Coagulase-negative staphylococci (CNS) are the major cause of nosocomial bloodstream infection. Emergence of vancomycin resistance among CNS is a serious public health concern, because CNS usually are multidrug-resistant, and glycopeptide antibiotics, among which only vancomycin is available in the United States, are the only remaining effective therapy. In this report, we describe the first bloodstream infection in the United States associated with a Staphylococcus epidermidis strain with decreased susceptibility to vancomycin.

We reviewed the hospital's microbiology records for all CNS strains, reviewed the patient's medical and laboratory records, and obtained all available CNS isolates with decreased susceptibility to vancomycin. Blood cultures were processed and CNS isolates identified by using standard methods; antimicrobial susceptibility was determined by using minimum inhibitory concentration (MIC) and disk-diffusion methods. Nares cultures were obtained from exposed healthcare workers (HCWs) to identify possible colonization by CNS with decreased susceptibility to vancomycin.

The bloodstream infection by an S epidermidis strain with decreased susceptibility to vancomycin occurred in a 49-year-old woman with carcinoma. She had two blood cultures positive for CNS; both isolates were S epidermidis. Although susceptible to vancomycin by the disk-diffusion method (16-17 mm), the isolates were intermediate by MIC (8-6 μg/mL). The patient had received an extended course of vancomycin therapy; she died of her underlying disease. No HCW was colonized by CNS with decreased susceptibility to vancomycin.

This is the first report in the United States of bloodstream infection due to S epidermidis with decreased susceptibility to vancomycin. Contact precautions likely played a role in preventing nosocomial transmission of this strain, and disk-diffusion methods may be inadequate to detect CNS with decreased susceptibility to vancomycin.

To study vancomycin-resistant Enterococcus (VRE) prevalence, risk factors, and clustering among hospital inpatients.

Rectal-swab prevalence culture survey conducted from February 5 to March 22,1996.

The Veterans' Affairs Medical Center, Atlanta, Georgia.

Hospital (medical and surgical) inpatients.

The overall VRE prevalence was 29% (42/147 patients). The VRE prevalence was 52% (38/73 patients) among patients who had received at least one of six specific antimicrobials during the preceding 120 days, compared with only 5% (4/74) among those who had not received the antimicrobials (relative risk, 9.6; P <.001). The longer the period (up to 120 days) during which antimicrobial use was studied, the more closely VRE status was predicted. Among 67 hospital patients in 28 multibed rooms, clustering of VRE among current roommates was not found.

At this hospital with relatively high VRE prevalence, VRE colonization was related to antibiotic use but not to roommate VRE status. In hospitals with a similar VRE epidemiology, obtaining cultures from roommates of VRE-positive patients may not be as efficient a strategy for identifying VRE-colonized patients as obtaining screening cultures from patients who have received antimicrobials.

To describe the hospital precautions used to isolate a Sabiá virus (arenavirus: Arenaviridae)-infected patient in a US hospital and to protect hospital staff and visitors.

Investigation of a single case of arenavirus laboratory-acquired infection and associated case-contacts.

A 900-bed, tertiary-care, university-affiliated medical center.

The case-patient became ill with Sabiá virus infection. The case-contacts consisted of healthcare workers, coworkers, friends, and relatives of the case-patient.

Enhanced isolation precautions for treatment of a viral hemorrhagic fever (VHF) patient were implemented in the clinical laboratory and patient-care setting to prevent nosocomial transmission. The enhanced precautions included preventing aerosol spread of the virus from the patient or his clinical specimens. All case-contacts were tested for Sabiá virus antibodies and monitored for signs and symptoms of early disease.

No cases of secondary infection occurred among 142 case-contacts.

With the frequency of worldwide travel, patients with VHF can be admitted to a local hospital at any time in the United States. The use of enhanced isolation precautions for VHF appeared to be effective in preventing secondary cases by limiting the number of contacts and promoting proper handling of laboratory specimens. Patients with VHF can be managed safely in a local hospital setting, provided that appropriate precautions are planned and implemented.

To identify risk factors that might explain a sudden increase in the rate of surgical-site complications following laminectomy.

Retrospective cohort study.

Patients who underwent laminectomy at a 120-bed hospital from August 1 through October 15, 1996 (the epidemic period). A case-patient was defined as a patient with postoperative surgical-site complications (surgical-site drainage, edema, or swelling) requiring surgical debridement.

Of the 148 patients who underwent a laminectomy during the epidemic period, 17 (11%) met our case definition. The rate of postoperative surgical debridement was 7.6-fold higher during the epidemic period than the preceding 19-month period (17/148 vs 15/995, P<.001). Development of surgical-site complications was associated with intraoperative receipt of morphine nerve paste (relative risk [RR], 11; P<.001), preoperative shaving by nurses rather than surgeons (RR, 6.6; P=.006), procedures done by a certain surgeon (RR, 3.1; P=.022), or receipt of iodine rather than povidone-iodine for preoperative skin antisepsis (RR, 5.1; P=.002). In multivariate analysis, only receipt of morphine nerve paste remained as a risk factor (RR, 18; P=.011). The paste was used to control postoperative pain and was applied directly to exposed dura and surrounding tissues. At the time of surgical debridement (median, 24 days postsurgery), the original surgical sites showed residual paste and a lack of healing. Ten of 16 cultures from surgical sites were positive; all but three grew skin commensals. Histological examination of surgical specimens showed a foreign-body reaction, but no marked acute inflammation.

The intraoperative use of morphine nerve paste may delay wound healing and increase postoperative morbidity. When new products are introduced, standardized protocols should be developed for their use, and systematic surveillance should be done to monitor for potential adverse outcomes.

To examine risk factors for, and determine the incidence of, device-associated infections among patients with an implantable vascular access device.

Grady Health System, including a 1,000-bed, inner-city, public, teaching hospital and human immunodeficiency virus (HIV), oncology, and sickle cell clinics in Atlanta, Georgia.

123 consecutive patients who received a PASPort implantable venous access device between January 1 and June 30, 1995.

Retrospective cohort study with follow-up ≥1 year following device implantation.

Underlying illnesses included HIV infection in 66 patients (median CD4 count, 24.4 cells/mm3), malignancy in 51, and sickle cell disease in 6. Mean age of patients was 43.7 years, 50% were male, and 74% were black. Thirty-one (25%) of 123 patients developed a primary or device-associated bloodstream infection (BSI), and 3 of the 31 patients experienced two separate episodes of infection. The overall rate of infection was 1.23 primary BSIs per 1,000 device days. Patients with cancer had a lower rate of infection than those with HIV infection, but the difference was not statistically significant (0.96 vs 1.50 BSIs/1,000 device days; relative risk, 0.58; 95% confidence interval, 0.27-1.26). Subgroup analysis of patients with different malignancies indicated that infection rates differed according to type of cancer, and there was a trend for heterogeneity across the different cancer strata (P=.06). Gram-positive pathogens accounted for 60% of the pathogens recovered. Six (19%) of 31 patients who developed an infection did so within the first 14 days after implantation. In 11 (32%) of the 34 BSIs, the port required removal; two patient deaths were attributed to device-associated bacteremias (0.072 deaths/ 1,000 device days).

Approximately one fourth of patients who had a vascular access device implanted developed a primary BSI, but the overall infection rate (per 1,000 device days) was relatively low, even among those with HIV infection. Primary BSI rates in patients with vascular access devices appeared to differ according to the specific underlying illness.

To investigate the contamination of a vitrectomy apparatus with Serratia marcescens.

Descriptive microbiological and molecular environmental study.

An 1,800-bed university hospital.

S marcescens was found inside the vitrectomy apparatus at the pressure transducer. Molecular typing by randomly amplified polymorphic DNA-automated laser flourescence analysis and pulsed-field gel electrophoresis identified a single pattern for all strains isolated from the apparatus. Surprisingly, the contaminating strain was identical to two strains of S marcescens isolated nearly 2 years earlier from two patients who were involved in a small outbreak of acute postoperative endophthalmitis following cataract surgery at another hospital. The emergency vitrectomies in these patients were performed at our hospital with the same apparatus that was found to be contaminated 2 years later.

Performing a systematic environmental search for the assumed bacterial reservoir within the system of the vitrectomy apparatus finally made it possible to find and eliminate the nidus for the gram-negative rod. Molecular typing demonstrated that all isolates belonged to a single genotype, and revealed unexpectedly a link to two vitrectomies performed 2 years earlier. The data support the hypothesis that the source of the contamination was one of these patients, and thus contamination of the apparatus was present for almost 2 years.

To assess the performance of the Study of the Efficacy of Nosocomial Infection Control (SENIC) risk index for the evaluation of the risk of surgical-site infection (SSI) in a country other than the United States, having a different health system.

350-bed university hospital in Spain belonging to the National Health System (Insalud).

Observational cohort study of 1,019 patients who underwent consecutive surgery from January to December 1992. Surgical-infection risk factors assessed by the traditional wound-classification system (clean, clean-contaminated, contaminated, and dirty-infected wound) and by the SENIC risk index (length of intervention more than 2 hours, more than three discharge diagnoses, abdominal surgery, and contaminated or dirty-infected wound) were compared by forward logistic regression.

The SENIC risk index showed a greater ability to predict SSI than the traditional wound-classification system. The study carried out in our institution reproduced the estimators provided by the SENIC study in the United States. The SENIC risk index provided a stepwise increase in SSI rates, according to the number of factors present, for every traditional wound-classification group. In the case of clean wounds, the incidence of surgical infection (per 100 interventions) increased (1.5, 2.4, 5.3, and 50; P<.001) for patients having from zero to three risk factors of the SENIC risk index.

This study shows that the SENIC risk index results are reproducible, and the index can be used to compare rates of wound infection across countries with different health systems than the United States.