多药耐药铜绿假单胞菌院内感染危险因素及预后因素分析

目的 分析多药耐药铜绿假单胞菌(MDRP)产生的危险因素，并探讨影响MDRP院内感染预后的因素。方法 采用病例对照研究方法。收集北京协和医院1999年1月～2002年12月MDRP引起的院内感染44例，并随机选择同时期敏感铜绿假单胞菌院内感染68例作为对照，采用单因素(t检验，χ^2检验)及多因素Logistic回归进行分析。结果 对112例铜绿假单胞菌院内感染单因素分析发现，下列因素与MDRP感染有关：高龄、高APACHE Ⅱ(acute physiology and chronic health evaluation)评分、2种以上细菌混合感染、院内获得性肺炎(HAP)、机械通气、患有慢性阻塞性肺疾病(COPD)、分离出MCIRP前15天用过氟喹喏酮、分离出MDRP前15天用过亚胺培南／美罗培南。但多因素Logistic回归分析仅确定了2项独立危险因素：机械通气[比值比(OR)=8．19]，分离出MDRP前15天用过亚胺培南／美罗培南(OR，44．80)。44例MDRP院内感染，死亡24例，好转20例，病死率为55％。单因素分析发现，下列因素与MDRP感染死亡相关：高APACHEⅡ评分、机械通气、未恢复对抗铜绿假单胞菌抗生素的敏感性。多因素Logistic回归分析发现了1项独立危险因素：未恢复对抗铜绿假单胞菌抗生素的敏感性(OR=10．70)。结论 机械通气，以及亚胺培南／美罗培南的使用是MDRP感染的危险因素。MDRP未恢复对抗铜绿假单胞菌抗生素的敏感性是MDRP感染预后差的危险因素。     

老年ICU患者铜绿假单胞菌多药耐药易感因素分析

在老年重症监护病房(ICU)感染患者中,铜绿假单胞菌是院内感染的最常见致病菌,容易产生耐药,而且时常出现多药耐药(multidrug resistant,MDR),甚至广泛耐药[1-2],给治疗带来极大的困难。现对本院ICU收住的12例MDR铜绿假单胞菌患者及10例非MDR铜绿假单胞菌患者的相关因素进行比较     

ICU 铜绿假单胞菌临床分布及耐药性分析

目的：调查 ICU 铜绿假单胞菌临床分布及耐药性分析,为临床诊断及合理应用抗生素提供科学依据。方法选择济宁医学院附属医院 ICU 一区2013年9月至2014年9月住院患者的临床标本进行常规细菌培养鉴定,以 K-B 纸片扩散法进行药物敏感性试验,对分离出的铜绿假单胞菌药敏试验结果进行统计分析。结果从各种标本中共分离到铜绿假单胞菌216株,其中呼吸道标本痰液百分比最高,占69%。在15种抗生素药敏试验中阿米卡星、头孢哌酮舒巴坦钠、头孢吡肟体外抗菌活性最好,铜绿假单胞菌株耐药性强,产生多重耐药菌63株。结论 ICU 铜绿假单胞菌感染主要为呼吸道感染,ICU中铜绿假单胞菌耐药率较高,应引起高度重视,要加强病原学检测,以有效控制感染。     

铜绿假单胞菌院内感染133例临床分析

目的探讨铜绿假单胞菌（PA）在医院内感染的临床特点及药敏情况,为临床预防和控制PA院内感染提供依据。方法回顾分析我院2006年1月至2008年6月铜绿假单胞菌院内感染临床资料。结果铜绿假单胞菌感染以下呼吸道为主,主要分布在脑外、ICU等科室,以老年患者居多,多种易感因素可以交叉存在或同时存在,并对大多数抗菌药物敏感率较低。结论掌握铜绿假单胞菌院内感染临床特点,为临床合理用药提供依据。     

胸外科院内感染铜绿假单胞菌耐药性与耐药机制研究北大核心CSCD

目的 分析胸外科院内感染患者的病原菌分布情况、铜绿假单胞菌耐药性及耐药机制。方法 收集1 095例接受胸外科手术患者的送检标本,采用全自动细菌鉴定仪鉴定病原菌。采用K-B纸片扩散法对临床常见的12种抗生素进行药敏试验,测定52株铜绿假单胞菌的耐药性。采用PCR对18株耐氨基糖苷类铜绿假单胞菌的氨基糖苷类修饰酶基因和16SrRNA甲基化酶基因扩增,通过扩增产物分析耐药机制。结果 1 095例患者入院诊断主要为肺癌(30.32%)与食管癌(25.11%)。93例发生术后感染,感染98例次,感染率为8.49%,主要为下呼吸道感染(52.04%)。93例胸外科院内感染患者中,培养分离病原菌共115株。86株革兰阴性菌,主要为铜绿假单胞菌;22株革兰阳性菌,主要为金黄色葡萄球菌;7株真菌。52株铜绿假单胞菌对临床常见抗生素药敏试验显示,氨曲南、头孢他啶、环丙沙星、左氧氟沙星的耐药率>30%,多粘菌素B的敏感性为100.00%。52株铜绿假单胞菌中,18株对氨基糖苷类耐药,15株产氨基糖苷类修饰酶,主要为acc(6′)-Ⅱ阳性株。产氨基糖苷类修饰酶阳性基因模式主要为acc(6′)-Ⅰ+acc(6′)-Ⅱ+ant(2″)-Ⅰ+ant(3″)-Ⅰ。18株耐氨基糖苷类铜绿假单胞菌中,16SrRNA甲基化酶基因型72.22%为armA阳性。结论 本院胸外科院内感染率为8.49%,主要为下呼吸道感染,铜绿假单胞菌为主要病原菌。耐氨基糖苷类铜绿假单胞菌的耐药基因型主要为armA、acc(6′)-Ⅱ。     

呼吸科重症监护室铜绿假单胞菌感染的临床分析

目的了解呼吸科重症监护室(ICU)住院患者铜绿假单胞菌感染的现状及其耐药具体情况。方法收集近三年本院呼吸科ICU 112例铜绿假单胞菌感染患者的的痰标本进行分离培养,并进行鉴定和药敏实验。结果呼吸科ICU住院患者铜绿假单胞菌株数和细菌占分离菌株百分率逐年升高,药敏试验结果显示对亚胺培南和美罗培南等药物较为敏感(7.1%,8.9%),对头孢曲松、复方新诺明、四环素、氨曲南等耐药性较高(50.9%～79.5%)。结论呼吸科ICU感染的铜绿假单胞菌具有多重耐药性,根据药敏结果选择合适的抗菌药物对提高临床疗效具有重要意义。     

重症监护病房感染患者铜绿假单胞菌的分离与耐药性分析

目的了解医院重症监护病房（内科ICU）感染患者铜绿假单胞菌耐药谱的变化,指导内科ICU合理用药。方法收集2007年1月-2008年12月内科ICU送检的感染患者标本,分离铜绿假单胞菌,分析各类标本分离的铜绿假单胞菌构成比;采用MicroScan NC31、NC33鉴定药敏复合板进行鉴定和药敏试验,按美国临床实验室标准化委员会（CLSI）标准对常用的8种抗生素进行耐药性分析。结果共分离出131株铜绿假单胞菌,主要来源于痰液,占80.2%。铜绿假单胞菌对头孢他啶的敏感率为77.2%,对环丙沙星的敏感率为51.4%,且呈上升趋势;对庆大霉素、亚胺培南、氨曲南和哌拉西林的敏感率在43.8%～51.8%之间,对复方磺胺的敏感率为2.2%,且呈下降趋势。有六种药物耐药率呈上升趋势。结论铜绿假单胞菌耐药现象严重,ICU应注意铜绿假单胞菌耐药性的监测。     

铜绿假单胞菌近7年的耐药性变迁及其抗生素应用分析

目的分析铜绿假单胞菌近7年的耐药性变迁情况。方法收集2001年1月至2007年6月我院分离的铜绿假单胞菌1076株,分析其耐药性变迁及临床抗生素的应用情况;结果对铜绿假单胞菌保持抗菌活性较强而耐药率30%的抗菌药物依次为美罗培南、亚胺培南及阿米卡星,对常用抗菌药物的耐药率有普遍增高的趋势;抗铜绿假单胞菌所用抗生素单用455例(44.4%);二联521例(50.9%);三联48例(4.7%)。结论铜绿假单胞菌耐药率高,耐药率有普遍增高的趋势;对严重铜绿假单胞菌感染、多药耐药(MDRP)或泛耐药(PDRP)的治疗,宜采用联合用药,β-内酰胺类+阿米卡星为较优化的组合治疗方案之一。     

老年患者下呼吸道医院感染的细菌耐药监测分析

目的探讨老年患者医院内下呼吸道感染病原菌及其细菌耐药情况。方法统计2008年1～12月下呼吸道感染的老年住院患者,痰液检232例,进行回顾性分析。结果老年患者医院内下呼吸道细菌感染较多,其中铜绿假单胞菌为痰液主要分离菌占26％,其次是鲍曼不动杆菌占20％。铜绿假单胞菌耐药性较高,对亚胺培南耐药率为38．1％,对美罗培南的耐药率为32,1％,而阿米卡星和环丙沙星对铜绿效果较好,耐药率分别为8．8％和17．8％。结论铜绿假单胞菌可能是老年人下呼吸道院内感染的主要病原体。     

慢性阻塞性肺疾病急性加重患者肺部感染铜绿假单胞菌临床分析

目的:调查医院慢性阻塞性肺疾病急性加重(AECOPD)住院患者合并肺部铜绿假单胞菌感染的临床特点及病原菌对常用抗菌药物的耐药性,为临床诊疗与合理用药提供参考依据。方法:回顾性分析2016-01—2018-12收治的120例AECOPD合并肺部铜绿假单胞菌感染患者,按照《全国临床检验操作规程》(第4版)留取痰液标本并进行分离培养与细菌鉴定及药敏试验,比较2种形态的铜绿假单胞菌的耐药性差异。结果:年龄高、伴有基础疾病、呼吸道侵入性操作史、长期应用广谱抗菌药物、使用激素、免疫抑制剂等是AECOPD合并肺部铜绿假单胞菌感染的危险因素;药敏试验显示,铜绿假单胞菌对多黏菌素、阿米卡星、妥布霉素、庆大霉素较敏感,耐药率均10.0%;非黏液型铜绿假单胞菌与黏液型铜绿假单胞菌对哌拉西林、哌拉西林/他唑巴坦、头孢他啶、头孢吡肟、亚胺培南、美罗培南、环丙沙星的耐药性差异有统计学意义(P0.05)。结论:铜绿假单胞菌是AECOPD合并肺部细菌感染最常见的病原菌,应引起高度重视。临床医生应提高标本送检率,并根据药敏结果合理选择抗菌药物治疗,防止或减缓耐药性的上升。     

综合重症监护病房老年患者医院感染现状及危险因素分析

目的 了解综合重症监护病房(intensive care unit,ICU)老年患者医院感染现状,探讨老年患者发生医院感染的危险因素.方法 回顾性调查2015年1月-2019年6月期间在上海市某三甲医院综合ICU内年龄≥65岁的老年住院患者发生医院感染的情况,分析主要感染类型和检出病原菌种类,采用病例对照研究方法,比较...     

重症监护病房医院感染早期预测模型的建立

目的:回顾性分析衡水市二级以上医院重症监护病房(ICU)的医院感染患者入住ICU 24 h内的高危因素,建立ICU医院感染早期预测模型。方法:回顾性查阅衡水市二级以上医院2011年1月至2015年12月ICU医院感染患者相关病原学数据和原始病历资料。记录患者一般临床资料,包括患者性别、年龄、转入原因,入住ICU 24 ...     

Risk factors for nosocomial imipenem-resistant Acinetobacter baumannii infections.

OBJECTIVES: To identify the risk factors for nosocomial imipenem-resistant Acinetobacter baumannii (IRAB) infections. METHODS: A prospective case-control study, set in an 1100-bed referral and tertiary-care hospital, of all patients who had nosocomial A. baumannii infections between January 1 and December 31, 2004. Only the first isolation of A. baumannii was considered. RESULTS: IRAB was isolated from 66 (53.7%) patients and imipenem-sensitive Acinetobacter baumannii (ISAB) was isolated from 57 (46.3%) patients during the study period. The mean duration of hospital stay until A. baumannii isolation was 20.8+/-13.6 days in IRAB infections, whereas it was 15.4+/-9.4 days in ISAB infections. Of the patients, 65.2% with IRAB infections and 40.4% with ISAB infections were followed at the intensive care unit (ICU). Previous carbapenem use was present in 43.9% of the patients with IRAB and 12.3% of the patients with ISAB infection. In univariate analysis female sex, longer duration of hospital stay until infection, ICU stay, emergent surgical operation, total parenteral nutrition, having a central venous catheter, endotracheal tube, urinary catheter or nasogastric tube, previous antibiotic use, and previous administration of carbapenems were significant risk factors for IRAB infections (p<0.05). In multivariate analysis, longer duration of hospital stay until A. baumannii isolation (odds ratio (OR) 1.043; 95% confidence interval (CI) 1.003-1.084; p=0.032), previous antibiotic use (OR 5.051; 95% CI 1.004-25.396; p=0.049), and ICU stay (OR 3.100; 95% CI 1.398-6.873; p=0.005) were independently associated with imipenem resistance. CONCLUSIONS: Our results suggest that the nosocomial occurrence of IRAB is strongly related to an ICU stay and duration of hospital stay, and that IRAB occurrence may be favored by the selection pressure of previously used antibiotics.     

Surgical site infections at the National Cancer Institute in Mexico: a case-control study

OBJECTIVES: To quantify the surgical infection rate and to identify risk factors associated with surgical site infection. METHODS: We conducted a case-control study of all surgical patients between January 1, 1993, and June 30, 1994. The frequency of surgical site infection per 100 surgeries was calculated. The odds ratio (OR) was estimated by using logistic regression analysis. SETTING: A 130-bed tertiary-care teaching hospital for adult patients with cancer. RESULTS: The study followed 3372 surgeries. Three hundred thirteen patients had a surgical site infection (rate per 100 surgeries: 9. 30). The risk factors associated with surgical site infection were diabetes mellitus (OR = 2.5, 95% confidence interval [CI] = 1.27-4. 91), obesity (OR = 1.76, 95% CI = 1.14-2.7), presence of surgical drains for >5 and <16 days (OR = 1.84, 95% CI = 1.02-3.31), and presence of surgical drains for >/=16 days (OR = 2.14, 95% CI = 1. 0-4.6). The bacteria most frequently isolated were Escherichia coli 38 (21.8% of the total of microorganisms found), Pseudomonas sp 22 (12.6%), Staphylococcus aureus 16 (9.2%), and coagulase-negative Staphylococcus 25 (13.6%). The coexistence of other nosocomial infections was greater among the cases (OR = 1.8, 95% CI = 1.1-3.1) than in the control group. CONCLUSIONS: The surgical site infection rate in our hospital is slightly higher than the rates reported for general hospitals. The risk factors associated with surgical site infection are similar to those previously reported. Diabetes mellitus, obesity, and prolonged presence of a surgical drain increased the risk of infection.     

Nosocomial bloodstream infections in ICU and non-ICU patients

BACKGROUND: Nosocomial bloodstream infections (BSI) create a serious health problem in hospitals all over the world. The objectives of our study were to explore putative disease markers and potential risk factors with nosocomial BSI in patients in intensive care units (ICU) and non-ICU patients and to determine risk factors associated with increased 28-day mortality rate in patients with nosocomial BSI acquired in combined medical-surgical ICU. However, the major purposes of this report were to identify epidemiologic differences between nosocomial BSI acquired in ICU and non-ICU, as well as analyses outcomes for patients with nosocomial BSI acquired in ICU. METHODS: A 1-year prospective cohort study was performed to determine the incidence of nosocomial BSI in hospitalized patients. Patient characteristics, risk factors related to health care, and source of infection of patients with BSI acquired in non-ICU were compared with those patient with BSI acquired in ICU. Also, nested case-control study of patients to nosocomial BSI acquired in ICU was performed to evaluate outcome. Patients were identified by active surveillance and positive blood culture during the study period. RESULTS: The incidence of nosocomial BSI was 2.2 per 1000 admission in non-ICU patients and 17.4 per 1000 admission in ICU patients. The 28-day crude mortality rate was 69% in ICU patients. A multivariate model showed that nasogastric tube (RR, 25.1; 95% CI: 3.845-163.85; P=.001), mechanical ventilation (RR, 13.04; 95% CI: 1.974-96.136; P=.008), and H2 blockers (RR, 12.16; 95% CI: 1.748-84.623; P=.012) were more prevalent among patients with BSI acquired in ICU, and aggressive procedures (RR, 8.65; 95% CI: 1.70-44.00; P=.009) were more prevalent among patients with BSI acquired in non-ICU patients. Risk factors independently associated with increased 28-day mortality rate in ICU patients were mechanical ventilation (OR, 8.63; 95% CI: 1.5-49.8; P=.016) and SAPS II >40 (OR, 6.0; 95% CI: 1.0-35.7; P=.049). The most common isolated nosocomial BSI pathogens (in both groups of patients) were coagulase-negative staphylococci (21%), Staphylococcus aureus (14%), and Klebsiella species (13%). Klebsiella species was the only organism independently influencing the poor outcome of nosocomial BSI in ICU patients (OR, 4.3; 95% CI: 1.2-15.3; P=.022). CONCLUSIONS: Our results show epidemiologic differences between non-ICU and ICU BSI. Also, this study suggests that severity of underlying host conditions, mechanical ventilation, and microbial agents (Klebsiella species) affect the outcome of NBI in patients in ICU.     

失代偿期乙型肝炎肝硬化患者发生医院感染临床特点及危险因素分析*

目的 分析失代偿期乙型肝炎肝硬化患者住院期间发生医院感染的临床特点及其危险因素。方法 2016年2月～2018年12月我院收治的失代偿期乙型肝炎肝硬化患者100例,查阅出院病历资料,分析患者发生医院感染的临床特点,应用Logistic 回归分析影响感染发生的因素。结果 100例失代偿期乙型肝炎肝硬化患者在住院期间发生医院感染者25例(25.0%),其中呼吸道感染10例(40.0%),腹膜感染7例(28.0%),肠道感染4例(16.0%);大肠埃希菌感染5例(29.4%),金黄色葡萄球菌感染4例(23.5%),肺炎克雷伯菌感染2例(11.8%),铜绿假单孢菌感染2例(11.8%),肺炎链球菌感染2例(11.8%);单因素分析显示不同性别、是否发生肝性脑病、是否预防性应用抗菌药物患者感染发生率无显著性差异(P>0.05),而不同年龄、住院时间长短、不同肝功能分级、是否行侵入性操作、血清白蛋白和血清胆红素高低、有无腹水和是否应用抗病毒药物患者医院感染发生率差异显著,经多因素回归分析显示年龄≥60岁(OR=4.176,P=0.023)、住院时间≥1月(OR=44.116,P=0.021)、肝功能分级差(OR=5.160,P=0.009)、进行了侵入性操作(OR=5.265,P=0.003)和有腹水(OR=2.921,P=0.033)为影响患者发生院内感染的独立危险因素。结论 失代偿期乙型肝炎肝硬化患者在住院期间易发生医院感染,对于感染高危人群应予以高度关注,重视手卫生和适度隔离,以减少院内感染的发生。     

重症监护病房机械通气相关性肺炎危险因素的前瞻性队列研究

目的　通过研究重症监护病房 (ICU)机械通气相关性肺炎 (VAP)的发病危险因素 ,为ICU的VAP防治提供基础的流行病学资料 ,为制定和采取预防控制措施提供科学依据。方法　以1999年 12月～ 2 0 0 1年 2月我院ICU行气管插管或气管切开患者为对象 ,采用前瞻性队列研究 ,作单因素和logistic回归分析 ,筛选VAP发病的可能危险因素。结果　研究期间共有 2 85例患者行人工气道机械通气 ,98例符合条件入选本研究 ,其中 5 2例发生VAP ,发生率为 5 3 1% ;以插管日计算 ,每 10 0 0个插管日发生 32 4例VAP。将 2 1项变量行单因素分析结果显示 ,COPD史 >15年、白蛋白 <30g/L、连续使用抗生素 >3d等 13项因素有统计学意义。logistic多因素分析显示 ,VAP的独立发病危险因素有 :同时使用 2种以上抗生素、重复气管插管、APACHEⅡ评分 >15分、胃液pH >4、机械通气时间延长。结论　ICU发生VAP是多种因素共同作用的结果。对已筛选的可能危险因素 ,需通过临床试验进一步证实。     

Nosocomial infection after lung surgery: incidence and risk factors

STUDY OBJECTIVES: To assess the incidence and risk factors for nosocomial infection after lung surgery. DESIGN: Prospective cohort study. SETTING: Service of thoracic surgery of an acute-care teaching hospital in Santander, Spain. PATIENTS: Between June 1, 1999, and January 31, 2001, all consecutive patients undergoing lung surgery were prospectively followed up for 1 month after discharge from the hospital to assess the development of nosocomial infection, the primary outcome of the study. INTERVENTIONS: During the hospitalization period, patients were visited on a daily basis. Postdischarge surveillance was based on visits to the surgeon. MEASUREMENTS AND RESULTS: We studied 295 patients (84% men; mean age, 60.9 years), 89% of whom underwent resection operations. Ninety episodes of nosocomial infection were diagnosed in 76 patients, including pneumonia (n = 10), lower respiratory tract infection (n = 47), wound infection (n = 16; one third were detected after hospital discharge), urinary tract infection (n = 9), and bacteremia (n = 8; three fourths were catheter-related bacteremia). Twenty patients had severe infections (pneumonia or empyema), with a mortality rate of 60%. COPD (adjusted odds ratio [OR], 2.70; 95% confidence interval [CI], 1.52 to 4.84), duration of surgery with an increased risk for each additional minute (Mantel-Haenzel chi(2) test for trend, p = 0.037), and ICU admission (OR, 3.69; 95% CI, 1.94 to 7.06) were independent risk factors for nosocomial infection. The use of an epidural catheter was a protective factor (OR, 0.45; 95% CI, 0.22 to 0.95). There were no differences according to the use of amoxicillin/clavulanate or cefotaxime for surgical prophylaxis. CONCLUSIONS: Nosocomial infections are common after lung surgery. One third of wound infections were detected after hospital discharge. The profile of a high-risk patient includes COPD as underlying disease, prolonged operative time, and postoperative ICU admission.     

Risk factors for ICU-acquired methicillin-resistant Staphylococcus aureus infections

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide, and MRSA infections are frequent in intensive care units (ICUs). OBJECTIVE: A prospective study was implemented to investigate the risk factors for ICU-acquired MRSA infections. METHODS: This study was conducted in surgical and neurologic ICUs from May to November 2003. The patients staying in ICUs more than 48 hours were included in the study. All of the patients were visited daily, and data were recorded on individual forms for each patient until discharge or death. Nasal swab cultures were done within 48 hours of ICU admission and repeated every week until the patients colonized with MRSA or were discharged from ICUs. ICU-acquired MRSA infection was diagnosed when MRSA was isolated from the infected site. RESULTS: Overall, 249 patients were followed during the study. MRSA infection was detected in 21 (8.4%) of these patients. The most frequent infection was primary bloodstream infection (10/21, 47%). It was followed by pneumonia (8/21, 38%) and surgical site infection (3/21, 14%). Nasal MRSA colonization was detected in 59 (23.7%) patients, and 12 of them (20.3%) developed MRSA infection. In univariate analysis, hospitalization period in an ICU, intraabdominal and orthopedic pathologies, mechanical ventilation, central venous catheter insertion, total parenteral nutrition, previous antibiotic use, surgical ICU stay, nasal MRSA colonization, and presence of more than 2 patients having nasal colonization in the same ICU at the same time were found significant for MRSA infections. In multivariate analysis; hospitalization period in an ICU (OR, 1.090; 95% CI: 1.038-1.144, P = .001), central venous catheter insertion (OR, 1.822; 95% CI: 1.095-3.033, P = .021), previous antibiotic use (OR, 2.337; 95% CI: 1.326-4.119, P = .003) and presence of more than 2 patients having nasal colonization in the same ICU at the same time (OR, 1.398; 95% CI: 1.020-1.917, P = .037) were independently associated with MRSA infections. CONCLUSION: According to the our results, hospitalization period in an ICU, presence of patients colonized with MRSA in the same ICU at the same time, previous antibiotic use, and central venous catheter insertion are independent risk factors for ICU-acquired MRSA infections. Detection of these factors helps to decrease the rate of MRSA infections in the ICUs.     

Severity-of-illness markers as predictors of nosocomial infection in adult intensive care unit patients

BACKGROUND: Patients admitted to intensive care units (ICUs) are at high risk for acquiring nosocomial infections. We examined the association between markers of severity of illness at ICU admission and the development of ICU-attributable nosocomial infections. METHODS: Retrospective cohort study of 851 patients admitted to the medical or surgical ICU in an urban teaching hospital from January 1997 to January 1998. Logistic regression analysis was used to identify predictors of nosocomial infection, including the Acute Physiology, Age, Chronic Health Evaluation III severity-of-illness scoring system. RESULTS: Patients receiving mechanical ventilation on day 1 of ICU admission (OR, 1.99; 95% CI, 1.29-3.06) and patients transferred to the ICU from another unit within the same hospital (OR, 2.04; 95% CI, 1.24-3.34) were twice as likely to acquire an ICU-attributable nosocomial infection compared with patients admitted from other sources. The day-1 Acute Physiology, Age, Chronic Health Evaluation III score was not a significant predictor of nosocomial infection. CONCLUSION: The need for mechanical ventilation on ICU day 1 and transfer to the ICU from another unit are independent predictors of ICU-attributable nosocomial infections. Up to 50% of ICU patients who develop nosocomial infections could be easily identified at ICU admission, allowing for targeted use of preventive strategies to reduce the risk of nosocomial infections.