In many hospitals, waste materials and used linens from the rooms of patients in isolation or the clinical laboratories are routinely double-bagged to reduce contamination of the external surface of the bag that could be transmitted to hospital personnel subsequently handling them. No studies have prospectively examined the value, if any, of double-bagging. We randomly assigned waste and linens from the rooms of 42 patients in contact isolation to be transported in single bags or double bags. Shortly after a single (or double) bag had been set outside the patient's room, the surface was cultured quantitatively in two locations near the knot; over 2 months, 209 bags were cultured. Surface contamination by Staphylococcus aureus (3% to 5%), enteric gram-negative bacilli (6% to 7%), or either (9% to 12%) was infrequent and comparable in both groups; moreover, quantitative levels of contamination in the two groups were almost identical (mean, 27 and 29 colony forming units [cfu] per bag). These data suggest that there is no advantage, as regards asepsis, to double-bagging potentially contaminated items from isolation rooms or clinical laboratories as compared with using a single bag. The use of a single-bag system with a heavyduty bag, as compared with double-bagging, saved our hospital $9,400 in 1985.

A prevalence study was carried out on a 100-bed Veterans Administration nursing home care unit to determine the extent of colonization with gentamicin-resistant gram-negative bacilli (GRGNB). Hand cultures of 12 employees and 17 environmental cultures were negative. Twenty-six of 86 (30%) patients were colonized with 49 GRGNB. Sixteen patients (19%) had urinary colonization. Multivariate analysis revealed significant associations between rectal or perineal colonization (P<0.01), and the presence of a urinary device (82% condom catheters) (P<0.05), with urinary colonization. The most common isolates were Providencia stuartii (20), Escherichia coli (nine) and Klebsiella pneumoniae (nine). Twenty-six of 49 isolates carried plasmids. Restriction endonuclease digestion of plasmid DNA was performed for 21. Cross-colonization, as defined by the presence of the identical species with the identical restriction endonuclease digestion profile of purified plasmid DNA found in different patients, was observed for eight of 21 (38%) strains. All were geographically clustered. No strains could transfer gentamicin-resistance by conjugation and only two plasmids could transform our E coli recipient to gentamicin resistance. One E coli plasmid was identical to two Citrobacter freundii plasmids and a P stuartii plasmid isolated from three different patients. This 105 kb plasmid is conjugative and encodes resistance to ampicillin, carbenicillin, tetracycline, and sulfonamides. Thus, 57% of strains were cross-colonizing or contained identical R-plasmids. Southern hybridization using a 1 kb TEM-1 gene probe demonstrated sequences homologous to this probe in five of five nursing home plasmids examined. These data demonstrate the utility of plasmid analysis in epidemiologic typing of multiple species of Enterobacteriaceae, and suggest wide dissemination of R-plasmids bearing the TEM-1β-lactamase gene among gram-negative bacilli colonizing patients residing in our nursing home.

Review of all hepatitis B surface antigen-positive patients reported to the county health department over the past 3 years showed that 60% of patients had been diagnosed at our hospital, which serves an inner city, predominantly black, indigent population. Sera from 524 adult patients admitted to the hospital were prospectively collected and tested for hepatitis B surface antigen, eight (1.5%) of which were antigen-positive. Census tract data allowed us to perform selective screening of sera from 95 other patients who were subsequently hospitalized and deemed “high risk” for hepatitis B infection. Nine of 95 (9.5%) selectively screened samples were positive for hepatitis B surface antigen, which represented a significantly higher rate of antigen carriage (P<0.0001) in hospitalized patients from “high risk” areas than that found in the general population screen. The methodology presented herein may be useful in providing a means of identifying hepatitis B surface antigen-positive patients from adult, urban, indigent care populations.

Over a 7-year period (1978-1984) the authors studied the rates of nosocomial bloodstream infections in acute-care hospitals participating in a statewide surveillance network in Virginia. A total of 4,617 hospital-acquired bloodstream infections were documented among 1,807,989 patients at risk for an overall rate of 25.5 cases per 10,000 patient admissions/discharges (annual range = 22.1 to 30.7). Compliance of reporting for Virginia hospitals averaged 58% (1 to 5 monthly reports in a study year), and 39% (≥6 monthly reports annually). Significant changes in bloodstream infection rates (cases per 10,000 patient admissions/discharges) due to specific pathogens included the following: coagulase-negative staphylococci increased from a rate of 1.3 to 4.5 (P=.0003), and those due to all gram-positive cocci increased from a rate of 7.5 to 11.4 (P=.03). Candida species increased from a rate of 0.1 to 1.5 (P=.005). The data show a continuing rise of nosocomial Candida BSI and clearly document the re-emergence of gram-positive cocci as major nosocomial bloodstream pathogens.

Hepatitis risk in a small suburban hospital was evaluated by laboratory screening of all hospital employees for hepatitis immunologic markers. Excluding four U.S.-born subjects who had received hepatitis vaccination, the laboratory screening revealed 21% of those tested had some hepatitis B antigen or antibody. Positive markers were found in 46% of foreign-born compared to 10% of native-born (P<0.001). Foreign-born participants accounted for 68% of the employee population. The country of origin appeared to have a statistically significant greater importance as a determinant of hepatitis B status than occupational area in this particular hospital setting.

Microbiologists traditionally have relied on biochemical and serologic tests to identify only group A, group B, and group D streptococci isolated from patients with serious infections. Until recently there has been little interest in the further classification of other streptococci isolated from clinical specimens.

In 1956, Guthof repeatedly isolated a particular streptococcus from dental abscesses and named the organism Streptococcus milleri in honor of the microbiologist, W.D. Miller. In 1976, Parker and Ball associated this microorganism with other pyogenic infections and later described the characteristics of 346 strains. The Streptococcus milleri group is now recognized as both virulent and invasive and some believe it is responsible for more suppurative infections than any other group of streptococci. Physicians need to consider the unique ability of these bacteria to form abscesses in a wide range of tissue. Microbiology laboratories, therefore, need to develop schemes to identify this important group of streptococci.

Currently available connectors for IV lines are not well protected against contamination. This also pertains to urinary and peritoneal catheters, as well as any other infusion or drainage system. The male portions of the connectors are particularly vulnerable to accidental contact with the environment, eg, the fingers of caretakers or the patient himself under the conditions of home therapy. Contamination of catheter hubs is well-documented and has recently been implicated as a cause of nosocomial infections with Malassezia furfur in neonates.