Frequency Of Drug Injection Research Articles

MATHEMATICAL MODELING OF PANCREATIC CANCER TREATMENT WITH CANCER STEM CELLS

Of all cancers, pancreatic cancer has a significantly low rate of survival, mostly due to lack of early screening. Thus, once detected, pancreatic cancer is usually in later stages, reducing the likelihood of full recovery. The most common treatment strategy is chemotherapy, although several immunotherapeutic drugs show promising results in extending the patient’s lifespan. In this paper, we provide a validated mathematical model for the pancreatic cancer after fitting the parameter values, such as tumor growth rate, inverse carrying capacity, activation and decay rate of pancreatic stellate cells, with the use of the experimental data presented by Cioffi et al. cioffi2015inhibition For treatments with the chemotherapeutic drugs, Abraxane and Gemcitabine, and the immunotherapeutic drug, Anti-CD47, we modified the model accurately and compared the simulation results with the experimental data not only to model pancreatic cancer treatment correctly but also to move forward with other drug trials. Then, we include the cancer stem cells, which are known to initiate tumors and cause a relapse post-chemotherapy, per cancer stem cell hypothesis so that cancer progression can be assessed based on this phenomenon. In addition, we investigate optimal drug protocols. We find out that the most effective treatment is dual therapy due to extending survival time when compared to other drugs. Moreover, this study reveals that drug dose is more effectual than frequency of drug injection on account of different treatment scheduling with the same dose over a week. The model could be a starting point to investigate pancreatic cancer progression based on cancer stem cell hypothesis and shed light on novel drug discoveries.

Gender matters? How does gender shape risk environment for syringe sharing among people who inject drugsin northern Mexico. Results from a cross-sectional survey

Introduction. HIV prevalence among people who inject drugs (PWID) is 5%. Studies have found a HIV prevalence around 10% among women who inject drugs (WWID) and 5% among men. Objective. To describe characteristics of risk environment that play different roles among men and women who inject drugs in Mexico that could be associated with those differentials. Method. In 2012 were interviewed in Hermosillo and Ciudad Juarez in places where population gathered. From them, 824 PWID 74.0% were men and 26.0% were women. Using chi-square test we analyzed associations of gender with demographics characteristics, drug use dynamics, and injecting behaviors. We fitted different generalized linear mixed models with random effects to test the hypothesis that predictors of receptive needle sharing have different effects on men and women. Results. Descriptive analysis showed that women live in conditions of higher vulnerability than men in terms of migration, educational attainment, occupation, and income. Women also reported a higher frequency of drug injection, a higher number of drugs used, and a higher prevalence of sharing needles. Variables significantly associated with the likelihood of sharing needles were: having being injected for someone else at first drug injection (adjusted odds ratio [AOR] = 1.60, 95% confidence interval CI [1.11, 2.25], p < .05); injecting once a day or more (AOR = 1.80, 95% CI [1.17, 2.70], p < .05), using alcohol or drugs at least half of the time at their sexual encounters (AOR = 1.64, 95% CI [1.16, 2.47], p < .05), experience of syringe confiscation by police (AOR = 1.54, 95% CI [1.13, 2.19], p < .05), and perceiving syringe availability as hard or very hard (AOR = 2.29, 95% CI [1.49, 3.32], p < .01). For women the most significant variable associated with syringe sharing was perception of syringe availability (AOR = 3.15, 95% CI [1.25, 7.91], p < .05), while for men was syringe confiscation by police (AOR = 1.74, 95% CI [1.20, 2.50], p < .05). Discussion and conclusion. Results suggests the need to design and implement harm reduction programs that tackle the specific need of WID. Enhancing syringe availability through permanent harm reduction programs, implemented in coordination between public health authorities and community-based organizations, is a basic action to stop HIV spreading among PWID in northern Mexico, along with the decriminalization policies towards these population.

Comparing injecting and sexual risk behaviors of long-term injectors with new injectors: A meta-analysis

The present meta-analysis aimed to investigate the effect of injection duration on injection and sexual high-risk behaviors among people who inject drugs (PWID), in order to inform development of intensive HIV prevention services for selected PWID sub-populations. We searched PubMed, Science Direct, Web of Science, and Cochrane electronic databases independently in December 2018. After reviewing for duplication, full-texts of selected articles were assessed for eligibility using certain Population, Intervention, Comparator, Outcomes (PICO) criteria. We used fixed and random-effects meta-analysis models to estimate the pooled prevalence, pooled odds ratio (OR) and 95% confidence intervals (CI). Our result indicated significant association between age of injection initiation > 17 years, frequency of drug injection > 5 times/day, injection by others, having sex partner, history of imprisonment with new injectors (OR = 0.93, 95%CI = 0.87–0.98), (OR = 0.51, 95%CI = 0.29–0.73), (OR = 1.11, 95%CI = 1.05–1.17), (OR = 2.08, 95%CI = 1.02–3.14) and (OR = 1.20, 95%CI = 1.03–1.37). Our research found that new injectors were more likely to report frequency of injections injected by others, has sex partner and prison detention. Our findings are significant for policy makers and public health practitioners to implement and design HIV prevention programs among PWID with shorter periods of injection. The findings of the present study extend our knowledge about new injection drug users, the significance of assured behaviors at IDUs’ initial injection, and the educational importance of syringe exchange programs.

Association between recreational drug use and sexual practices among people who inject drugs in Southwest China: a cross-sectional study

ObjectiveTo describe the differences in sexual practices among individuals with various drug administration patterns.SettingA detoxification centre in Southwest China, a part of the Chinese national sentential surveillance network for hepatitis...

Comparing risk environments for HIV among people who inject drugs from three cities in Northern Mexico

BackgroundA large body of research has investigated the rise of injection drug use and HIV transmission in Tijuana and Ciudad Juarez (CJ). However, little is known about the dynamics of injecting in Hermosillo. This study compares drug-related behaviors and risk environment for HIV of people who inject drugs (PWID) across Tijuana, CJ, and Hermosillo to identify factors that could explain differences in HIV prevalence.MethodsData from Tijuana belong to a prospective study (El Cuete IV). Data from Hermosillo and Ciudad Juarez belong to a cross-sectional study. Both studies collected data in places where PWID spend time. All participants completed quantitative behavioral and serological testing for HIV. Datasets were merged using only comparable variables. Descriptive statistics tests were used to compare sociodemographic and behavioral characteristics of people who inject drugs PWID sampled in each city. A logistic regression model was built to identify factors independently associated with the likelihood of reporting receptive syringe sharing in the past 6 months.ResultsA total of 1494 PWID provided data between March 2011 and May 2012. HIV prevalence differed significantly between participants in Tijuana (4.2%), CJ (7.7%), and Hermosillo (5.2%; p < 0.05). PWID from Hermosillo reported better living conditions, less frequency of drug injection, and lower prevalence of syringe sharing (p < 0.01). PWID from CJ reported a higher prevalence of syringe sharing and confiscation by police (p < 0.01). In a multivariable logistic regression model, living in Hermosillo compared to Tijuana (adjusted odds ratio [AOR] = 0.42, 95% confidence interval [CI] 0.29–0.61) and being female (AOR = 0.61, 95% CI 0.45–0.83) were protective against syringe sharing. Having used crystal meth (AOR = 1.62, 95% CI 1.24–2.13, p = 0.001), having experienced syringe confiscation by police in the last 6 months (AOR = 1.78, 95% CI 1.34–2.40), and lower perception of syringe availability (AOR = 2.15, 95% CI 1.59–2.91) were significantly associated with syringe sharing (p < 0.05).ConclusionsDifferences in HIV prevalence across cities reflect mainly differences in risk environments experienced by PWID, shaped by police practices, access to injection equipment, and dynamics of drug markets. Findings highlight the importance of ensuring sterile syringe availability through harm reduction services and a human rights approach to drug harms in northern Mexico and to generate better understanding of local dynamics and contexts of drug use for designing proper harm reduction programs.

Delivering direct acting antiviral therapy for hepatitis C to highly marginalised and current drug injecting populations in a targeted primary health care setting

BackgroundThe Kirketon Road Centre (KRC) is a community-based public health facility in Sydney, Australia, that provides healthcare to people who inject drugs (PWID), including hepatitis C virus (HCV) treatment. From March 2016, the Australian Government has provided access to direct-acting antivirals (DAA) for adults with chronic HCV, without liver disease stage or drug and alcohol use restrictions. The aim of this study was to report DAA treatment outcomes among highly marginalised PWID treated at KRC. MethodsAll individuals initiating DAA treatment at KRC and due for sustained virological response (SVR12) testing by end 2016 were included. Demographic, drug use behaviour, clinical parameters, adherence support and HCV treatment outcomes, including SVR12 were recorded. Factors associated with SVR12, loss-to-follow-up (LTFU) and delayed SVR12 testing (>SVR16) were assessed by multivariate analysis. SVR12 was assessed by intention-to-treat (ITT) and modified ITT, the latter excluding individuals with an end-of-treatment response (ETR) but no SVR12 assessment, or who postponed their SVR12 date due to treatment interruption. ResultsA total of 72 individuals commencing DAAs were included, of whom 67% were male, 30% homeless, and 32% Aboriginal. All had a lifetime history of injecting drug use, with 75% having injected within the last six months, and 44% injecting at least weekly; 25% were also enrolled in opioid substitution therapy. Twenty-five (35%) individuals elected to receive an enhanced adherence-support package. Fifty-nine of 72 (82%) individuals due for SVR12 attended for testing, of whom 59/59 (100%) achieved SVR, providing an ITT SVR of 82%. A further six individuals had undetectable HCV RNA at ETR, but no SVR12 assessment, and one interrupted treatment, providing a mITT SVR of 91%. Homelessness was associated with delayed SVR12 testing (OR 24.9 95%CI 2.9–212.8, p=0.003). There was no association between LTFU and frequency of drug injection, last drug injected, or planned treatment duration. ConclusionThis study confirms that PWID can be successfully treated for HCV in a real-world setting using an integrated primary health care model. It also demonstrates feasibility to upscale DAA therapy in high-risk PWID populations, with potential individual and population-level public health benefits. Enhanced efforts are required to optimise post-treatment follow-up.

Predictors of HIV Care Engagement, Antiretroviral Medication Adherence, and Viral Suppression Among People Living with HIV Infection in St. Petersburg, Russia.

Over 1 million HIV infections have been diagnosed in Russia, and HIV care uptake and viral suppression are very low. 241 HIV-positive individuals in St. Petersburg were enrolled through social networks, provided blood for viral load testing, and completed measures of medication-taking adherence, readiness, and self-efficacy; psychosocial well-being; and substance use. Outcomes included attending an HIV care appointment in the past 6months, >90% ART adherence, and undetectable viral load. 26% of participants had no recent care appointment, 18% had suboptimal adherence, and 56% had detectable viral load. Alcohol use consistently predicted all adverse health outcomes. Having no recent care visit was additionally associated with being single and greater past-month drug injection frequency. Poor adherence was additionally predicted by lower medication-taking self-efficacy and lower anxiety. Detectable viral load was additionally related to younger age. Comprehensive interventions to improve HIV care in Russia must address substance abuse, anxiety, and medication-taking self-efficacy.

The oral health of heroin drug users: case study in Bosnia and Herzegovina

BackgroundInjection drug use is a major public health problem. Oral health problems and the appearance of dental disease among injection drug users (IDUs) are caused by their lifestyle. The aim of the present study was to examine the relations between socioeconomic factors, drug use, and oral hygiene habits on the oral health of heroin drug users.MethodsA cross-sectional survey on oral health was carried out as part of UNICEF’s research on the biological and behaviours survey among injection drug users in Sarajevo, Banja Luka and Zenica in Bosnia and Herzegovina. A sample of 519 IDUs participated in the survey. Respondent Driven Sampling (RDS) was used to obtain the sample. The data were obtained through face–to–face interviews using a structured questionnaire related to socio-demographic characteristics, duration of drug injection, frequency of drug injection in the last month and oral health.ResultsOlder participants (OR = 1.06; 95% CI = 1.02 -1.10), part–time employment (OR = 3.57; 95% CI = 1.02 - 12.20) and unemployment (OR = 3.23; 95% CI = 1.23 - 8.33) in comparison to full-time employment as the referent category, and longer duration of drug injection (OR = 1.06; 95% CI = 1.003 - 1.12) were predictors of bad oral health. A higher level of education (OR = 0.56; 95% CI = 0.39 - 0.79), more frequent tooth brushing (OR = 0.59; 95% CI = 0.49 - 0.71), and regular dental checkups (OR = 3.30; 95% CI = 1.42 - 7.67) were predictors of good oral health.ConclusionsSocioeconomic characteristics of IDUs as well as their lifestyles may contribute to oral health problems. Heroin drug users have specific dental needs, and programmes to improve their oral health should be an integral part of strategies to prevent addictions including treatments and harm reduction programmes.

Relationships Among Depression, PTSD, Methamphetamine Abuse, and Psychosis

Objective: Research suggests several possible associations among methamphetamine abuse, psychotic symptoms, depression, and posttraumatic stress disorder (PTSD), but the exact nature and clinical significance of these associations is unclear. Individuals who abuse methamphetamine increasingly present in hospital emergency rooms with acute psychiatric symptoms. The aim of this study was to identify patterns of depressive symptoms and explore predictors of acute versus sustained depressive symptoms in individuals who abuse methamphetamine and who have had psychotic symptoms. Methods: This longitudinal study, conducted in Vancouver, British Columbia, included 295 participants with methamphetamine use disorder who were seeking psychiatric help for depressive or psychotic symptoms, assessed at baseline and monthly for 6 months. Measures included substance use (including frequency, quantity, and route of administration), family history of psychosis and depression, trauma exposure, and PTSD symptoms. Results: Trajectory analyses on depressive symptoms revealed two profiles of depression: one with more severe and sustained depressive symptoms and one with decreasing and lower levels of depressive symptoms. Group comparisons showed that those with more severe and persistent depressive symptoms had more family history of depression ( p < .05), more years of alcohol and cocaine abuse ( p < .01), more traumatic events ( p < .001), and more PTSD symptoms ( p < .001). Logistic regression suggested that the strongest predictors of belonging to the high depression group were more severe psychotic symptoms at baseline (odds ratio [OR] = 2.03, p < .001), followed by quantity of methamphetamine used in the month preceding baseline (OR = 1.13, p < .05), severity of PTSD symptoms at baseline (OR = 1.07, p < .001), and the frequency of drug injection (OR = 1.25, p < .05). Conclusions: Our results are similar to those of other studies suggesting that depression and psychosis often coexist and that the intensity of methamphetamine abuse is linked to the severity of the depressive symptoms. The individuals who took part in this study had many coexisting problems, such as PTSD symptoms, polysubstance abuse, depression, and psychosis. In fact, depression, psychosis, PTSD, and substance abuse appeared to be intertwined in their development and expression. A more comprehensive treatment program to help individuals with multiple coexisting psychiatric and substance misuse issues is needed.

A study of the prevalence and risk factors leading to HIV infection among a sample of street children and youth of Kathmandu

BackgroundThe true prevalence of HIV and other sexually transmitted diseases among street children in Nepal is virtually unknown while information on related behavioural risk factors in this population is non-existent. The risk of HIV infection among street children and adolescents may be especially high due to their marginalized social and economic conditions. This study was conducted to determine the prevalence of HIV infection among a sample of street children and youth of Kathmandu and to identify risk factors associated with HIV infection in this group.A sample of street children and youth was recruited based on the purposive sampling of ten streets in Kathmandu, Nepal, known to have a high density of street children and youth. A total of 251 street children (aged 11–16 years) and youth (aged 17–24 years) were enrolled, with informed consent, from November, 2008 through June, 2009. Most of the participants (95%) were male. Case status was determined by serological assessment of HIV status; data on risk factors were obtained using structured survey interviews. HIV prevalence and rates of a number of behavioural risk factors suspected to play a role in HIV transmission among street children and youth were determined, including unprotected sex, intravenous drug use, and other risky sex and substance use behaviours.ResultsAmong the 251 children and youth, we found an overall HIV prevalence of 7.6%. As the sample size of females was small (n = 13) and the behavioural risk factors are likely to be quite different for boys and girls, we conducted separate analyses by gender. As our small sample of females is unlikely to be representative and lacks power for statistical testing, our report focuses on the results for the males surveyed.The strongest behavioural risk factor to emerge from this study was intravenous drug use; 30% of the male subjects were injecting drug users and 20% of those were HIV positive. Furthermore, frequency of drug injection was a highly significant predictor with a dose–response relationship; males reporting occasional injection drug use were nearly 9 times more likely to be HIV positive than never users, while weekly drug injectors had over 46 times the risk of non-users, controlling for exposure to group sex, the only other significant risk factor in the multivariate model.ConclusionsThis sample of street children and youth of Kathmandu has a nearly 20-fold higher prevalence of HIV infection than the general population of Nepal (0.39%). The children and youth engage in number of high risk behaviours, including intravenous drug use, putting them at significant risk of contracting HIV and other sexually transmitted infections.

Factors Correlated With Hepatitis C and B Virus Infections Among Injecting Drug Users in Tehran, IR Iran

Background: In Iran, the number of injecting drug users (IDUs) has increased in recent years. The rates of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections among IDUs are reportedly high. Objectives: The purpose of this study was to assess factors correlated with HCV and HBV infections among IDUs in Tehran. Patients and Methods: A cross-sectional study included 899 IDUs recruited from the community, drug treatment centers, and drop-in-centers. The study involved interviews conducted using an adapted version of the WHO Drug Injection Study Phase II (Version 2b) questionnaire and blood testing for the HCV antibody, hepatitis B surface antigen, and hepatitis B core antibody. A logistic regression model was used to identify independent factors correlated with HCV and HBV infections. Results: HCV infection was found to be primarily associated with female gender [odds ratio (OR) 5.0, 95% confidence interval (CI) 2.0-10.0)], unmarried status (OR 2.9, 95% CI 1.9-4.4), drug use for more than 10 years (OR 2.7, 95% CI 1.8-3.9), drug injection frequency of more than once per day (OR 2.6, 95% CI 1.6-4.2), history of imprisonment (OR 2.5, 95% CI 1.6-4.0)], and a history of shared injection needles in prison (OR 2.3, 95% CI 1.5-3.6). HBV infection was mainly correlated with a history of imprisonment (OR 1.9, 95% CI 1.4-2.7) and drug use for more than 10 years (OR 1.4, 95% CI 1.1-1.9). Conclusions: Because a considerable number of IDUs in Iran are receiving reduction services, tailoring services for prevention of hepatitis infection are necessary.

Factors Correlated With Hepatitis C and B Virus Infections Among Injecting Drug Users in Tehran, IR Iran

Background: In Iran, the number of injecting drug users (IDUs) has increased in recent years. The rates of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections among IDUs are reportedly high. Objectives: The purpose of this study was to assess factors correlated with HCV and HBV infections among IDUs in Tehran. Patients and Methods: A cross-sectional study included 899 IDUs recruited from the community, drug treatment centers, and drop-in-centers. The study involved interviews conducted using an adapted version of the WHO Drug Injection Study Phase II (Version 2b) questionnaire and blood testing for the HCV antibody, hepatitis B surface antigen, and hepatitis B core antibody. A logistic regression model was used to identify independent factors correlated with HCV and HBV infections. Results: HCV infection was found to be primarily associated with female gender [odds ratio (OR) 5.0, 95% confidence interval (CI) 2.0-10.0)], unmarried status (OR 2.9, 95% CI 1.9-4.4), drug use for more than 10 years (OR 2.7, 95% CI 1.8-3.9), drug injection frequency of more than once per day (OR 2.6, 95% CI 1.6-4.2), history of imprisonment (OR 2.5, 95% CI 1.6-4.0)], and a history of shared injection needles in prison (OR 2.3, 95% CI 1.5-3.6). HBV infection was mainly correlated with a history of imprisonment (OR 1.9, 95% CI 1.4-2.7) and drug use for more than 10 years (OR 1.4, 95% CI 1.1-1.9). Conclusions: Because a considerable number of IDUs in Iran are receiving reduction services, tailoring services for prevention of hepatitis infection are necessary.

Factors Correlated With Hepatitis C and B Virus Infections Among Injecting Drug Users in Tehran, IR Iran

In Iran, the number of injecting drug users (IDUs) has increased in recent years. The rates of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections among IDUs are reportedly high. The purpose of this study was to assess factors correlated with HCV and HBV infections among IDUs in Tehran. A cross-sectional study included 899 IDUs recruited from the community, drug treatment centers, and drop-in-centers. The study involved interviews conducted using an adapted version of the WHO Drug Injection Study Phase II (Version 2b) questionnaire and blood testing for the HCV antibody, hepatitis B surface antigen, and hepatitis B core antibody. A logistic regression model was used to identify independent factors correlated with HCV and HBV infections. HCV infection was found to be primarily associated with female gender [odds ratio (OR) 5.0, 95% confidence interval (CI) 2.0-10.0)], unmarried status (OR 2.9, 95% CI 1.9-4.4), drug use for more than 10 years (OR 2.7, 95% CI 1.8-3.9), drug injection frequency of more than once per day (OR 2.6, 95% CI 1.6-4.2), history of imprisonment (OR 2.5, 95% CI 1.6-4.0)], and a history of shared injection needles in prison (OR 2.3, 95% CI 1.5-3.6). HBV infection was mainly correlated with a history of imprisonment (OR 1.9, 95% CI 1.4-2.7) and drug use for more than 10 years (OR 1.4, 95% CI 1.1-1.9). Because a considerable number of IDUs in Iran are receiving reduction services, tailoring services for prevention of hepatitis infection are necessary.

Comparing HIV-related syringe-sharing behaviors among female IDU engaging versus not engaging in commercial sex

Background To compare the prevalence of syringe-sharing behaviors and other HIV-related characteristics among female injecting drug users (IDU) engaging and not engaging in sex work and to identify factors associated with such risk behaviors in the two groups. Methods Data were obtained from 1923 female respondents of behavioral surveillance studies conducted in Sichuan, China. Results The prevalence of having at least one of the three syringe-sharing behaviors (borrowing, lending, or injecting from pre-filled syringes) was 45.3% in the female sex workers (FSW) group and 37.2% in the non-FSW group (adjusted OR = 1.28, p < 0.05). Compared with non-FSW, FSW were more likely to have injected drugs for 3 or more years, have non-regular sex partners, believe that condom use could prevent HIV, and have received free condoms/lubricants (OR = 1.34–5.08, p < 0.05); FSW were less likely to be older, better educated, and have attempted quitting drugs (OR = 0.31–0.68, p < 0.05). Being FSW, older, longer injecting drug use, higher drug injection frequency, and having regular sex partner were associated with injecting with others’ used syringes (multivariate OR = 1.26–1.92, p < 0.05) while the reverse was true for education level and voluntary HIV antibody testing (multivariate OR = 0.44–0.64, p < 0.05). Of all sampled FSW, 39.3% did not use a condom in the last episode of sex work. Conclusions Female IDU involving in sex work are at high risk of HIV transmission and the risk may even be higher than their non-FSW counterparts. The bridging effect poses a threat to the HIV epidemic in China and effective preventive services are warranted.

Nationwide Increase in the Number of Hospitalizations for Illicit Injection Drug Use-Related Infective Endocarditis

Infective endocarditis is a potentially fatal consequence of illicit injection drug use. We estimate that the number of hospitalization for injection drug use-related infective endocarditis increased by 38%-66% in the United States between 2000-2001 and 2002-2003, a period during which the number of at-risk persons (i.e., injection drug users) remained stable. Increasing methamphetamine use and/or drug injection frequency may have increased the incidence of infective endocarditis among active injection drug users.

Assessing the Differential Impact of an HIV Prevention Intervention: Who's Putting The Message into Practice?

Recent data suggest that educational interventions aimed at reducing HIV risk behaviors have shown some success. Nonetheless, HIV risk behaviors are not always reduced by interventions and probably do not reduce risk behavior randomly. That is, the success of interventions may be related to participant characteristics. Identifying participant characteristics related to both intervention completion and reduction in risk behaviors may be useful for further developing explanatory models of health behavior and for targeting and customizing interventions. In this study differences between participants who completed an AIDS educational intervention (N = 741) and those who did not complete the intervention are first examined (N = 652) and then variables related to reducing drug and sexual risk behaviors among those who completed the intervention and follow-up interviews are examined. Results show that the majority of respondents report decreasing five out of six risk behaviors, with the smallest percentage (48.8%) decreasing rates of unprotected sex and the largest percentage (83.4%) decreasing frequency of drug injection. Different variables were found to be related to changes in the various risk behaviors. However, some relatively consistent results emerge. For all risk variables, the frequency of the specific behavior at baseline predicted the amount of change in that behavior, with those having higher levels of risk behaviors reducing their behavior the most. Positive HIV test results significantly decreased three of the four sexual risk behaviors examined, and living in a very rural area was found to be significantly related to three of the six risk behaviors. However, perceived chance of getting AIDS did not significantly reduce any of the risk behaviors. Gender and education level were also not related to changes in any of the risk behaviors. Implications include the importance of developing approaches to retain higher proportions of younger participants, males and homeless in interventions. It is particularly important to develop specific approaches to retain women in interventions. Because very rural participants were more likely to decrease crack use and alcohol or drug use with sex, rural interventions should target these behaviors at the outset of the intervention.

The effect of drug-injection behavior on genetic evolution of HIV-1.

The effect of injection-drug use on human immunodeficiency virus type 1 (HIV-1) env genetic evolution was examined in 15 seroconverting injection-drug users followed up for 4 years. After adjustment for non-drug-related independent variables significantly associated with genetic diversity (time since seroconversion and progressor status), injection frequency was positively and highly significantly associated with HIV-1 env genetic diversity (P=.003). The mutation rate in those who had injected at least once a day during the previous 6 months was estimated to be 62% greater than the rate in those who had not injected at all. If the positive effect of drug-injection frequency on env genetic diversity extends to the HIV-1 pol gene, the risk of emergence of resistance to antiretroviral drugs may be enhanced by increased drug-injection frequency, especially under the selection pressure of antiretroviral therapy.

Risk behaviors, HIV seropositivity, and tuberculosis infection in injecting drug users who operate shooting galleries in Puerto Rico.

This study was designed to assess HIV risk behaviors, HIV seroprevalence, and tuberculosis (TB) infection in shooting gallery managers in Puerto Rico. The subjects were 464 injection drug users (IDUs), of whom 12.5% reported managing shooting galleries. The median frequency of drug injection was higher in shooting gallery managers than in nonmanagers. A trend was observed for purified protein derivative (PPD) reactivity to increase according to the length of time spent as a gallery manager, but this trend was not statistically significant. However, anergy rates increased significantly with increase in the number of months spent as shooting gallery manager (p = .021). Multivariate analyses showed that IDUs reporting shooting gallery management experience of > or = 25 months were more likely to be infected with HIV. Prevention programs need to emphasize strategies to protect the health of shooting gallery clients and, in particular, shooting gallery managers. Additional studies are required to determine effective strategies for reducing the risk of HIV and TB infection in shooting galleries.

Variation in Drug Injection Frequency Among Out-of-Treatment Drug Users in a National Sample

This article analyzes data on drug injection frequency in a sample of more than 13,000 out-of-treatment drug injectors interviewed across 21 U.S. cities and Puerto Rico through the National Institute on Drug Abuse (NIDA) Cooperative Agreement for AIDS Community-Based Outreach/Intervention Research Program. The goals of the article are to present findings on injection frequency and to predict variation in terms of a set of variables suggested by previous research, including location, ethnicity, gender, age, educational attainment, years since first use of alcohol and marijuana, income, living arrangement, homelessness, drugs injected, and duration of injection across drugs. Three models were tested. Significant intersite differences were identified in injection frequency, although most of the other predictor variables we tested accounted for little of the variance. Ethnicity and drugs injected, however, were found to be significant. Taken together, location, ethnicity, and type of drug injected provide a configuration that differentiated and (for the variables available for the analysis) best predicted injection frequency. The public health implications of these findings are presented.

Drug-Injecting Street Youth: A Comparison of HIV-Risk Injection Behaviors Between Needle Exchange Users and Nonusers

Injection drug use, the second most common risk factor associated with HIV infection in the United States after sexual transmission, is especially prevalent among street youth, many of whom routinely share their drug injection equipment. To prevent sharing behavior among street youth, a needle exchange program for youth was established in Hollywood, California. This study compared the drug use and needle-sharing behaviors of youth who were users of the needle exchange with those of youth who were not. Results indicate that while demographic characteristics and drug injection frequency were similar in the two groups, needle exchange users were significantly less likely to share needles, share other injection equipment, use other drugs to help them “come down,” use unsterile needles when “high” or “craving” drugs, and report difficult access to sterile needles. These findings suggest that needle exchange programs may reduce needle-sharing behavior among street youth.