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Biomedical subjects

D K Henderson

Publications and source records attributed to D K Henderson.

At least 37 records · Page 2Linked to original sources
PubMed1994

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.

Adolescent↗
PubMed1994

Temporal association between implementation of universal precautions and a sustained, progressive decrease in percutaneous exposures to blood.

To evaluate whether implementation of universal precautions was temporally associated with a decrease in reported parenteral exposures to blood, we analyzed data on self-reported parenteral injuries that were prospectively collected at the Clinical Center, National Institutes of Health (Bethesda, MD), from 1985 through 1991. We also assessed whether implementation of universal precautions, in concert with initiation of a program of postexposure chemoprophylaxis with zidovudine, was associated with decreased time to reporting of occupational exposures. Our data, possibly confounded by the occurrence of an occupational infection due to human immunodeficiency virus infection in 1988, nonetheless demonstrate a temporal association between a progressive, significant decrease in percutaneous injuries and the implementation of universal precautions that has been sustained through subsequent years. The analysis remains significant, regardless of the surrogate denominator chosen for analysis. No trend toward more rapid reporting of exposures was identified. Implementation of universal precautions appears to have contributed to decreased parenteral injuries in our hospital but did not affect reporting efficiency.

Blood-Borne Pathogens↗
PubMed1994

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.

Blood-Borne Pathogens↗
PubMed1992

NIH conference. Respiratory disease in the immunosuppressed patient.

Pulmonary complications, both infectious and noninfectious, are an important cause of morbidity in patients with various types of immunosuppression. The appropriate response to these clinical problems requires an understanding of pulmonary host defense and of the various types of systemic immunosuppression. Infectious and noninfectious pulmonary complications may vary according to the type of immunosuppression as well as to the degree and duration of immunosuppression. Appropriate clinical management also requires an understanding of the clinical problems commonly seen in specific groups of immunosuppressed patients and an understanding of the sensitivity, specificity, and potential complications associated with the available diagnostic approaches to those patients. Because respiratory disease in these patient groups may progress rapidly to respiratory failure, an expeditious evaluation based on the knowledge of likely causes of respiratory disease and prompt specific or empiric therapy are indicated. Specific sets of algorithms for the evaluation of both focal and diffuse pulmonary disease may facilitate such an evaluation. In addition, an aggressive approach to the prevention of pulmonary disease including immunization, prophylaxis, and immunomodulation (for example, colony stimulating factors) may be warranted in specific subgroups at risk.

Algorithms↗
PubMed1992

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.

Antibodies, Viral↗
PubMed1992

Management of occupational exposures to bloodborne pathogens: hepatitis B virus, hepatitis C virus, and human immunodeficiency virus.

Being a health care worker in today's world is not without risks. Accidental exposure to blood carries with it a definite risk of transmission of infection by various bloodborne pathogens, especially the hepatitis B, hepatitis C, and human immunodeficiency viruses. While infectious disease specialists, hospital epidemiologists, and infection control clinicians can develop many important strategies to reduce this risk--aggressive training, utilization of safer needles, identification of high-risk activities, and efficient disposal systems--their overriding responsibility is to design and implement a comprehensive plan for expeditiously and effectively dealing with accidental exposures when they occur. Among other things, the plan must address a number of key issues, including testing, administering postexposure prophylaxis, providing short- and long-term follow-up care, and, particularly, counseling for helping the health care worker deal with the tremendous anxiety associated with the injury. Drs. Julie L. Gerberding of the University of California, San Francisco, and San Francisco General Hospital and David K. Henderson of the National Institutes of Health and the Warren G. Magnuson Clinical Center have both made significant contributions in this area; in this month's AIDS Commentary they discuss the essential elements of such a plan.

HIV Infections↗
PubMed1992

Evolving epidemiology of HIV infection among adults.

Whereas new, or changes in existing, routes of transmission of HIV have not been identified in the 11 years since AIDS was identified as a clinical syndrome, changes in the epidemiology of HIV infection in the US have been identified during that period. The role of injection drug use as a risk for both parenteral and sexual transmission of HIV has increased substantially during this period. Heterosexual transmission is becoming more prominent as the epidemic continues to "mature" in the US. The likelihood that heterosexual transmission will become progressively more important in the spread of HIV in the US in the next several years seems high. The ability of individuals in some populations at risk for infection to modify risk behaviors has led to a reduction in transmission of HIV in those populations. The addition of nucleoside analog antiretrovirals and effective chemoprophylaxis for Pneumocystis carinii pneumonia has led to increases in both the quality and duration of life for some populations of HIV-infected patients. Neither a chemotherapeutic cure nor a vaccine is on the immediate horizon; education and behavior modification remain the cornerstones of current prevention efforts. For a variety of complex reasons, inappropriate scrutiny has been focused on the remote risks of health-care provider-to-patient transmission of HIV. In the past 11 years medical science has made remarkable progress in understanding the etiology, biology, epidemiology, pathogenesis, and prevention of HIV infection. Despite this progress, a great deal of work remains to be done not only in the medical and basic science arenas but also in the behavioural and sociological sciences.

Adult↗
PubMed1991

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.

Acquired Immunodeficiency Syndrome↗
PubMed1991

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.

Body Fluids↗
PubMed1990

Risk for occupational transmission of human immunodeficiency virus type 1 (HIV-1) associated with clinical exposures. A prospective evaluation.

OBJECTIVES: To summarize the results of a 6-year, ongoing, prospective study of the risk for human immunodeficiency virus type 1 (HIV-1) transmission among health care workers, and to estimate the magnitude of the risk for HIV-1 infection associated with different types of occupational exposures. DESIGN: Prospective cohort study; the median follow-up for employees sustaining parenteral exposures was 30.2 months (range, 6 to 69 months). SUBJECTS: Health care workers at the Clinical Center, National Institutes of Health, including those reporting parenteral and nonparenteral occupational exposures to HIV-1. MEASUREMENTS AND MAIN RESULTS: One thousand three hundred and forty-four clinical health care workers reported 179 percutaneous and 346 mucous membrane exposures to fluids from HIV-1-infected patients during a 6-year period. Responding to a supplementary questionnaire, 559 of these workers reported 2712 cutaneous exposures to blood from HIV-1-infected patients and more than 10,000 cutaneous exposures to blood from all patients during a 12-month period. Occupational transmission of HIV-1 occurred in a single worker after a parenteral exposure to blood from an HIV-1-infected patient. No infections occurred after either mucous membrane or cutaneous exposures to blood from HIV-1-infected patients. Use of newer diagnostic technologies (for example, antigen detection, gene amplification) has not resulted in the identification of occupationally transmitted seronegative infections. CONCLUSIONS: Combining our results with those of other prospective studies, the risk for HIV-1 transmission associated with a percutaneous exposure to blood from an HIV-1-infected patient is approximately 0.3% per exposure (95% CI, 0.13% to 0.70%); the risks associated with occupational mucous membrane and cutaneous exposures are likely to be substantially smaller. These data support the use of barrier precautions and suggest a need for strategies that change health care providers' attitudes and behaviors.

Accidents, Occupational↗