Julie Louise Gerberding

Investigation of bioterrorism-related anthrax, United States, 2001: epidemiologic findings.

In October 2001, the first inhalational anthrax case in the United States since 1976 was identified in a media company worker in Florida. A national investigation was initiated to identify additional cases and determine possible exposures to Bacillus anthracis. Surveillance was enhanced through health-care facilities, laboratories, and other means to identify cases, which were defined as clinically compatible illness with laboratory-confirmed B. anthracis infection. From October 4 to November 20, 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified; 5 of the inhalational cases were fatal. Twenty (91%) case-patients were either mail handlers or were exposed to worksites where contaminated mail was processed or received. B. anthracis isolates from four powder-containing envelopes, 17 specimens from patients, and 106 environmental samples were indistinguishable by molecular subtyping. Illness and death occurred not only at targeted worksites, but also along the path of mail and in other settings. Continued vigilance for cases is needed among health-care providers and members of the public health and law enforcement communities.

Risk of Exposure of Surgical Personnel to Patients' Blood during Surgery at San Francisco General Hospital

We undertook an observational study of 1307 consecutive surgical procedures at San Francisco General Hospital to record descriptions of intraoperative exposures to blood and other body fluids, determine the factors predictive of these exposures, and identify interventions that might reduce their frequency. During a two-month period, circulating nurses took note of parenteral and cutaneous exposures to blood and recorded information about all procedures. In a follow-up validation study, 50 additional procedures were observed by the study investigators to determine the accuracy of the data collected by the nurses. A total of 960 gloves used by surgical personnel during the validation study were examined to determine the perforation rate. Accidental exposure to blood (parenteral or cutaneous) occurred during 84 procedures (6.4 percent; 95 percent confidence interval, 5.1 to 7.8 percent). Parenteral exposure occurred in 1.7 percent. The risk of exposure was highest when the procedures lasted more than three hours, when blood loss exceeded 300 ml, and when major vascular and intraabdominal gynecologic surgery was involved. Neither knowledge of diagnosed human immunodeficiency virus (HIV) infection nor awareness of a patients high-risk status for such infection influenced the rate of exposure. Double gloving prevented perforations of the inner glove and cutaneous exposures of the hand. We conclude that all surgical personnel are at risk for intraoperative exposure to blood. Our data support the practice of double gloving and the increased use of water-proof garments and face shields to prevent mucocutaneous exposures to blood. No evidence was found to suggest that preoperative testing for HIV infection would reduce the frequency of accidental exposures to blood.

Guidelines for the prevention of intravascular catheter-related infections.

BACKGROUNDnAlthough many catheter-related bloodstream infections (CRBSIs) are preventable, measures to reduce these infections are not uniformly implemented.nnnOBJECTIVEnTo update an existing evidenced-based guideline that promotes strategies to prevent CRBSIs.nnnDATA SOURCESnThe MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.nnnSTUDIES INCLUDEDnLaboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations.nnnOUTCOME MEASURESnReduction in CRBSI, catheter colonization, or catheter-related infection.nnnSYNTHESISnThe recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis).nnnCONCLUSIONnSuccessful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Management of Occupational Exposures to Blood-Borne Viruses

Exposures to blood-borne pathogens pose a serious occupational threat to health care workers. Safer needle devices for performing phlebotomy and other procedures and universal infection-control precautions will not completely eliminate the risk, and prophylactic treatment will remain an important component of prevention efforts. This article will review post-exposure care for the three blood-borne pathogens that are most commonly involved in occupational transmission — hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Assessment of Exposure Occupational exposures include contact of the eyes, mouth, other mucous membranes, or broken skin and parenteral contact with blood or other .xa0.xa0.

Postexposure Treatment of People Exposed to the Human Immunodeficiency Virus through Sexual Contact or Injection-Drug Use

Among health care workers who have occupational exposures to the human immunodeficiency virus (HIV), a recent case–control study indicates that treatment with zidovudine after exposure decreases th...

Occupational Exposures to Body Fluids among Medical Students: A Seven-Year Longitudinal Study

Medical students may be vulnerable to accidental exposures to blood because they lack experience and skill, even though they are eager to learn new procedures (1-7). The risk for exposure to and infection by bloodborne pathogens among medical students is not known, and published reports probably underestimate the actual risk because many exposures are not reported. Health care workers, especially physicians in training (2, 4, 6), often do not report exposures because of fear of losing insurance and employment, disbelief in the efficacy of prophylaxis, or a tendency to deny personal risk. Early in the course of the AIDS epidemic, the University of California, San Francisco, recognized the potential risk for exposure among medical students, and it implemented curricular changes to encourage universal precautions and the safer use of needles during bedside procedures. It also created a comprehensive postexposure care system, including needlestick hotlines, to facilitate reporting of exposures at the teaching hospitals affiliated with the University of California, San Francisco, for all health care workers, including students. However, surveys of graduating students showed that many accidental exposures occurred despite the training given. Our study was done to 1) identify factors associated with occupational exposure that might be modified to protect medical students from unnecessary risk and 2) describe the epidemiology of occupational exposures sustained by medical students at the University of California, San Francisco, over a 7-year period. Methods We hypothesized that the following variables might be associated with the probability of occupational exposure to blood: type of clerkship, previous completion of a clerkship in an area suspected of conferring a high risk for occupational exposure (obstetrics [2], surgery [3], or medicine [4-6]), and year of graduation (7). All occupational exposures reported by medical students who graduated from the University of California, San Francisco, School of Medicine between 1990 and 1996 were retrospectively reviewed. Eligible exposures were only those reported between June 1989 and May 1996. Exposures occurred through needle punctures, lacerations, and other injuries caused by sharp objects; mucosal splashes; and contact of nonintact skin with blood or bloody body fluids. Data Collection Occupational exposures were initially reported to needlestick hotlines, which are managed by employee health services, at the hospitals affiliated with the University of California, San Francisco. In 1989, San Francisco General Hospital instituted the first hotline, through which housestaff, students, staff, and faculty could report occupational exposures. In June 1990, similar programs were implemented at all of the other hospitals in San Francisco that are affiliated with the University of California, San Francisco: Moffitt-Long Hospital, the Veterans Affairs Medical Center, and Mt. Zion Hospital. These hotlines were endorsed by the Chancellors AIDS Coordinating Committee at the University of California, San Francisco, and were designed to be anonymous, available 24 hours a day, and staffed by experts in exposure management. Students were encouraged to report injuries to the hotline service closest to them. During their orientation to clerkships, students received pocket-sized laminated cards printed with the telephone numbers of the hotlines at the various hospitals. These cards were also given to all new housestaff and were prominently displayed in emergency departments, nursing stations, and resident lounges at all hospitals. Students who reported an exposure to the hotline received baseline and follow-up care at the employee health services on the campus where the exposure occurred. Students could report occupational exposures to the Student Health Service before 1991, but after this date, the hotlines were available at all sites and all exposed students were managed by employee health services. Thus, this study used data derived from the employee health services hotlines. The clerkship schedules for each eligible medical student were provided by the Office of Student and Curricular Affairs to a statistician who had no access to reported exposure data. This statistician assigned each student a study identification number from a table of random numbers. The list of all students and their identification numbers was then forwarded to the clinical personnel responsible for the treatment and surveillance of occupational exposures at the hospitals affiliated with the University of California, San Francisco. The clinicians (who already knew the names of exposed students because they provided postexposure clinical care) extracted relevant data, including exposure history, type of exposure, and the results of baseline and follow-up tests for bloodborne viruses, from the students confidential exposure record. No other data on exposures were available from the student health service or other providers. The exposure data were linked to the students identification numbers in a computer database. To maintain confidentiality, the clinicians then deleted the student names from the database and returned the exposure data to the study personnel without including personal identifiers. The protocol for this study was approved by the University of California, San Francisco, Committee on Human Research. School of Medicine Curriculum All medical students at the University of California, San Francisco, School of Medicine are required to participate in the same 10 core clerkships (totaling 52 weeks) during the third and fourth years of medical school. Eight of these clerkships are in anesthesia, family and community medicine, obstetrics-gynecology, medicine, neurology, pediatrics, psychiatry, and surgery and surgical specialties; 1 is a medicine subinternship; and 1 is another subinternship in which the student has primary responsibility for patient care (more than two thirds of students elect to take emergency medicine). Schedules are determined by lottery, and the sequence and location of clerkships vary widely. All students in the years studied rotated through all four of the San Francisco hospitals affiliated with the University of California, San Francisco. Training in Exposure Prevention In June 1989, the University of California, San Francisco, implemented a requirement that all third-year medical students be trained in universal precautions and exposure prevention as a component of a 1-week introduction to clerkships. First conceived to provide clinical skills and training in universal precautions, this program has evolved into a mini-course intended to improve the experience and performance of third-year medical students in clerkships. The course is taught by clinical faculty and fourth-year medical students. Through lectures; small group seminars; panel discussions; and hands-on practice with phlebotomy, intravenous catheter insertion, arterial blood sampling, and blood culture techniques, students learn the essentials of bedside clinical procedures in a safe, low-stress environment. All students watch the same videotape and hear discussions about universal precautions and exposure prevention provided by occupational health and infection control nurses. Since 1993, this course has also included hands-on instruction in the use of safer needle devices for phlebotomy and intravenous catheter insertion. Each year, the students rate the course as excellent. Assessment of Underreporting Previous investigators (2, 4, 6) have established that occupational exposures among housestaff and medical students are substantially underreported. We hypothesized that the needlestick hotlines would increase the rate of reporting once students became comfortable with these confidential services. To estimate the degree of underreporting, we conducted anonymous surveys of medical students to ascertain the number of exposures sustained and the proportion of exposures reported to the hotlines. Students in the class of 1991 were queried in the winter of 1990 (just as the needlestick hotline was implemented), and students in the class of 1996 were queried just before graduation in June 1996. The anonymous questionnaires were distributed by the Office of Curricular Affairs. Statistical Analysis The proportion of exposed students was defined as the number of students reporting one or more exposures divided by the number of students enrolled at the University of California, San Francisco, School of Medicine during the study period. For each student who had multiple exposures, one exposure was chosen by using a table of random numbers to avoid the possibility of bias toward students who reported or sustained more exposures. Categorical data were compared by using the chi-square test. Comparisons with a P value less than 0.05 (two-tailed) were considered statistically significant. Results One thousand twenty-two medical students were enrolled in the University of California, San Francisco, School of Medicine classes of 1990 through 1996 (Table 1). Of these students, 119 (11.7% [95% CI, 9.0% to 15.2%]) reported one or more occupational exposures to the needlestick hotlines. Only 10 students (2%) reported two exposures. Most occupational exposures were caused by needle punctures (Table 2). Table 1. Graduation Year and Graduating Class Size of Students Who Reported Occupational Exposures Table 2. Types of Occupational Exposures Sustained by Medical Students Infections with Bloodborne Pathogens This study was not designed to evaluate the incidence of infection with bloodborne pathogens, but no students who reported eligible exposures were known to have acquired HIV, hepatitis C virus (HCV), or hepatitis B virus (HBV) infection. In 1993, the medical school purchased disability insurance for all students to provide coverage for occupational infections. After 4 years of experience with the same insurance broker, no disability clai

Incidence and Clinical Implications of Isolation of Mycobacterium kansasii: Results of a 5-Year, Population-Based Study

Mycobacterium kansasii, a nontuberculous mycobacterium, causes pulmonary disease that is indistinguishable from M. tuberculosis infection in immunocompetent persons. Before the AIDS epidemic, M. kansasii was a relatively infrequent pathogen [1]: In 1980, the incidence of M. kansasii infection was estimated to be 0.52 cases per 100 000 persons [2]. However, recent case series suggest increased isolation of M. kansasii from HIV-positive patients [3, 4] and increasing rates of M. kansasii infection in HIV-negative patients [5]. National surveillance between 1981 and 1987 detected 138 cases of disseminated M. kansasii infection per 100 000 persons with AIDS [6]; this incidence is more than 200-fold higher than the incidence in the general population. In both the HIV-positive and HIV-negative populations, the highest rates of M. kansasii infection were detected in an inverted-T geographic distribution that covered the southern and central United States [2, 6]. This endemic distribution suggests an environmental reservoir; however, M. kansasii has not been recovered from soil [7, 8], has only rarely been detected in natural bodies of water [9, 10], and has infrequently been cultured from potable water supplies [8, 11-14]. Mycobacterium kansasii has traditionally been considered the most virulent of the nontuberculous mycobacteria [15]; 75% to 97% of HIV-negative persons fulfill criteria for infection [1, 16]. Co-infection with HIV seems to alter the spectrum of clinical disease. Cavitary lung disease, which is diagnostic of pulmonary infection in HIV-negative patients [16-18], is documented in less than 50% of HIV-positive patients [19, 20]. Concomitant pathogens are identified in 30% to 46% of HIV-positive patients [21, 22], further obscuring the relative contribution of M. kansasii as a cause of pulmonary disease. Disparate reports documenting the frequency of colonization in the HIV population have led to confusion about the clinical significance and need for treatment of M. kansasii infection [4, 19, 23, 24]. Despite the changing epidemiology of M. kansasii infections, no updated population-based evaluation has been done in the AIDS era. Limitations of existing studies include hospital-based case ascertainment, which biases toward more seriously ill patients, and exclusion of HIV-negative patients. These limitations mask changing disease patterns in the population as a whole. Monitoring disseminated disease as part of AIDS surveillance may significantly underestimate the overall incidence of M. kansasii infection because pulmonary disease accounts for more than 65% of infections [4, 19]. Our study used population-based laboratory surveillance to find all cultures that were positive for M. kansasii in three counties in northern California. By including both HIV-positive and HIV-negative patients, we could assess the role of impaired immunity in the clinical presentation, significance of a positive respiratory culture, and risk for infection. Methods Surveillance Strategy and Case Mapping Active laboratory-based surveillance and auditing of all 43 hospital and clinic laboratories and 4 health departments in Alameda County, Contra Costa County, and San Francisco County between 1 January 1992 and 31 December 1996 were used to identify persons with positive cultures for M. kansasii. The organism was isolated by using standard methods [25]. Between 1992 and 1993, a designated laboratory employee at each facility prospectively notified surveillance staff of each positive culture. Monthly summaries of laboratory isolates were reviewed to ensure complete ascertainment of cases. We accrued cases identified between 1994 and 1996 by retrospectively reviewing laboratory records using a combination of computerized database searches and manual audits of mycobacteriology laboratory records. To abstract clinical, demographic, and microbiological data, we reviewed charts by using a standardized definition to establish the presence of pulmonary infection [26]. A diagnosis of HIV or AIDS was established by using the 1993 Centers for Disease Control and Prevention case definition [27]. Patients with negative serologic test results in the 6 months before M. kansasii culture were classified as HIV negative; those who were not tested or were seronegative more than 6 months before the index culture were classified as HIV unknown. Serostatus was validated by cross-referencing patients with the California Office of AIDS database of patients who had a confirmed AIDS diagnosis. California Department of Finance data [28] that projected the annual population of each county were used as rate denominators for the general population. The California Office of AIDS provided midyear estimates of the number of living persons with AIDS and HIV [29, 30]. Cumulative incidence rates were calculated for each year of the study by dividing the number of adult patients older than 20 years of age by the annual estimated adult population. Atlas GIS software (Strategic Mapping, Inc., Santa Clara, California) was used to assign patients living in San Francisco County to residential census tracts. Demographic and socioeconomic data were obtained by linkage with the 1990 U.S. Census report through the Summary Tape File 3 database. The geographic analysis was restricted to San Francisco County. Statistical Analysis Data were entered into an EPI-Info 6.04 database (Centers for Disease Control and Prevention, Atlanta, Georgia) and analyzed by using Stata 4.0 statistical software (Stata Corp., College Station, Texas). Dichotomous variables were assessed by using chi-square tests or the Fisher exact test. Continuous variables were compared by using the Student t-test or the two-sample Wilcoxon rank-sum test for nonparametric data. Poisson exact CIs were calculated for rates. All tests were two-sided; a P value of 0.05 or less was considered statistically significant. Results Mycobacterium kansasii was isolated from 283 patients. Thirteen patients were excluded because they lived outside the surveillance area (n = 7) or because their place of residence was unknown (n = 6). One hundred eighty-seven patients (69.3%) were HIV-positive, 33 (12.2%) were HIV-negative, and 50 (18.5%) had an unknown HIV status. The HIV-negative and HIV-unknown patients had homogeneous demographic characteristics (data not shown) and were combined to form a presumed HIV-negative group. Cross-reference of these patients with the California State AIDS Registry identified one (1.2%) potential case of misclassification: a patient with unknown HIV status at the time of M. kansasii isolation who subsequently received an AIDS diagnosis. Demographic and Socioeconomic Characteristics Patients who were HIV positive and those who were HIV negative differed significantly with respect to several characteristics (Table 1). The median age of HIV-negative patients was 22 years greater than that of HIV-positive patients, although the single infected child was an HIV-negative 2-year-old boy. Patients who were HIV positive were more likely to be male and African American and to have reported use of injection drugs. Homelessness (defined as no housing or housing in shelters) or marginal housing (defined as temporary residence in a low-rent hotel) in the year before M. kansasii culture was significantly more common among HIV-positive patients. Table 1. Baseline Characteristics of HIV-Positive and Presumed HIV-Negative Patients with Mycobacterium kansasii Cultured from Clinical Specimens* Incidence and Geographic Analysis The mean annual incidence of M. kansasii infection between 1992 and 1996 (based on the 269 adult patients) was 2.4 cases per 100 000 persons (95% CI, 2.1 to 2.7 cases per 100 000); the rate of infection was higher among male patients (5.1 cases per 100 000 [CI, 4.5 to 5.9 cases per 100 000]) and African Americans (8.1 per 100 000 [CI, 6.5 to 10.0 cases per 100 000]). Mean incidence varied markedly by HIV status: The rate per 100 000 persons was 0.75 in the general population (CI, 0.6 to 0.9 cases per 100 000), 115.1 in HIV-positive persons (CI, 99.2 to 132.9 cases per 100 000), and 646.5 in persons with AIDS (CI, 553.5 to 750.7 cases per 100 000). Among persons with AIDS, the rate of isolation of M. kansasii was disproportionately elevated for African Americans (1533 cases per 100 000 [CI, 1197 to 1933 cases per 100 000]) and women (1450 cases per 100 000 [CI, 873 to 2265 cases per 100 000]). African-American women with AIDS had the highest isolation rate of M. kansasii (2137 cases per 100 000 [CI, 1196 to 3524 cases per 100 000]). The geographic analysis was restricted to San Francisco County, which contributed 78% of HIV-positive patients and 46% of HIV-negative patients even though it had the smallest population of the three surveillance counties. Fifteen residents of San Francisco County were excluded from the geographic analysis because of homelessness (n = 14) or incomplete address (n = 1). Patients with M. kansasii infection resided in 72 (47.4%) of the 152 county census tracts, and 38 (53%) of these tracts had more than one case (Figure 1). Ten census tracts had an isolation rate of more than 1 case per 1000 residents (range, 1.08 to 7.35 cases per 1000 residents). These high-density tracts, which contained 5.6% of the San Francisco County population, accounted for 34.5% of mapped M. kansasii cases in the county. Figure 1. Map of San Francisco, California, showing geographic distribution of patients with Mycobacterium kansasii infection by HIV status and median household income of census tract. Median income differed between the 72 census tracts that contained patients with M. kansasii infection and the 80 census tracts that did not (

Prophylaxis for Occupational Exposure to HIV

32 317 compared with

Hospital-Onset Infections: A Patient Safety Issue

38 048; P = 0.001). Median incomes were

The Care of Persons with Recent Sexual Exposure to HIV

24 112 for tracts with more than 1 case per 1000 residents and