Carol A. Ciesielski

A case-control study of HIV seroconversion in health care workers after percutaneous exposure

BACKGROUND The average risk of human immunodeficiency virus (HIV) infection after percutaneous exposure to HIV-infected blood is 0.3 percent, but the factors that influence this risk are not well understood. METHODS We conducted a case-control study of health care workers with occupational, percutaneous exposure to HIV-infected blood. The case patients were those who became seropositive after exposure to HIV, as reported by national surveillance systems in France, Italy, the United Kingdom, and the United States. The controls were health care workers in a prospective surveillance project who were exposed to HIV but did not seroconvert. RESULTS Logistic-regression analysis based on 33 case patients and 665 controls showed that significant risk factors for seroconversion were deep injury (odds ratio= 15; 95 percent confidence interval, 6.0 to 41), injury with a device that was visibly contaminated with the source patients blood (odds ratio= 6.2; 95 percent confidence interval, 2.2 to 21), a procedure involving a needle placed in the source patients artery or vein (odds ratio=4.3; 95 percent confidence interval, 1.7 to 12), and exposure to a source patient who died of the acquired immunodeficiency syndrome within two months afterward (odds ratio=5.6; 95 percent confidence interval, 2.0 to 16). The case patients were significantly less likely than the controls to have taken zidovudine after the exposure (odds ratio=0.19; 95 percent confidence interval, 0.06 to 0.52). CONCLUSIONS The risk of HIV infection after percutaneous exposure increases with a larger volume of blood and, probably, a higher titer of HIV in the source patients blood. Postexposure prophylaxis with zidovudine appears to be protective.Background The average risk of human immunodeficiency virus (HIV) infection after percutaneous exposure to HIV-infected blood is 0.3 percent, but the factors that influence this risk are not well understood. Methods We conducted a case–control study of health care workers with occupational, percutaneous exposure to HIV-infected blood. The case patients were those who became seropositive after exposure to HIV, as reported by national surveillance systems in France, Italy, the United Kingdom, and the United States. The controls were health care workers in a prospective surveillance project who were exposed to HIV but did not seroconvert. Results Logistic-regression analysis based on 33 case patients and 665 controls showed that significant risk factors for seroconversion were deep injury (odds ratio = 15; 95 percent confidence interval, 6.0 to 41), injury with a device that was visibly contaminated with the source patients blood (odds ratio = 6.2; 95 percent confidence interval, 2.2 to 21), a procedure inv...

Molecular Epidemiology of HIV Transmission in a Dental Practice

Human immunodeficiency virus type 1 (HIV-1) transmission from infected patients to health-care workers has been well documented, but transmission from an infected healthcare worker to a patient has not been reported. After identification of an acquired immunodeficiency syndrome (AIDS) patient who had no known risk factors for HIV infection but who had undergone an invasive procedure performed by a dentist with AIDS, six other patients of this dentist were found to be HIV-infected. Molecular biologic studies were conducted to complement the epidemiologic investigation. Portions of the HIV proviral envelope gene from each of the seven patients, the dentist, and 35 HIV-infected persons from the local geographic area were amplified by polymerase chain reaction and sequenced. Three separate comparative genetic analyses—genetic distance measurements, phylogenetic tree analysis, and amino acid signature pattern analysis—showed that the viruses from the dentist and five dental patients were closely related. These data, together with the epidemiologic investigation, indicated that these patients became infected with HIV while receiving care from a dentist with AIDS.

Transmission of Human Immunodeficiency Virus in a Dental Practice

OBJECTIVE To determine if patients of a dentist with the acquired immunodeficiency syndrome (AIDS) became infected with human immunodeficiency virus (HIV) during their dental care and, if so, to identify possible mechanisms of transmission. DESIGN Retrospective epidemiologic follow-up of the dentist, his office practice, and his former patients. SETTING The practice of a dentist with AIDS in Florida. PARTICIPANTS A dentist with AIDS, his health care providers and employees, and former patients of the dentist, including eight HIV-infected patients. MEASUREMENTS Identification of risks for HIV transmission (if present), degree of genetic relatedness of the viruses, and identification of infection control and other office practices. RESULTS Five of the eight HIV-infected patients had no confirmed exposures to HIV other than the dental practice and were infected with HIV strains that were closely related to those of the dentist. Each of the five had invasive dental procedures, done by the dentist after he was diagnosed with AIDS. Four of these five patients shared visit days (P greater than 0.2). Breaches in infection control and other dental office practices to explain these transmissions could not be identified. CONCLUSION Although the specific incident that resulted in HIV transmission to these patients remains uncertain, the epidemiologic evidence supports direct dentist-to-patient transmission rather than a patient-to-patient route.

OCCUPATIONALLY ACQUIRED HUMAN IMMUNODEFICIENCY VIRUS (HIV) INFECTION: NATIONAL CASE SURVEILLANCE DATA DURING 20 YEARS OF THE HIV EPIDEMIC IN THE UNITED STATES

OBJECTIVE To characterize occupationally acquired human immunodeficiency virus (HIV) infection detected through case surveillance efforts in the United States. DESIGN National surveillance systems, based on voluntary case reporting. SETTING Healthcare or laboratory (clinical or research) settings. PATIENTS Healthcare workers, defined as individuals employed in healthcare or laboratory settings (including students and trainees), who are infected with HIV. METHODS Review of data reported through December 2001 in the HIV/AIDS Reporting System and the National Surveillance for Occupationally Acquired HIV Infection. RESULTS Of 57 healthcare workers with documented occupationally acquired HIV infection, most (86%) were exposed to blood, and most (88%) had percutaneous injuries. The circumstances varied among 51 percutaneous injuries, with the largest proportion (41%) occurring after a procedure, 35% occurring during a procedure, and 20% occurring during disposal of sharp objects. Unexpected circumstances difficult to anticipate during or after procedures accounted for 20% of all injuries. Of 55 known source patients, most (69%) had acquired immunodeficiency syndrome (AIDS) at the time of occupational exposure, but some (11%) had asymptomatic HIV infection. Eight (14%) of the healthcare workers were infected despite receiving postexposure prophylaxis (PEP). CONCLUSIONS Prevention strategies for occupationally acquired HIV infection should continue to emphasize avoiding blood exposures. Healthcare workers should be educated about both the benefits and the limitations of PEP, which does not always prevent HIV infection following an exposure. Technologic advances (eg, safety-engineered devices) may further enhance safety in the healthcare workplace.

Drug Use, High-Risk Sex Behaviors, and Increased Risk for Recent HIV Infection among Men who Have Sex with Men in Chicago and Los Angeles

We examined how drugs, high-risk sexual behaviors, and socio-demographic variables are associated with recent HIV infection among men who have sex with men (MSM) in a case–control study. Interviewers collected risk factor data among 111 cases with recent HIV infection, and 333 HIV-negative controls from Chicago and Los Angeles. Compared with controls, cases had more unprotected anal intercourse (UAI) with both HIV-positive and HIV-negative partners. MSM with lower income or prior sexually transmitted infections (STI) were more likely to be recently HIV infected. Substances associated with UAI included amyl nitrate (“poppers”), methamphetamine, Viagra® (or similar PDE-5 inhibitors), ketamine, and gamma hydroxybutyrate (GHB). Cases more frequently used Viagra®, poppers, and methamphetamine during UAI compared with controls. In multivariate analysis, income, UAI with HIV-positive partners, Viagra®, and poppers remained associated with recent HIV seroconversion. Better methods are needed to prevent HIV among MSM who engage in high-risk sex with concurrent drug use.

Surveillance for thrombocytopenia in persons infected with HIV : Results from the multistate adult and adolescent spectrum of disease project

Thrombocytopenia in persons infected with HIV is prevalent and has numerous causes. To study the occurrence, associations, and effect on survival of thrombocytopenia in HIV-infected persons, we used surveillance data from a longitudinal survey of the medical records of 30,214 HIV-infected patients who received medical care from January 1990 through August 1996 in more than 100 medical clinics in 10 U.S. cities. Thrombocytopenia was defined as a physician diagnosis of thrombocytopenia or a platelet count of < 50,000 platelets/ microliter. Analysis of associations of thrombocytopenia was conducted using logistic regression. In HIV+ patients, the 1-year incidence [corrected] of thrombocytopenia was 8.7% in persons with one or more AIDS-defining opportunistic illnesses (clinical AIDS), 3.1% in patients with a CD4 count < 200 cells/mm3 but not clinical AIDS (immunologic AIDS), and 1.7% in persons without clinical or immunologic AIDS. The incidence of thrombocytopenia was associated with clinical AIDS (adjusted odds ratio [AOR] 2.2; 99% confidence interval [CI] 1.7-3.0), immunologic AIDS (AOR 1.5, CI 1.0-2.1), history of injecting drug use (AOR 1.4, CI 1.0-1.9), anemia (AOR 5.0, CI 3.8-6.7), lymphoma (AOR 3.7, CI 1.3-10.6), and black race (AOR 0.7, CI 0.5-0.9). After controlling for anemia, clinical AIDS, CD4 count, neutropenia, antiretroviral therapy, and Pneumocystis carinii pneumonia prophylaxis, thrombocytopenia was significantly associated with decreased survival (risk ratio 1.7; 95% CI, 1.6-1.8). Thrombocytopenia in HIV-infected persons is an important clinical condition associated with shorter survival.

Preventing bloodborne pathogen transmission from health-care workers to patients. The CDC perspective.

The development of recommendations to manage the risk of bloodborne pathogen transmission from health-care workers to patients during invasive procedures has been difficult, primarily because of the limitations of available scientific data. Ultimately, both health-care workers and patients will be protected best by compliance with infection control precautions and by development of new instruments, protective equipment, and techniques that reduce the likelihood of intraoperative blood exposure without adversely affecting patient care.

Duration of time between exposure and seroconversion in healthcare workers with occupationally acquired infection with human immunodeficiency virus

Through December 1994, 41 healthcare workers with a documented seroconversion to human immunodeficiency virus (HIV) in temporal association to an occupational exposure were reported to the Centers for Disease Control and Prevention (CDC). Each tested positive for HIV antibodies within 12 months of the occupational exposure. Two (5%) of the 41 tested negative for HIV antibodies >6 months following the occupational exposure but were seropositive within 12 months of the injury. Both denied any subsequent exposures to HIV after the initial exposure, and in one case genetic sequencing confirmed the source of the infection. Four of the healthcare workers took postexposure zidovudine prophylaxis; each reported an acute retroviral syndrome within 6 weeks of their exposure, and each of the four seroconverted to HIV within 6 months of the exposure. Our data suggest that zidovudine prophylaxis does not delay the development of HIV antibodies beyond 6 months. Because many of the healthcare workers had follow-up testing at irregular intervals, with long periods between tests, it was not possible to define precisely when seroconversion occurred. However, our findings are compatible with previously published estimates that 95% of infected persons will develop HIV antibodies within 6 months of infection.

Toxoplasmic encephalitis in HIV-infected persons : risk factors and trends

Objective:To evaluate the incidence of and risk factors for toxoplasmic encephalitis among HIV-infected persons. Design:Medical facility-based prospective medical record reviews of consecutive patients. Methods:We analysed data collected from January 1990 through August 1995 in more than 90 inpatient and outpatient medical facilities in nine US cities. Incidence was calculated as cases per 100 person-years and risk ratios (RR) for annual incidence were calculated using proportional hazards regression while controlling for city, sex, race, age, county of birth, HIV exposure mode, and prior prescription of trimethoprim–sulfamethoxazole (TMP–SMX). Results:The incidence of TE was 4.0 cases per 100 person-years among persons with a CD4+ T-lymphocyte count of < 100×106/l. In multivariate analysis, among the nine cities the annual incidence of toxoplasmosis was significantly lower only in Denver [RR, 0.3; 95% confidence interval (CI), 0.1–0.7; referent city, Seattle]. Persons prescribed TMP–SMX were half as likely to develop toxoplasmic encephalitis as those who were not (RR, 0.5; 95% CI, 0.4–0.7). Of the 4173 persons with AIDS (1987 Centers for Disease Control and Prevention definition) who died during the study period, 267 (6.4%) had toxoplasmic encephalitis in the course of HIV disease. Conclusions:Toxoplasmic encephalitis in HIV-infected persons varies by geographic area in the United States. TMP–SMX reduces the risk for toxoplasmic encephalitis.

The Geographic Distribution of Lyme Disease in the United States

In 1982, national surveillance for Lyme disease was established by the Centers for Disease Control to monitor trends and determine endemic geographic areas. Initially, the endemic areas corresponded to the known distribution of Ixodes dammini, a five-state area of the northeastern seaboard (New York, New Jersey, Connecticut, Rhode Island, and Massachusetts) and Wisconsin and Minnesota. Increasing numbers of cases have been reported outside these areas, however, 86% of the provisional 5731 cases reported to CDC were acquired in these seven states. The number of reported cases increased from 491 in 1982 to approximately 1500 per year in 1984-1986, making Lyme disease the most commonly reported tick-borne illness in the United States. The apparently widening distribution of Lyme disease indicates that physicians in all regions of the country should be familiar with its signs and symptoms. Investigations of the vector in areas endemic for Lyme disease where Ixodes ticks are not found are warranted.