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Biomedical subjects

D Vlahov

Publications and source records attributed to D Vlahov.

At least 235 records · Page 13Linked to original sources
PubMed1994

Impact of HIV infection on non-AIDS mortality among Italian injecting drug users.

OBJECTIVES: To estimate the excess mortality of injecting drug users (IDU) stratified by HIV serostatus compared with the general population in Italy. To compare total and cause-specific mortality in HIV-positive versus HIV-negative IDU, in order to identify possible HIV-related non-AIDS causes of death in this population. METHODS: All IDU attending two drug-treatment centres in Rome who underwent HIV testing between 1985 and 1991 were enrolled into a prospective study. The end-point of the study was death from any cause by 31 December 1991. Mortality rates were compared using age-adjusted standardized mortality ratios and person-time techniques. RESULTS: Of the 2431 IDU, 1661 (68.3%) were HIV-seronegative and 82 seroconverted. Of 181 deaths, comprising 89 from AIDS and 92 from other causes, the mortality rate was 4.5 and 0.8 per 100 person-years in HIV-seropositives and HIV-seronegatives, respectively. For non-AIDS mortality in HIV-seropositives, the overall rate was 1.7 per 100 person-years. Deaths from overdose and endocarditis/embolus tended to be higher in HIV-seropositive than HIV-seronegative IDU, although there was no difference in the rate of deaths due to pneumonia by HIV serostatus. CONCLUSIONS: These data are consistent with other studies demonstrating a higher frequency of mortality among HIV-seropositive IDU. The excess in overdose mortality among HIV-seropositives is disturbing and merits further investigation.

Adult↗
PubMed1994

Comparison of clinical manifestations of HIV infection between male and female injecting drug users.

OBJECTIVE: To compare occurrence of clinical symptoms, physical examination findings and hematologic variables in male and female HIV-seropositive injecting drug users (IDU) with similar CD4+ lymphocyte counts. METHOD: We interviewed and examined 118 female and 444 male AIDS-free HIV-seropositive IDU for clinical signs and symptoms. HIV serology and T-lymphocyte subset evaluations were performed. Comparisons were analyzed by Mantel-Haenszel procedures. RESULTS: In this population, median age for men was 35 years versus 33 years for women; median CD4 cell count was 490 x 10(6)/l for men versus 480 x 10(6)/l for women. The overall frequency of oral candidiasis increased as CD4 cell count decreased, but did not vary by sex. Recent history of genital herpes was more frequent (P < 0.05) in women than men, but this difference was not significant on physical examination. Symptoms of diarrhea, fatigue, weight loss, shortness of breath, presence of enlarged posterior cervical lymph nodes did not vary by CD4 cell count or sex, and no strong interactions were evident. Although absolute values of hematocrit were higher (P < 0.001) and platelet count lower (P < 0.001) in HIV-seropositive men than women, distributions of hematocrit and platelet count by sex were similar for HIV-seropositive participants and HIV-seronegative controls. CONCLUSION: Our data on IDU prior to a diagnosis of AIDS suggest that constitutional signs and symptoms are generally similar among men and women early in HIV infection. Additional follow-up is needed to determine whether differential rates of signs and symptoms by sex appear with progression of HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1994

Validation of the proposed World Health Organization staging system for disease and infection in a cohort of intravenous drug users.

OBJECTIVE: To assess the prognostic utility of the clinical criteria of the World Health Organization's (WHO) proposed staging system for HIV disease and infection in a cohort of intravenous drug users (IVDU) from the ALIVE study. METHODS: All study subjects known to be HIV-seropositive were included in this analysis. Subjects were classified as WHO clinical stage 1, 2, or 3 at their initial seropositive evaluation. Product-limit estimates and Cox proportional hazard models were used to compare time of progression to AIDS (stage 4) for the first three clinical stages. RESULTS: Of the original cohort of 2921 IVDU in the ALIVE study, 694 were known to be HIV-positive by January 1992. At the time of their index visit, 49% of the cohort were WHO clinical stage 1, 10% stage 2 and 41% were stage 3. Demographic characteristics of the three groups were similar. Product-limit estimates for progression to AIDS over a 3-year period were 6.5% (SE, 1.5%), 10.4% (SE, 4.1%) and 17.1% (SE, 2.5%) for clinical stages 1, 2, and 3, respectively (log-rank P = 0.003). In a proportional hazards model adjusting for race, age, sex and injection status within 6 months prior to enrollment, the hazard for progression to AIDS was 1.51 [95% confidence interval (CI), 0.60-3.77] and 2.39 (95% CI, 1.40-4.08) for stages 2 and 3, respectively, relative to stage 1. CONCLUSION: This study, in a population of IVDU, supports the utility of the WHO staging system in predicting progression from HIV seropositivity to AIDS on the basis of clinical signs and symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Drug-related behavior change for HIV transmission among American injection drug users.

While high risk drug-related behaviors for human immunodeficiency virus (HIV) transmission among injection drug users (IDUs) are asserted to have declined over time in response to the AIDS epidemic, evidence from longitudinal cohorts has been sparse. In a cohort of 810 IDUs (442 seronegatives and 368 seropositives) in Baltimore, we identified drug-related risk behaviors at four consecutive semi-annual visits. Using robust methods for repeated measurements and multiple logistic regression, we estimated the probabilities of maintaining and reducing risk behaviors according to HIV serostatus and time in the study. Seropositive participants were more likely to maintain lower risk behaviors, and behavior maintenance increased with time in study for both seronegative and seropositive IDUs. Greater risk reduction (towards non-use and not sharing injection equipment) was seen among seropositive IDUs, with behavior change occurring soon after enrollment in the study. While behavior changes have been reported, many active IDUs, especially those still at risk for acquiring HIV infection, have not adequately reduced their risk. Continuing prevention programs and efforts in vaccine development are imperative to reduce the risk of HIV infection among IDUs.

Baltimore↗
PubMed1994

Drug smoking, Pneumocystis carinii pneumonia, and immunosuppression increase risk of bacterial pneumonia in human immunodeficiency virus-seropositive injection drug users.

To examine the risk factors for the first episode of bacterial pneumonia among human immunodeficiency virus (HIV)-seropositive injection drug users (IDUs), medical record review was performed on IDUs participating in a cohort study from January 1988 to June 30, 1992. HIV-seropositive IDUs with a first episode of bacterial pneumonia (n = 40) were matched with up to five HIV-seropositive control subjects without bacterial pneumonia (n = 197) by date of entry (+/- 3 mo) and length of follow-up. Odds ratios (OR) were estimated using conditional logistic regression. The incidence of bacterial pneumonia was 1.93 in 100 person-years in HIV seropositive and 0.45 in 100 person-years in HIV seronegative subjects (relative incidence = 4.3; 95% CI 2.4 to 7.5). In univariate analyses, CD4 lymphocyte count < 200 cells/microliters previous episode of Pneumocystis carinii pneumonia (PCP), age between 30 and 40 yr and smoking illicit drugs (marijuana, cocaine, or crack) were associated with bacterial pneumonia. Cigarette smoking was associated with an increased odds of bacterial pneumonia (OR = 2.0), but this was not statistically significant because it was nearly universal in this cohort. In multivariate analysis, CD4 < 200 cells/microliters (OR = 6.75, 95% CI 2.13 to 21.42) and smoking illicit drugs (OR = 2.24, 95% CI 1.03 to 4.89) remained significantly associated with bacterial pneumonia. The odds ratio for cigarette smoking in the final model remained at 2.08 but was still not significant (95% CI 0.49 to 8.70). Smoking illicit drugs had the strongest effect on risk of bacterial pneumonia among HIV-seropositive IDUs with a previous history of PCP (OR = 22.94; 95% CI 2.18 to 241.10).

AIDS-Related Opportunistic Infections↗
PubMed1994

A pilot syringe exchange program in Washington, DC.

The Washington, DC City Council authorized a pilot syringe exchange program to operate for only 60 days at a single drug abuse treatment facility in the District. Only adults on the waiting list for treatment were eligible (n = 467). Of the 33 who enrolled, median duration of drug injection was 18 years. Twenty-seven participants denied needle sharing. Of 209 needles distributed, 69% were returned. Low enrollment might have been due to restrictive entry criteria, inconvenient location, incorrect syringe size, and attitudes of treatment staff. For future efforts to have a public health impact, wider accessibility will be needed.

Adult↗
PubMed1994

The trading of sex for drugs or money and HIV seropositivity among female intravenous drug users.

OBJECTIVES: Data from 538 women in a cohort study recruited in 1988-1989 were analyzed to determined whether trading sex for drugs or money was independently associated with human immunodeficiency virus (HIV) seroprevalence in a population of female intravenous drug users. METHODS: The women were grouped according to the number of partners with whom they reported trading sex for drugs or money during the previous 10 years: none, 1 through 49 (low), or 50 or more (high); the prevalence of HIV seropositivity in the three groups was 23.2%, 23.7%, and 47.6%, respectively. Logistic regression was used to compare the low- and high-trade groups separately with the group that reported no trading. RESULTS: Low trading was not associated with seroprevalent HIV infection. In a multivariate model, high trading (compared with no trading) was significantly associated with HIV seropositivity after adjustment for cocaine use, history of sexually transmitted diseases, and duration of intravenous drug use. CONCLUSIONS: These data indicate that, among intravenous drug-using women, high levels of trading sex for drugs or money were independently associated with HIV infection. This group needs to be targeted for further intensive intervention.

Adult↗
PubMed1994

Correlates of needle sharing among injection drug users.

OBJECTIVES: The sharing of contaminated injection equipment is the primary mode of human immunodeficiency virus (HIV) transmission for injection drug users. This study examined demographic factors, life events, and drug use practices that are potential risk factors for sharing injection equipment. METHODS: Between February 1988 and March 1989, 2921 active injection drug users were interviewed and questioned about their backgrounds, life-styles, and patterns of injection drug use. RESULTS: Of 2524 participants who reported injecting drugs within the 6 months prior to study enrollment, 70.4% reported recent needle sharing. A multivariate analysis found needle sharing to be more frequent among those with a history of arrest and lower socioeconomic status, even after accounting for other demographic and drug use variables. In addition, recent needle sharing was higher in male homosexual or bisexual men than in their heterosexual counterparts. CONCLUSIONS: These data suggest that injection drug users have an economic motive to share needles and that the availability of free and legal needles may reduce levels of needle sharing.

Adult↗
PubMed1994

Preparations for AIDS vaccine trials. Incident human immunodeficiency virus (HIV) infections in a cohort of injection drug users in Baltimore, Maryland.

In order to prepare for a possible trial of a preventive human immunodeficiency virus (HIV) vaccine in a population of injection drug users (IDUs) we followed a cohort to determine their HIV incidence, compliance with follow-up visits at 3-month intervals (i.e., quarterly) and their attitudes toward HIV vaccine trial participation. A population of 671 HIV-seronegative subjects were recruited from a cohort of IDUs already in follow-up in Baltimore, MD (the ALIVE study). We detected 19 seroconverters in 1677.80 person-quarters of follow-up, an annual incidence of 4.52/100 person-years. Compliance with quarterly follow-up was 93% at 6 months and 89% at 9 months. Although many subjects (n = 104) are not yet due for their 12-month visit, compliance to date has been 76%. The most sensitive risk behaviors associated with HIV seroconversion have been continued injection of illicit drugs and the frequency of drug use. Other reported drug associated risk behaviors, e.g., needle sharing and shooting gallery use, have decreased despite a high HIV incidence; we believe some of the reported reductions in high-risk behavior represent socially desirable responses by the study subjects. Although the difficulties in successfully doing a trial of an HIV vaccine in the population should not be underestimated, our data suggest that such a trial would be feasible.

AIDS Vaccines↗
PubMed1994

Interest in HIV vaccines among injection drug users in Baltimore, Maryland.

To gauge interest about participation in human immunodeficiency virus type 1 (HIV vaccines, we interviewed 375 HIV-seronegative injecting drug users who are participants in an ongoing longitudinal study of HIV infection. Nearly all (93%) responded that they thought it likely that an HIV vaccine would become available, and 85% expressed interest in participating in a study of vaccine effectiveness. However, levels of interest decreased to 47% when respondents were informed that the vaccine might result in a positive HIV test and to 27% when offered to be in a study where the vaccine might contain a piece of the virus. Factors that increased interest in trial participation included assurances of confidentiality, being fully informed about the protocol and remuneration. Most respondents (78%) felt that injecting drug users would maintain other risk reduction activities (e.g., condom use) if they participated in a vaccine study. These data suggest a high level of interest for participation in HIV vaccine trials, but that more education about vaccines and the risks involved is needed. Ongoing communication with the community and responsiveness to community concerns is crucial to achieve a successful vaccine study.

AIDS Vaccines↗
PubMed1994

HIV vaccines for injection drug users in the context of a comprehensive prevention agenda.

Human immunodeficiency virus (HIV) infection among injecting drug users remains a major health problem. Traditional approaches to prevent parenteral transmission of HIV infection in this population include abstinence facilitated through treatment for drug abuse, HIV testing with education and counseling, disinfection of needles with bleach between uses, and needle exchange programs. While each of these strategies are important and contribute to risk reduction, high-risk behavior and transmission of HIV infection continues. The development and distribution of safe and effective HIV vaccines in this population is urgently needed.

AIDS Vaccines↗
PubMed1994

Field effectiveness of needle disinfection among injecting drug users.

To examine the putative protective effect of disinfectant use on HIV seroconversion among injecting drug users, we conducted a nested case-control study of black heterosexuals comparing 34 HIV seroconverters with 154 persistent seronegatives matched on gender, cocaine injection (yes/no), date of study entry, and duration of follow-up. Injecting drug users who reported using disinfectant all the time had an odds ratio of seroconversion of 0.87, as compared with those who reported no use of disinfectants; the corresponding odds ratio was 1.00 for those who used disinfectants less than all the time. We examined the effect of drug use and sex practice variables, and responses to a socially desirable responding scale as possible confounders for the effect of needle disinfection on HIV seroconversion; the adjusted odds ratios for disinfectant use and HIV seroconversion were unchanged in this analysis. Despite limited statistical power and the potential for residual confounding, these data suggest that disinfection of injection equipment is not a substitute for abstinence from drugs or use of sterile injection equipment.

1-Propanol↗
PubMed1994

Inadequate bleach contact times during syringe cleaning among injection drug users.

Objectives were to measure syringe cleaning strategies used by injection drug users (IDUs) and to assess syringe contact with bleach during cleaning demonstrations. IDUs were interviewed about cleaning activities during their most recent injection episode; they demonstrated these activities on videotape. Coders reviewed the videotapes, categorized activities, and used stop watches to record bleach exposure. Of 161, 146 subjects reported cleaning at last injection, 85 (58%) of 146 used full strength bleach. Of bleach users, 20% had total contact time (duration of bleach inside syringe) of > or = 30 s; combining draw (time taken to fill syringe) and contact times, 54% of bleach users had total "flush" times of > or = 30 s. Median observed time per bleach flush was 16 s. Median reported cleaning times were twice as long as observed. Recent reports indicate 30 s of exposure to undiluted bleach is necessary to inactivate HIV in the laboratory; here, 80% of IDUs using bleach had contact of < 30 s. Judgment of contact time was inaccurate. On average, instructions advocating two bleach flushes may reach 30 s; here, half the subjects had insufficient time with two flushes. The majority showed inadequate techniques, therefore, alternate cleaning strategies should be developed.

Adult↗
PubMed1993

Bacterial pneumonia in adult populations with human immunodeficiency virus (HIV) infection.

Recurrent bacterial pneumonia was recently added to the definition of the acquired immunodeficiency syndrome (AIDS), based on the observation that bacterial pneumonia rates have been increased in human immunodeficiency virus (HIV)-infected persons and are indicative of immunosuppression in this population. Nonetheless, risk factors for bacterial pneumonia among HIV-infected persons remain largely uninvestigated. Identification of risk factors that may be associated with bacterial pneumonia can guide development of future interventions and further clarify target groups for such interventions. From a methodological viewpoint, diagnostic algorithms need to be further standardized to provide comparable estimates of disease incidence. Epidemiologic studies will also need to address the effectiveness of chemoprophylaxis and vaccine interventions in HIV-infected populations. Since clinical trials will not be feasible for testing efficacy of interventions that are already recommended, observational data will be critically important in guiding clinical practice.

AIDS-Related Opportunistic Infections↗
PubMed1993

Increased mortality associated with vitamin A deficiency during human immunodeficiency virus type 1 infection.

OBJECTIVE: To determine whether plasma vitamin A levels are associated with immunologic status and clinical outcome during human immunodeficiency virus type 1 (HIV-1) infection. PATIENTS AND METHODS: Analysis of vitamin A levels, CD4 T cells, complete blood cell count, and serologic markers for liver disease in a random subsample of 179 subjects from a cohort of more than 2000 intravenous drug users with longitudinal follow-up to determine survival. RESULTS: Mean (+/- SE) follow-up time was 22.8 +/- 1.1 months, and 15 subjects died during follow-up. More than 15% of the HIV-1-seropositive individuals had plasma vitamin A levels less than 1.05 mumol/L, a level consistent with vitamin A deficiency. The HIV-1-seropositive individuals had lower mean plasma vitamin A levels than HIV-1-seronegative individuals (P < .001). Vitamin A deficiency was associated with lower CD4 levels among both seronegative individuals (P < .05) and seropositive individuals (P < .05). In the HIV-seropositive participants, vitamin A deficiency was associated with increased mortality (relative risk = 6.3; 95% confidence interval, 2.1 to 18.6). CONCLUSION: Vitamin A deficiency may be common during HIV-1 infection, and vitamin A deficiency is associated with decreased circulating CD4 T cells and increased mortality. Vitamin A is an essential micronutrient for normal immune function, and vitamin A deficiency seems to be an important risk factor for disease progression during HIV-1 infection.

Adult↗