with KPC-producing isolates of 21% (8 of 39 patients screened). After implementation of the intervention, monthly PPS was performed 5 times, which showed prevalences of colonization with KPC-producing isolates of 12%, 5%, 3%, 0%, and 0% (P < .001). From January 1, 2008, until the intervention, 8 KPC-positive clinical cases—suspected to be due to horizontal transmission—were detected. From implementation of the intervention through December 31, 2008, only 2 KPC-positive clinical cases, both in August 2008, were detected. From January 1 through December 31, 2008, 8 patients were detected as carriers of KPC-producing isolates at admission to the institution, 4 patients before and 4 patients after the intervention.

A bundled intervention was successful in preventing horizontal spread of KPC-producing gram-negative rods in a long-term acute care hospital, despite ongoing admission of patients colonized with KPC producers.

Recognition of seasonal trends in hospital infections may improve diagnosis, use of empirical therapy, and infection prevention interventions. There are very few data available regarding the seasonal variability of these infections. We quantified the seasonal variation in the incidences of hospital infection caused by common bacterial pathogens and estimated the association between temperature changes and infection rates.

A cohort of all adult patients admitted to the University of Maryland Medical Center during the period from 1998 through 2005 was analyzed. Time-series analyses were used to estimate the association of the number of infections per month caused by Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Staphylococcus aureus, and enterococci with season and temperature, while controlling for long-term trends.

There were 218,594 admissions to the index hospital, and analysis of 26,624 unique clinical cultures that grew the organisms of interest identified increases in the mean monthly rates of infection caused by P. aeruginosa (28% of isolates recovered; P < .01), E. cloacae (46%; P < .01), E. coli (12%; P < .01), and A. baumannii (21%; P = .06). For each 10°F increase, we observed a 17% increase in the monthly rates of infection caused by P. aeruginosa (P = .01) and A. baumanii (P = .05).

Significantly higher rates of gram-negative infection were observed during the summer months, compared with other seasons. For some pathogens, higher temperatures were associated with higher infection rates, independent of seasonality. These findings have important implications for infection prevention, such as enhanced surveillance during the warmer months, and for choice of empirical antimicrobial therapy among hospitalized adults. Future, quasi-experimental investigations of gram-negative infection prevention initiatives should control for seasonal variation.