Hospital acquired infections surveillance and control in intensive care services. Results of an incidence study

Hospital acquired infections (HAI) continue to constitute a major health problem for hospital patients. Such a problem is particularly relevant in Intensive Care Wards. Here infections appear to be directly or indirectly related to the patients' death, and the patients, of course, represent a selected group of the most susceptible hosts in the whole hospital due to their immunosuppressed states, underlying diseases and the numerous and highly invasive diagnostic and therapeutic procedures to which they are submitted.This paper reports the results of a one-year surveillance incidence study carried out in four Intensive Care Wards at Padua Hospital by means of a daily visits to the wards and careful collection of the patients' data in a computerized sheet. Two-hundred-thirty-one of the 859 patients considered developed one or more HAI (HAI percentage 26.9%) for a total of 382 HAIs (Infections ratio 44.5%). Nosocomial pneumonias were the most frequent infections detected, whereas urinary tract infections, bacteremias and wound infections were less common in such patients. The study also confirmed the importance of invasive procedures and surgical operations in the predisposition to HAIs. In particular, the importance of the urinary catheter and of tracheal intubation was outlined. In addition, HAI appeared to be related to the duration of hospitalization and to the severity of the patients' illness. HAIs (especially nosocomial pneumonias) were also closely related to the patients' death. Pseudomonas aeruginosa, S. aureus, Acinetobacter and Streptococcus D were the most frequently isolated agents in the infected patients. Gram-negative agents accounted for 57% of all agents isolated and were particularly frequent in both pneumonias and urinary tract infections.Finally, this study underlined the necessity of particular and specific surveillance programs in Intensive Care Wards in order to obtain detailed data for a clear analysis of the problem.     

Nosocomial infections in heart surgery patients: active surveillance in two Italian hospitals

In Italy no nosocomial infection surveillance database has been established despite the fact that a decrease of nosocomial infection rates was one of the priorities of the Italian National Health Plan 1998--2000. Heart surgery operations are the most frequent high risk procedures in western countries. Active surveillance was performed at the heart surgery wards of two Italian hospitals (Rome and Catania, Southern Italy) in accordance with the methods described for the National Nosocomial Infections Surveillance (NNIS) System of the USA. In both hospitals surgical site infections (SSIs) were the most frequently encountered type of nosocomial infections, accounting for 57.2% in Rome and 50% in Catania, and SSI rates in coronary artery bypass grafts with both chest and donor site incisions, calculated by risk index equal to 1, were above the 90th percentile for the NNIS System. The urinary catheter-associated urinary tract infection (UTI) rate (5.8%) in Catania exceeded the 90th percentile for the NNIS System, while the device-associated UTI (1.6%), bloodstream (4.1%) and pneumonia (8.0%) rates, from the hospital in Rome, did not. All device utilization ratios were lower than the 10th percentile for the NNIS System. Our study demonstrated that the NNIS methodology is applicable to Italian hospitals, although with some limitations mainly regarding the minimal surveillance duration required for significant interhospital comparison, and highlighted the need of a national comparison of surveillance data as benchmark.     

Five-year surveillance of nosocomial infections in Ankara Training and Research Hospital

The objective of this study was to assess the rate of nosocomial infections (NIs), frequency of nosocomial pathogens and antimicrobial susceptibility changes in a 530-bed hospital over a five-year period. Hospital-wide laboratory-based NI surveillance was performed prospectively between 1999 and 2003. The Centers for Disease Control and Prevention's definitions were used for NIs and nosocomial surgical site infections, and NI rates were calculated by the number of NIs per number of hospitalized patients on an annual basis. NI rates ranged between 1.4% and 2.4%. Higher rates were observed in the neurology, neurosurgery, paediatric and dermatology departments; the low rate of NIs overall may be due to the surveillance method used. The most commonly observed infections were urinary tract, surgical site and primary bloodstream infections, and the most frequently isolated pathogens were Escherichia coli, Klebsiella pneumoniae, Enterococcus spp. and Staphylococcus aureus. Carbapenems were the most effective agents against enterobacteriaceae. Meticillin resistance among S. aureus isolates was less than 50%, and all S. aureus and Enterococcus spp. isolates were susceptible to glycopeptides apart from one glycopeptide-resistant E. faecium isolate identified in 2003. Data obtained by the same method enabled comparison between years and assisted in the detection of recent changes. Antimicrobial susceptibility data on nosocomial pathogens provided valuable guidance for empirical antimicrobial therapy of NIs.     

普通外科手术部位感染目标性监测研究

目的通过对徐州医学院附属医院普通外科手术部位感染（SSI）的目标性监测研究,探讨影响手术部位感染的危险因素。方法采用前瞻性目标研究的方法,由医院感染专职人员对普通外科所有手术患者切口情况进行观察,并于手术后1个月进行电话回访,了解手术切口愈合情况。结果1 589例次手术患者中,155例次手术部位发生感染,感染率为9.75%;不同手术类别相同危险指数的手术以剖腹探查手术和结肠手术感染发生最高;有56例患者在出院后发生手术部位感染,随访感染占总感染例数的36.13%,随访感染以Ⅰ、Ⅱ类手术为主;经单因素及多因素Logistic回归分析得出,白蛋白及血红蛋白值异常、急诊手术、失血、切口类型、引流为手术部位感染的危险因素。结论手术危险指数越高,切口污染越严重,SSI发生率就越高;加强手术患者出院后的追踪随访,有助于了解SSI的真实情况;普外科SSI存在着多种危险因素,采取针对性的措施进行目标性监测,才能有效降低SSI的发生率。     

Reducing neonatal nosocomial bloodstream infections through participation in a national surveillance system

A national nosocomial surveillance system for neonatal intensive care patients with a very low birthweight was set up in Germany in 2000 (NEO-KISS). Forty-eight neonatal intensive care units (NICUs) participated in the programme, which focused upon nosocomial bloodstream infections (BSIs) and pneumonia. Only data from NICUs participating for at least three years were included and the years compared. The relative risks and their 95% confidence intervals (CIs) were calculated and a multiple logistic regression analysis performed to identify significant risk factors. Twenty-four units that met the selection criteria accumulated data for 3856 patients and 152 437 patient-days in their first three years of participation. The incidence density of BSIs decreased significantly by 24% from 8.3 BSIs per 1000 patient-days in the first year to 6.4 in the third year. In the multiple logistic regression analysis, BSI in the third year of participation was significantly lower than in the first year of participation (odds ratio=0.73, 95% CI 0.60-0.89). The year of participation was an independent risk factor for BSI but not for pneumonia. Our data suggest that participation in ongoing surveillance of nosocomial infections in NICUs, requiring individual units to feedback data, may lead to a reduction in BSI rates.     

Surgical antibiotic prophylaxis: effect in postoperative infections

Objective: to assess the risk of surgical wound infection and hospital acquired infections among patients with and without adequate antibiotic prophylaxis. Also, to provide models to predict the contributing factors of hospital infection and surgical wound infection. Design: survey study. Prospective cohort study over 14 months, with data collected by a nurse and a epidemiologist through visits to the surgical areas, a review of the medical record and consultation with the medical doctor and nurses attending the patients. Setting: Two hundred and fifty bed, general hospital serving Puertollano (Ciudad Real), population – 50,000. Results: between February 1998 and April 1999, 754 patients underwent surgery, 263 (34.88%) received appropriate peri-operative prophylaxis while 491 (65.12%) received inadequate prophylaxis. For those who received adequate antibiotic prophylaxis, the percentage of nosocomial infection was 10.65% compared with the group who received inadequate prophylaxis in which the percentage of nosocomial infection was 33.40%. The relative risk of nosocomial infection was, therefore, 4.21 times higher in the latter group (confidence intervals 95%: 2.71–6.51). A patient in the inadequate prophylaxis group had a 14.87% chance of wound infection while a patient in the adequate prophylaxis group had a 4.56% chance of wound infection. The relative risk of wound infection was 3.65 times higher in the group that received inadequate prophylaxis (confidence intervals 95%: 1.95–6.86). The final regression logistic model to assess nosocomial infection incorporated seven prognostic factors: age, length of venous periferic route, vesicle catheter, duration of operation, obesity, metabolic or neoplasm diseases and adequate or inadequate prophylaxis. When we incorporated these variables in the multi-factorial analysis we found that the relative risk of developing nosocomial infection was 2.33 times higher in the group which received inadequate prophylaxis. When we applied the second logistic multiple regression model (wound infection), we discovered that the probability of developing surgical wound infection was 2.32 times higher in the group which received inadequate prophylaxis as opposed to the group, which received adequate prophylaxis. The goodness of fit (Hosmer–Lemeshow test) showed a correct significance in all models. Conclusions: a multi-factorial analysis was applied to identify the high-risk patients and the risk factors for postoperative infections. Through the application of these multiple regression logistic models, we conclude that the correct antibiotic prophylaxis is effective and will subsequently reduce postoperative infection rates, especially in high-risk patients. Therefore, the choice of antimicrobial agent should be made on the basis of the criteria of hospital committee.     

Implementation of a novel on-ward computer-assisted surveillance system for device-associated infections in an intensive care unit

For the presented study a computer-based surveillance system for detecting nosocomial infections (NI) with direct data input from attending on-ward physicians was implemented. During a 12-month period surveillance of ventilator-associated pneumonia (VAP) and catheter-associated bloodstream infections (BSI) was performed prospectively by on-ward physicians guided by infection control specialists on an 11-bed medical intensive care unit in a German university hospital. In 603 patients 3282 patient days were assessed. Completeness of data entry during the routine phase was 94% for ventilator days and 88% for central venous catheter days. The concordance of infection detection by automated evaluation and evaluation based clinical considerations was fairly good and was quantified by kappa measures of 0.49 for VAP and 0.57 for BSI. Detected infection rates ranged within the German national reference data. Personnel costs for on-ward physicians and infection control personnel were 1.01 Euro per device day in the routine phase. Time expenditure of less than 3 min per device day, rendered in about equal parts by physicians and infection control personnel, was lower than in studies relying on on-ward assessment by infection control personnel.     

Reduction of urinary tract infections acquired in an intensive care unit during a 10-year surveillance program

Purpose To describe trends of urinary catheter-related infections (UCRIs) acquired by patients hospitalized in intensive care units (ICU) in relation with an infection control program. Materials and methods Prospective surveillance in one ICU of a university hospital in Lyon (France) between 1995 and 2004. Results A 66% reduction of urinary catheter-related infections (UCRIs) acquired by patients hospitalized was observed between 1995 and 2004 after adjustement on age, gender, antibiotic use at admission, and duration of exposure to urinary catheter. Conclusions These results, obtained by continuous epidemiological monitoring of nosocomial infections, are encouraging with regard to the improvement of infection control measures and the evolution of medical practices. Further studies in ICUs are needed to confirm this trend.     

Prevalence study of hospital-acquired infections in 14 Greek hospitals: planning from the local to the national surveillance level

A prevalence study of hospital-acquired infections (HAI) was carried out in 14 of 112 Greek hospitals (15.7%), scattered throughout Greece. Five of seven Greek university hospitals and nine regional hospitals participated in the one-day study, and 3925 hospitalized patients (10.5% of the total hospital beds in Greece) were recorded. The aim of this project was to organize a surveillance of HAI with the participation of the greatest possible number of Greek hospitals, transferring the experience from the local Cretan infection control network in an effort to create a nationwide network. Special attention was paid to recruit all Greek university hospitals in our attempt to expand the study base. Co-ordination of the participating centres, education of the infection control teams on surveillance methods, preparation of agreed definitions, and elaboration of the protocol for the collection of the data were the major objectives of this study. The difficulties, however, were limited resources and the lack of skilled personnel. The overall prevalence of HAI was found to be 9.3%. The most common HAI recorded involved lower respiratory tract infections (30.3%), followed by urinary tract infections (22.7%), bloodstream infections (15.8%), and surgical site infections (14.8%). The greatest prevalence rate was found in the adult ICU (48.4%), followed by the neonatal ICU (30.3%). The duration of hospitalization, the number of operations, the total number of used devices and invasive procedures were significantly correlated with HAI. Positive cultures were found in 51.5% of the cases. The most frequently isolated micro-organisms were: Pseudomonas aeruginosa (16.6%), Escherichia coli (10.8%), Klebsiella pneumoniae (10.3%), Staphylococcus epidermidis (8.1%) and Staphylococcus aureus (7.6%). The administration of antibiotics was also recorded. The prevalence of antibiotic use was 51.4%.     

实施两种监测方法对普通外科医院感染基线数据影响探讨

目的通过分析医院感染两种主要监测方法对普通外科术后医院感染感染率的差异,探讨实施两种监测方法对普通外科医院感染感染率基线数据的影响。方法 2008年3月1日-9月30日目标性监测医院普通外科1589例住院手术患者的医院感染发生情况;与2007年同期前瞻性全面综合性监测医院普通外科2322例住院手术患者医院感染资料进行统计学对比分析。结果目标性监测1589例普通外科手术患者术后共发生224例、249例次医院感染,医院感染率为14.10%,例次感染率为15.67%;明显高于2007年同期前瞻性全面综合性监测2322例手术患者术后医院感染率2.45%,例次感染率2.93%,经统计学分析比较差异有统计学意义(P<0.01)。结论目标性监测方法能提高医院感染的发现率,应在全面综合性监测的基础上强化医院感染重点科室及部位的目标性监测,更有利于获得准确的医院感染基线数据。     

手术部位感染目标性监测及抗菌药物应用分析

目的调查手术部位感染分布及围手术期抗菌药物使用,为预防外科手术部位感染及合理使用抗菌药物提供科学依据。方法前瞻性监测2009年4月-2011年3月2 019例手术部位感染目标监测病例,应用医院感染监控管理系统分析手术部位感染发生率及围手术期抗菌药物使用率。结果 2 019例手术患者发生医院感染17例,医院感染率0.84%,其中发生手术部位感染10例,感染率0.50%;围手术期术前抗菌药物使用率为73.80%,术中仅2例患者追加给药,术后预防用药≤24h患者334例占16.54%;抗菌药物使用种类显示,排前3位的分别为三、四代头孢菌素、氨基糖苷类、青霉素/+酶抑制剂,使用率分别为34.13%、26.06%、17.16%。结论手术部位感染以器官腔隙感染为主,围手术期抗菌药物使用不规范,应严格控制抗菌药物预防性应用,以减少抗菌药物滥用。     

Epidemiological study of surgical wound infections

The present report describes the results obtained in an epidemiological study of surgical wound infections through a continuous and active epidemiological surveillance program lasting one year and which covered all the Surgical Services of the University Clinical Hospital.The number of infections studied was 217, with an overall infection rate of 3%. The majority of the infections (46.5%) were detected in the General Surgery Service. Regarding the infection rate by Services, the highest corresponded to the Urology Service, with a rate of 10%.In 26% of the cases, other hospital-acquired infections occurred in patients who underwent a surgical operation.The microorganisms responsible for the infections observed were mainly Gramnegative (67%), and within these the most commonly isolated were E. coli and Proteus spp..     

外科感染常见的病原菌及其耐药性分析

目的 探讨外科感染常见的病原菌种类及其耐药性. 方法 采集外科感染标本,用美国德灵公司的药敏分析/细菌鉴定仪Microscan Wat RA way - 40系统进行细菌鉴定并作药敏分析. 结果 2010年12月-2011年12月共分离得到病原菌763株,分别归属于10个种属,以金黄色葡萄球菌、大肠埃希菌、变形杆菌最常见.药敏分析表明这些细菌对抗生素有交叉以及多重耐药性,对于革兰阳性菌万古霉素仍然有很好的抗菌效果. 结论 导致外科感染的病原菌的种类有不断上升的趋势,而且对于多种抗生素都有很高的耐药性,在外科治疗的过程中要积极预防和控制.