Comparison of methods for calculation and depiction of incidence infection rates in long-term care facilities.

Assessment of changes in endemic infections in health care facilities are often based on comparison of infection rates over time. This study compared two methods for calculating and depicting infection data at a hospital-based nursing home care unit. Prospective incidence surveillance of nursing home acquired infections was conducted over a 12-month period, during which time denominator information on census and patient care days was also collected. Monthly infection rates were calculated based on (a) census (number infections per month/average monthly census), and (b) care duration (number infections per month/average monthly resident stay days). Results showed average monthly infection incidence of 27.4 episodes, (range 19-37), with average monthly census of 166.2 (range 160.0-180.0) and average monthly patient days of 5056 (range 4631-5583). The average census based monthly infection rate was 16.5 (range 11.9-22.4); average care duration based monthly infection rate was 5.4 (range 3.8-7.2) episodes per 1000 patient care days. Results indicate care duration based rates demonstrate less marked rate fluctuation than census based findings, and that duration based rates are more similar to values observed in acute care hospital nosocomial infection rates, thus are less likely to be misunderstood or misinterpreted by staff. Institutions should consider analyzing their methods for depicting infection data to provide consistency and clarity in data reporting.

Documentation and evaluation of fevers in hospital-based and community-based nursing homes.

We reviewed clinical evaluation practices and documentation of fever (greater than or equal to 100.2 degrees F) in all febrile patients over a two-month period in a hospital-based nursing home (HBNH) compared with a community-based nursing home (CBNH). Results showed 38 febrile (mean 101.9 degrees F) HBNH patients and 26 febrile (mean 101.5 degrees F) CBNH patients. Median time from fever onset to physician contact was 4 hours in HBNH and 12.5 hours in CBNH episodes (P less than 0.01). Laboratory studies were initially performed in 68% of HBNH and 31% of CBNH episodes (P less than 0.005), and diagnosis of fever source was documented in 76% of HBNH and 16% of CBNH episodes (P less than 0.005). Overall assessment stratification showed 81% febrile HBNH patients had both evaluation and therapy performed compared with 38% in CBNH (P less than 0.0001); 39% of febrile CBNH patients had no evaluation or therapy performed. Results indicate lack of documentation, and fever evaluation in CBNHs may preclude complete detection of nursing home-acquired infections and thereby hamper preventive responses to potential infection problems.

Prevalence survey of infections and their predisposing factors at a hospital-based nursing home care unit.

A prevalence survey was performed at a Veterans Administration nursing home care unit to detect the frequency, demographics, features, and potential risk factors associated with infections, compare different methods for calculating infection rates, and compare prevalence data with routine physician reporting of infections during a one-month period. In 176 evaluable residents, 22 nursing home-acquired infections were detected, with rates of 12.5% by infections per residents at risk, and 4.6% by infections per 1000 resident-days. Fifty percent of these infections (11 of 22) involved the urinary tract, seven of which were associated with indwelling catheters. Factors potentially associated with increased overall infection rates included immobility (P less than .02), acute-care hospitalization in the 28 days preceding the study (P less than .01) and antibiotics given preceding the infection (P less than .001). An indwelling urinary catheter (P less than .01) potentially was associated with an increased urinary tract infection rate. During the concurrent period, routine physician reporting of infection detected four of the 22 infections (18%) that were identified by the survey. These findings suggest that physician reporting of infection underestimates infection risk as compared with conventional surveillance practices, and that hospital-based care units may have infection problems more similar to acute-care hospitals than to community nursing homes. Identification of potential risk factors is critical in planning preventive practices based on institution-specific needs.

Survey of nursing personnel attitudes toward infections and their control in the elderly.

To better understand nursing practice in geriatric care settings as it relates to infections, a survey of nursing attitudes about a variety of infection control issues was undertaken. Nurses were recruited from four settings: a university-affiliated, private nursing home (N = 46), a hospital-based nursing home (N = 33), a private nursing home (N = 20), and a home care agency (N = 26). The nurses appropriately recognized the importance of pneumonia and influenza as major threats to health in these settings and also reported some indifference regarding the notification of physicians about fevers under 38.9 degrees C (102.0 degrees F). Among the groups, similar attitudes about infection control principles were recorded, except that the ratings by the home care agency nurses were different from those of the institution-based nurses in the following areas: isolation as a means to prevent infection spread, proper waste disposal methods, and frequency of catheter change. Assessment of personnel attitudes and practices are important in detecting problems, guiding in-service programing, and revising care practices.

Cyclosporine therapy and refractory Pneumocystis carinii pneumonia. A potential association.

In surveillance of 75 patients receiving renal transplants in 1984 at our institution, five cases of Pneumocystis carinii pneumonia were detected. All five cases occurred in a subgroup of 11 patients who had received cyclosporine. A retrospective epidemiologic survey of the infected patients revealed all five were heterosexual white men with onset of Pneumocystis pneumonia two to six months after cadaveric transplantation. All received cyclosporine and corticosteroids, and four of five patients also received azathioprine; none was neutropenic or had evidence of concurrent cytomegalovirus infection. Only one of these patients responded to therapy with sulfamethoxazole and trimethoprim, one patient responded to pentamidine therapy, and the remaining three patients died. Cyclosporine use may be related to development of Pneumocystis infections that are refractory to conventional antiprotozoal therapy, and transplantation programs should closely survey patients for such complications.

A quality control analysis of aminoglycoside management.

Aminoglycoside administration practices were evaluated in a teaching hospital using three study methods: a chart review of 40 randomly selected patients receiving aminoglycosides was conducted retrospectively; 93 health care personnel involved in ordering and administering aminoglycosides to patients were interviewed regarding their understanding of aminoglycoside utilization practices; and ten patients having serum peak and trough aminoglycoside determinations were closely monitored for accuracy of dose administration and obtaining blood specimens at appropriate times. The chart review showed that during 15 of 32 evaluable therapy courses no determinations of serum aminoglycoside concentration were obtained. The survey demonstrated that only 24% of the residents actually used the results of peak and trough determinations to adjust dosage regimens. Direct observation of health care personnel disclosed only two of ten instances in which doses were administered and serum concentration specimens obtained with no apparent problems. Most personnel in our hospital were unaware of these pervasive suboptimal or inconsistent practices associated with aminoglycoside administration and interpretation of laboratory results.

Late-onset, warfarin-caused necrosis occurring in a patient with infectious mononucleosis.

A 25-year-old man with Klinefelter's syndrome and recurrent thromboplebitis , for which he had been receiving long-term warfarin sodium therapy, had bilateral ecchymoses on the hips coincident with serologically confirmed Epstein-Barr virus-caused mononucleosis. Biopsy specimens taken from the hip lesions showed microscopic findings consistent with a diagnosis of warfarin necrosis. Direct immunofluorescence microscopy disclosed vessel-wall deposition of IgM and heavy upper-dermal deposition of IgG. Electron microscopy disclosed nonspecific endothelial cell blebs that projected into the vessel lumen. The temporal association of mononucleosis with the onset of warfarin necrosis suggests that the viral illness may have precipitated an immunologic endothelial surface reaction, leading to thrombosis and secondary hemorrhage with infarction. To our knowledge, the appearance of warfarin necrosis in a patient receiving long-term, stable anticoagulation therapy has not been previously reported.

Clinical economics: a method for prospective health resource data collection.

Information about the economic benefit of new drugs is becoming increasingly important for formulary considerations, reimbursement policies and related considerations. Although economic benefits of drugs have been analysed and reported, the economic benefits of drugs have rarely been examined in the course of randomised therapeutic trials. We designed a modular survey instrument, the Resource Utilisation Survey (RUS), to collect economic outcomes in prospective trials. A pilot test of the RUS was conducted using clinical trial methods in a study of nizatidine versus placebo in preventing ulcers induced by nonsteroidal anti-inflammatory drugs. The purpose of the pilot study was to evaluate the RUS instrument and corresponding study design issues in clinical trials for either acute or chronic diseases. With the lessons learned from the pilot study, the RUS has been used successfully in other ongoing clinical trials.

Aminoglycoside serum concentration sampling via central venous catheters: a potential source of clinical error.

Two patients receiving aminoglycosides via central venous Silastic catheters were noted to have serum drug concentrations markedly divergent from expected results. Study of these patients, and of four additional patients prospectively selected for study, demonstrated that three of five patients had higher peak and/or trough aminoglycoside serum concentrations--when blood was obtained from the central venous catheter--than were contained in simultaneous samples from peripheral blood; these divergent results were noted after the catheter had been in use for more than 1 week; divergent results were not improved by additional catheter flushing prior to central venous blood sampling. These observations suggest that spurious aminoglycoside serum concentration results may sometimes be obtained when blood sampling is performed from central venous Silastic catheters, and can result in improper drug dosage alterations. It is necessary to access the timing, processing, and reliability of serum drug-monitoring practices on a routine basis to preclude such problems, and to reassess individual patient-monitoring studies which are inconsistent with anticipated results.

Serial bilirubin determinations as a prognostic marker in clinical infections.

Patients with documented serious infection and total bilirubin values of greater than 2 mg/dl were surveyed for serial changes in bilirubin and other laboratory and clinical features. Of 19 patients studied, 12 (Group A) had persisting or increasing hyperbilirubinemia, and 7 (Group B) had decline in bilirubin after infection onset. None demonstrated marked changes in other liver tests. Only one patient had infection directly involving the hepatobiliary system. There were no significant differences between the two groups with respect to underlying illnesses, active hepatobiliary diseases, pathogens, bacteremia, or administration of cholestatic drugs. All Group A patients died because of uncontrolled infections, whereas all Group B patients survived with resolution of infection (p less than .001). Ten of 15 patients with available preinfection liver tests demonstrated serial bilirubin increases without marked changes in other liver tests prior to clinical recognition of infection. These findings demonstrate that hyperbilirubinemia disproportionate to increases in other tests may manifest before recognition of infection and that persistent or progressive hyperbilirubinemia is indicative of ongoing active infection.

Has the FDA Amendments Act of 2007 impaired drug development?

Perched at the midpoint of "v.4" of the Prescription Drug User Fee Act (PDUFA-4), better known as the US Food and Drug Administration Amendments Act (FDAAA), it seems presumptuous to draw critical conclusions based on an "interim analysis" of this work in progress. Because drug development is a complex process measured in decades, one must rely on "surrogate markers" to impute FDAAA outcomes. Even so, there are many indications that the FDAAA has doused the fires of innovation, in scope, spirit, and interim results.

Survival of enteric pathogens in common beverages: an in vitro study.

This in vitro study was undertaken to determine the potential for survival of enteric pathogens in common drinking beverages. Three carbonated soft drinks, two alcoholic beverages, skim milk, and water were inoculated with Salmonella, Shigella, and enterotoxigenic Escherichia coli, and quantitative counts were performed over 2 days. Our studies showed poorest survival of all three organisms in wine, and greatest growth in milk and water. Beer and cola allowed survival of small numbers of Salmonella and E. coli at 48 h, whereas sour mix and diet cola were sterile by 48 h. Survival features may correlate with pH of the beverages. These observations may be useful in guiding travellers for appropriate beverage consumption while visiting areas endemic for "traveller's diarrhea."

Frequency and characteristics of hyperbilirubinemia associated with bacteremia.

One hundred consecutive patients with blood cultures positive for microbial growth were prospectively surveyed for the presence of hepatic abnormalities and clinical evidence of infection. Complete data for 82 patients were available for analysis. Fifty-four percent had elevated bilirubin levels, and 34% had total bilirubin values of greater than or equal to 2.0 mg/dl. The levels of total bilirubin were disproportionately elevated compared with those of aspartate aminotransferase, alkaline phosphatase, and cholesterol. Nine of the 23 patients with elevated bilirubin levels had an increase in serum bilirubin one to nine days before their initial positive blood culture. Disproportionate elevations of direct and total serum bilirubin values compared with values for other liver-function tests appear to be associated with bacteremia in adults more frequently than previously recognized and may have some predictive value in such patients.

Evaluation of new anti-infective drugs for the treatment of vascular access device-associated bacteremia and fungemia. The European Working Party of the European Society of Clinical Microbiology and Infectious Diseases.

For clinical trials of anti-infective drugs for the treatment of vascular access device-related bloodstream infections, patients should be identified and enrolled on the basis of current standards for the clinical diagnosis of such infections. To ensure comparability of patients, only those infected with staphylococci and Candida species should be included. A prospective, randomized, double-blind design is recommended. Future protocols may include abbreviated courses of therapy, treatment with combinations of drugs, or a progression from parenteral to oral therapy. Clinical response is judged as cure, failure, or indeterminate response; there is no "improved" category. Microbiological response is categorized as eradication, persistence, or relapse and is of paramount importance. Several months of follow-up may be necessary for the detection of late relapses or metastatic infections. This guideline does not apply to studies of bacteremia or fungemia secondary to non-device-related, organ-based primary infections (e.g., pneumonia, urinary tract infection), which should be assessed in relation to the primary disorder.

Adherence of microorganisms to breast prostheses: an in vitro study.

The quantitative and morphological characteristics of microbial adherence of four organisms--Staphylococcus epidermidis, S. aureus, Escherichia coli and Candida albicans--to the surfaces of different breast prostheses were observed. Semiquantitative adherence studies based on a modification of Maki's roll culture technique even after short contact times showed (1) increased microbial adherence at higher concentrations of the organisms and (2) differences in adherence properties between gram-positive bacteria and other organisms tested, noted also at lower organism concentrations. Scanning electron microscopy (SEM) to identify microorganisms on foam-covered prostheses, however, revealed organisms in the interstitial spaces that were not recovered by the plating technique. Other features on SEM were extracellular "slime" produced by S. epidermidis, which appears to act as a cement by which bacteria are held against prosthetic surfaces. These in-vitro findings suggest that brief exposure of the prostheses to a few organisms, particularly gram-positive bacteria, at the time of implantation would be sufficient inoculum for bacterial adherence to prosthetic surfaces.

Quantitative epifluorescence assay of adherence of coagulase-negative staphylococci.

A quantitative epifluorescence assay was developed to assess the adherent qualities of clinical isolates of coagulase-negative staphylococci. This method compared favorably with the standardized tube adherence assay, yet demonstrated a wide range of surface binding affinities among the slime-producing and non-slime-producing strains of coagulase-negative staphylococci examined. This technique can also be adapted to evaluate the adherence of bacteria to other plastics and biomedical materials used to manufacture implantable medical devices.

Influence of bacterial adherence to intravascular catheters on in-vitro antibiotic susceptibility.

Slime-producing and non-slime-producing strains of coagulase-negative staphylococci (CNS) were evaluated for nafcillin susceptibility in the presence and absence of polyvinylchloride (PVC) catheters. Semiquantitative roll cultures of catheters with adherent organisms after exposure to predicted bactericidal concentrations of nafcillin were carried out to assess survival of these organisms. Slime-producing and non-slime-producing CNS had similar minimum inhibitory (MIC) and bactericidal (MBC) concentrations in the absence of catheters and similar MIC in the presence of catheters. However, the mean MBC of slime-producing CNS, and to a lesser extent of non-slime-producing strains was higher in the presence than in the absence of catheters. Slime-producing CNS were recovered from PVC catheters after overnight incubation in cidal concentrations (greater than 4.0 micrograms/ml) of nafcillin (average 350 colony-forming units per 1 cm). Thus nafcillin-sensitive CNS strains, particularly those producing slime, are able to survive exposure to cidal concentrations of the drug when adherent to PVC catheters.

Prevalence of hepatitis B carriers in a mental health in-patient facility: implications for employee screening and vaccination.

Health care employees in a variety of institutional settings may be exposed to Hepatitis B virus through blood contact with patients carrying this infectious agent. Employees may be protected from such risk by administration of pre-exposure Hepatitis B vaccine or post-exposure immunoglobulin prophylaxis. Prior to establishing a Hepatitis B vaccination program for employees, a prevalence survey of hepatitis B surface antigen (HBsAg) positivity in mental health care facility inpatients was conducted to assess employee exposure risk. Survey results demonstrated that 15/270 inpatients (5.5 percent) had positive HBsAg serologies. These results suggest that positivity may be much higher in mental health care facilities than in acute care hospitals. Mental health care facilities should routinely survey inpatient populations for the presence of HBsAg positivity and consider establishing Hepatitis B serologic screening and vaccination programs for personnel involved in delivering care.