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David Vlahov

Publications and source records attributed to David Vlahov.

At least 145 records · Page 8Linked to original sources
PubMed2003

A tumor necrosis factor-alpha-inducible promoter variant of interferon-gamma accelerates CD4+ T cell depletion in human immunodeficiency virus-1-infected individuals.

A polymorphism, -179G/T, in the promoter of the interferon (IFN)-gamma gene (IFNG) confers differential tumor necrosis factor-alpha (TNF-alpha) inducibility to the IFNG promoter. The rarer allele, -179T, but not -179G, is inducible by TNF-alpha. We investigated the effects of IFNG -179G/T on AIDS pathogenesis. In 298 African American human immunodeficiency virus (HIV)-1 seroconverters, the IFNG -179G/T genotype was associated with accelerated progression to CD4 <200 and AIDS-1993, a finding suggesting that IFNG -179T is a risk factor for AIDS progression, as measured by CD4 cell count. It is possible that increased IFN-gamma production induced by TNF-alpha when -179T is present causes CD4 cell depletion by apoptosis.

Adult↗
PubMed2003

Income distribution and risk of fatal drug overdose in New York City neighborhoods.

Accidental drug overdose is a substantial cause of mortality for drug users. Neighborhood-level factors, such as income distribution, may be important determinants of overdose death independent of individual-level factors. We used data from the Office of the Chief Medical Examiner to identify all cases of accidental deaths in New York City (NYC) in 1996 and individual-level covariates. We used 1990 US Census data to calculate the neighborhood-level income distribution. This multi-level case-control study included 725 accidental overdose deaths (cases) and 453 accidental deaths due to other causes (controls) in 59 neighborhoods in NYC. Overdose deaths were more likely in neighborhoods with higher levels of drug use and with more unequal income distribution. In multi-level models, income maldistribution was significantly associated with risk of overdose independent of individual-level variables (age, race, and sex) and neighborhood-level variables (income, drug use, and racial composition). The odds of death due to drug overdose were 1.63-1.88 in neighborhoods in the least equitable decile compared with neighborhoods in the most equitable decile. Disinvestment in social and economic resources in unequal neighborhoods may explain this association. Public health interventions related to overdose risk should pay particular attention to highly unequal neighborhoods.

Adolescent↗
PubMed2003

Haplotype diversity in the interleukin-4 gene is not associated with HIV-1 transmission and AIDS progression.

Interleukin-4 (IL-4) is a pleiotropic cytokine produced primarily by activated CD4(+) T lymphocytes, mast cells, and basophils. It modulates the functions of a variety of cell types involved with the immune response. This cytokine differentially regulates two major HIV-1 coreceptors and activates viral expression, and is thus a reasonable candidate gene for analyses in HIV-1/AIDS cohort studies. Population genetic variation in five single nucleotide polymorphisms (SNPs) in the 5' region of the IL-4 gene was assessed in five racial groups. Neutrality tests reveal that the populations are evolving in accord with the infinite-sites model. However, coalescent simulations suggest greater haplotype diversity among African Americans than expected. This increased variation is presumably attributable to recombination or gene conversion. Genetic epidemiological analyses were conducted among European American and African American participants enrolled in five USA-based HIV-1/AIDS cohorts. One SNP, -589T, known to influence IL-4 transcription was previously shown to be associated with HIV-1/AIDS in both Japanese and French populations. Present analyses failed to identify any significant associations with HIV-1 infection or progression to AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Prevalence of and risk factors for viral infections among human immunodeficiency virus (HIV)-infected and high-risk HIV-uninfected women.

Viruses that can persist in the host are of special concern in immunocompromised populations. Among 871 human immunodeficiency virus (HIV)-infected and 439 high-risk HIV-uninfected women, seroprevalences of cytomegalovirus, hepatitis B virus, hepatitis C virus, and herpes simplex virus types 1 and 2 and prevalence of human papillomavirus DNA in cervicovaginal lavage fluids were all >50% and were 2-30 times higher than prevalences in the general population. Prevalences were highest among HIV-infected women, of whom 44.2% had >or=5 other infections, and were relatively high even among the youngest women (age 16-25 years). In multivariate analyses, viral infections were independently associated not only with behaviors such as injection drug use and commercial sex but also with low income, low levels of education, and black race. Disadvantaged women and women who engage in high-risk behaviors are more likely to be coinfected with HIV and other viruses and, thus, may be at high risk of serious disease sequelae.

AIDS-Related Opportunistic Infections↗
PubMed2003

Psychological distress and progression to AIDS in a cohort of injection drug users.

OBJECTIVE: We investigated whether distress was independently associated with more rapid progression to AIDS among HIV-infected injection drug users (IDUs). DESIGN: A cohort study of IDUs in Baltimore followed from 1988 through 1999. A total of 451 IDUs met the eligibility criteria of being HIV-seropositive but AIDS-free at baseline. METHODS: We used Cox proportional hazards models to investigate progression to AIDS within 2 years of baseline, controlling for CD4 lymphocyte count, HIV-1 viral load, and oral thrush. RESULTS: Of the 451 participants, 76.3% were male and 95.8% were African-American; the median age at enrollment was 34 years. The cumulative incidence of AIDS within 2 years of baseline was 7.1%. In multiple regression analysis, distress was associated with more rapid time to AIDS (adjusted relative hazard [RH] = 2.39; 95% CI: 1.16-4.90). The strongest association was observed among IDUs with the lowest (<200 x 10 /L) CD4 counts (adjusted RH = 4.94; 95% CI: 1.30-18.77). CONCLUSIONS: Psychological distress was independently associated with shorter time to AIDS among HIV-infected IDUs, especially among those with the lowest CD4 cell counts, but was not predictive of mortality in this cohort. Further study of the effects of psychological distress on AIDS progression within this population is warranted.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Variability in the incidence of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus infection among young injecting drug users in New York City.

Cohort studies of young (aged 18-30 years) injecting drug users recruited in 1997-1999 in the Harlem and Lower East Side areas of New York City, New York, were used to assess the incidence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). The authors found that HIV incidence was low at both sites: 0.8/100 person-years at the Harlem site and 0/100 person-years at the Lower East Side site. In contrast, HBV incidence was moderate (12.2/100 person-years) at the Harlem site and high (30.7/100 person-years) at the Lower East Side site. Similarly, HCV incidence was moderate (9.3/100 person-years) at the Harlem site and high (34.0/100 person-years) at the Lower East Side site. Results show that high rates of HBV and HCV transmission do not imply high rates of HIV transmission, even within an area of high HIV seroprevalence.

Adolescent↗
PubMed2003

Effects of CCR5-Delta32 and CCR2-64I alleles on HIV-1 disease progression: the protection varies with duration of infection.

OBJECTIVE: To examine temporal variation in the effects of CCR5-Delta32 and CCR2-64I chemokine receptor gene polymorphisms on HIV-1 disease progression. DESIGN: Pooled analysis of individual patient data from 10 cohorts of HIV-1 seroconverters from the United States, Europe, and Australia. METHODS: We studied HIV-1 seroconverters of European (n = 1635) or African (n = 215) ancestry who had been genotyped for CCR5-Delta32 and CCR2-64I. We used Cox proportional hazards models with time-varying coefficients to determine whether the genetic protection against AIDS (1987 case definition) and death varied with time since seroconversion. RESULTS: Protection against AIDS conferred by CCR5-Delta32 held constant at a 31% (RH 0.69, 95% CI 0.54, 0.88) reduction in risk over the course of HIV-1 infection, whereas protection against death held constant at a 39% reduction in risk (RH 0.61, 95% CI 0.45, 0.88). When the period from AIDS to death was isolated, the survival benefit of CCR5-Delta32 diminished 2 years after AIDS. Protection against AIDS conferred by CCR2-64I was greatest early in the disease course. Compared with individuals without CCR5-Delta32 or CCR2-64I, individuals with one or two copies of CCR2-64I had a 58% lower risk of AIDS during the first 4 years after seroconversion (RH 0.42, 95% CI 0.23, 0.76), a 19% lower risk during the subsequent 4 years (RH 0.81, 95% CI 0.59, 1.12), and no significant protection thereafter. CONCLUSION: The protection against AIDS provided by CCR5-Delta32 is continuous during the course of infection. In contrast, the protection provided by CCR2-64I is greatest early in the course of infection.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Readiness for cessation of drug use among recent attenders and nonattenders of a needle exchange program.

Needle exchange programs (NEPs) represent a bridge to drug abuse treatment. NEP attenders tend to have more severe drug problems, however, and may be less ready to reduce their drug use than other drug users. This study investigated the relationship between NEP attendance and readiness for cessation of drug use. Since the period from 1988 through 1989, a community-based sample of injection drug users (IDUs) in Baltimore has undergone semiannual interview-administered questionnaires and HIV testing. A total of 288 IDUs completed a questionnaire on readiness for cessation of drug use. Readiness for drug use cessation was assessed from a 28-item validated scale of problem drug use and intention to quit, based on the "stages of change" model. Logistic regression was used to determine factors associated with readiness for cessation of drug use, including sociodemographics, drug use behaviors, and NEP attendance. Thirty percent of respondents attended the NEP in the past month. Stage of change in readiness for cessation of drug use did not differ between NEP attenders and nonattenders (OR = 0.9; 95% CI: 0.5-1.6). Similar proportions of persons recently attending and not attending the NEP were classified as ready to stop drug use (about 30%). In multivariate analysis, readiness for cessation of drug use was associated with speedball injection and previous enrollment in drug treatment but not with NEP attendance. NEP attenders, although exhibiting characteristics consistent with more severe drug dependence, were as motivated for cessation of drug use as were nonattenders. These findings suggest that formal collaboration between NEPs and drug treatment programs could increase the proportion of IDUs in treatment.

Adult↗
PubMed2003

Social circumstances of initiation of injection drug use and early shooting gallery attendance: implications for HIV intervention among adolescent and young adult injection drug users.

To determine correlates of early shooting gallery (SG) attendance and HIV prevalence and incidence among new injection drug users (IDUs), baseline data from a prospective cohort study of street-recruited IDUs aged 15 to 30 years and injecting < or =5 years were used to identify early high-risk practices and salient social circumstances associated with early SG attendance to help in the design of innovative intervention strategies. Of 226 IDUs, 10.6% were HIV-seropositive, and HIV incidence was 6.6 per 100 person-years (95% CI: 2.2-13.3). Median age was 25 years, and most participants were African American (64%) and female (61%). Using multiple logistic regression, early SG attendees were three times as likely to be HIV-seropositive and twice as likely to be initiated by an older IDU. Early SG attendees were also five times more likely to share injection equipment and over three times more likely to report a high-risk injecting network soon after initiating injection. These data suggest that young new IDUs who attend SGs early tend to be initiated by older high-risk IDUs and to share and inject within a high-risk social setting early on as well. Hence, older IDUs may serve as a bridge group to SGs, transmitting HIV from older to younger IDUs.

Adolescent↗
PubMed2003

Hepatitis C virus infection among noninjecting drug users in New York City.

The prevalence of hepatitis C virus (HCV) infection among noninjecting drug users has been reported to be higher than in the general population, but the reasons for this observation remain unclear. Noninjecting drug users aged 15-40 years and who used drugs for no longer than 10 years were enrolled in the study. The participants were interviewed about risk behaviors and had specimens drawn for serological testing. Of 276 enrolled, 4.7% were infected with HCV. Drug users who had ever sniffed or snorted heroin in combination with cocaine were significantly more likely to be infected with HCV compared with those who never sniffed or snorted heroin with cocaine. No other drug use or sexual risk behaviors were found to be associated with HCV infection. These findings suggest that sniffing or snorting heroin with cocaine may explain the increase frequently found in HCV infection among noninjectors, but further studies are necessary.

Administration, Intranasal↗
PubMed2003

Elevated C-reactive protein levels are associated with endothelial dysfunction in chronic cocaine users.

OBJECTIVE: To examine the relationship of the serum C-reactive protein (CRP) and endothelial function and their associations with coronary artery calcification, lipid profile and cardiac changes. METHODS: The analyses for serum lipids and CRP, echocardiography, spiral computed tomography scans and endothelial function assay were performed in 53 participants with a history of chronic cocaine use. RESULTS: There were no statistically significant differences in demographic characteristics and drug use between CRP normal (<1.9 mg/l) and abnormal groups. The brachial artery diameter percentage changes in the third scan (immediately after deflation of cuff) and the fourth scan (90 s after deflation of cuff) were significantly associated with the CRP levels (the third: beta=-0.054, S.E.=0.027; P=0.028; the fourth: beta=-0.065, S.E.=0.026; P=0.016). The multiple regression models showed that CRP was the only significant predictor of artery diameter changes (%) in these two scans. The CRP abnormal group had more coronary artery calcification (calcium scores >5, 16.7 vs. 0%; P=0.036) and more cardiac diastolic dysfunction expressed as deceleration time >240 ms (16.7 vs. 0%; P=0.036). CONCLUSIONS: Elevated serum CRP levels are associated with endothelial dysfunction, coronary artery calcification and cardiac diastolic dysfunction in chronic cocaine users.

Adult↗
PubMed2003

Feasibility of referring drug users from a needle exchange program into an addiction treatment program: experience with a mobile treatment van and LAAM maintenance.

We evaluated program entry, retention, and early treatment response of needle exchange program (NEP) attenders referred to a drug treatment program using levomethadyl acetate hydrochloride (LAAM). Of 163 referrals, 114 (70%) entered the program, and 84% were retained for at least 90 days. Comparing baseline and follow-up visits after 1 month, there were significant reductions in the Addiction Severity Index subscale scores for drug and alcohol use and legal situation. We observed a 31% and 22% reduction in heroin- and cocaine-positive urine tests, respectively (p < .0001). Although LAAM is no longer considered a first line treatment for heroin addiction, these results demonstrate the feasibility of utilizing long-acting agonist therapies such as LAAM to treat opioid dependence among NEP attenders.

Adult↗
PubMed2003

Psychiatric medication use among Manhattan residents following the World Trade Center disaster.

To assess medication use in New York after the September 11th attacks, a telephone survey was conducted in October 2001 (N = 1,008). The prevalence of psychiatric medication use 30 days before the disaster was 8.9 and 11.6% 30 days after, a small but significant increase. The most important factor predicting postdisaster use was predisaster use--92% of those who used medications postdisaster used them predisaster. In addition, 3.3% used psychiatric medications 30 days postdisaster, but not 30 days before. Those who had panic attacks, posttraumatic stress disorder (PTSD), and insurance coverage, were the most likely medicated (26.5%). However, among those who used postdisaster medications (n = 129), new users tended to be those with panic attacks (44.1%) and those with panic attacks and PTSD (69.2%).

Adult↗
PubMed2003

Opiates, cocaine and alcohol combinations in accidental drug overdose deaths in New York City, 1990-98.

AIMS: Accidental drug overdose contributes substantially to mortality among drug users. Multi-drug use has been documented as a key risk factor in overdose and overdose mortality in several studies. This study investigated the contribution of multiple drug combinations to overdose mortality trends. DESIGN: We collected data on all overdose deaths in New York City between 1990 and 1998 using records from the Office of the Chief Medical Examiner (OCME). We standardized yearly overdose death rates by age, sex and race to the 1990 census population for NYC to enable comparability between years relevant to this analysis. FINDINGS: Opiates, cocaine and alcohol were the three drugs most commonly attributed as the cause of accidental overdose death by the OCME, accounting for 97.6% of all deaths; 57.8% of those deaths were attributed to two or more of these three drugs in combination. Accidental overdose deaths increased in 1990-93 and subsequently declined slightly in 1993-98. Changes in the rate of multi-drug combination deaths accounted for most of the change in overdose death rates, whereas single drug overdose death rates remained relatively stable. Trends in accidental overdose death rates within gender and racial/ethnic strata varied by drug combination suggesting different patterns of multi-drug use among different subpopulations. CONCLUSIONS: These data suggest that interventions to prevent accidental overdose mortality should address the use of drugs such as heroin, cocaine and alcohol in combination.

Adult↗
PubMed2003

The role of Medicaid HMO enrollment in the longitudinal utilization of medical care services in a cohort of injecting drug users in Baltimore, Maryland.

Although injecting drug users (IDUs) are highly dependent on Medicaid, the literature has not explored the effect of Medicaid HMO enrollment on medical care utilization. This longitudinal analysis compares 6-month utilization levels of IDUs in Medicaid HMOs with those of other Medicaid-enrolled IDUs and IDUs in other insurance arrangements. The analysis includes 1064 participants from the AIDS Link to Intravenous Experience (ALIVE) study, a natural history study of HIV infection in a community-based sample of IDUs in Baltimore, Maryland. A generalized linear modeling approach was used to examine self-reported inpatient admissions, ER visits, and ambulatory care visits from January 1995 through June 1997. Non-HMO Medicaid beneficiaries had more inpatient admissions and ambulatory care visits than Medicaid HMO enrollees. These findings suggest that HMO enrollment has been effective in lowering utilization among IDUs in Medicaid, but it is unclear whether utilization differences are the result of inappropriate utilization or access issues.

Adult↗
PubMed2003

Factors associated with accelerated atherosclerosis in HIV-1-infected persons treated with protease inhibitors.

Recent evidence suggests that as a group protease inhibitors (PIs) may accelerate certain factors associated with atherosclerosis. The objective of this study was to evaluate the effect of individual PIs (indinavir, lopinavir, nelfinavir, ritonavir, and saquinavir) on certain factors associated with atherosclerosis. Persons who took saquinavir and/or ritonavir were compared with those on other PIs. Between May 2000 and July 2001, the lipid profiles, C-reactive protein (CRP) levels, coronary artery calcium (CAC) scores, and blood cell morphologic parameters were measured in 98 black adult participants aged 25 to 45 years with HIV-1 infection in Baltimore, Maryland. Among these 98, there were 55 (56.1%) taking PIs. Students' t-test and chi2 test were used to detect the between-group differences. Study participants in both the PI and non-PI groups were similar in age, sex, body mass index, blood pressure, red and white blood cell counts, time since HIV diagnosis, and duration on anti-retroviral therapy. Compared with those who took non-PI regimens, those who took indinavir, nelfinavir, or saquinavir had significantly higher levels of mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH). Those taking any PI had significantly higher total cholesterol and low-density lipoprotein. Those taking nelfinavir, ritonavir, or saquinavir were more likely to have a higher CAC score (>5) than those on non-PI regimens. There were no differences in the lipid profiles, MCV, MCH, CRP, and CAC between those taking saquinavir and/or ritonavir and those taking other PIs. Overall, the changes noted might lead to anticipation of clinical changes linked to accelerated atherosclerosis in patients on PIs.

Adult↗
PubMed2003

Posttraumatic stress in women after the September 11 terrorist attacks in New York City.

BACKGROUND: Women have been shown to be at higher risk than men of developing posttraumatic stress disorder (PTSD) after traumatic events. Women in New York City were more likely than men to have probable PTSD 5-8 weeks after the September 11, 2001, terrorist attacks on the World Trade Center. We explored the factors that could explain the higher prevalence of probable PTSD among women in the aftermath of the attacks. METHODS: Data from a telephone survey of a randomly selected group of residents of Manhattan living south of 110th street, conducted 5-8 weeks after September 11, were used in these analyses. The survey assessed demographic information, lifetime experience of traumatic events, life stressors, social support, event exposure variables, perievent panic attacks, postevent concerns, and probable PTSD related to the attacks. We determined the contribution of key covariates that could explain the gender-probable PTSD relation through stratified analyses and manual stepwise logistic regression model building. RESULTS: Among 988 respondents, women were two times more likely than men to report symptoms consistent with probable PTSD after the September 11 attacks. When adjusted for potential confounders, the association between gender and probable PTSD diminished from OR = 2.2 (95% confidence interval [CI] 1.3-3.6) to OR = 1.2 (95% CI 0.7-2.2). CONCLUSIONS: These results suggest that specific behavioral and biographic factors (including previous traumatic experiences and psychological disorders, social responsibilities, and perievent emotional reactions) explained most of the excess burden of probable PTSD among women after a disaster. Isolating the characteristics that place women at greater risk for probable PTSD after disasters can inform public health prevention strategies and spur further research.

Adolescent↗