Universal screening for Clostridioides difficile in a tertiary hospital: risk factors for carriage and clinical disease.

OBJECTIVES: The role of asymptomatic carriers in Clostridioides difficile infection (CDI) epidemiology is not fully understood. Our aim was to evaluate CD carriage prevalence on admission, associated risk factors, and the risk of developing CDI. METHODS: A 10-week surveillance program for CD carriage of all medical patients admitted to the Sheba Medical Centre was implemented, utilizing an admission rectal swab PCR. Healthcare facility-onset CDI (HO-CDI) was recorded and divided into HO-CDI diagnosed in CD carriers and non-carriers. RESULTS: A total of 4601 admissions were recorded in 3803 patients; 2368 patients had technically analysable rectal swabs, of whom 81 (3.4%) were CD carriers. A multivariate logistic regression model showed that previous hospitalization, old age (>85 years) and low Norton scores were significant independent predictors of CD carriage. Carriers were more likely to receive antimicrobial therapy during hospitalization than non-carriers were. The incidence of HO-CDI in non-carriers was 4.6 cases per 10 000 patient-days; the incidence of HO-CDI in carriers was 76.7 cases per 10 000 patient-days (RR 16.6, 95% CI 4.0-69.1, p .002). CONCLUSIONS: In a prospective study, the rate of CD carriage on admission in medical patients was 3.4%. CD carriers were older, frailer, and more likely to have been hospitalized recently. HO-CDI incidence was significantly higher among CD carriers than among non-carriers, with at least a third of CDI in screened patients developing in carriers. Targeted screening of high-risk groups for CD carriage should be further considered.

hVISA and MRSA endocarditis: an 8-year experience in a tertiary care centre.

It is not clear if patients with heterogeneous intermediate resistance to vancomycin (hVISA) infectious endocarditis (IE) differ from methicillin-resistant S. aureus (MRSA) IE patients. All cases of hVISA and MRSA IE diagnosed at the Sheba Medical Centre from 2003 to 2010 were included. Isolates were screened prospectively for hVISA. Medical records were reviewed. The t-test, chi-square test, Fisher exact test and Kaplan Meier analysis were used. Fourteen hVISA IE and 32 MRSA IE were identified. The mean age was 76 years, mean Charlson score was 4.5 and 24% of patients had prosthetic valves. Pacemakers and implantable cardioverter-defibrillators (P/ICDs) were more common in the hVISA group (50% vs. 22%, p 0.05). P/ICDs IE occurred in 29% of hVISA patients vs. 6.3% of MRSA patients (p 0.06). hVISA patients had more positive blood cultures (eight vs. five, p 0.007) and a trend toward longer bacteraemia (15 vs. 7.5 days, p 0.08). Vancomycin minimal inhibitory concentrations (MICs) were similar in the two groups (1.5 µg/mL vs. 1.1 µg/mL, p 0.11). The MIC to daptomycin was higher in hVISA (0.75 µg/mL vs. 0.32 µg/mL, p 0.049). MRSA patients received vancomycin. hVISA patients were switched to other antibiotics. Cardiac surgery and/or P/ICD extraction was performed more commonly in hVISA patients (50% vs. 16%, p 0.027). Mortality was high in both groups (57-66%). The median time to death was 39 days in the hVISA group and 19 days in the MRSA group (p 0.3). hVISA IE is associated with P/ICDs. Both hVISA and MRSA are associated with high mortality. Low rates of surgical intervention and P/ICD extraction reflect the high co-morbidity of patients. Caution should be employed in the empirical use of daptomycin in hVISA patients.

Epidemiology of carbapenem resistant Klebsiella pneumoniae colonization in an intensive care unit.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged during recent years in several intensive care units. The objective of our study was to determine the incidence of CRKP and the risk factors associated with acquisition during intensive care unit (ICU) stay. This prospective cohort study was conducted between May 2007 and April 2008 in a medical-surgical ICU at a tertiary medical center. Rectal surveillance cultures were obtained from patients on admission and twice weekly. Of screened patients, 7.0% (21/299) were CRKP colonized on admission to the ICU. One hundred eighty (81%) patients were screened at least twice. Of these, 48 (27%) patients acquired CRKP during ICU stay. Of the 69 CRKP colonized patients (both imported and ICU acquired), 29% (20/69) were first identified by microbiologic cultures, while screening cultures identified 49 patients (71%). Of these, 23 (47%) subsequently developed clinical microbiological cultures. Independent risk factors for CRKP acquisition included recent surgery (OR 7.74; CI 3.42-17.45) and SOFA score on admission (OR 1.17; CI 1-1.22). In conclusion, active surveillance cultures detected a sizable proportion of CRKP colonized patients that were not identified by clinical cultures. Recent surgical procedures and patient severity were independently associated with CRKP acquisition.

An outbreak of Burkholderia cenocepacia bacteremia in immunocompromised oncology patients.

BACKGROUND: Burkholderia cepacia is a common environmental bacterium that is resistant to disinfectants, and therefore is often encountered as a hospital-acquired pathogen. We describe an outbreak of B. cenocepacia bacteremia among hospitalized oncology patients. METHODS: A matched case-control study and an extensive environmental investigation were conducted. Species were identified by RFLP of the amplified recA gene. DNA was fingerprinted by pulsed-field gel electrophoresis (PFGE). RESULTS: Between November 2005 and September 2006, B. cenocepacia bacteremia developed in 17 patients with underlying malignancy of whom 14 had tunneled central venous catheters. All patients had fever and chills which subsided following removal of the central catheter and administration of ceftazidime. Extensive epidemiological investigation could not find a common source for the outbreak. Patients were hospitalized in three different buildings with different health care personnel. Medications were prepared in different sites by different personnel. A multivariate analysis demonstrated that the independent risk factors for developing nosocomial B. cenocepacia bacteremia were hospitalization at the center for long-term support (OR 28.8; 95% CI 1.83-453.4) and reduced use of antibiotics during the last month (OR 0.07; 95% CI 0.01-0.40). All isolates had identical antimicrobial susceptibility; PFGE indicated that a complex of closely related strains was involved in the outbreak. All isolates were identified as B. cenocepacia, known to infect cystic fibrosis patients. Strict infection control measures terminated the outbreak. CONCLUSIONS: B. cenocepacia is an emerging nosocomial pathogen among oncology patients.

An outbreak of Mycobacterium jacuzzii infection following insertion of breast implants.

BACKGROUND: Surgical wound infections caused by rapidly growing mycobacteria developed in 15 women after insertion of breast implants from August to November 2003 at a single medical center. METHODS: A case-control study was conducted that included the identified patients, as well as women who underwent breast operations at the same center who did not develop infections. The study was accompanied by an extensive environmental investigation. Isolates were identified by standard bacteriological methods and by comparison of their 16S rRNA, HSP65, RPOB, SODA, and RECA gene sequences. Isolates were compared by random amplified polymorphic DNA analysis and by pulsed-field gel electrophoresis. RESULTS: The risk factors for infection included surgery performed by 1 specific surgeon (odds ratio, 21.3; 95% confidence interval, 3.64-125.6). Identical strains of mycobacteria were isolated from the infected wounds of the patients; from the eyebrows, hair, face, nose, ears, and groin of this particular surgeon; and from this surgeon's outdoor whirlpool. The isolates exhibited a biochemical profile overlapping that of Mycobacterium wolinskyi, but their sequences of 16S rRNA and HSP65, RPOB, SODA, and RECA genes differed. We propose the name "Mycobacterium jacuzzii" for this new species. DNA fingerprints of cultured isolates from the surgical wounds, areas of the surgeon's body that grow hair, and the surgeon's whirlpool were identical. When the surgeon discontinued his use of the whirlpool and began cleaning the hairy areas of his body with a shampoo containing triclosan, the outbreak ended. CONCLUSIONS: This outbreak brings to light the possibility of the colonization of human skin and human-to-human transmission of environmental mycobacteria during surgery that involves implant insertion.

Development of antimicrobial drug resistance among Shigellas isolated at an Israeli hospital from 1977 through 1990.

BACKGROUND: Treatment of diarrhea due to Shigella sp. has become complicated in recent years by drug resistance. The emergence of resistance to antibiotics important in the treatment of shigellosis was studied among Shigella sp. isolated at the Sheba Medical Center between 1977 and 1990. METHOD: A retrospective study of resistance patterns of Shigella sp. using the Kirby-Bauer disc diffusion test. RESULTS: In the early 1980s S. sonnei replaced S. flexneri as the most frequent isolate. Ampicillin resistance rose steadily, peaking at 70% for S. sonnei in 1990 and 50% for S. flexneri in 1987 and 1990. Resistance to tetracycline roughly paralleled this. By 1990, 68% of S. sonnei and 75% of S. flexneri were insensitive. Cotrimoxazole resistance developed rapidly from 1981. By 1990, 88% of strains of S. sonnei had become resistant, compared to 63% of S. flexneri. S. boydii and S. dysenteriae were encountered less frequently, but showed important rates of resistance. Chloramphenicol remained active against almost all strains of S. sonnei, while resistance in S. flexneri reached about 30% in the late 1980s. Relatively few isolates were resistant to all four drugs. Only 20/841 (2.4%) of strains tested from 1984 to 1990 were resistant to nalidixic acid. CONCLUSION: The data presented document the emergence of antibiotic resistance as a serious public health problem among strains of Shigella isolated at a large medical center in Israel.