Surveillance Of Hospital-acquired Infections Research Articles

Ventilator-associated pneumonia after procedures in cardiac surgery

Surveillance of hospital-acquired infections in intensive care wards is a very important but time-consuming process requiring involvement of all medical personnel [1]. This means published data on infections after cardiac surgery are rather limited [2]. The aim of this study was to analyze the epidemiology and etiology of ventilator-associated pneumonia (VAP) following coronary surgery in ICU patients.

Hospital-acquired infection surveillance in a neonatal intensive care unit

Hospital-acquired infections (HAIs) represent an important cause of morbidity and mortality in neonatal intensive care units (NICUs). All neonates admitted for > 48 hours between January 2003 and December 2006 in the NICU of the teaching hospital Umberto I of Rome, Italy were considered. Of the 575 neonates evaluated, 76 (13.2%) developed a total of 100 HAIs, including 36 bloodstream infections (BSIs), 33 pneumonias, 19 urinary tract infections, 8 conjunctivitis, and 4 onphalitis. There were 7.8 HAIs/1000 patient-days and 12.5 BSIs/1000 days of umbilical catheterization. Logistic analysis identified an association with mechanical ventilation (odds ratio [OR] = 3.05; 95% confidence interval [CI] = 1.75 to 5.31; P < .01) and birth weight <or= 1500 g (OR = 2.34; 95% CI = 1.36 to 4.03; P < .01). Thirty-five neonates (6.1%) died. Klebsiella pneumoniae (37.7%) and coagulase-negative staphylococci (28.6%) were the most frequently isolated microorganisms. Only 3 Candida spp determined BSIs (8.3%). BSI mortality was higher in infections with gram-negative pathogens (36.4%) than in infections with gram-positive pathogens (4.5%). Although we found a low infection and mortality rate, attention should be directed toward antibiotic-resistant gram-negative pathogens.

Surveillance of hospital-acquired infections in Liguria, Italy: results from a regional prevalence study in adult and paediatric acute-care hospitals

A multi-hospital prevalence study of hospital-acquired infections (HAIs) was carried out between 19 March and 6 April 2007 in Liguria, Italy, being the first to be performed in this region. Of the 29 existing public acute hospitals, 25 took part in the investigation (86.2%). In total, 3176 patients were enrolled in the study, representing a regional average bed-occupancy rate of nearly 70%. Three-hundred and ten HAIs were diagnosed from 283 patients, with an overall prevalence of infections and cases of 9.8% and 8.9%, respectively. Prevalence varied considerably between hospitals, ranging from 0 to 24.4% [95% confidence interval (CI): 15.53-33.27]. Urinary tract infections (UTIs) (30.0%) and respiratory tract infections (RTIs) (26.1%) presented the highest relative frequency, followed by bloodstream infections (BSIs) (14.8%), surgical site infections (11.6%) and gastrointestinal infections (6.5%). Intensive care units (ICUs) and haemato-oncological units showed the highest specific prevalence of HAI, respectively 42.5% (95% CI: 34.48-50.52) and 13.3% (6.28-20.32), with RTI and BSI as the predominant infections. Spinal units (33.3%; 13.14-53.46) and functional-rehabilitation units (18.9%; 17.75-24.06) demonstrated a high rate of urinary tract infections. Uni- and multivariate analyses were performed to assess the main risk factors and conditions associated with HAI, both overall and by site. Our study provides an overall picture of the epidemiology of HAI in Liguria, which may be usefully employed as a starting point to plan and organise future surveillance and control programmes.

Answers linked to Phillips P, Cortina-Borja M, Millar M, Gilbert R. Risk-adjusted surveillance of hospital-acquired infections in neonatal intensive care units: a systematic review. J Hosp Infect 2008; 70:203-211.

Answers linked to Phillips P, Cortina-Borja M, Millar M, Gilbert R. Risk-adjusted surveillance of hospital-acquired infections in neonatal intensive care units: a systematic review. J Hosp Infect 2008; 70:203-211.

Questions linked to Phillips P, Cortina-Borja M, Millar M, Gilbert R. Risk-adjusted surveillance of hospital-acquired infections in neonatal intensive care units: a systematic review. J Hosp Infect 2008; 70:203–211.

Questions linked to Phillips P, Cortina-Borja M, Millar M, Gilbert R. Risk-adjusted surveillance of hospital-acquired infections in neonatal intensive care units: a systematic review. J Hosp Infect 2008; 70:203–211.

Caesarean section surgical site surveillance in a private healthcare setting: a collaboration with the Victorian Hospital Acquired Infection Surveillance System (VICNISS) Coordinating Centre

The aim of this study was to test the application of the Victorian Hospital Acquired Infection Surveillance System (VICNISS) surveillance methods in a large private sector provider of maternity services, and compare the infection rates and compliance with national guidelines for surgical antibiotic prophylaxis with the VICNISS aggregate results. VICNISS methods were adopted for a 3-month period for surveillance of surgical site infections following caesarean sections, with the involvement of many sectors within the hospital including surgeons, anaesthetists, maternity services and operating theatre staff. During the study period there were 96 emergency and 205 elective caesareans. There was one superficial infection. The rate of compliance for choice of surgical antibiotic prophylaxis was 95.3%. The collaboration demonstrated the willingness and ability of private healthcare providers to contribute to State infection control surveillance data and highlights the opportunity for State programs to benefit from the inclusion of private sector surveillance data.

Risk-adjusted surveillance of hospital-acquired infections in neonatal intensive care units: a systematic review

Comparisons of bacteraemia incidence between neonatal intensive care units (NICUs) can identify centres with effective infection control, whose practices can be shared with other units. For fair comparisons, infection incidence must be risk-adjusted to control for differences between centres in the vulnerability of babies and the intensity of invasive procedures which can introduce infection. We reviewed risk adjustment methods for between-NICU comparisons of bacteraemia incidence, both in the published literature and in regional and national NICU infection monitoring systems. PubMed and Embase were searched for studies reporting risk-adjusted bacteraemia incidence in more than one NICU. An internet search found NICU infection monitoring systems in Western industrialised countries. In all nine studies that met the inclusion criteria, risk adjustment reduced but did not eliminate variation in bacteraemia incidence between NICUs. In both the studies and the regional monitoring systems, adjustment for baby susceptibility generally involved stratification by factors measured at birth. Adjustment for Length of stay and invasive procedures involved reporting incidence by days with a device, such as central venous catheter days. Methods for NICU infection monitoring lack consistency. Adjustment for factors measured at birth fails to capture changes in susceptibility throughout admission and adjustment for device days does not adequately reflect risk to babies not treated with the device. Further research should address variation in risk for all babies throughout their NICU stay.

The national nosocomial surveillance network in Hungary: results of two years of surgical site infection surveillance

In 2004, a secure web-based national nosocomial infection surveillance system was established in Hungary. The system, named NNSR (Nemzeti Nosocomiális Surveillance Rendszer), is based on the US National Nosocomial Infection Surveillance System (NNIS). Surgical procedures, definitions, surveillance methodology and patient risk indices are those established by NNIS. In this paper, we present the results of the first two years of the surgical patient component of our system. During this period, 41 hospitals participated and selected 11 surgical procedures for surveillance. Altogether 15812 procedures were surveyed and 360 resulting surgical site infections (SSI) were recorded. The overall SSI rate was 2.27%. The most commonly selected procedures and corresponding SSI rates were caesarean section (1.31%), herniorrhaphy (2.09%), cholecystectomy (1.52%) and hip replacement (2.91%). Standardised infection ratios (SIR) were calculated for chosen surgical procedures in order to compare against NNIS published rates. SSI rates for colonic surgery, caesarean section and mastectomy were lower than expected according to the NNIS data but higher for cholecystectomy, herniorrhaphy and hip prosthesis infection rates. We intend to recruit more participating hospitals, leading to a robust national database that can be used to target infection control interventions for patients in Hungary.

Building a data warehouse for infection control

Recently, the convergence of several themes in health care has stimulated interest in exploiting data collected during clinical encounters to monitor and improve the quality of health care. Infection control departments can be supported by assembling previously collected electronic data into a data warehouse to monitor infections, report communicable diseases, and detect clusters of organisms. I present the rationale for constructing a data warehouse and describe the steps and challenges of developing a data warehouse to support infection control activities.

MRSA infections in smaller hospitals, Victoria, Australia

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) cause significant morbidity, mortality, and associated costs. Trained infection control (IC) nurses in 84 smaller (<100 acute beds) hospitals during a 20-month period collected data on MRSA infections. The aggregate rate for all MRSA infections confirmed by the Victorian Hospital Acquired Infection Surveillance System Coordinating Centre IC nurse was 1.5 per 10,000 acute care occupied bed days (OBDs) (95% CI: 1.2-1.8). MRSA infections of 0.5 per 10,000 OBDs were detected >48 hours after admission (95% CI: 0.3-0.7). The aggregate rate for MRSA infections in sterile sites was 0.2 per 10,000 OBDs (95% CI: 0.0-0.4) and in nonsterile sites was 1.3 per 10,000 OBDs (95% CI: 1.0-1.6). The results suggested that serious MRSA infections in Victoria's smaller hospitals are an infrequent event. Most are "inherited" either from the community or other health care facilities.

An Alternative Scoring System to Predict Risk for Surgical Site Infection Complicating Coronary Artery Bypass Graft Surgery

To analyze the risk factors for surgical site infection (SSI) complicating coronary artery bypass graft (CABG) surgery and to create an alternative SSI risk score based on the results of multivariate analysis. A prospective cohort study involving inpatient and laboratory-based surveillance of patients who underwent CABG surgery over a 27-month period from January 1, 2003 through March 31, 2005. Data were obtained from 6 acute care hospitals in Victoria, Australia, that contributed surveillance data for SSI complicating CABG surgery to the Victorian Hospital Acquired Infection Surveillance System Coordinating Centre and the Australasian Society of Cardiac and Thoracic Surgeons, also in Victoria. A total of 4,633 (93%) of the 4,987 patients who underwent CABG surgery during this period were matched in the 2 systems databases. There were 286 SSIs and 62 deep or organ space sternal SSIs (deep or organ space sternal SSI rate, 1.33%). Univariate analysis revealed that diabetes mellitus, body mass index (BMI) greater than 35, and receipt of blood transfusion were risk factors for all types of SSI complicating CABG surgery. Six multivariate analysis models were created to examine either preoperative factors alone or preoperative factors combined with operative factors. All models revealed diabetes and BMI of 30 or greater as risk factors for SSI complicating CABG surgery. A new preoperative scoring system was devised to predict sternal SSI, which assigned 1 point for diabetes, 1 point for BMI of 30 or greater but less than 35, and 2 points for BMI of 35 or greater. Each point in the scoring system represented approximately a doubling of risk of SSI. The new scoring system performed better than the National Nosocomial Infections Surveillance System (NNIS) risk index at predicting SSI. A new weighted scoring system based on preoperative risk factors was created to predict sternal SSI risk following CABG surgery. The new scoring system outperformed the NNIS risk index. Future studies are needed to validate this scoring system.

Validation of Coronary Artery Bypass Graft Surgical Site Infection Surveillance Data From a Statewide Surveillance System in Australia

To measure the accuracy and determine the positive predictive value (PPV) and negative predictive value (NPV) of data submitted to a statewide surveillance system for identifying surgical site infection (SSI) complicating coronary artery bypass graft (CABG) surgery. Retrospective review of hospital medical records comparing SSI data with surveillance data submitted by infection control consultants (ICCs). Victorian Hospital Acquired Infection Surveillance System (VICNISS) Coordinating Centre in Victoria, Australia. All patients reported to have an SSI following CABG surgery and a random sample of approximately 10% of patients reported not to have an SSI following CABG surgery. The VICNISS ascertainment rate for CABG procedures in Victoria was 95%. One hundred sixty-nine medical records were reviewed, and reviewers agreed with ICCs about 46 (96%) of the patients reported as infected by the ICCs and 31 (91%) of the patients identified with a sternal SSI by the ICCs. In one-third of SSIs, the depth of SSI documented by ICCs was discordant with that documented by the reviewers. Disagreement about patients with donor site SSI was frequent. When the review findings were used as the reference standard, the PPV for ICC-reported SSI was 96% (95% confidence interval [CI], 86%-99%), and the NPV was 97% (95% CI, 92%-99%). For ICC-reported sternal SSI, the PPV was 91% (95% CI, 76%-98%) and the NPV was 98% (95% CI, 94%-100%). There was broad agreement on the number of infected patients and the number of patients with sternal SSI. However, discordance was frequent with respect to the depth of sternal SSI and the identification of donor site SSI. We recommend modifications to the methodology for National Nosocomial Infection Surveillance System-based surveillance for SSI following CABG surgery.

A point prevalence survey of hospital-acquired infections and antimicrobial use in a paediatric hospital in north-western Russia

We carried out a one-day prevalence survey of hospital-acquired infections (HAIs) and antimicrobial use in February 2006 in a paediatric hospital in Arkhangelsk, north-western Russia. A total 472 patients aged less than 18 years old were included in the study, of which 395 (84%) had been inpatients in the hospital for at least 48 h on the study day. The overall prevalence of HAI amongst the latter group of patients was 17% [67/395; 95% confidence interval (CI): 13.8-21.2] with upper respiratory tract infections being most frequently diagnosed (45%), followed by lower respiratory tract infections (19%) and urinary tract infections (12%). The highest proportion of HAI was found in patients less than one year old and in those with hospital stays of longer than 10 days. Antimicrobial agents were given to 39% of all hospitalized patients (183/472; 95% CI: 34.5-43.2). Cephalosporins accounted for 39% (82/211) of all antimicrobial prescriptions, followed by the penicillins (22%; 46/211). This study established a baseline for surveillance of HAI and antimicrobial use within the hospital, and facilitated the adoption of targeted infection control measures.

Surveillance of hospital-acquired infections in Australia – One Nation, Many States

Surveillance programmes for hospital-acquired infections differ amongst the Australian states. Victoria, New South Wales, Queensland and South Australia have recent substantial initiatives in development of statewide programmes. Whilst the definitions for surgical site infections (SSIs) and bloodstream infections (BSI) developed by the Australian Infection Control Association (AICA) do not differ from the US National Nosocomial Infection Surveillance (NNIS) programme definitions for SSI and intensive care unit (ICU) acquired central line-associated BSI, only two states use NNIS risk adjustment methods in reporting infection rates. Differences exist in the surgical procedures under surveillance, ICU surveillance, hospital-wide BSI surveillance, staff health immunization surveillance, process measures such us surgical antibiotic prophylaxis and small hospital programmes. Only in the area of antibiotic use surveillance has national consensus been reached. In Victoria, NNIS risk adjustment had limited usefulness in predicting SSIs, especially after coronary artery bypass graft (CABG) surgery. Ventilator-associated pneumonia (VAP) surveillance had limited acceptance, and is not undertaken in other states. Regular reporting of surgical antibiotic prophylaxis data has been followed by improvement in choice of antibiotic in some procedures. The South Australian programme for the surveillance of multiresistant organisms (MROs) has documented substantial improvement in meticillin-resistant Staphylococcus aureus (MRSA) morbidity over time coincident with the introduction of hand hygiene programmes and other measures. In Queensland, statewide monitoring of needlestick injuries is established. In Victoria, the small hospital programme concentrated on process measures, and in Queensland with a standardized investigation pathways for "signal" events. Data quality presented substantial challenges in small Victorian hospitals. Whilst state-based programmes have facilitated communication between hospitals and their coordinating centre, Australia still lacks national coordination and a national database on hospital infections. The differing approaches of the states illustrate many of the fundamental questions facing hospital infection surveillance today.

Effect of neonatal intensive care unit environment on the incidence of hospital-acquired infection in neonates

The influence of the inanimate hospital environment and hospital design on nosocomial infection is a topic for discussion. This study evaluated the impact of the neonatal intensive care unit (NICU) environment on the risk of hospital-acquired infection (HAI). HAI surveillance was performed during a four-year period when the NICU was moved initially from an old facility to temporary accommodation and then eventually to a new and better-designed facility. The rate of HAI rose significantly from 12.8 to 18.6% (P<0.01) after moving to the temporary unit, which had a lower sink:cot ratio and a higher monthly admission rate. In contrast, the rates of catheter-associated staphylococcal bacteraemia decreased significantly after moving to the new NICU (P<0.0001). Since peripherally inserted central catheters (PICCs) were introduced concomitantly with the move to the new unit, however, the catheter type may have contributed towards this reduction in CVC-related staphylococcal bacteraemias. Moving to a temporary NICU with poor handwashing facilities and higher admission activity resulted in higher rates of HAI.

P1943 Intensity of care is the major determinant of coagulase-negative staphylococcal bacteraemia in NICU: implications for risk adjusted surveillance of hospital-acquired infections

P1943 Intensity of care is the major determinant of coagulase-negative staphylococcal bacteraemia in NICU: implications for risk adjusted surveillance of hospital-acquired infections

Performance of the National Nosocomial Infections Surveillance Risk Index in Predicting Surgical Site Infection in Australia

The Victorian Hospital Acquired Infection Surveillance System (VICNISS) hospital-acquired infection surveillance system was established in 2002 in Victoria, Australia, and collates surgical site infection (SSI) surveillance data from public hospitals in Australia. To evaluate the association between the US National Nosocomial Infections Surveillance (NNIS) system's risk index and SSI rates for 7 surgical procedures. SSI surveillance was performed with NNIS definitions and methods for surgical procedures performed between November 2002 and September 2004. Correlations were assessed using the Goodman-Kruskal gamma statistic. Data were submitted for the following numbers of procedures: appendectomy, 545; coronary artery bypass graft (CABG), 4,632; cholecystectomy, 1,001; colon surgery, 623; cesarean section, 4,857; hip arthroplasty, 3,825; and knee arthroplasty, 2,416. NNIS risk index and increasing SSI rate were moderately well correlated for appendectomy ( gamma =0.55), colon surgery ( gamma =0.48), and cesarean section ( gamma =0.42). A fairly positive correlation was found for cholecystectomy ( gamma =0.17), hip arthroplasty ( gamma =0.2), and knee arthroplasty ( gamma =0.16). However, for CABG surgery, a poor association was found ( gamma =0.02). The NNIS risk index was positively correlated with an increasing SSI rate for all 7 procedures; the strongest correlation was found for appendectomy, cesarean section, and colon surgery, and the poorest correlation was found for CABG surgery. We believe that risk stratification with the NNIS risk index is appropriate for comparison of data for most procedures and superior to use of no risk adjustment. However, for some procedures, particularly CABG, further studies of alternative risk indexes are needed to better stratify patients.

The establishment of a statewide surveillance program for hospital-acquired infections in large Victorian public hospitals: A report from the VICNISS Coordinating Centre

A 1998 survey of acute Victorian public hospitals (VPH) revealed that surveillance of hospital-acquired infections (HAI) was underdeveloped, definitions and methodology varied considerably, and results disseminated inconsistently. The survey identified the need for an effective surveillance system for HAI. To develop and support a standardized surveillance program for HAIs in large acute VPH and to provide risk-adjusted, procedure-specific, HAI rates. In 2002, the independent Victorian Nosocomial Infection Surveillance System (VICNISS) Coordinating Centre (VCC) was established to develop and support the standardized surveillance program. A multidisciplinary team was recruited. A communication strategy, surveillance manual, user groups, and Web site were developed. Formal education sessions were provided to participating infection control nurse consultants (ICCs). Surveillance activities were based on the US Centers for Diseases Control and Prevention's National Nosocomial Infection Surveillance System (NNIS) surgical site infection and intensive care unit (ICU) components. NNIS methods were modified to suit local needs. Data collection was paper based or through existing hospital software. An advisory committee of key stakeholders met every second month. The surveillance program was rolled out over 12 months to all 28 large adult VPH. Data on over 20,000 surgical procedures performed at participating sites between November 11, 2002, and December 31, 2004, were submitted. Thirteen hospitals contributed to the ICU surveillance activities. Following aggregation and analysis by the VCC, hospital- and state-level results were posted on the Web page for hospitals to review. A standardized approach for surveillance of HAI was established in a short time frame in over 28 VPH. VICNISS is a tool that will continue to provide participating hospitals with a basis for continuous quality improvement.

SURGICAL ANTIBIOTIC PROPHYLAXIS IN SMALLER HOSPITALS

In 2004, The Victorian Hospital Acquired Infection Surveillance System Coordinating Centre established a smaller hospital (<100 beds) surveillance programme that included an optional 'surgical antibiotic prophylaxis' (SAP) module. Appropriate SAP is believed to be one of the most effective strategies to reduce surgical site infections after certain surgical procedures. Trained infection control nurses in the participating hospitals were asked to collect SAP data for the first 50 consecutive procedures that could be classified into 1 of 12 surgical groups. The choice, timing and duration of antibiotics were compared against the Australian Therapeutic Antibiotic version 12 Guidelines and the US National Surgical Infection Prevention Project Advisory Statement. Fifty-one of the 87 smaller hospitals that participated in the surveillance programme of The Victorian Hospital Acquired Infection Surveillance System Coordinating Centre carried out surgery. Over 20 months, 25 of these hospitals contributed data on 1872 procedures. Antibiotic choice, timing and duration were 52.6, 54.7 and 76.1%, respectively, concordant with published recommendations. For antibiotic choice in five surgical groups (appendectomy, colon surgery, gastric surgery and abdominal and vaginal hysterectomies), less than half of the procedures were concordant with the Australian Therapeutic Antibiotic Guidelines. Substantial opportunities exist in smaller hospitals to improve compliance with published SAP recommendations. Further studies are required to determine the reasons for poor compliance with these recommendations.

Hospital-acquired infection surveillance in a neurosurgical intensive care unit

A prospective study on hospital-acquired infection (HAI) was undertaken in the eight-bed neurosurgical intensive care unit (NSICU) of a teaching hospital in Rome, Italy. All patients admitted for >48 h between January 2002 and December 2004 were included. The infection control team collected the following data from all patients: demographic characteristics, patient origin, diagnosis, severity score, underlying diseases, invasive procedures, HAI, isolated micro-organisms and antibiotic susceptibilities. Overall, 323 patients were included in the study. Mean age was 55.5 years (range 17-91), and mean American Society of Anesthesiologists' score was 2.88. Seventy (21.7%) patients developed 132 NSICU HAIs: 43 pneumonias, 40 bloodstream infections (BSIs), 30 urinary tract infections (UTIs), 10 cases of meningitis associated with an external ventricular drain (EVD) and nine surgical site infections (SSIs). The SSI rate was high (5.6%), but a reduction was achieved during the three-year period. There were 7.2 bloodstream infection episodes per 1000 days of device exposure; 11.00 pneumonias per 1000 days of mechanical ventilation and 4.5 UTIs per 1,000 days of urinary catheterisation. Among patients with an EVD, the SSI relative risk was 11.3 [95% confidence intervals (CI) 4.2-30.6; P<0.01]. Sixty-one (18.9%) patients died. Logistic regression analysis showed that mortality was significantly associated with infection [odds ratio (OR)=2.28; 95%CI 1.11-4.71; P=0.02] and age (OR=1.04; 95%CI 1.01-1.06; P=0.002). Candida spp. were the leading cause of UTIs (40.0%) and the third most common cause of BSIs (12.7%). Antibiotic-resistant pathogens included meticillin-resistant staphylococci (77.5%), carbapenem-resistant Pseudomonas aeruginosa (36.4%), and extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (75.0%). Although the overall incidence of infection (21.7%) was within the range of published data, the associated mortality, the increasing severity of illness of patients, and the emergence of multi-drug-resistant organisms shows the need to improve infection control measures.