Epidemiologic Study On Healthcare-Associated Infection

ObjectivesThe object of this study is to investigate the prevalence and risk factors of healthcare-associated infection (HCAI), ventilator-associated pneumonia (VAP), and catheter-associated urinary tract infection (CAUTI) in Hubei Province, China, and to set up the HCAI forecast model of artificial neural networks (ANNs) and Logistic regression by the descriptive, analytical or theoretical epidemiologic methods. We also investigate the hospitals'ability and situation of prevention and control of the HCAI outbreak and make some proposals and advices.Methods1. The point prevalence surveys were carried out in 10 tertiary care hospitals in 2007 and 13 tertiary care hospitals in 2008 in Hubei Province, China. All patients in these hospitals who had been hospitalized on the day of the surveys were included. The following information was recorded for each patient:sex, age, current diagnoses, HCAI status, site of infection, results of microbiology culture, and whether the patient was on antibiotics. Medical records were reviewed for HCAI, using the definitions established by the Ministry of Health.2. A multi-centre prospective cohort study was performed in 17 intensive care units (ICUs) in tertiary care hospitals in Hubei Province. All patients receiving mechanical ventilation (MV) who had been hospitalized in these ICUs for more than 48 h were included during the study period. Information on onset of VAP, micro-organisms associated with VAP, and potential risk factors for patients receiving MV were collected from medical and nursing records and recorded on a form. The univariate and multivariate logistic regression analyses were performed to identify risk factors for VAP.3. The nested case-control study was conducted in an ICU in a tertiary care hospital in Hubei Province. All patients were selected from patients after urinary catheterization in the ICU. Individuals with urinary tract infection (UTI) served as cases, and the patients free of UTI as controls. A multivariable logistic regression model was performed to identify the independent risk factors for CAUTI.4. Data of patients who had hospitalized in the ICU for more than 48h in a tertiary care hospital in Hubei Province were collected to construct the HCAI prediction model of ANNs and Logistic regressions. The prediction effects were evaluated by the Likelihood ratio test, Hosmer and Lemeshow goodness-of-fit test and the receive roperator characteristic curve.5. Questionnaires were used to investigate the organizational framework, functional realization, program and support about the prevention and control of the HCAI outbreak in the conveniently sampled 121 hospitals in China. The data was analyzed and some proposals and advices were made.Results1. In total, the prevalence of HCAI in Hubei Province in 2007 and 2008 was 3.61%, with the frequency of HCAI being 3.76% in 2007 and 3.84% in 2008. Higher HCAI rates were found in patients from university hospitals, male patients, patients aged >55years or<10years, and in ICU patients compared with other groups. The HCAI rates differed among patients with different foundational diseases. Respiratory tract infection was the most common HCAI, followed by surgical site infection, urinary tract infection and gastrointestinal tract infection. Gram-negative bacteria were isolated most frequently and the most frequent organism was Pseudomonas aeruginose, followed by Escherichia coli, Staphylococcus aureus, Acinetobacter baumannii and Klebsiella pneumoniae. Antibiotic use was documented for 52.49% patients, and cephalosporins, penicillins, and quinolones were the most commonly used agents for treatment or prophylaxis.2. Among ventilated patients, the crude incidence rate and density of VAP were 20.89% and 28.90 cases per 1000 ventilator-days in Hubei Province. Multivariate analysis using logistic regression revealed risk factors, including male sex, coma, infections at other sites, chronic obstructive pulmonary disease, serious foundational disease, bronchoscopy, tracheostomy, use of antiacids, and the period of antimicrobial use >4 days. Gram-negative bacteria were isolated most frequently and the most frequently isolated causative pathogens were Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus. Frequencies of imipenem-resistant P. aeruginosa, imipenem-resistant A. baumannii and Ciprofloxacin-resistant P. aeruginosa isolates were 36.69%,64.97% and 49.12% respectively. Of all Staphylococcus aureus isolates,45.67% were meticillin resistant.3. Among patients, the incidence rate of CAUTI was 20.52%, and the density of infection was 33.05 per 1000 catheter-days in Hubei Province. By the multinomial logistic regression analysis, the CAUTI risk factors included the duration of catheterization (≥7 days), benign prostatic hypertrophy (BPH), and the duration of antimicrobial treatment (≥5 days). Of the isolates, fungi, especially Candida albicans, were isolated most frequently, followed by Escherichia coli and Pseudomonas aeruginosa.4. The follow variables were factors of the HCAI prediction model of the logistic regression equation:the period of the patients in ICU, tracheal intubation, BPH, artery and venous cannula, age, tumor as the foundation disease, et al. The HCAI prediction model of ANNs was {25-4-1}, and the most important factors in this model are the period of the patients in ICU, use of antibacterials, age, the foundation diseases, use of catheters, et al. The areas under ROC (Receiver-operating characteristic curve) were 0.856 and 0.861 respectively.5. There are some weaknesses in the organizational framework, functional realization, program and support about the prevention and control of the HCAI outbreak. The hospitals should strengthen the prevention and control of HCAI outbreak.Conclusions The point prevalences of HCAI in tertiary care hospitals in 2007 and 2008 in Hubei Province were steady and at relative low level. The incidence rates of VAP and CAUTI among patients in Hubei Province were higher than those of the developed countries, and the prevention and control of HCAI should be strengthened to improve the situation. The model of ANNs was better than the logistic regression in predicting the HCAI among ICU patients. There're some weaknesses in the prevention and control of the HCAI outbreak in Chinese hospials. To prevent and control HCAI outbreak effectively, the sanitation stringency should be constructed and perfected in these hospitals.InnovationThe study systematically investigated the prevalence and risk factors of HCAI among patients in Hubei Province. It's the first time in China to perform a multi-centre prospective cohort study of VAP, and to use questionnaires to investigate the prevention and control of the HCAI outbreak in hospitals and then to make some proposals.