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Biomedical subjects

R Heimer

Publications and source records attributed to R Heimer.

At least 19 recordsLinked to original sources
PubMed2001

Can HIV-1-contaminated syringes be disinfected? Implications for transmission among injection drug users.

Bleaching of syringes has been advocated to prevent HIV-1 transmission among injection drug users (IDUs). Bleach is frequently distributed by needle exchange, outreach, and educational programs targeting IDUs. We applied a sensitive HIV-1 microculture assay to determine the effectiveness of bleach in disinfecting syringes contaminated with HIV-1. This study demonstrates that in a laboratory environment designed to replicate injection behaviors, undiluted bleach is highly effective in reducing the viability of HIV-1 even after minimal contact time. However, it did not reduce the HIV-1 recovery to zero. Furthermore, three washes with water were nearly as effective as a single rinse with undiluted bleach in reducing the likelihood that contaminated syringes harbored viable HIV-1. Given the reality that IDUs share syringes and may not have access to a new, sterile syringe for each injection, the results suggest that they should be encouraged through harm reduction interventions to clean their syringes, preferably with undiluted bleach.

Disinfectants↗
PubMed2000

The social geography of AIDS and hepatitis risk: qualitative approaches for assessing local differences in sterile-syringe access among injection drug users.

While significant gains have been achieved in understanding and reducing AIDS and hepatitis risks among injection drug users (IDUs), it is necessary to move beyond individual-level characteristics to gain a fuller understanding of the impact of social context on risk. In this study, 6 qualitative methods were used in combination with more traditional epidemiologic survey approaches and laboratory bioassay procedures to examine neighborhood differences in access to sterile syringes among IDUs in 3 northeastern cities. These methods consisted of (1) neighborhood-based IDU focus groups to construct social maps of local equipment acquisition and drug use sites; (2) ethnographic descriptions of target neighborhoods; (3) IDU diary keeping on drug use and injection equipment acquisition; (4) ethnographic day visits with IDUs in natural settings; (5) interviews with IDUs about syringe acquisition and collection of syringes for laboratory analysis; and (6) focused field observation and processual interviewing during drug injection. Preliminary findings from each of these methods are reported to illustrate the methods' value in elucidating the impact of local and regional social factors on sterile syringe access.

Anthropology, Cultural↗
PubMed2000

Survival of HIV-1 in syringes: effects of temperature during storage.

In a previous paper we demonstrated that HIV-1 survival in syringes was strongly associated with the volume of blood remaining and with the duration of storage at room temperature. The current study was performed to determine the effects of storage temperature upon the survival of HIV-1 inside syringes. At 4 degrees C, 50% of all syringes contained viable HIV-1 at 42 days of storage, the longest storage duration tested. At room temperature (20 degrees C), the last day that syringes with 2 microL of infected blood were positive was Day 21, and viable HIV-1 was recovered from 8% of syringes. The last day on which syringes with 20 microL were positive was Day 42, and viable HIV-1 was recovered from 8% of syringes. Above room temperature (27, 32, and 37 degrees C), the likelihood of encountering syringes with viable HIV-1 when periods of storage exceeded 1 week decreased to less than 1%. The temperatures at which drug injectors are likely to store their used syringes will vary according to climate, season, and circumstances faced by the injector. The survival of HIV-1 in contaminated syringes varied over a range of temperatures, and this may be a factor influencing the syringe-borne transmission of HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Viability of HIV-1 in syringes: implications for interventions among injection drug users.

We have determined that the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs can exceed 6 weeks. The percentage of syringes with viable virus varied with the volume of blood remaining in the syringes and the temperature at which syringes were stored. These experiments underscore the need for needle exchange programs and other HIV prevention interventions that promote the availability of clean syringes and the removal of potentially infectious ones from circulation.

Acquired Immunodeficiency Syndrome↗
PubMed1999

HIV-1 transmission in injection paraphernalia: heating drug solutions may inactivate HIV-1.

In response to recent concerns about risk of HIV-1 transmission from drug injection paraphernalia such as cookers, ethnographic methods were used to develop a descriptive typology of the paraphernalia and practices used to prepare and inject illegal drugs. Observational data were then applied in laboratory studies in which a quantitative HIV-1 microculture assay was used to measure the recovery of infectious HIV-1 in cookers. HIV-1 survival inside cookers was a function of the temperature achieved during preparation of drug solutions; HIV-1 was inactivated once temperature exceeded, on average, 65 degrees C. Although different types of cookers, volumes, and heat sources affected survival times, heating cookers 15 seconds or longer reduced viable HIV-1 below detectable levels.

Cooking↗
PubMed1999

Survival of HIV-1 in syringes.

We performed a study to determine the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs (IDUs). We describe the effectiveness of a microculture assay in detecting viable virus in volumes of blood typical of those commonly found inside used syringes. Using this assay and modeling the worse-case situation for syringe sharing, we have recovered viable, proliferating HIV-1 from syringes that have been maintained at room temperature for periods in excess of 4 weeks. The percentage of syringes with viable virus varied with the volume of residual blood and the titer of HIV-1 in the blood. These experiments provide a scientific basis for needle exchange schemes, harm reduction, and other interventions among IDUs that support the nonsharing and removal of used syringes from circulation.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Serologic testing of horses for granulocytic ehrlichiosis, using indirect fluorescent antibody staining and immunoblot analysis.

OBJECTIVE: To diagnose granulocytic ehrlichiosis in horses, compare results of indirect fluorescent antibody (IFA) staining procedures with those of immunoblot analysis, and compare serologic test findings with polymerase chain reaction (PCR) results. ANIMALS: 69 horses with high rectal temperatures (> or = 39 C) and lethargy, anorexia, or limb edema. PROCEDURE: 43 convalescent serum samples obtained from 38 horses 2 to 18 weeks after onset of illness were analyzed by use of immunoblot procedures and IFA staining methods, using the NCH-1 or BDS ehrlichial strains. Blood samples from 69 acutely ill horses were tested by PCR to detect ehrlichial DNA. RESULTS: Antibodies to Erlichial equi were detected in serum samples obtained during all seasons; seropositivity rates ranged from 50 to 93%. In IFA assays using the BDS or NCH-1 strain, seropositivity rates were 70 and 79%, respectively, whereas in immunoblot analyses using the NCH-1 strain, a seropositivity value of 79% was recorded. By immunoblot analysis, all serum samples of all seropositive horses were reactive to a protein having molecular mass of about 44 kd. Blood samples from 29 of 69 (42%) acutely ill horses contained ehrlichial DNA. CONCLUSION AND CLINICAL RELEVANCE: Results of the various serologic testing procedures were in close agreement with each other. All serologic testing methods are suitable for laboratory diagnosis of equine granulocytic ehrlichiosis.

Animals↗
PubMed1998

Detection of HIV-1 nucleic acid and HIV-1 antibodies in needles and syringes used for non-intravenous injection.

BACKGROUND: HIV antibodies and HIV DNA have been detected in needles and syringes that have been used for intravenous injections in HIV-infected persons. During intravenous injection, blood is typically aspirated into the lumen of the syringe. During intramuscular or subcutaneous injection, however, blood is not usually introduced into the syringe. OBJECTIVES: To investigate the presence of HIV antibodies, HIV proviral DNA, HIV RNA, and human DNA in needles and syringes that had been used for intramuscular or subcutaneous injection in persons known to have HIV infection. METHODS: Discarded disposable needles and syringes used by health-care personnel for medically indicated intramuscular or subcutaneous injections of HIV-infected patients were collected. Residual material was extracted from the syringes. The extracts were analyzed by enzyme immunoassay for the presence of HIV antibodies. PCR was conducted to detect HIV and human DNA, as well as HIV RNA. RESULTS: HIV antibodies were detected in 16 (6.2%) out of 260 syringes. Human DNA or HIV-specific DNA were not detected. A second set of 80 syringes was collected to examine the presence of HIV RNA. HIV RNA was detected in three (3.8%) out of 80 syringes. CONCLUSION: This analysis demonstrates that the risk of transmitting HIV from syringes that have been used for intramuscular or subcutaneous injection may be low, but is not zero.

DNA, Viral↗
PubMed1998

Development and duration of antibody response against Ehrlichia equi in horses.

OBJECTIVE: To characterize antibody response in horses with clinical signs of Ehrlichia equi infection. DESIGN: Prospective study. ANIMALS: 13 horses with confirmed acute E equi infection. PROCEDURE: Sequential serum sampling was performed in Connecticut and New York during 1995 and 1996 to identify horses with naturally acquired equine granulocytic ehrlichiosis (EGE). Horses with clinical signs of EGE (i.e., fever without respiratory involvement) were confirmed as having E equi infection by polymerase chain reaction detection of ehrlichial DNA and by a minimum fourfold increase in total antibody titer by indirect fluorescent antibody staining methods. Infection was corroborated by use of DNA sequencing. RESULTS: 11 of 13 horses did not have detectable antibody in serum samples obtained at onset of disease. Seroconversion was evident in samples obtained 19 to 81 days thereafter. Median time to peak antibody response was 46 days after onset and median titer was 1:320. For 11 of 13 horses, antibody titers were < or = 1:40 by 215 days after onset. CLINICAL IMPLICATIONS: E equi was found in horses in the northeastern United States and caused EGE. Concentration of antibodies to E equi increased within 19 to 81 days of disease onset and were low during early weeks of infection. Therefore, antibody detection may be of limited value for early serologic diagnosis. We suggest that disease may develop from a reinfection, and retrospective serologic studies to determine exposure to E equi may reflect a disproportionate number of negative reactions.

Acute Disease↗
PubMed1998

Reactivity of human sera to different strains of granulocytic ehrlichiae in immunodiagnostic assays.

Sera from 35 patients diagnosed with human granulocytic ehrlichiosis in Connecticut were tested by indirect IFA staining methods with 5 strains of Ehrlichia equi or the human granulocytic ehrlichiosis agent to assess the suitability of different strains in laboratory analyses. Antigens included horse-derived infected neutrophils (MRK and BDS strains) and human isolates cultured in human promyelocytic leukemia cells (NCH-1, RCH, and Webster). Of 35 sera, 23 (65.7%) reacted to all 5 strains. Seropositivity was highest (97.1%) in assays that contained the MRK strain from California and lowest (71. 4%) in tests with the NCH-1 strain from Nantucket, Massachusetts. In parallel testing of 32 sera with the NCH-1 strain by indirect IFA and Western blot analyses, results were concordant for 30 samples (93.8%). All strains of ehrlichiae can be used in IFA analyses for antibody detection, but assay sensitivity varied with the strain used.

Animals↗
PubMed1998

Syringe use and reuse: effects of syringe exchange programs in four cities.

We determined the effect of syringe exchange programs (SEPs) on syringe reuse patterns. Five methods were employed to estimate injections per syringe made by exchange clients in four cities. In San Francisco, Chicago, and Baltimore, self-reported data on the number of injections per syringe were obtained. In New Haven, self-reported injection frequencies were combined with syringe tracking data to derive two methods for estimating the mean injections per syringe. The average number of injections per syringe declined by at least half after establishment of SEPs in New Haven, Baltimore, and Chicago, all cities where such an analysis could be made. There were significant increases in the percentages of exchangers reporting once-only use of their syringes in San Francisco, Baltimore, and Chicago, all cities where the data were amenable to this form of analysis. Self-report and syringe tracking estimates were in agreement that SEP participation was associated with decreases in syringe reuse by drug injectors. SEP participation was associated with increases in the once-only use of syringes. These findings add to earlier studies supporting the role of SEPs in reducing the transmission of syringe-borne infections such as HIV and hepatitis.

Baltimore↗
PubMed1998

A single tissue culture system for the propagation of the agents of the human ehrlichioses.

Two newly emergent human diseases found in the United States, human monocytotropic ehrlichiosis (HME) and human granulocytotropic ehrlichiosis (HGE), are caused by pathogens of the genus Ehrlichia. The causative agent of HGE can be propagated in HL-60 human promyelocytic leukemia cells. Herein, we report the development of a method to propagate E. chaffeensis, the causative agent of HME, in HL-60 cells, thus providing a common system for the study of both species. The continuous propagation of E. chaffeensis requires the induction of HL-60 differentiation along the monocytic pathway toward phenotypically mature macrophages by the addition of 25-OH vitamin D3 to the growth medium.

Animals↗
PubMed1998

Syringe exchange programs: lowering the transmission of syringe-borne diseases and beyond.

OBJECTIVE: This chapter attempts to describe the factors influencing the transmission of syringe-born viruses, to review the effects of syringe exchange programs (SEPs) in terms of these factors, and to explore the gamut of health-promoting activities of SEPs. RESULTS: The chapter is divided into six sections: biological factors in syringe-borne viral transmission, behavior and viral transmission, quantifying viral transmission, preventing viral transmission, impediments to preventing viral transmission, and research for preventing viral transmission. Understanding how biological and behavioral factors influence transmission of human immunodeficiency virus (HIV) and hepatitis builds a framework to investigate the epidemiology and the impact of SEPs on disease transmission. Even under circumstances in which these programs do not appear to be effective, understanding the implications of the biological and behavioral factors can contribute to our understanding of program benefits and limitations. Furthermore, program benefits may not be restricted to direct effects on disease transmission. Many programs offer services to drug injectors that include risk reduction training, facilitated entry into substance abuse treatment, and medical care. CONCLUSIONS: SEPs can reduce the transmission of syringe-borne viruses without increasing illicit drug use. However, lack of resources, acceptance, and consequently, protection of many of those at risk when they are most vulnerable have hampered program effectiveness. New studies need to be designed to explicate the full measure of program benefit within covered communities and identify the means by which SEPs can expand benefit to individuals at greatest risk.

Community-Institutional Relations↗
PubMed1997

Propagation of granulocytic Ehrlichia spp. from human and equine sources in HL-60 cells induced to differentiate into functional granulocytes.

Ehrlichia spp. from human and equine sources in the northeastern Unites States were detected by PCR, isolated, and propagated in the HL-60 promyelocytic leukemia cell line. Growth of Ehrlichia from both equine and human sources was enhanced by addition of retinoic acid, which causes granulocytic differentiation of the HL-60 cells. DNA sequencing of a portion of the 16S rDNA gene supported the hypothesis that the same pathogen was responsible for both equine and human granulocytic ehrlichiosis.

Animals↗
PubMed1996

Hepatitis in used syringes: the limits of sensitivity of techniques to detect hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA, and antibodies to HBV core and HCV antigens.

Hepatitis virus infections are common among injecting drug users. Syringes containing hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA were identified by polymerase chain reaction (PCR); syringes containing antibodies to HBV core antigen and HCV were identified by EIA. Syringe use was simulated to determine the sensitivity of these assays. The mean limits for PCR were 0.082 microliter of blood for HBV and 0.185 microliter for HCV; the mean limits for EIA were 0.185 microliter for HBV and 0.023 microliter for HCV. HBV PCR testing of 681 syringes returned to the needle exchange program in New Haven, Connecticut, revealed a decline from 7.8% HBV-positive at the program's outset to 2.6%. HCV antibodies were found in 12.1% of 207 syringes tested. Syringe testing can help estimate the prevalence and incidence of hepatitis virus infections when standard seroepidemiologic analyses cannot be applied.

Base Sequence↗