Lack of association between the increased incidence of Clostridium difficile-associated disease and the increasing use of alcohol-based hand rubs.

OBJECTIVE: To determine whether there is an association between the increasing use of alcohol-based hand rubs (ABHRs) and the increased incidence of Clostridium difficile-associated disease (CDAD). SETTING: A 500-bed university-affiliated community teaching hospital. METHODS: Use of ABHRs during the period 2000-2003 was expressed as the number of liters of ABHR used per 1000 patient-days. The proportion of hand hygiene episodes performed by using an ABHR was determined by periodic observational surveys. CDAD was defined as a physician-ordered stool assay positive for C. difficile toxin A or A/B. The incidence of CDAD was expressed as the number of unique patients who had 1 or more positive CDAD test results per 1,000 patient-days. RESULTS: During 2000-2003, the use of ABHR increased 10-fold, from 3 to greater than 30 L/1,000 patient-days (P<.001). The proportion of hand hygiene episodes performed using an ABHR increased from 10% to 85% (P<.001). The incidence of CDAD in 2000, 2001, 2002, and 2003 was 1.74, 2.33, 1.14, and 1.18 cases/1,000 patient-days, respectively. CONCLUSION: Despite a significant and progressive increase in the use of ABHRs in our facility during a 3-year period, there was no evidence that the incidence of CDAD increased. These findings suggest that factors other than the increased use of ABHRs are responsible for the increasing incidence of CDAD noted since 2000 in other facilities.     

Recommendations for surveillance of Clostridium difficile-associated disease.

BACKGROUND: The epidemiology of Clostridium difficile-associated disease (CDAD) is changing, with evidence of increased incidence and severity. However, the understanding of the magnitude of and reasons for this change is currently hampered by the lack of standardized surveillance methods. OBJECTIVE AND METHODS: An ad hoc C. difficile surveillance working group was formed to develop interim surveillance definitions and recommendations based on existing literature and expert opinion that can help to improve CDAD surveillance and prevention efforts. DEFINITIONS AND RECOMMENDATIONS: A CDAD case patient was defined as a patient with symptoms of diarrhea or toxic megacolon combined with a positive result of a laboratory assay and/or endoscopic or histopathologic evidence of pseudomembranous colitis. Recurrent CDAD was defined as repeated episodes within 8 weeks of each other. Severe CDAD was defined by CDAD-associated admission to an intensive care unit, colectomy, or death within 30 days after onset. Case patients were categorized by the setting in which C. difficile was likely acquired, to account for recent evidence that suggests that healthcare facility-associated CDAD may have its onset in the community up to 4 weeks after discharge. Tracking of healthcare facility-onset, healthcare facility-associated CDAD is the minimum surveillance required for healthcare settings; tracking of community-onset, healthcare facility-associated CDAD should be performed only in conjunction with tracking of healthcare facility-onset, healthcare facility-associated CDAD. Community-associated CDAD was defined by symptom onset more than 12 weeks after the last discharge from a healthcare facility. Rates of both healthcare facility-onset, healthcare facility-associated CDAD and community-onset, healthcare facility-associated CDAD should be expressed as case patients per 10,000 patient-days; rates of community-associated CDAD should be expressed as case patients per 100,000 person-years.     

Predicting Clostridium difficile toxin in hospitalized patients with antibiotic-associated diarrhea.

OBJECTIVE: Clostridium difficile infection is implicated in 20%-30% of cases of antibiotic-associated diarrhea. Studying hospitalized patients who received antibiotic therapy and developed diarrhea, our objective was to compare the clinical characteristics of patients who developed C. difficile-associated diarrhea (CDAD) with those of patients with a negative result of a stool assay for C. difficile toxin. METHODS: A prospective study was done with a cohort of 217 hospitalized patients who had received antibiotics and developed diarrhea. Patients with CDAD were defined as patients who had diarrhea and a positive result for C. difficile toxin A/B by an enzyme immunoassay of stool. The variables that yielded a significant difference on univariate analysis between patients with a positive assay result and patients with a negative assay result were entered into a logistic regression model for prediction of C. difficile toxin.Setting. A 900-bed tertiary care medical center. RESULTS: Of 217 patients, 52 (24%) had a positive result of assay for C. difficile toxin A/B in their stool. The logistic regression model included impaired functional capacity, watery diarrhea, use of a proton pump inhibitor, use of a histamine receptor blocker, leukocytosis, and hypoalbuminemia. The area under the receiver operating characteristic curve for the model as a predictor of a positive result for the stool toxin assay was 0.896 (95% confidence interval, 0.661-1.000; P<.001), with 95% specificity and 68% sensitivity. CONCLUSIONS: Our results may help clinicians to predict the risk of CDAD in hospitalized patients with antibiotic-associated diarrhea, to guide careful, specific empirical therapy, and to direct early attention to infection control issues.     

Changing epidemiology of Clostridium difficile-associated disease in children.

OBJECTIVE: To determine temporal trends in the incidence rate for Clostridium difficile-associated disease (CDAD) in a pediatric patient population. METHODS: We performed an observational, retrospective cohort study that included children who visited or were admitted to Children's National Medical Center during the period from July 2001 through June 2006. The CDAD incidence rates were determined and examined for changes over time using the Poisson regression method. RESULTS: A total of 513 patients whose stool specimens tested positive for C. difficile toxin were identified. Of these patients, 61% were children aged 2 years or older. The proportion of patients with CDAD in this age group has steadily increased from 46% in 2001 to 64% in 2006. Largely as a result of an increasing number of cases of community-associated CDAD, the incidence of CDAD increased significantly in the outpatient setting, particularly in the emergency department (1.18 cases per 1,000 visits in 2001 vs 2.47 cases per 1,000 visits in 2006; P=.02). The incidence among inpatients decreased during the study period (1.024 cases per 1,000 patient-days in 2001 vs 0.680 cases per 1,000 patient-days in 2006; P=.004). In the neonatal intensive care unit, C. difficile toxin was detected in stool specimens collected from 22 patients aged from 15 days to 6 months. CONCLUSION: This study revealed a steady increase in the number of patients seen in the emergency department with community-acquired CDAD. Findings from this study suggest that the characteristics of CDAD in children--a population that has not been considered to be at high risk for this disease in the past--are changing. Further investigations are warranted to explore deviations from the established burdens of the disease and patient risk factors.     

Clinical features of Clostridium difficile-associated infections and molecular characterization of strains: results of a retrospective study, 2000-2004.

BACKGROUND: Recent outbreaks of severe cases of Clostridium difficile-associated diarrhea (CDAD) reported in North America, the United Kingdom, and The Netherlands have emphasized the importance of an ongoing epidemiological surveillance of CDAD. OBJECTIVE: To determine the epidemiology of CDAD over the years 2000-2004 and the rate of nosocomial transmission of C. difficile. DESIGN: Retrospective survey of inpatients with CDAD and molecular characterization of the strains isolated. SETTING: A 760-bed teaching hospital. METHODS: All CDAD cases diagnosed from January 1, 2000, to December 31, 2004, were reviewed. A CDAD case was defined as diarrhea in a hospitalized patient who had a stool specimen that tested positive for C. difficile cytotoxin or had a positive toxigenic culture result. CDAD was considered to be severe if a patient fulfilled at least 1 of the following 3 criteria: (1) presence of a fever (defined as temperature higher than 38.5 degrees C), abdominal pain, and leukocyte count greater than 10,000 cells/mm(3); (2) endoscopically or histologically proven pseudomembranous colitis; or (3) complications (defined as death with C. difficile infection as the primary or a contributing cause, toxic megacolon, perforation, toxic shock, and/or colectomy). CDAD was considered community-acquired if the diarrhea occurred in the patient within 72 hours after admission and if the patient had no history of hospitalization in the previous month; otherwise, CDAD was considered healthcare-associated. All the strains isolated were serogrouped and were characterized by toxinotyping and PCR ribotyping. Detection of toxin A, toxin B, and binary toxin was performed by PCR. RESULTS: One hundred fifty-one cases of CDAD were diagnosed; 147 clinical records could be reviewed, and 131 strains were studied. The overall incidence of CDAD was 1.1 cases per 1,000 patients admitted, but incidence rates were higher in 2003-2004, compared with 2000-2002 (P=.017). Diarrhea was community acquired in 28 patients (19%). For patients with healthcare-associated CDAD, transmission of the strain from patient to patient (ie, infection with a strain of the same serogroup and PCR ribotype as the strain isolated from another patient hospitalized in the same ward or in a linked ward in the previous 2 months) was demonstrated in 12 cases (10.1%). Eleven percent of strains were positive for binary toxin. Binary toxin-positive strains were associated with more-severe diarrhea (P=.01) and with a higher case-fatality rate (P=.03). A specific clone of C. difficile (serogroup H, PCR ribotype sa026) accounted for 35 (26.7%) of all the strains isolated, but this clone was found both in healthcare-associated and community-acquired cases. Three strains belonged to toxinotype III, but only 1 was related to the hypervirulent clone involved in recent outbreaks. CONCLUSION: The incidence of CDAD is low in our hospital, and cross-infection is limited. These results also suggest that strains with binary toxin might be more virulent.     

Comparison of AP-PCR typing and PCR-ribotyping for estimation of nosocomial transmission of Clostridium difficile

We recently attempted to clarify an increased incidence of Clostridium difficile-associated diarrhoea (CDAD) in our hospital by arbitrarily primed polymerase chain reaction (AP-PCR) typing of isolates from 147 consecutive patients collected during a 12 month period (Wullt et al. J Hosp Infect 1999;43:265-273). In the present study we compared the results based on previous AP-PCR data with those based on recent PCR ribotyping of the same isolates and re-analysis of a subset of isolates by AP-PCR typing. The pattern of PCR ribotypes was similar among inpatients and outpatients. A cluster of three closely related PCR ribotypes, related to those of the serogroup H and A8 type strains, dominated and comprised 31% of inpatient and 28% of outpatient C. difficile isolates. The apparent nosocomial transmission rate among inpatients with CDAD was only 9% by AP-PCR typing compared with 18 or 36% by PCR ribotyping depending on the definition used (proportion of patients sharing C. difficile type and ward within two or 12 months). Corresponding rates for all CDAD patients were 5% by AP-PCR and 11 or 21% by PCR ribotyping. Thus, most CDAD patients apparently became ill due to their endogenous strain of C. difficile. Because of the low concordance between the two typing methods the proportion of patients fulfilling the criteria for nosocomial transmission by both methods was only 1%. Re-examination of isolates from patients with recurrences revealed a reproducibility problem with AP-PCR typing. We conclude, that of these two PCR-based options for typing of C. difficile PCR ribotyping offers a superior experimental robustness compared with AP-PCR typing.     

Emergence and control of fluoroquinolone-resistant, toxin A-negative, toxin B-positive Clostridium difficile.

BACKGROUND: Clostridium difficile is a major cause of infectious diarrhea in hospitalized patients. Between August 2003 and January 2004, we experienced an increase in the incidence of C. difficile-associated disease. We describe the investigation into and management of the outbreak in this article. METHODS: A total of 73 consecutive patients with nosocomial C. difficile-associated diarrhea were identified. C. difficile isolates were characterized using toxin-specific enzyme immunoassays, a tissue-culture fibroblast cytotoxicity assay, polymerase chain reaction (PCR), and antimicrobial susceptibility tests. Rates of recurrence and of C. difficile colitis were recorded. Changes in antibiotic use and infection control policies were documented. RESULTS: The incidence of C. difficile-associated diarrhea peaked at 21 cases per 1,000 patient admissions. Of the C. difficile isolates recovered, 85 (95%) were identical toxin A-negative and toxin B-positive strains, corresponding to toxinotype VIII and PCR ribotype 017. All clonal isolates were resistant to multiple antibiotics, including ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin (minimum inhibitory concentrations [MICs] of greater than 32 micro g/mL) and erythromycin, clarithromycin, and clindamycin (MICs of greater than 256 micro g/mL). Recurrent C. difficile-associated disease occurred in 26 (36%) of the patients. At least 10 (14%) of the patients developed C. difficile colitis. Additional infection control measures introduced included the use of ward memos, a hand-hygiene awareness campaign, increased environmental cleaning, attention to prescribing practices for antibiotics, increased awareness of diarrheal illness, and early isolation of affected patients. Total use of fluoroquinolones did not change throughout the study period. Despite persistence of this toxin-variant strain, the incidence of C. difficile-associated disease in our institution decreased to fewer than 5 cases per 1,000 admissions. CONCLUSIONS: We report on the emergence of a fluoroquinolone- and clindamycin-resistant, toxin A-negative, and toxin B-positive strain of C. difficile associated with an outbreak of C. difficile-associated disease in our institution during a 6-month period. We found that careful attention to improvement of infection control interventions was the most important means of controlling this nosocomial pathogen.     

一起医院内集聚性诺如病毒胃肠炎的调查

目的 调查分析一起在上海市徐汇区某社区卫生服务中心内科病房内发生的集聚性诺如病毒GⅡ型胃肠炎疫情的特征及其原因.方法 采用统一的集体性腹泻个案调查表进行现场流行病学调查,使用病例对照研究方法分析相关危险因素,采用RT-PCR方法检测病毒核酸.结果 该起疫情共报告病例22例,发病率为31.0％,以呕吐腹泻为主要临床表现,疫情流行持续8d,引入率为30.3％;时间分布呈单峰,空间分布有集聚性;通过实验室检测确定有两名护工隐性感染,在11份粪便、肛拭标本中检出9份诺如病毒GⅡ型核酸阳性,6份环节标本呈核酸阴性;由隐性感染护工护理的患者发病率高于非感染护工护理的患者(x2 =4.98,P=0.026),OR值为11.2(95％ CI=1.80～116.80);空间分布的集聚性与隐性感染护工护理的床位高发病率有较好的一致性.结论 该次疫情是一起发生在医疗机构内由诺如病毒GⅡ型引起的集聚性胃肠炎疫情,隐性感染的护工是传染源之一,接触传播是重要的传播途径;该次疫情在对手卫生、标准防护执行力进行干预及落实各项消毒隔离措施后得到有效控制.     

The role of Clostridium difficile and viruses as causes of nosocomial diarrhea in children.

OBJECTIVE: We report surveillance of nosocomial diarrhea in children at our institution during the past decade and note different epidemiology of diarrhea due to viruses and Clostridium difficile. DESIGN: A prospective cohort study. SETTING: A university-affiliated pediatric hospital with 180 beds serving an urban area and providing referral care for the Maritime Provinces of Canada. PARTICIPANTS: Children younger than 18 years. METHODS: Surveillance was conducted from 1991 to 1999 using personal contact with personnel and review of microbiology and medical records. Nosocomial diarrhea was defined as loose stools occurring more than 48 hours after admission, with at least two loose stools in 12 hours and no likely non-infectious cause. RESULTS: Nosocomial diarrhea was the third most common nosocomial infection (217 of 1,466; 15%), after bloodstream and respiratory infections, with from 0.5 to 1 episode per 1,000 patient-days. Of 217 nosocomial diarrhea episodes, 122 (56%) had identified pathogens: C. difficile (39 of 122; 32%), rotavirus (38 of 122; 31%), adenovirus (36 of 122; 30%), and other viral (9 of 122; 7%). The median age was 1.3 years (range, 11 days to 17.9 years), 0.80 year for children with viral diarrhea, 3.9 years for children with C. difficile, and 1.5 years for children with diarrhea without a causative organism identified (P< .0001). Most children with nosocomial diarrhea were incontinent (diapered) at the time of their first episode (138 of 185; 75%), but preexisting incontinence was more common in those with viral diarrhea (93%) compared with those with no organism identified (71%) or those with C. difficile-associated diarrhea (CDAD) (49%) (P <.0001). CONCLUSIONS: C. difficile is the single most common cause of nosocomial diarrhea in our tertiary-care center, although all viral pathogens account for 69% of cases. Diapered status appears to be a risk factor for CDAD in children, and CDAD occurs more often in older children than viral nosocomial diarrhea. Further characterization of risk factors for, and morbidity associated with, nosocomial CDAD in children is warranted.     

Outbreak of vancomycin-resistant Enterococcus faecium in a neonatal intensive care unit.

An outbreak of vancomycin-resistant Enterococcus faecium involving 28 infants in a neonatal intensive care unit was observed. Successful control of the outbreak was achieved following use of patient and staff cohorting, contact isolation precautions, patient and environmental surveillance cultures, environmental decontamination, molecular typing, introduction of an alcohol-based hand disinfectant, and decreased use of vancomycin.     

Acquisition of Clostridium difficile from the hospital environment

An outbreak of antibiotic-associated colitis that occurred on a ward of a Michigan hospital during February-April, 1984, was studied by bacteriophage-bacteriocin typing. Stools from the seven involved patients yielded Clostridium difficile isolates of types B1537 or Cld7;B1537. C. difficile was recovered from 31.4% of environmental cultures obtained on the ward, and the majority of isolates were types B1537 or Cld7;B1537. When the ward was disinfected with unbuffered hypochlorite (500 parts per million (ppm) available chlorine), surface contamination decreased to 21% of initial levels and the outbreak subsequently ended. Phosphate buffered hypochlorite (1,600 ppm available chlorine, pH 7.6) was even more effective; its use resulted in a 98% reduction in surface contamination. These findings suggest that environmental contamination with C. difficile is important in the epidemiology of antibiotic-associated colitis, and that hypochlorite is effective in eliminating C. difficile from the hospital environment.     

Morbidity, mortality, and healthcare burden of nosocomial Clostridium difficile-associated diarrhea in Canadian hospitals.

OBJECTIVE: To assess the healthcare burden, morbidity, and mortality of nosocomial Clostridium difficile-associated diarrhea (N-CDAD) in Canadian hospitals. DESIGN: Laboratory-based prevalence study. SETTING: Nineteen acute-care Canadian hospitals belonging to the Canadian Hospital Epidemiology Committee surveillance program. PATIENTS: Hospitalized patients in the participating centers. METHODS: 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. RESULTS: 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. CONCLUSION: 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.     

Environmental survey to assess viral contamination of air and surfaces in hospital settings

This report describes an outbreak of Clostridium difficile infection (CDI) in a vascular surgery ward in 2009 caused by a high-level clindamycin-resistant ribotype 106. A case of CDI was defined as a patient with diarrhoea, positive for C. difficile toxin and negative for other enteric pathogens. Cultures were sent to the Scottish Salmonella Shigella and Clostridium difficile Reference Laboratory (SSSCDRL) for PCR ribotyping, antibiotic susceptibility testing and PCR detection of ermB. The mean age of the nine patients was 73 years (range: 38–90 years). All had received clindamycin and ciprofloxacin. All cases were typed as PCR ribotype 106 and they showed high-level resistance to clindamycin. Five of these isolates were tested by PCR for the presence of the ermB gene and no amplification was detected. This strain has rarely been isolated from patients on this ward. The outbreak was controlled successfully by closure of the ward with terminal cleaning, reinforcement of infection control precautions and the introduction of a new antibiotic policy. It is notable that this outbreak was caused by a strain with high-level clindamycin resistance not mediated by ermB. It also re-emphasizes that outbreaks of CDI can be caused by C. difficile PCR ribotypes other than 027. The outbreak was most likely associated with the use of clindamycin and ciprofloxacin cross-infection with spores in this environment. Implementation of strict infection control precautions, antimicrobial stewardship and enhanced environmental cleaning are key components in managing such an outbreak successfully. The number of meticillin-resistant Staphylococcus aureus acquisitions also fell substantially after these interventions.     

Molecular findings and antibiotic-resistance in an outbreak of Acinetobacter baumannii in an intensive care unit

We investigated an outbreak of Acinetobacter baumannii in the intensive care unit (ICU) of a hospital in Rome, Italy. The outbreak involved 14 patients whose isolates were most frequently recovered from bronchoalveolar lavage. All isolates were multidrug-resistant and showed diminished susceptibility or resistance to carbapenems. A. baumannii strains with a similar antibiotic susceptibility pattern were isolated from the environment. Pulsed-field gel electrophoresis identified a single clone from both the patients' and environmental isolates. Because of the lack of a single source of infection, the eradication of the epidemic required a broad approach, including contact isolation and cohorting, aggressive environmental disinfection, and close monitoring of the ward staff's performance. Infected patients were successfully treated with combined therapy. Although considered of low virulence, A. baumannii can be particularly aggressive and difficult to treat in ICU patients.     

Control of a regional outbreak of vanA glycopeptide-resistant Enterococcus faecium, Eastern France, 2004-2009

At the end of 2004, an outbreak of glycopeptide-resistant enterococci (GRE) spread from the Nancy Teaching Hospital to more than 40 facilities in the Lorraine region. Because this outbreak appeared to be uninhibited, a regional task force was set up to organize and co-ordinate the management of the outbreak, visiting the affected facilities to publicize the existing recommendations and take stock of the problems encountered in the field. The task force then proposed control measures specific to the region. The proposed measures included promoting the use of alcohol-based hand-rub solutions, isolation measures, enhanced screening policies, cohorting GRE-colonized patients and contacts in special wards with dedicated staff where possible, or failing that, isolating them in single rooms with additional "contact" precautions, maintaining these precautions for GRE-colonized patients until a negative stool sample was obtained after antibiotic treatment (which is a more restrictive definition of "cleared" than usually employed), regional co-ordination of the follow-up of GRE-colonized patients with the weekly publication of a list of institutions that were or had been affected to allow isolation measures to be adopted as soon as known-GRE-colonized patient were readmitted. It was not possible to determine the efficacy of each individual measure on the course of the outbreak. Nevertheless, we observed that the number of new GRE-colonized patients started to decrease following their implementation. Ultimately, 1077 GRE colonizations were recorded in Lorraine, and the outbreak is now under control.     

Do infection control measures work for methicillin-resistant Staphylococcus aureus?

OBJECTIVE: To review evidence regarding the effectiveness of control measures in reducing transmission of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. DESIGN: Literature review and surveillance cultures of hospitalized patients at high risk for MRSA colonization or infection. SETTING: A 500-bed, university-affiliated, community teaching hospital. RESULTS: The percentage of nosocomial S. aureus infections caused by MRSA increased significantly between 1982 and 2002, despite the use of various isolation and barrier precaution policies. The apparent ineffectiveness of control measures may be due to several factors including the failure to identify patients colonized with MRSA. For example, cultures of stool specimens submitted for Clostridium difficile toxin assays at one hospital found that 12% of patients had MRSA in their stool, and 41% of patients with unrecognized colonization were cared for without using barrier precautions. Other factors include the use of barrier precaution strategies that do not account for multiple reservoirs of MRSA, poor adherence of healthcare workers (HCWs) to recommended barrier precautions and handwashing, failure to identify and treat HCWs responsible for transmitting MRSA, and importation of MRSA by patients admitted from other facilities. Control programs that include active surveillance cultures (ASCs) of high-risk patients and use of barrier precautions have reduced MRSA prevalence rates and have been cost-effective. Using a staged approach to implementing ASCs can minimize logistic problems. CONCLUSION: MRSA control programs are effective if they include ASCs of high-risk patients, use of barrier precautions when caring for colonized or infected patients, hand hygiene, and treating HCWs implicated in MRSA transmission.     

Incidence of Clostridium difficile infection: a prospective study in an Indian hospital

Clostridium difficile is the commonest cause of hospital-acquired diarrhoea. A prospective study comprising of 156 patients and 54 healthy controls was undertaken to assess C. difficile associated diarrhoea (CDAD) incidence in an Indian hospital. Methods used included C. difficile culture and enzyme linked immunosorbent assay (ELISA) for Toxin A. Attempts were made to type isolates by antibiogram and SDS-PAGE. Of the 210 stool samples tested, 12 gave positive results in at least one assay. Of these, 11 were positive by the ELISA method, eight by culture, and seven by both methods. Neither the organisms nor the toxin was found in healthy controls or neonates. The average disease incidence of CDAD estimated by using both methods was 15%. Two antibiotypes of the isolates were obtained and of the isolates characterized by SDS-PAGE, two had identical patterns. This study shows that CDAD is an emerging problem in Indian hospitals. Monitoring should enable the development and implementation of policies and procedures that minimize the risk of this nosocomial pathogen.     

Outbreak of multi-resistant Escherichia coli on a surgical ward: course, measures and consequences for future admissions of contaminated patients

In the period July-September 2003, a multi-resistant Escherichia coli strain caused an outbreak on a surgical ward in the Deventer Hospital, the Netherlands. This strain produced a beta-lactamase with an extended spectrum, making it resistant to third generation cephalosporins. Furthermore, the strain was resistant to trimethoprim-sulphamethoxazole (co-trimoxazole), gentamicin and quinolones, so that only treatment with carbapenems was possible. 8 patients were colonised. Genotyping of the strains by means of amplified fragment length polymorphism indicated the spread of a single strain. A multidisciplinary crisis team coordinated the infection control measures and the communication to involved persons and the press. Control measures consisted of contact isolation of colonised patients and extra attention to hand hygiene. After this proved to be ineffective, all patients on the ward were screened and the ward was closed for several days. The outbreak was stopped by strict cohorting ofthe colonised patients. There were no indications for transmission of resistance genes by plasmids. Several months later, on visiting the outpatient clinic, 3 other patients appeared to have been colonised by the epidemic E. coli strain during their admission. They had not been screened because they had already been discharged when all patients on the ward were screened for colonisation. In a follow-up study 9 months after the outbreak, 3 of the 6 investigated patients, who had in the meantime returned home, were still found to be colonised. Such patients constitute a risk for the re-introduction of multi-resistant bacteria into the hospital and should be preventively screened and isolated on admission.     

Control of an outbreak of pandrug-resistant Acinetobacter baumannii colonization and infection in a neonatal intensive care unit.

OBJECTIVE: To investigate the potential reservoir and mode of transmission of pandrug-resistant (PDR) Acinetobacter baumannii in a 7-day-old neonate who developed PDR A. baumannii bacteremia that was presumed to be the iceberg of a potential outbreak. DESIGN: Outbreak investigation based on a program of prospective hospital-wide surveillance for nosocomial infection. SETTING: A 24-bed neonatal intensive care unit in a 2,200-bed major teaching hospital in Taiwan that provides care for critically ill neonates born in this hospital and those transferred from other hospitals. INTERVENTIONS: Samples from 33 healthcare workers' hands and 40 samples from the environment were cultured. Surveillance cultures of anal swab specimens and sputum samples were performed for neonates on admission to the neonatal intensive care unit and every 2 weeks until discharge. The PDR A. baumannii isolates, defined as isolates resistant to all currently available systemic antimicrobials except polymyxin B, were analyzed by pulsed-field gel electrophoresis. Control measures consisted of implementing contact isolation, reinforcing hand hygiene adherence, cohorting of nurses, and environmental cleaning. RESULTS: One culture of an environmental sample and no cultures of samples from healthcare workers' hands grew PDR A. baumannii. The positive culture result involved a sample obtained from a ventilation tube used by the index patient. During the following 2 months, active surveillance identified PDR A. baumannii in 8 additional neonates, and isolates from 7 had the same electrokaryotype. Of the 9 neonates colonized or infected with PDR A. baumannii, 1 died from an unrelated condition. Reinforcement of infection control measures resulted in 100% adherence to proper hand hygiene protocol. The outbreak was stopped without compromising patient care. CONCLUSIONS: In the absence of environmental contamination, transient hand carriage by personnel who cared for neonates colonized or infected with PDR A. baumannii was suspected to be the mode of transmission. Vigilance, prompt intervention and strict adherence to hand hygiene protocol were the key factors that led to the successful control of this outbreak. Active surveillance appears to be an effective measure to identify potential transmitters and reservoirs of PDR A. baumannii.     

An outbreak of multidrug-resistant Pseudomonas aeruginosa associated with increased risk of patient death in an intensive care unit.

OBJECTIVE: To investigate an outbreak of multidrug-resistant Pseudomonas aeruginosa in an intensive care unit (ICU). DESIGN: Epidemiologic investigation, environmental assessment, and ambidirectional cohort study. SETTING: A secondary-care university hospital with a 10-bed ICU. PATIENTS: All patients admitted to the ICU receiving ventilator treatment from December 1, 1999, to September 1, 2000. RESULTS: An outbreak in an ICU with multidrug-resistant isolates of P aeruginosa belonging to one amplified fragment-length polymorphism (AFLP)-defined genetic cluster was identified, characterized, and cleared. Molecular typing of bacterial isolates with AFLP made it possible to identify the outbreak and make rational decisions during the outbreak period. The outbreak included 19 patients during the study period. Infection with bacterial isolates belonging to the AFLP cluster was associated with reduced survival (odds ratio, 5.26; 95% confidence interval, 1.14 to 24.26). Enhanced barrier and hygiene precautions, cohorting of patients, and altered antibiotic policy were not sufficient to eliminate the outbreak. At the end of the study period (in July), there was a change in the outbreak pattern from long (December to June) to short (July) incubation times before colonization and from primarily tracheal colonization (December to June) to primarily gastric or enteral July) colonization. In this period, the bacterium was also isolated from water taps. CONCLUSION: Complete elimination of the outbreak was achieved after weekly pasteurization of the water taps of the ICU and use of sterile water as a solvent in the gastric tubes.