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Biomedical subjects

D Vlahov

Publications and source records attributed to D Vlahov.

At least 91 records · Page 5Linked to original sources
PubMed2000

Trends in crime and the introduction of a needle exchange program.

OBJECTIVES: This study sought to determine whether introduction of a needle exchange program would be associated with increased crime rates. METHODS: Trends in arrests were compared in program and nonprogram areas before and after introduction of a needle exchange program in Baltimore. Trends were modeled and compared via Poisson regression. RESULTS: No significant differences in arrest trends emerged. Over the study period, increases in category-specific arrests in program and nonprogram areas, respectively, were as follows: drug possession, 17.7% and 13.4%; economically motivated offenses, 0.0% and 20.7%; resistance to police authority, 0.0% and 5.3%; and violent offenses, 7.2% and 8.0%. CONCLUSIONS: The lack of association of overall and type-specific arrest data with program implementation argues against the role of needle exchange programs in increasing crime rates.

Adult↗
PubMed2000

The effect of a needle exchange program on numbers of discarded needles: a 2-year follow-up.

OBJECTIVES: This study estimates the quantity and geographic distribution of discarded needles on the streets of Baltimore, Md, during the 2 years after a needle exchange program opened. METHODS: Thirty-two city blocks were randomly sampled. Counts were taken of the number of syringes, drug vials, and bottles before the needle exchange program opened and then at 6 periodic intervals for 2 years after the program opened. Nonparametric and generalized estimating equation models were used to examine change over time. RESULTS: Two years after the needle exchange program opened, there was a significant decline in the overall quantity of discarded needles relative to that of drug vials and bottles (background trash). The block mean of number of needles per 100 trash items was 2.42 before the program opened and 1.30 2 years later (mean within-block change = -0.028, P < .05). There was no difference in the number of discarded needles by distance from the program site. CONCLUSIONS: These data suggest that this needle exchange program did not increase the number of distribution of discarded needles.

Baltimore↗
PubMed1999

Prevalence and incidence of HIV among incarcerated and reincarcerated women in Rhode Island.

This study explores recent temporal trends in HIV prevalence among women entering prison and the incidence and associated risk factors among women reincarcerated in Rhode Island. Results from mandatory HIV testing from 1992 to 1996 for all incarcerated women were examined. In addition, a case control study was conducted on all seroconverters from 1989 to 1997. In all, 5836 HIV tests were performed on incarceration in 3146 women, 105 of whom tested positive (prevalence, 3.3%). Between 1992 and 1996, the annual prevalence of HIV among all women known to be HIV-positive was stable (p = .12). Age >25 years, nonwhite race, and prior incarceration were associated with seropositivity. Of 1081 initially seronegative women who were retested on reincarceration, 12 seroconverted during 1885 person-years (PY) of follow-up (incidence, 0.6/100 PY). Self-reported injection drug use (IDU; odds ratio [OR], 3.7; 95% confidence interval [CI], 1.3-10.1) was significantly associated with seroconversion, but sexual risk was not (OR, 1.1; 95% CI, 0.4-3.5). Incarceration serves as an opportunity for initiation of treatment and linkage to community services for a population that is at high risk for HIV infection.

Case-Control Studies↗
PubMed1999

Reduced risk of AIDS lymphoma in individuals heterozygous for the CCR5-delta32 mutation.

Non-Hodgkin's lymphoma (NHL) has been increasing in frequency in the industrialized world, but the environmental and genetic factors that contribute to susceptibility are not known. B-cell lymphomas represent a major cause of morbidity and mortality in HIV-infected individuals. The identification of a deletion in the CCR5 chemokine receptor gene that alters the risk for infection and progression to AIDS led us to examine a potential role of this gene in AIDS lymphoma. A matched case-control analysis was performed using all eligible NHL cases in the Multicenter AIDS Cohort Study. Patients were matched for age, study center, time AIDS-free, and slope of the CD4+ T-cell decline. The CCR5-delta32 allele was found to be associated with a 3-fold lower risk of NHL among individuals after controlling for time of infection and progression toward AIDS. The CCR5 gene was not associated with a difference in risk for Kaposi's sarcoma, another common malignancy in AIDS patients, or opportunistic infections. Costimulation of normal phorbol 12-myristate 13-acetate-treated B cells with the CCR5 ligand RANTES induced a proliferative response, indicating that RANTES is a mitogen for B cells. Taken together, these findings suggest that the CCR5 gene plays a role in the risk of NHL in HIV-infected patients, perhaps through a mechanism involving a decreased response of B cells to the mitogenic activity of RANTES.

AIDS-Related Opportunistic Infections↗
PubMed1999

Comparison of clinical manifestations of HIV infection among women by risk group, CD4+ cell count, and HIV-1 plasma viral load. HER Study Group. HIV Epidemiology Research.

OBJECTIVES: To compare the prevalence of HIV-related symptoms, physical examination findings, and hematologic variables among women whose risk for HIV is injection drug use since 1985 as opposed to sexual contact and to evaluate the influence of HIV plasma viral load and CD4+ cell count on clinical manifestations according to risk. METHODS: Participants of the HIV Epidemiology Research Study (HERS; a multicenter, prospective, controlled study of HIV infection in women) were administered a risk behavior and symptom interview, underwent a physical examination, and received hematologic testing, including CD4+ cell counts done on study entry. Plasma HIV-1 viral loads were performed on stored frozen plasma using an ultrasensitive branched-DNA (b-DNA) signal amplification assay. CD4+ counts were categorized as <200 cells/microl, 200 to 499 cells/microl, or > or =500 cells/microl, and HIV viral loads were characterized in tertiles. RESULTS: Cross-sectional analysis was conducted on data available for 724 HIV-infected women: 387 had a history of intravenous drug use and 337 were infected through heterosexual contact. The median CD4+ count was 376 cells/microl; the median HIV-1 viral load was 1135 copies/ml; and 281 of 724 HIV-infected women (38.8%) had an undetectable HIV-1 viral load. In analyses adjusting for CD4+ cell level alone and for plasma viral load combined with CD4+ cell level, injection drug users (IDUs) were more likely than those infected through heterosexual contact to report a recent episode of memory loss and weight loss, but less likely to have recent episodes of genital herpes; to have enlarged livers and a body mass index (BMI) <24, and to have hematocrit levels <34% and platelet counts <150,000 cells/ml. After adjustment for CD4+ cell level and risk group, high and medium HIV-1 plasma viral load levels were associated with the presence of oral hairy leukoplakia on examination, and only the highest level of plasma viral load was associated with recent histories of fever and thrush, oral hairy leukoplakia, pseudomembranous candidiasis, and BMI <24 on examination, and hematocrit <34%. CONCLUSIONS: In this cohort of women, the distribution of HIV-1 plasma viral load was lower than that previously reported in populations of HIV-infected men. This study also shows some differences in frequency of signs, symptoms, and laboratory values between risk groups of HIV-infected women, but these results may be due to effects of injection drug use rather than HIV infection. Signs and symptoms identified as associated with increasing levels of viral load that were not different across risk groups suggest more direct association of these findings with HIV infection.

Adult↗
PubMed1999

New evidence to reconcile in vitro and epidemiologic data on the possible role of heroin on CD4+ decline among HIV-infected injecting drug users.

Long-term effects of drug type and other drug use related risk factors on CD4+ cell decline were assessed in 224 HIV-infected injecting drug users (IDUs) from Baltimore (ALIVE), USA, and 63 IDUs from Amsterdam, The Netherlands. Higher frequencies of borrowing used injection equipment since 1980 resulted in a higher CD4+ count already present before seroconversion (P = 0.049). Use of mainly heroin in the seroconversion interval resulted in a sharper CD4+ decline until the first 6 months after seroconversion (P = 0.004), but CD4+ values converged later on. This finding might reconcile earlier discordant epidemiological and laboratory study results regarding the possible effects of heroin.

Adult↗
PubMed1999

HLA and HIV-1: heterozygote advantage and B*35-Cw*04 disadvantage.

A selective advantage against infectious disease associated with increased heterozygosity at the human major histocompatibility complex [human leukocyte antigen (HLA) class I and class II] is believed to play a major role in maintaining the extraordinary allelic diversity of these genes. Maximum HLA heterozygosity of class I loci (A, B, and C) delayed acquired immunodeficiency syndrome (AIDS) onset among patients infected with human immunodeficiency virus-type 1 (HIV-1), whereas individuals who were homozygous for one or more loci progressed rapidly to AIDS and death. The HLA class I alleles B*35 and Cw*04 were consistently associated with rapid development of AIDS-defining conditions in Caucasians. The extended survival of 28 to 40 percent of HIV-1-infected Caucasian patients who avoided AIDS for ten or more years can be attributed to their being fully heterozygous at HLA class I loci, to their lacking the AIDS-associated alleles B*35 and Cw*04, or to both.

Acquired Immunodeficiency Syndrome↗
PubMed1999

HIV prevalence and risk behaviors among new initiates into injection drug use over the age of 40 years old.

Injection drug users (IDUs) who have recently initiated an injecting career have high risk behaviors for HIV infection. The average age of an IDUs first injection is typically reported as 19-20 years, and some literature has reported 'maturing out' of drug use typically around 40 years old. The purpose of this study was to discriminate risk behaviors among newer injectors by age of initiation. This cross-sectional study includes volunteers enrolled using extensive community recruitment techniques in 1988 and 1989 in Baltimore, MD. Of the 722 injection drug users who had initiated injection within the prior six years, 124 were over 35 years old of whom 53 were 40 years and older. Rates of HIV were lower among those over 40 years (13.2%) than those who were 35-39 years (22.5%) or under 35 years old (20.9%). The behavioral characteristics of those aged 35-39 were similar to those under 35 years old, but those over 40 years old when compared with less than 39 years reported injecting at least daily less frequently (88.7% vs 76.5%, p = 0.042), using a needle from a sterile wrapper (19.0% vs 36.6%, p = 0.006), and injecting with their own works (52.6% vs 28.8%, p = 0.021). This study shows that people initiate injection drug use across a wide age range and that needle hygiene practices early after initiation tend to be safer in older compared to younger initiates.

Adult↗
PubMed1999

Direct comparison of time to AIDS and infectious disease death between HIV seroconverter injection drug users in Italy and the United States: results from the ALIVE and ISS studies. AIDS Link to Intravenous Experiences. Italian Seroconversion Study.

OBJECTIVE: To compare the rate of HIV disease progression in a sample of polydrug injectors (AIDS Link to Intravenous Experiences [ALIVE] study) with that in a sample of predominantly opiate injectors (Italian Seroconversion Study [ISS]). DESIGN: Prospective cohort studies of HIV-positive individuals whose date of seroconversion (SC) is known with a good degree of precision. The ALIVE study involves a community-based cohort of injection drug users (IDU) in the United States and the ISS reports on a clinic-based cohort of seroconverters in Italy with different exposure modalities to HIV. METHODS: Data from the two cohorts were combined. The date of SC was estimated as the midpoint in time between the last negative and the first positive HIV test. Time-to-event (i.e., AIDS or death from an infectious disease) statistical methods were used. Relative hazards (RH) of progression to event were adjusted by age at SC, gender, and year of SC. RESULTS: Of the 1003 IDUs (251 from ALIVE and 752 from ISS), 226 progressed to AIDS, and 146 died after AIDS or from an infectious disease; of these, 10 were without an AIDS diagnosis. The two groups of IDUs differed in terms of age at SC (median, 35 years for ALIVE and 25 years for ISS), proportion of women (24% versus 31%), race (7.6% versus 100% white), and year of seroconversion (i.e., ISS participants seroconverted, on average, earlier than ALIVE participants). Although the univariate analysis suggested possible differences for progression to AIDS, or to death from infectious disease between cohorts, multivariate analyses that adjusted for age showed no significant differences by cohort, gender, race, or time of seroconversion. The median time to AIDS for 25-year-old persons was 12.3 years for ALIVE and 11.8 years for ISS; for 35-year-old persons, it was 8.5 and 8.2 years, respectively. These estimates were similar to those for non-IDUs observed in the ISS and to those from large cohort of homosexual men. CONCLUSION: Our results confirm the importance of accounting for age when considering the incubation period for HIV infection. Despite differences in drug use characteristics, the similar median times to AIDS, for each age, between the two cohorts of IDUs and between the IDUs and the non-IDUs suggest a negligible effect of injection drug use on HIV progression.

Acquired Immunodeficiency Syndrome↗
PubMed1999

A prospective, community-based evaluation of liver enzymes in individuals with hepatitis C after drug use.

Serum alanine transaminase (ALT) levels are used to select hepatitis C virus (HCV)-infected patients for treatment and liver biopsy. However, the natural history of these measurements is poorly understood. To examine the hypothesis that ALT levels vary over time in HCV-infected patients, serial serum ALT levels were prospectively measured in a cohort of 1,235 persons with a history of prior illicit drug use. Over 25 months of follow-up, there was a median of four evaluations per patient. ALT values were higher in 1,164 (94%) HCV-infected individuals than in 71 (6%) HCV-uninfected individuals. The remainder of the analysis focused on these HCV-infected individuals, 647 (62%) of whom had normal ALT values at their initial visit. However, 323 (49%) of these had at least one elevated ALT over the next 25 months. Of the 395 patients whose ALT was initially abnormal, 332 (84%) had at least one normal value over the next 25 months. Overall, among individuals with four or more visits, ALT values were persistently normal in 42%, persistently elevated in 15%, and intermittently elevated in 43%. Because serum ALT levels have high visit-to-visit variability, single assessments should not be used to manage HCV-infected individuals. Further investigation is needed to ascertain the correlation of serial ALT trends with important disease outcomes.

Adult↗
PubMed1999

Persistence of viremia and the importance of long-term follow-up after acute hepatitis C infection.

The purpose of this investigation was to prospectively characterize acute hepatitis C virus (HCV) infections and to evaluate the hypothesis that the outcome is affected by identifiable clinical or viral factors. One hundred forty-two people with a history of illicit drug use who were HCV antibody-negative in 1988 were followed semiannually through 1996. HCV seroconversion (second generation enzyme immunoassay and recombinant immunoblot assay) was recognized in 43 (30%) of the participants, who were followed up for a median of 72 months. HCV RNA was detected and quantified by polymerase chain reaction in a median of 10 specimens per participant and showed two distinct patterns of viremia: viral clearance was noted in 6 (14%) of the participants, and viral persistence was observed in 37 (86%) of the participants. Subjects with viral clearance were more likely to be white (P =.004), have jaundice (P =.03), and have lower peak viral titer (P =.003). However, the outcome for a given person could not be predicted by clinical features, RNA level, or HCV subtype (as ascertained by analysis of core-E1 complementary DNA sequence). No acute infections were recognized by health care providers. At the time of seroconversion, HCV RNA was detectable in 81% of participants, and recombinant immunoblot assay (RIBA) was positive in 85% of participants. We conclude that approximately 85% of people with acute hepatitis C develop persistent viremia. However, acute infections are uncommonly recognized clinically, underscoring the importance of screening individuals at risk. Long-term follow-up, but no single laboratory test, is necessary to ascertain the outcome and in some cases make the diagnosis of acute HCV infection.

Adult↗
PubMed1999

Needle-exchange attendance and health care utilization promote entry into detoxification.

This study was undertaken to identify factors associated with entry into detoxification among injection drug users (IDUs), and to assess the role of needle-exchange programs (NEPs) as a bridge to treatment. IDUs undergoing semiannual human immunodeficiency virus (HIV) tests and interviews were studied prospectively between 1994 and 1998, during which time an NEP was introduced in Baltimore. Logistic regression was used to identify independent predictors of entry into detoxification, stratifying by HIV serostatus. Of 1,490 IDUs, similar proportions of HIV-infected and uninfected IDUs entered detoxification (25% vs. 23%, respectively). After accounting for recent drug use, hospital admission was associated with four-fold increased odds of entering detoxification for HIV-seronegative subjects. Among HIV-infected subjects, hospital admission, outpatient medical care, and having health insurance independently increased the odds of entering detoxification. After accounting for these and other variables, needle-exchange attendance also was associated independently with entering detoxification for both HIV-infected (adjusted odds ratio [AOR] = 3.2) and uninfected IDUs (AOR = 1.4). However, among HIV-infected subjects, the increased odds of detoxification associated with needle exchange diminished significantly over time, concomitant with statewide reductions in detoxification admissions. These findings indicate that health care providers and NEPs represent an important bridge to drug abuse treatment for HIV-infected and uninfected IDUs. Creating and sustaining these linkages may facilitate entry into drug abuse treatment and serve the important public health goal of increasing the number of drug users in treatment.

Adult↗
PubMed1999

Evaluating supervised HAART in late-stage HIV among drug users: a preliminary report.

OBJECTIVE: To examine response to highly active antiretroviral therapy (HAART) among a sample of treatment-experienced patients in the late stage of human immunodeficiency virus (HIV) infection in residential health care facilities (RHCFs) in New York City facilities designated for HIV/AIDS (acquired immunodeficiency syndrome) when access and adherence are maximized. METHODS: Medical record review of 111 patients. RESULTS: Demographics were mean age 42 years; 58% male; 60% African-American; 31% Hispanic; 57% injection drug users (IDUs); 23% with history of dementia; 52% hepatitis C virus (HCV) antibody seropositive; 80% on HAART, of whom 18% had lipodystrophy. Of 88 patients on HAART, 52% had a decreased viral load (>1/2 log) versus 13% of 23 not on HAART (P<.05); a >1/2 log viral load increase was seen in 8% and 35%, respectively (P<.05). Those with viral load increase were more likely than those with stable/decreased viral load to be IDUs (71% vs. 64%) and to have HCV seropositivity (86% vs. 53%), even with similar initial CD4+ cell count, viral load, and follow-up time. CONCLUSION: In a predominantly minority IDU population who are treatment experienced, 50% of the patients successfully responded to treatment with supervised therapy. The RHCFs in New York City provide a unique opportunity to examine further factors associated with response to HAART in an environment in which medication administration and adherence are maximized and monitored carefully.

Adult↗
PubMed1999

Criteria for assessing cutaneous anergy in women with or at risk for HIV infection. HIV Epidemiologic Research Study Group.

BACKGROUND: Controversy exists about both the clinical utility of anergy testing and the optimal criteria for defining anergy. OBJECTIVE: We sought to assess various definitions of cutaneous anergy for ability to distinguish HIV status, level of immunodeficiency, and ability to mount a tuberculin reaction among women with or at risk for HIV infection. METHODS: HIV-seropositive (n = 721) and HIV-seronegative (n = 358) at-risk women at academic medical centers in Baltimore, Detroit, New York, and Providence had cutaneous testing with mumps, Candida, tetanus toxoid, and tuberculin antigens. Associations with HIV status and CD4+ lymphocyte levels were analyzed. RESULTS: Candida, mumps, and tetanus antigens alone or in combination elicited reactions significantly less often in HIV-seropositive than in HIV-seronegative women and less often in seropositive women with lower CD4+ counts, regardless of induration cutpoint chosen to define a positive reaction. The best antigen combinations for distinguishing groups included tetanus and mumps. Some women nonreactive to the 3 antigens ("anergic") had positive tuberculin reactions among both seropositive subjects (range, 1.1% to 2.9% depending on induration cutpoint for defining anergy) and seronegative subjects (range, 8.9% to 14%). CONCLUSION: Absence of reactions to Candida, mumps, and tetanus antigens alone or in combination and at any induration cutpoint is associated with HIV status and with CD4+ level. Combinations, including tetanus and mumps antigens with an induration cutpoint of less than 2 mm, may be the best for defining anergy.

Antigens, Fungal↗
PubMed1999

Cell-associated infectious HIV-1 viral load as a predictor of clinical progression and survival among HIV-1 infected injection drug users and homosexual men.

Cell-associated infectious HIV-1 viral load was measured using semi-quantitative microculture techniques to determine its predictive capability for progression to AIDS or survival among HIV-1 infected injecting drug users (IDU) and homosexual men (HM). The authors followed 296 IDU and 240 HM from February 1992 through September 1995 for: (i) death, (ii) AIDS, and (iii) AIDS or bacterial infection. At baseline, viral load was quantified using microculture techniques to determine infectious units per million peripheral blood mononuclear cells (IUPM). Data were analyzed using standard statistical methods for survival analysis. Of the 536 total participants, 106 died (20%), and 98 of the 481 AIDS-free participants developed AIDS (20%). The relative hazard of AIDS for a viral load of > or = 100 IUPM, relative to a negative culture (0 IUPM), was 6.73 (95% CI: 2.23-20.3) after adjusting for risk group, initial CD4+ count, and other covariates. The adjusted relative hazard of death for a viral load of > or = 100 IUPM vs. 0 IUPM was 2.57 (95% CI: 0.97 6.80). Viral load predicted time to death within the < 200 cells/ul CD4+ stratum. The predictive value of viral load on HIV-1 progression did not vary by risk group. These data show that cell associated infectious HIV-1 viral load was significantly predictive of progression across risk groups for AIDS and death among those severely immune compromised.

AIDS-Related Opportunistic Infections↗
PubMed1999

Prevalence of lower genital tract infections among human immunodeficiency virus (HIV)-seropositive and high-risk HIV-seronegative women. HIV Epidemiology Research Study Group.

This study was undertaken to assess whether the prevalence of lower genital tract infections among human immunodeficiency virus (HIV)-seropositive women was higher than among high-risk HIV-seronegative women at their baseline visit for the HIV Epidemiology Research Study. Results were available for 851 HIV-seropositive and 434 HIV-seronegative women. Human papilloma virus (HPV) infection was more prevalent among HIV-seropositive women (64% vs. 28%). Bacterial vaginosis was common (35% vs. 33%), followed by trichomoniasis (12% vs. 10%), syphilis (8% vs. 6%), Chlamydia trachomatis infection (4% vs. 5%), candidal vaginitis (3% vs. 2%), and Neisseria gonorrhoeae infection (0.8% vs. 0.3%). Alcohol use (odds ratio [OR], 1.8; 95% confidence interval [CI], 1. 3-2.4) and smoking (OR, 1.8; 95% CI, 1.3-2.5) were associated with bacterial vaginosis. Bacterial vaginosis (OR, 2.3; 95% CI, 1.5-3.4), trichomoniasis (OR, 2.3; 95% CI, 1.1-4.7), and syphilis (OR, 3.1; 95% CI, 1.3-7.4) were found to be more prevalent among black women. Our study showed no statistically significant difference in the prevalence of lower genital tract infections except for HPV between HIV-infected and demographically and behaviorally similar HIV-uninfected high-risk women.

Adult↗