To assess the potential for nosocomial spread of parvovirus B19 from a chronically infected patient.

Employees exposed to the index case and control (unexposed) employees were evaluated by baseline and follow up parvovirus B19 serologies and hematologic assessments, and completed baseline and follow up epidemiologic questionnaires.

A chronically infected patient was hospitalized on a hematology ward in a research referral hospital for 3.5 weeks prior to a diagnosis of parvovirus B19 infection and the institution of isolation precautions.

Sera were screened for parvovirus B19 DNA (dot blot analysis), and IgG and IgM anti-B19 antibodies (capture immunoassay). Hematologic assessment included CBC, differential, and reticulocyte count.

The index case had parvovirus B19 DNA at approximately lo6 genome copies per ml of serum, elevated IgM and low levels of IgG B19 antibodies. Of the 21 exposed staff, 11 (52%) had IgG B19 antibodies and were immune; of the 8 unexposed staff, 6 (75%) had IgG B19 antibodies. No employees developed IgM B19 antibodies, B19 DNA, hematologic abnormalities, or clinical symptoms.

In contrast to reports of documented nosocomial transmission of B19 parvovirus from patients in transient aplastic crisis, nosocomial transmission did not occur-even in the absence of isolation precautions-presumably from the lower level of B19 viremia in our chronically infected (rather than acutely infected) patient.

Analyze changes that have occurred among U.S. hospitals over a 17-year period, 1975 through 1991, in the percentage of Staphylococcus aureus resistant to b-lactam antibiotics and associated with nosocomial infections.

Retrospective review. The percentage of methicillin-resistant S aureus (MRSA) was defined as the number of S aureus isolates resistant to either methicillin, oxacillin, or nafcillin divided by the total number of S aureus isolates for which methicillin, oxacillin, or nafcillin susceptibility test results were reported to the National Nosocomial Infections Surveillance (NNIS) System.

NNIS System hospitals.

Of the 66,132 S aureus isolates that were tested for susceptibility to methicillin, oxacillin, or nafcillin during 1975 through 1991, 6,986 (11%) were resistant to methicillin, oxacillin, or nafcillin. The percentage MRSA among all hospitals rose from 2.4% in 1975 to 29% in 1991, but the rate of increase differed significantly among 3 bed-size categories: <200 beds, 200 to 499 beds, and 2500 beds. In 1991, for hospitals with <200 beds, 14.9% of S aureus isolates were MRSA, for hospitals with 200 to 499 beds, 20.3% were MRSA; and for hospitals with >500 beds, 38.3% were MRSA. The percentage MRSA in each of the bed-size categories rose above 5% at different times: in 1983, for hospitals with 2500 beds; in 1985, for hospitals with 200 to 499 beds; and in 1987, for hospitals with <200 beds.

This study suggests that hospitals of all sizes are facing the problem of MRSA, the problem appears to be increasing regardless of hospital size, and control measures advocated for MRSA appear to require re-evaluation. Further study of MRSA in hospitals would benefit our understanding of this costly pathogen.

Gloves containing chlorhexidine gluconate in an instant-release matrix on their inner surface (CHG gloves) were tested to determine their ability to rapidly inactivate infectious pathogens that may permeate or leak through the latex surface.

CHG gloves were exposed for 1 to 10 minutes to blood or media containing infectious pathogens (e.g., bacteria, fungi, parasites, and viruses) as well as to lymphocytes and macrophages that are known to be the primary carriers of human immunodeficiency virus (HIV). Inactivation of pathogens was determined either by in vitro assay or in vivo infectivity. Stressed control and CHG glove fingers were submerged in a viral pool (retrovirus or bacteriophage) and after a set time, the glove interiors were checked for presence of permeated viz-ions.

CHG gloves rapidly inactivate all the pathogens tested including retrovirus and hepatitis B virus (90% to 100%). In the stressed glove fingers, live virus was detected in 26% of the control group but not in any of the CHG group.

The use of CHG gloves may reduce the risk of exposure to infectious fluidborne pathogens should the integrity of the latex barrier be compromised by overt failure or by permeation of viruses. Rapid destruction of lymphocytes and macrophages may facilitate inactivation of HIV associated with these cells. Tests have shown that CHG coating does not alter physical properties of the glove, and, furthermore, CHG gloves do not show potential for dermal irritation or sensitization.

To study the epidemiology of Yersinia enterocolitica infections in hospitalized patients and to determine the frequency of hospital-acquired infection and the modes of transmission within the hospital.

Descriptive study in which the clinical microbiology laboratory reported all positive Yersinia cultures to the infection control department; each case was investigated to determine the source of infection.

A 700-bed university teaching hospital.

All patients who were culture-positive for Y enterocolitica after admission to the University of Cincinnati Hospital during the 4-year period between 1987 and 1990.

Of 18 patients who were diagnosed with Yersinia infections, 8 (44%) were community-acquired. These patients were admitted with gastrointestinal symptoms and had their first positive cultures between days 1 and 5 of their hospitalizations. Five patients (28%) had hospital-acquired infections, having developed diarrhea after admission for unrelated problems, and became culture-positive between days 18 and 66. The remaining 5 patients could not be classified as either community- or hospital-acquired. These patients had gastrointestinal symptoms at the time of admission, but these could have been explained by other diseases. Their first positive stool cultures were not obtained until the second week or later during hospitalization, and 3 of these patients had negative stool cultures prior to a positive culture.

Although Y enterocolitica has not previously been recognized as a common hospital problem, at least 28% of our patients acquired their Yersinia infections in the hospital. In some cases, cross infections, transmitted by healthcare workers, occurred between patients. Four of the 18 infections occurred in patients with acquired immunodeficiency syndrome.

To investigate a cluster of postoperative bleeding following open heart surgery.

A cohort and case/control study.

Palo Alto Veterans Administration Medical Center, Palo Alto, California.

Six (21.4%) of 28 patients undergoing open heart surgery who developed severe, nonsurgical, postoperative bleeding from July 1 through August 30, 1988 (outbreak period). All case-patients had chest tube drainage of > 1000 ml within 4 hours of surgery but did not have identifiable bleeding vessel(s) on exploration.

Upon comparison of the pre-outbreak (January 1986 through June 1988) and the outbreak period, a significant increase was found in the incidence of postoperative nonsurgical bleeding (5/440 versus 6/28, p = .0006), but not of postoperative surgical bleeding (8/440 versus 0/28, p = 1 .0). Of all patients undergoing open heart surgery during the outbreak period, case patients were found to be older (67.8 versus 60.6, p= .02) and to have received a larger volume of hetastarch (HES), a synthetic colloidal plasma-volume expander (mean = 19.4 ml/kg versus 14.1 ml/kg, p= .02).

We conclude that the use of large volumes of HES during surgery in the elderly open heart surgery patient may increase the risk for severe, nonsurgical postoperative bleeding, probably caused by alterations of the coagulation system. As the incidence of open heart surgery increases among the elderly, surgeons and anesthesiologists should be alert to possible adverse reactions from exposures not associated with adverse reactions in younger patients.

To determine the impact of catheter management on the acute and long-term outcome of catheter-related coagulase-negative staphylococcal bacteremia.

Retrospective surveillance of catheter-related sepsis using quantitative blood and catheter cultures.

University-affiliated tertiary cancer center.

seventy patients with catheter-related coagulase-negative staphylococcal bacteremia were studied by retrospective chart review. The clinical characteristics of the patients and the management of the bacteremias were determined. The impact of immuno-suppressive risk factors, antibiotic therapy, and catheter management on the recurrence of the bacteremia was investigated.

Acute sepsis-related morbidity and mortality were not related to catheter management. However, during a 12-week followup period, the bacteremia recurred in 20% of the patients whose catheters remained in place, compared with only 3% of those whose catheters were removed (p<.05). By multivariate analysis, patients whose catheters remained in place were 2.9 times more likely to experience a recurrence than those whose catheters were removed (odds ratio = 2.9, 95% confidence interval = 1.2-8.8, p= .03). All other potential risk factors were equally distributed between patients, with and without a recurrence.

Although patients with catheter-related coagulase-negative staphylococcal bacteremia could be treated successfully while the catheter remains in place with the majority remaining free of recurrence, catheter retention results in a significantly higher risk for the recurrence of the bacteremia.

Determine the epidemiology and risk factors for colonization with vancomycin-resistant Enterococcus faecium.

Survey; case-control study.

Children's hospital.

Pediatric oncology patients.

Contact isolation, restriction of vancomycin prescribing.

There was a high prevalence of colonization with vancomycin-resistant enterococci among pediatric oncology patients. The length of hospitalization and the administration of vancomycin and other intravenous antibiotics was associated with colonization. Prevention of colonization was associated with restriction of vancomycin use and contact isolation.

Vancomycin use may predispose to colonization with vancomycin-resistant E faecium. Vancomycin-resistant E faecium may be nosocomially spread. Contact isolation and restriction of vancomycin use may prevent spread of vancomycin-resistant E faecium.

To compare the frequency of the pathogens of nosocomial pneumonia in a community-based teaching hospital to the frequencies previously published, and to evaluate recommendations for the therapy of nosocomial pneumonia in this setting.

Retrospective review of prospectively acquired data accrued during 9 randomized single-blinded and 4 single-agent investigational antibiotic studies for the therapy of pneumonia in hospitalized patients between 1981 and 1989.

The study was performed at a university affiliated, community-based teaching Department of Veterans Affairs Medical Center.

Patients were hospitalized on the acute medical/surgical and intermediate medicine wards. Informed consent was obtained prior to enrolling patients into the respective antimicrobial studies. Pneumonia was documented radiographicahy and clinically for each patient.

Two hundred thirty-one episodes of nosocomial pneumonia were treated. Overall, 51% of pneumonias were caused by Streptococcus pneumoniae or Hemophilus influenzae with or without other organisms that were not gram-negative bacilli. Gram-negative bacilli, with or without other organisms, accounted for only 26% of all nosocomial pneumonias. Overall, monotherapy with a cephalosporin (usually a broad-spectrum agent) was equally efficacious compared with combination therapy (87% versus 81%, respectively). Cure rates for nosocomial pneumonias from gram-negative bacilli treated with these 2 therapies also were similar (70% versus 60%, respectively).

In nontertiary care settings, gram-negative bacilli may cause fewer episodes of nosocomial pneumonia (26% in this study) than noted by previously published reports, which indicated that these organisms account for 50% of nosocomial pneumonias. Further, S pneumoniae and H influenzae may account etiologicahy for many of these nosocomial pneumonias. Monotherapy with an extended-spectrum cephalosporin may be more appropriate than combined treatment with a b-lactam and an aminoglycoside in a nontertiary care setting, thereby reducing potential toxicity in an older, hospitalized patient population.

To compare the clinical virulence of nosocomially acquired methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S aureus (MSSA) infections in 1989.

A retrospective comparison of host factors, in-hospital exposures, sites of infections, and outcomes of patients with nosocomial MRSA and MSSA infections.

University of Illinois Hospital, Chicago, Illinois.

Forty-four adult patients with nosocomial S aureus infections.

The 22 MRSA-infected and 22 MSSA-infected persons were similar regarding mean age, gender, underlying diseases, and exposure to surgery. Before developing infection, MRSA-infected persons were more likely to have received antibiotics (73% compared with 27%, odds ratio = 7.1, 95% confidence interval [CI95] = 2.0-25.8 p = .003) and to have stayed in the hospital >2 weeks (64% compared with 18%, odds ratio = 7.9, CI95 = 2.0-31.6, p = .002). Bacteremia was the most common presentation in the MRSA and MSSA groups (55% and 59%, respectively). Infectious complications and death were infrequent in both groups.

MRSA and MSSA strains infect patients with similar demographic features and underlying diseases, but MRSA infections are significantly more common among patients with previous antibiotic therapy and a prolonged preinfection hospital stay. Clinical presentations and outcomes did not differ significantly between the 2 groups. Thus, similar to studies in the early 1980s, our findings do not suggest greater intrinsic virulence of MRSA.

To investigate an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) among patients using chromosomal typing of the isolates.

Comparison of epidemiological and clinical data to endonuclease restriction fragmentation analysis (RFA) of the MRSA isolates associated with an outbreak. Total DNA from the MRSA isolates was restricted with HINDIII and HAEIII for typing.

Tertiary care academic medical center.

An epidemiological investigation of an outbreak of MRSA among patients in private rooms was evaluated by routine infection control methods. The MRSA isolates from blood cultures of 7 patients and the nares of a nurse were collected during the outbreak. MRSA isolates from 23 patients not associated with the outbreak also were collected. The total DNA of the MRSA isolates were restricted with HINDIII and HAEIII and electrophoresed on 0.6% agarose gels.

MRSA from 4 of the 7 bacteremic patients and the nurse on the outbreak unit had the same endonuclease restriction pattern. The patients were linked in that they were compromised by severe psoriasis or skin ulcers, were on the unit during the same period, and had oatmeal baths in a common bathtub. Of 50 staff members screened, the nurse was the only person detected as colonized by the strain. The other 3 patients on the unit as well as the 23 patients in other locations not associated with the outbreak had MRSA isolates with different RFA patterns. The use of the bathtub was discontinued and further transmission of MRSA was stopped.

A comparison of the relatedness of MRSA by RFA demonstrated the uniqueness of the epidemiologically linked isolates and the utility of the RFA technique in the performance of routine infection control investigations.

Evaluate the impact of a shielded 3 cc safety syringe on needlestick injuries among healthcare workers.

Surveillance study.

Three medical centers.

The total number of needlesticks from all sources rose from 134 during the baseline period to 140 during the study phase. However, the overall rate of needlesticks involving 3 cc syringes decreased from 14/100,000 inventory units to 2/100,000, and the frequency declined substantially at each of the participating medical centers.

These results suggest that shielded syringes and related technology may offer potential for reducing the risk of needlestick injuries among hospital and other healthcare employees. This study should be viewed as a preliminary effort to assess the potential of shielded-syringe technology for reducing the risk of needlestick injuries among healthcare workers. The results are encouraging, but more clinical experience with this new device and longer follow up are essential to provide the data necessary for a definitive assessment of efficacy.

To determine if the spread of Clostridium difficile-associated diarrhea is related to the use of electronic thermometers in an acute hospital and a chronic healthcare facility.

After finding that a significant percentage (20.8%) of electronic rectal thermometer handles were contaminated with C difficile, all electronic thermometers were replaced with disposables. A before/after trial was conducted to determine if the change to disposable thermometers would reduce the incidence of C difficile-associated diarrhea.

The study took place in a 343-bed acute hospital and a 538-bed skilled nursing facility.

All patients who underwent routine microbiological evaluation for nosocomially acquired diarrhea over a l-year period were included in the study. Nosocomial diarrhea was defined as 3 or more loose stools per day for 2 consecutive days and/or abdominal findings such as pain, distention, and ileus occurring 3 or more days after admission.

During the 6-month postintervention period, the incidence of C difficile-associated diarrhea was reduced from 2.71/ 1,000 patient days to 1.76/ 1,000 patient days in the acute hospital and from 0.41/1,000 patient days to 0.1 1/1,000 patient days in the skilled nursing facility The protective effect of the intervention was statistically significant for both facilities.

Replacement of electronic thermometers with single-use disposables significantly reduced the incidence of C difficile-associated diarrhea in both acute care and skilled nursing care facilities. Data suggest that the rectal route may be important in the transmission of C difficile in these settings.

To elucidate the epidemiology of widespread ciprofloxacin resistance in our Veterans Affairs medical center using whole cell DNA analysis.

In vitro study of ciprofloxacin resistant and susceptible Enterobacteriaceae isolated during the course of a clinical epidemiologic study of quinolone resistance.

Veterans Affairs Medical Center with acute care and long-term care divisions.

We examined 40 ciprofloxacin-resistant strains of Serratia marcescens, Proteus mirabilis, and Providencia stuartii using restriction endonuclease analysis of whole cell DNA and compared them with concomitantly isolated ciprofloxacin sensitive strains. We sought to determine whether resistant strains were identical to susceptible strains, indicating in vivo emergence of resistant strains from susceptible strains, and whether resistant strains were shared among patients. All 26 ciprofloxacin-resistant S marcestens isolates shared a single ecoRI restriction pattern. Multiple patterns were seen in the ciprofloxacin-susceptible S marcescens isolates; however, several isolates had a pattern matching that of the resistant isolates. Similar results were seen among the P mirabilis isolates. Three different ecoRI patterns were found among the ciprofloxacin-resistant P stuartii isolates; none matched those found among the susceptible isolates. The frequency of spontaneous emergence of ciprofloxacin resistance in susceptible S marcescens strains with restriction pattern matching that of the resistant strains was significantly higher than that of nonmatching strains.

Ciprofloxacin-resistant strains of Enterobacteriaceae became widespread within a short period of time. Resistant strains of S marcestens and P mirabilis arose from endemic susceptible strains. The resistant strain of S marcescens appeared to arise from a susceptible strain with a relatively high frequency of spontaneous ciprofloxacin resistance.