Heterophilic interference in specimens yielding false-reactive results on the Abbott 4th generation ARCHITECT HIV Ag/Ab Combo assay.

BACKGROUND: False-reactivity in HIV-negative specimens has been detected in HIV fourth-generation antigen/antibody or 'combo' assays which are able to detect both anti-HIV-1/HIV-2 antibodies and HIV-1 antigen. OBJECTIVES: We sought to characterize these specimens and determine the effect of heterophilic interference. STUDY DESIGN: Specimens previously testing as false-reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay and re-tested on a different (Siemens ADVIA Centaur HIV Ag/Ab) assay. A subset of these specimens were also pre-treated with heterophilic blocking agents and re-tested on the Abbott assay. RESULTS: Here we report that 95% (252/264) of clinical specimens that were repeatedly reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay (S/Co range, 0.94-678) were negative when re-tested on a different fourth generation HIV combo assay (Siemens ADVIA Centaur HIV Ag/Ab). All 264 samples were subsequently confirmed to be HIV negative. On a small subset (57) of specimens with available volume, pre-treatment with two different reagents (HBT; Heterophilic Blocking Tube, NABT; Non-Specific Blocking Tube) designed to block heterophilic antibody interference either eliminated (HBT) or reduced (NABT) the false reactivity when re-tested on the ARCHITECT HIV Ag/Ab combo assay. CONCLUSIONS: Our results suggest that the Abbott ARCHITECT HIV Ag/Ab combo assay can be prone to heterophilic antibody interference.

Canadian recommendations for laboratory interpretation of multiple or extensive drug resistance in clinical isolates of Enterobacteriaceae, Acinetobacter species and Pseudomonas aeruginosa.

The goal of this document was to provide Canadian laboratories with a framework for consistent reporting and monitoring of multidrug resistant organisms (MDRO) and extensively drug resistant organisms (XDRO) for common gram-negative pathogens. This is the final edition of the interim recommendations, which were modified after one year of broad consultative review. This edition represents a consensus of peer-reviewed information and was co-authored by the Canadian Public Health Laboratory Network and the Canadian Association of Clinical Microbiology and Infectious Diseases. There are two main recommendations. The first recommendation provides standardized definitions for MDRO and XDRO for gram-negative organisms in clinical specimens. These definitions were limited to antibiotics that are commonly tested clinically and, to reduce ambiguity, resistance (rather than non-susceptibility) was used to calculate drug resistance status. The second recommendation identifies the use of standardized laboratory reporting of organisms identified as MDRO or XDRO. Through the broad consultation, which included public health and infection prevention and control colleagues, these definitions are ready to be applied for policy development. Both authoring organizations intend to review these recommendations regularly as antibiotic resistance testing evolves in Canada.

The relation of physical activity and exercise to mental health.

Mental disorders are of major public health significance. It has been claimed that vigorous physical activity has positive effects on mental health in both clinical and nonclinical populations. This paper reviews the evidence for this claim and provides recommendations for future studies. The strongest evidence suggests that physical activity and exercise probably alleviate some symptoms associated with mild to moderate depression. The evidence also suggests that physical activity and exercise might provide a beneficial adjunct for alcoholism and substance abuse programs; improve self-image, social skills, and cognitive functioning; reduce the symptoms of anxiety; and alter aspects of coronary-prone (Type A) behavior and physiological response to stressors. The effects of physical activity and exercise on mental disorders, such as schizophrenia, and other aspects of mental health are not known. Negative psychological effects from exercise have also been reported. Recommendations for further research on the effects of physical activity and exercise on mental health are made.

Outreach-based HIV prevention for injecting drug users: a review of published outcome data.

OBJECTIVE: Over the past decade, a body of observational research has accrued about the effects of outreach-based human immunodeficiency virus (HIV) interventions for drug users. The authors reviewed the findings related to postintervention behavior changes and integrated findings across studies to provide the best estimate of program impact. METHODS: The authors conducted a computerized literature search to locate published accounts of HIV intervention effects on drug users. Thirty-six publications covered outreach-based HIV risk reduction interventions for out-of-treatment injecting drug users (IDUs) and reported intervention effects on HIV-related behaviors or HIV seroincidence. Two-thirds of the publications reported that participation in street-based outreach interventions was followed with office-based HIV testing and counseling. The authors described the theoretical underpinnings of outreach intervention components, the content of the interventions, and the outcome measures that investigators used most frequently. The authors also described and critiqued the evaluation study designs that were in place. Because most of the evaluations were based on pretest and posttest measures of behavior rather than on controlled studies, results were examined with respect to accepted criteria for attributing intervention causality, that is, the plausibility of cause and effect, correct temporal sequence, consistency of findings across reports, strength of associations observed, specifically of associations, and dose-response relationships between interventions and observed outcomes. RESULTS: The majority of the published evaluations showed that IDUs in a variety of places and time periods changed their baseline drug-related and sex-related risk behaviors following their participation in a outreach-based HIV risk reduction intervention. More specifically, the publications indicated that IDUs regularly reported significant follow-up reductions in drug injection, multiperson reuse of syringes and needles, multiperson reuse of other injection equipment (cookers, cotton, rinse water), and crack use. The studies also showed significant intervention effects in promoting entry into drug treatment and increasing needle disinfection. Although drug users also significantly reduced sex-related risks and increased condom use, the majority still practiced unsafe sex. One quasi-experimental study found that reductions in injection risk led to significantly reduced HIV seroincidence among outreach participants. Few investigators looked at dosage effects, but two reports suggested that the longer the exposure to outreach-based interventions, the greater the reductions in drug injection frequency. CONCLUSIONS: Accumulated evidence from observational and quasi-experimental studies strongly indicate that outreach-based interventions have been effective in reaching out-of-treatment IDUs, providing the means for behavior changes and inducing behavior change in the desired direction. The findings provide sound evidence that participation in outreach-based prevention programs can lead to lower HIV incidence rates among program participants.

A comparison of the empirical utility of three composite measures of adolescent overall drug involvement.

Researchers have relied on a number of measurement techniques to construct a summated index of drug involvement to reflect both the qualitative and quantitative dimensions of adolescent drug-using behavior. The purpose of this study was to examine the adequacy of three strategies for constructing a composite measure--stage-of-drug-use, unweighted sum of frequencies of use of different substances, and a weighted composite index of substance use. Data for this study were derived from two independent samples of adolescents. The three drug-use measures were assessed both as predictors of consequences of drug use and as outcome measures explained by familial, intrapersonal and interpersonal factors. The weighted composite index of substance use, though conceptually and methodologically superior to the simple (unweighted) sum of frequency, did not perform any better as a predictor or as an outcome variable than the unweighted measure. The weighted composite index of drug involvement is somewhat complicated to calculate and requires substantial resources. The decision whether to use a weighted composite index or a simple sum of frequencies measure of overall drug involvement should be based on both scientific and practical considerations.

Women living with drug abuse and HIV disease: drug abuse treatment access and secondary prevention issues.

In collaboration with the National Institute on Drug Abuse, the Health Resources and Services Administration is conducting a multisite, longitudinal study on issues of service needs, service utilization, and access to care for drug abusers with HIV. This article discusses access to drug abuse treatment and HIV secondary prevention for 116 women interviewed during the study's first year in five U.S. cities. Using interview data from 115 service providers in those same cities, it also discusses drug abuse treatment availability and barriers to service expansion for drug users with HIV. Study findings indicate that there are highly significant gaps between the drug abuse treatment services these women feel they need and those they have been able to receive; these were particularly pronounced for drug detoxification and residential and outpatient drug-free treatment. Women who used crack cocaine or injection drugs had particularly high levels of need for residential and outpatient drug abuse treatment, while women who use crack were found to have significantly less experience with the drug abuse treatment system than IDUs. HIV secondary prevention was also found to be a critical need for these women, many of whom were engaging in behaviors that place them at risk for reinfection, infection with other diseases, and transmission to others. Providers indicated that lack of funding was the major barrier to expanding services for this population; other barriers, such as lack of ancillary services and transportation, were also noted. Two positive findings were that many drug abuse treatment agencies in these cities provide a wide range of ancillary services and that many different kinds of agencies offer drug abuse treatment services.

Psychological adjustment and substance use among adolescents before and after a parental divorce.

This study examined the well-being of adolescents before and after a parental divorce. The sample consisted of adolescents who were administered self-report measures of psychological adjustment and substance use over a 5-year period. 48 adolescents experienced the disruption of their parents' marriage during this time. Data were available at an average of 12 months before the separation and 5 months after the divorce. The control group consisted of the 578 adolescents in the original sample whose parents remained continuously married. The most important finding was a striking gender difference in the timing of the effects of divorce, with boys demonstrating ill effects after the divorce but not prior to the separation, and girls showing negative reactions prior to the separation but not becoming worse after the divorce.

A test of nonrespondent bias in a family-based study: a research note.

The increasing use of family samples from "normal" populations (as opposed to clinical samples) in substance abuse research raises concern about the validity of responses from participating families. Nonparticipating families may have greater numbers of substance users who wish to conceal problems, when compared to families which cooperate with researchers. Unobtrusive analyses of institutional records of a health maintenance organization comparing families agreeing to participate in a substance use study (N = 508) with those families unwilling to participate (N = 538) reveal no significant differences in the use of chemical dependency services between the two groups. Surveys of the non-participating families indicate that the major reasons for noncooperation were the lack of time and inconvenience in getting family members together. These findings suggest the feasibility of sampling families from normal populations.

Modifying the process of treatment to meet the threat of AIDS.

Treatment for drug users is unlikely to receive sufficient resources to expand to the level of treatment need. Moreover, there is indication that a substantial minority of injection drug users have never initiated needed treatment in spite of long histories of injecting drugs. Given the potential for that population to contract and spread AIDS, it is important that we explore street-based treatment alternatives derived from findings regarding the efficacy of outreach/intervention programs. Those programs were found both to reduce drug-taking behaviors of injecting drug users and to prepare those users for clienthood. Additional strategies that need to be explored include: aftercare, behavioral counseling for sex partners of drug treatment clients, and partial (i.e., survival) treatment services for clients who cannot be accommodated within existing treatment capacity.

A rapid method for the preparation of the neutrophil fraction of granulocytes from human blood by centrifugation on isotonic Nycodenz gradients.

A rapid method for the preparation of neutrophils of the granulocyte fraction of human blood is described. A leucocyte-rich fraction is loaded onto preformed isotonic Nycodenz gradients, formed by mixing a stock isotonic Nycodenz solution with a NaCl diluent solution. After low speed centrifugation a neutrophil fraction of high viability, yield and purity can be isolated from the gradients.

The impact of changing methods of data collection on the reliability of self-reported drug use of adolescents.

The purpose of this study is to determine the impact of different modes of data collection on the reliability of self-reported drug use of adolescents in a panel study. Adolescents were assigned to four groups based upon the ways they chose to respond to the survey instruments: 1) mailed questionnaires in both years, 2) survey interview in one year and mailed questionnaire in the next year, 3) mailed questionnaire in one year and survey interview in the following year, and 4) survey interview in both years. The quality of the self-reported data was examined in terms of return rates, missing data, internal consistency, and consistency of reported information over time. No significant differences were found between groups, suggesting that the mode of data collection does not affect the reliability of adolescents' self-reports of substance use.

Reliability and validity of adolescent self-reported drug use in a family-based study: a methodological report.

Given the sensitive topic of drug abuse and the private nature of the family, researchers must overcome a number of methodological obstacles when studying drug abuse and the family. The purpose of this study was to determine whether adolescents would provide honest and accurate answers to drug use questions in the context of their homes with their families participating in the same survey. Although there is no direct objective validation of the self-report measures used in this study, evidence from the analysis of the survey data suggests that adolescent self-reports are, in most cases, reliable and valid, and that the setting in which respondents complete questionnaires does not, in general, result in systematic reporting bias.

Interpersonal influences in adolescent drug use--the role of older siblings, parents, and peers.

Drawing data from the first year of a longitudinal study of 508 families with focal adolescents aged 11 to 13 years and their older siblings (14 to 18 years), the investigators examined the influence of older siblings' drug-using attitudes and behaviors, in comparison with parental and peer drug-using attitudes and behaviors, on focal adolescents' nonuse and use of substances. Older siblings are frequently a source of drugs and use substances with their young siblings, though peers remain the primary source and the most frequent coursers. For most substances, frequency of use was predicted by older sibling and peer substance use, each after controlling for the other. Parental drug use was found to be minimal in comparison to older siblings and peers. Findings relative to the potentially important role of older siblings in influencing their younger siblings' drug-using behavior are discussed.