Healthcare personnel intestinal colonization with multidrug-resistant organisms.

OBJECTIVES: This study aims to assess the association between patient contact and intestinal carriage of multidrug-resistant organisms (MDRO) by sampling healthcare personnel (HCP) and staff without patient contact. METHODS: For this observational study, we recruited 400 HCP who worked in our 200-bed research hospital and 400 individuals without patient contact between November 2013 and February 2015. Participants submitted two self-collected perirectal swabs and a questionnaire. Swabs were processed for multidrug-resistant Gram-negative bacteria and vancomycin-resistant enterococci (VRE). Questionnaires explored occupational and personal risk factors for MDRO carriage. RESULTS: Among 800 participants, 94.4% (755/800) submitted at least one swab, and 91.4% (731/800) also submitted questionnaires. Extended spectrum ß-lactamase-producing organisms were recovered from 3.4% (26/755) of participants, and only one carbapenemase-producing organism was recovered. No VRE were detected. The potential exposure of 68.9% (250/363) of HCP who reported caring for MDRO-colonized patients did not result in a rate of MDRO carriage among HCP (4.0%; 15/379) significantly higher than that of staff without patient contact (3.2%; 12/376; p 0.55). CONCLUSIONS: This is the largest US study of HCP intestinal MDRO carriage. The low colonization rate is probably reflective of local community background rates, suggesting that HCP intestinal colonization plays a minor role in nosocomial spread of MDROs in a non-outbreak setting. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01952158.

Long-lasting, specific immunologic unresponsiveness associated with cryptococcal meningitis.

A sensitive radioimmunoassay and an antibody class-specific enzyme-linked immunosorbent assay were used to determine whether patients cured of cryptococcosis responded normally to immunization with cryptococcal capsular polysaccharide (CPS) and type III pneumococcal polysaccharide. 10 normal volunteers and 8 patients who had been cured of cryptococcal meningitis and who had been cured of cryptococcal meningitis and who had no serious underlying diseases were immunized with both antigens. Geometric mean titers to CPS measured by radioimmunoassay were 1:1 in both groups before vaccination, but were 1:3 in patients and 1:119 in controls following immunization (P less than 0.01, Student's t test). Analysis of the class-specific response to immunization with CPS found little anti-CPS IgG or IgA. Geometric mean postvaccination IgM titers were 1:31 in patients and 1:238 in controls (P less than 0.01). Responses to immunization with type III pneumococcal polysaccharide were similar in patients and controls, with IgA, IgM, and IgG mean titers of 1:1129, 1:369, and 1:158 in patients and 1:1504, 1:1039, and 1:163 in controls (P greater than 0.2 for each antibody class). Cured cryptococcal meningitis is often associated with prolonged specific immunologic unresponsiveness.

Conservation of the Caenorhabditis elegans cuticle collagen gene col-12 in Caenorhabditis briggsae.

The functional importance of the majority of Caenorhabditis elegans cuticle collagen genes is unknown. We have identified, cloned and sequenced the Caenorhabditis briggsae homologue of the C. elegans gene col-12, a cuticle collagen for which no mutants have yet been identified. Homology in the flanking sequence has allowed us to unambiguously identify this gene as the col-12 homologue, as opposed to some other closely related member of this large multigene family. The whole of the predicted polypeptide is highly conserved (94.9% identical), including those regions not yet shown by mutational analysis to be important for C. elegans cuticle collagen function. These include the whole of the N-terminal non-Gly-X-Y domain and the X and Y positions of the Gly-X-Y domain. This may be a consequence of the requirement of cuticle collagens to participate in intermolecular interactions throughout the full length of the polypeptide. There is increasing evidence to suggest that conservation between C. elegans and C. briggsae is confined to functionally significant sequence. Hence, the conservation of col-12 between these two species provides evidence that this member of the cuticle collagen family has a significant structural function.

Chronic fungal sinusitis in apparently normal hosts.

Several fungal species are capable of causing either noninvasive fungal sinusitis or invasive disease characterized by erosion into mucosa, submucosa, bone, and deeper contiguous structures. The diagnosis of invasive infection becomes firmly established only after histologic demonstration of hyphae within these areas. Computerized tomography and magnetic resonance imaging can assist in distinguishing between invasive and noninvasive disease by outlining bone and adjacent structures. The 2 forms of chronic fungal sinusitis mandate different therapeutic approaches. While patients with noninvasive infection require only surgical removal of hyphal masses and the reestablishment of sinus drainage for a successful outcome, invasive infection necessitates not only thorough surgical debridement of abnormal tissues but may also require prolonged antifungal chemotherapy. All patients require long-term follow-up. Even the combined approach has sometimes proven disappointing during long-term follow-up of disease, rendering investigational therapy appropriate in some patients.

Postexposure chemoprophylaxis for occupational exposure to human immunodeficiency virus type 1: current status and prospects for the future.

Occupational exposures to the human immunodeficiency virus (HIV) continue to occur in the health care setting. Each such exposure is associated with risk for occupational infection. Although occupational HIV infections have been uncommon in health care workers, the occurrence of even one such infection is traumatic for the health care worker and his or her institution. To attempt to prevent infection following occupational exposures, some institutions and investigators have elected to offer postexposure chemoprophylaxis with zidovudine. Unfortunately, data describing the use of nucleoside analogues in animals and humans as antiviral chemoprophylaxis are quite limited and data simply do not exist that definitely support or refute their use in this setting. One can mount an equally reasonable argument for or against the use of these agents in this setting in 1990. This article reviews the available data regarding postexposure chemoprophylaxis, summarizes the clinical experience with zidovudine use for postexposure chemoprophylaxis to date, and evaluates prospects for additional chemoprophylaxis options in the future.

Indolent epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia in an intensive care unit traced to a contaminated blood gas analyzer.

An epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia occurred in the medical intensive care unit at the Clinical Center of the National Institutes of Health. Sixteen patients in the intensive care unit became colonized or infected with this organism in a 21-month period; whereas P. cepacia had been isolated only 16 times in the preceding 90 months from the entire hospital. Further analysis demonstrated a significant association of the epidemic cases with bloodstream isolation of the organism (p less than 0.001, Fisher's exact test). Mortality associated with bacteremia caused by P. cepacia was 38 percent. Intensive investigation of the intensive care unit and its surrounding environment eventually demonstrated that a blood gas analyzer in a satellite laboratory adjacent to the intensive care unit was the reservoir for the outbreak. Replacement of the machine resulted in termination of the outbreak, P. cepacia continues to represent an environmental threat to hospitalized patients.

Frequency of nonparenteral occupational exposures to blood and body fluids before and after universal precautions training.

PURPOSE: During annual periods before and after Universal Precautions training, we compared the frequency of health care workers' self-reported cutaneous exposures to blood and various body substances from any patient and from patients presumed infected with human immunodeficiency virus type 1 (HIV-1). SUBJECTS AND METHODS: Self-reported cutaneous exposures to blood, sputum, urine, feces, and other body substances were evaluated separately in 559 workers during the first survey and 269 workers during the second. RESULTS: Mean annual blood exposures decreased from 35.8 to 18.1, and mean annual exposures to all substances decreased from 77.8 to 40.0 (p less than 0.001 for both determinations). Two matched analyses of a subset of 200 participants who completed both surveys had similar results. Reported exposures to blood, presumably infectious blood, sputum, presumably infectious sputum, and urine were significantly decreased. Participants were tested for antibodies to HIV-1; no participant reporting cutaneous exposures acquired HIV-1 infection. The upper bound for the 95% confidence interval for the risk of HIV-1 infection associated with a single cutaneous exposure was 0.04% for blood presumed to contain HIV-1 and 0.02% for any body substance presumed to contain HIV-1. CONCLUSIONS: These data suggest that Universal Precautions training significantly decreased but did not eliminate cutaneous exposures to blood and body substances. The results further suggest that the risk for HIV-1 infection associated with cutaneous exposures is substantially lower than the risk associated with parenteral exposures.

Comparative ocular pathogenicity of Cryptococcus neoformans, Candida glabrata, and Aspergillus fumigatus in the rabbit.

In a previous study, 88% of rabbits with disseminated infection caused by Candida albicans developed ophthalmoscopically visible, hematogenous endophthalmitis (chorioretinitis) over a 2 week period. To determine the incidence of this ocular complication in disseminated infection caused by Cryptococcus neoformans, Candida glabrata, and Aspergillus fumigatus compared with that caused by C. albicans, the first three species of fungi were injected intravenously (between 10(5) and 10(9) organisms per animal) into 36 New Zealand white rabbits. No chorioretinal lesions were seen by indirect ophthalmoscopy over a 2 week period. C. glabrata and A. fumigatus were not cultured from chorioretinas despite positive cultures from brains and kidneys at 1 and 2 weeks. In contrast, C. neoformans was cultured from 12 of 18 chorioretinas. (mean Log10 3.45 colony forming units/gm of tissue) as well as from the brains and kidneys. The less intense inflammatory cell response to C. neoformans compared with that 10 C. albicans seen on histopathologic examination most likely explains the nondetectability of the cryptococcal chorioretinitis by indirect ophthalmoscopy. These data suggest that C. glabrata. A. fumigatus, and possibly C. neoformans have less ocular pathogenicity than C. albicans in rabbits and correlate with the small number of documented human cases of ophthalmoscopically visible hematogenous endophthalmitis caused by fungi other than C. albicans.

Nosocomial human parvovirus B19 infection: lack of transmission from a chronically infected patient to hospital staff.

OBJECTIVE: To assess the potential for nosocomial spread of parvovirus B19 from a chronically infected patient. DESIGN: 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. SETTING: 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. METHODS: 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. RESULTS: The index case had parvovirus B19 DNA at approximately 10(6) 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. CONCLUSIONS: 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.

Rapid identification of respiratory viruses: impact on isolation practices and transmission among immunocompromised pediatric patients.

OBJECTIVE: To determine whether empiric isolation of patients with acute respiratory virus infection symptoms could be discontinued when preliminary shell vial cultures were negative, and the impact of this approach on hospital resources. DESIGN: In 1993, we retrospectively reviewed respiratory virus test results from 1992 to 1993 and extended data collection prospectively through the 1993 to 1994 season. The rapid test and 48-hour shell vial results were compared to a standard of rapid test plus 5-day shell vial culture results to determine the sensitivity and specificity of these "preliminary" results. SETTING: A 400-bed tertiary referral research hospital. PATIENTS: Patients from any inpatient unit or clinic with acute respiratory virus infection symptoms who had a specimen submitted for respiratory virus culture. Patients were placed on empiric respiratory isolation pending culture results. RESULTS: The overall sensitivity of the combined rapid and 48-hour culture results in adults and children was 97%. All 15 pediatric patients with respiratory syncytial virus infection who had specimens submitted on first suspicion of respiratory virus infection were positive by rapid test. Culture results were positive within 48 hours for 100% of patients with influenza A (15 patients), influenza B (6), and parainfluenza (18) viruses. Of 59 pediatric inpatients who were isolated empirically awaiting 5-day culture results, 31 (52%) ultimately were determined to be culture negative. CONCLUSIONS: Empiric isolation of symptomatic children can be discontinued at 48 hours when both the rapid test and the early culture results are negative. Our institution would have saved 93 days of unnecessary isolation over 2 years had such a policy been in place.

Adverse exposures and universal precautions practices among a group of highly exposed health professionals.

An anonymous national survey of a representative population of healthcare workers who were thought likely to have frequent and intensive exposures to blood and other body fluids (certified nurse-midwives [CNMs]), was conducted to assess the type and frequency of self-reported occupational exposures to blood and body fluids experienced, the extent to which barrier precautions and other infection control measures were used, whether or not reported use of barriers was associated with a lower perceived rate of exposures and factors that influenced the use of infection control procedures. Of those responding, 74% had soiled their hands with blood at least one time in the preceding six months, 51% had splashed blood or amniotic fluid in their faces and 24% reported one or more needlestick injuries during that same period. Our study also found evidence of an association between the practice of needle recapping and the occurrence of needlestick injury (p = .003). Despite a high level of training and knowledge, only 55% reported routinely practicing universal precautions (UPs). Several factors that potentially influenced the use of UPs were studied, including healthcare worker perceptions of risk of occupational bloodborne infection, knowledge of routes of transmission of bloodborne pathogens and rationale for not using appropriate barriers. Our data suggest that occupational exposures occur frequently and that healthcare workers' (HCWs') perceptions of risk for occupational infection play an important role in influencing use of UPs. This study emphasizes the importance of developing new strategies for UP training.

Risky business: using necessarily imprecise casualty counts to estimate occupational risks for HIV-1 infection.

Although the genesis of healthcare worker anxiety regarding occupational risks of HIV-1 infection is clear, the reasons for continued insistence on a meticulous "casualty count" become less clear with time. One could, in fact, argue that the precise number of such infections has become virtually meaningless, because the routes of occupational/nosocomial transmission of HIV-1 and the magnitude of risk for infection following an adverse exposure in the healthcare setting have been well-characterized. Nevertheless, with the substantial limitations of these data clearly in mind, we have summarized the numbers of healthcare workers reported to have HIV-1 infection in each of the above categories in Table 2. The likelihood that an individual case represents true occupational infection decreases as one moves down the table. Having waded through the depths of this literature, we have reached the conclusion that, of the available data, the magnitude of risk for occupational HIV-1 infection remains the single most useful and instructive statistic available. Longitudinal cohort studies of HCWs involved in the day-to-day care of HIV-1-infected patients and in the handling and processing of specimens from such patients provide the best available evidence regarding the magnitude of risk for transmission of this virus in the healthcare setting. Fourteen prospective studies are currently in progress, with approximately 2,000 HCWs enrolled (Table 4). Six HCWs enrolled in these studies have developed serologic evidence of HIV-1 infection following percutaneous exposures, yielding an infection rate per participant of 0.32% and an infection rate per exposure of 0.31%.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of occupational exposures to hepatitis C virus: current practice and controversies.

Unlike hepatitis B virus and human immunodeficiency virus, there currently are no immunization or chemoprophylactic interventions available to prevent infection after an occupational exposure to hepatitis C virus (HCV). A "Reality Check" session was held at the 4th Decennial International Conference on Nosocomial and Healthcare-Associated Infections to gather information on current practices related to management of occupational exposures to HCV, generate discussion on controversial issues, and identify areas for future research. Infection control professionals in attendance were knowledgeable in most issues addressed regarding the management of occupational exposures to HCV. Areas of controversy included the use of antiviral therapy early in the course of HCV infection and the appropriate administrative management of an HCV-infected healthcare worker.

Measles immunity in a population of healthcare workers.

OBJECTIVES: To evaluate measles seroprevalence among cohorts of new employees and to evaluate vaccine responses of susceptible adult healthcare workers. DESIGN: New employees were screened for measles susceptibility as part of employee evaluations. Anti-IgG measles antibody tests were completed on 2,473 workers. Demographic, measles history, and measles vaccination information was collected using a short questionnaire. Susceptible workers were vaccinated and screened for vaccine responses following vaccination. RESULTS: Ninety-three workers (4%) were seronegative, and 56 (2%) were equivocal. Individuals in the youngest cohort (born after 1956) were significantly more likely to be susceptible than those in the middle cohort (born 1951 to 1956) and those in the oldest cohort (born before 1951) (P < 0.01). The middle cohort included eight (5%) of the 149 seronegative or equivocal workers. Among the members of the youngest cohort, those from the United States were more likely to be susceptible (P < 0.01) than those from outside the United States. Of the 106 vaccinated susceptible workers whose follow-up serologies were determined, 90 (85%) developed positive IgG serologies, six had equivocal results, and 10 were seronegative. Eleven of the 16 non- or hyporesponders were revaccinated and re-evaluated; nine developed low positive IgG antimeasles levels, one exhibited an equivocal response, and one failed to respond. CONCLUSIONS: A small but important proportion of healthcare workers are susceptible to measles. Whenever feasible, measles immunity programs for healthcare workers should include workers born before 1957. Of workers born after 1956, those from outside the United States are more likely to be immune than workers from inside the United States. Using the currently available vaccine, revaccination of initial non- or hyporesponders appears to be effective.

Tolerability of postexposure antiretroviral prophylaxis for occupational exposures to HIV.

A substantial body of evidence provides support (but not definitive proof of efficacy) for the use of antiretroviral agents as postexposure prophylaxis for occupational exposures to HIV in the healthcare workplace. Despite the lack of definitive evidence of the efficacy of these agents in this setting, over the past decade this intervention has become the standard of care for healthcare workers who sustain occupational exposures to HIV. Administration of these agents--even for a relatively short 28-day postexposure course--is often fraught with difficulty. All of the agents currently used for postexposure prophylaxis regimens have substantial adverse effects, and significant adverse effects occur in more than two-thirds of individuals electing prophylaxis. This manuscript reiterates current US Federal Government guidelines for the administration of postexposure prophylaxis, specifically noting that zidovudine plus lamivudine (with or without a protease inhibitor) remains the recommended regimen. The paper summarises the significant toxicities associated with nucleoside reverse transcriptase inhibitors (primarily nausea, vomiting, diarrhoea and bone marrow suppression), non-nucleoside reverse transcriptase inhibitors (rash, fever, gastrointestinal symptoms and hepatitis, including hepatic decompensation necessitating liver transplantation) and protease inhibitors (nausea, vomiting, diarrhoea, abdominal pain, hyperglycaemia, hyperlipidaemia, headache and anorexia). As a class, the antiretroviral agents have an extraordinary number of drug interactions. The non-nucleoside reverse transcriptase inhibitors and the protease inhibitors are metabolised through the cytochrome P450 pathway, and the effects of concomitant administration of protease inhibitors with other agents in the same class are discussed, as well as the effects of concomitant administration of protease inhibitors with non-nucleoside agents. The potential for numerous and medically risky drug interactions emphasises the importance of planning antiretroviral prophylaxis in consultation with practitioners or clinical pharmacists who are skilled in the use of these agents and knowledgeable about the potential for significant drug interactions that could either reduce the benefit of prophylaxis or increase the potential for toxicity. Another common problem encountered by individuals managing postexposure prophylaxis programmes relates to the administration of chemoprophylaxis to a pregnant healthcare worker who has sustained an occupational exposure to HIV. We address what is known about the potential for toxicity and emphasise the recently published warning concerning the deaths of pregnant women and their offspring from lactic acidosis while receiving regimens containing stavudine and didanosine.

Postexposure prophylaxis for occupational exposures to hepatitis B, hepatitis C, and human immunodeficiency virus.

Bloodborne pathogens are becoming increasingly prevalent in, and therefore contributing increasing levels of risk to, the health-care work-place environment. This problem is magnified in the blood-intense operating room and obstetric environments. Whereas we will never be able to eliminate such risks entirely from the health-care workplace, a multifaceted approach to the management of these risks throughout the hospital environment and particularly in risk-intense environments will likely create a safer milieu and climate. Such an improved environment will clearly be necessary as we continue to strive to provide optimal care for all patients, irrespective of their bloodborne infection status.

Risks for exposures to and infection with HIV among health care providers in the emergency department.

This article reviews the information available that is relevant to the risk of occupational infection with HIV, attempts to frame this evidence in perspective for emergency health care providers, and underscores the strategies that have been shown to be effective in reducing these risks.

Managing occupational risks in the dental office: HIV and the dental professional.

Despite universal precautions, work behavior modifications and technological advances, health care workers continue to experience occupational exposures to HIV and other bloodborne pathogens. Although the risk for infection is low when compared with other bloodborne pathogens, 39 documented cases of HIV seroconversion have been recorded. Recent attention has focused on secondary prevention of HIV infection through post-exposure chemoprophylaxis.

Symposium on infections in the compromised host. The acquired immunodeficiency syndrome.

The Acquired Immunodeficiency Syndrome (AIDS) is a recently recognized syndrome caused by a newly described retrovirus, Human T-Cell Lymphotropic Virus-III(HTLV-III). A disease that selectively attacks the immune system, manifested by opportunistic infections and unusual neoplasms, AIDS has continued to be confined primarily to several unique at-risk populations. AIDS has evoked unprecedented interest in the medical community, and care of patients with this nearly universally fatal syndrome presents many unique challenges to the health care team.