Workplace drug testing, different matrices different objectives

Drug testing is used by employers to detect drug use by employees or job candidates. It can identify recent use of alcohol, prescription drugs, and illicit drugs as a screening tool for potential health and safety and performance issues. Urine is the most commonly used sample for illicit drugs. It detects the use of a drug within the last few days and as such is evidence of recent use; but a positive test does not necessarily mean that the individual was impaired at the time of the test. Abstention from use for three days will often produce a negative test result. Analysis of hair provides a much longer window of detection, typically 1 to 3 months. Hence the likelihood of a falsely negative test using hair is very much less than with a urine test. Conversely, a negative hair test is a substantially stronger indicator of a non-drug user than a negative urine test. Oral fluid (saliva) is also easy to collect. Drugs remain in oral fluid for a similar time as in blood. The method is a good way of detecting current use and is more likely to reflect current impairment. It offers promise as a test in post-accident, for cause, and on-duty situations. Studies have shown that within the same industrial settings, hair testing can detect twice as many drug users as urine testing. Copyright (C) 2012 John Wiley & Sons, Ltd.

Frequency of subtype B and F1 dual infection in HIV-1 positive, Brazilian men who have sex with men

Background: Because various HIV vaccination studies are in progress, it is important to understand how often inter- and intra-subtype co/superinfection occurs in different HIV-infected high-risk groups. This knowledge would aid in the development of future prevention programs. In this cross-sectional study, we report the frequency of subtype B and F1 co-infection in a clinical group of 41 recently HIV-1 infected men who have sex with men (MSM) in Sao Paulo, Brazil. Methodology: Proviral HIV-1 DNA was isolated from subject's peripheral blood polymorphonuclear leukocytes that were obtained at the time of enrollment. Each subject was known to be infected with a subtype B virus as determined in a previous study. A small fragment of the integrase gene (nucleotide 4255-4478 of HXB2) was amplified by nested polymerase chain reaction (PCR) using subclade F1 specific primers. The PCR results were further confirmed by phylogenetic analysis. Viral load (VL) data were extrapolated from the medical records of each patient. Results: For the 41 samples from MSM who were recently infected with subtype B virus, it was possible to detect subclade F1 proviral DNA in five patients, which represents a co-infection rate of 12.2%. In subjects with dual infection, the median VL was 5.3 x 10(4) copies/ML, whereas in MSM that were infected with only subtype B virus the median VL was 3.8 x 10(4) copies/ML (p > 0.8). Conclusions: This study indicated that subtype B and F1 co-infection occurs frequently within the HIV-positive MSM population as suggested by large number of BF1 recombinant viruses reported in Brazil. This finding will help us track the epidemic and provide support for the development of immunization strategies against the HIV.

Risk factors for hepatitis C virus infection in Inland Brazil: An analysis of pooled epidemiological sectional studies

In order to assess the contribution of different parenteral routes as risk exposure to the hepatitis C virus (HCV), samples from nine surveys or cross-sectional studies conducted in two Brazilian inland regions were pooled, including a total of 3,910 subjects. Heterogeneity among the study results for different risk factors was tested and the results were shown to be homogeneous. Anti-HCV antibodies were observed in 241 individuals, of which 146 (3.7%, 95% CI?=?3.24.4) had HCV exposure confirmed by immunoblot analysis or PCR test. After adjustment for relevant variables, a correlation between confirmed HCV exposure and injection drug use, tattooing, and advance age was observed. In a second logistic model that included exposures not searched in all nine studies, a smaller sample was analyzed, revealing an independent HCV association with past history of surgery and males who have sex with other males, in addition to repeated injection drug use. Overall, these analyses corroborate the finding that injection drug use is the main risk factor for HCV exposure and spread, in addition to other parenteral routes. J. Med. Virol. 84:756762, 2012. (C) 2012 Wiley Periodicals, Inc.

Prevalence and risk factors of Hepatitis C virus infection in Brazil, 2005 through 2009: a cross-sectional study

Abstract Background Hepatitis C chronic liver disease is a major cause of liver transplant in developed countries. This article reports the first nationwide population-based survey conducted to estimate the seroprevalence of HCV antibodies and associated risk factors in the urban population of Brazil. Methods The cross sectional study was conducted in all Brazilian macro-regions from 2005 to 2009, as a stratified multistage cluster sample of 19,503 inhabitants aged between 10 and 69 years, representing individuals living in all 26 State capitals and the Federal District. Hepatitis C antibodies were detected by a third-generation enzyme immunoassay. Seropositive individuals were retested by Polymerase Chain Reaction and genotyped. Adjusted prevalence was estimated by macro-regions. Potential risk factors associated with HCV infection were assessed by calculating the crude and adjusted odds ratios, 95% confidence intervals (95% CI) and p values. Population attributable risk was estimated for multiple factors using a case–control approach. Results The overall weighted prevalence of hepatitis C antibodies was 1.38% (95% CI: 1.12%–1.64%). Prevalence of infection increased in older groups but was similar for both sexes. The multivariate model showed the following to be predictors of HCV infection: age, injected drug use (OR = 6.65), sniffed drug use (OR = 2.59), hospitalization (OR = 1.90), groups socially deprived by the lack of sewage disposal (OR = 2.53), and injection with glass syringe (OR = 1.52, with a borderline p value). The genotypes 1 (subtypes 1a, 1b), 2b and 3a were identified. The estimated population attributable risk for the ensemble of risk factors was 40%. Approximately 1.3 million individuals would be expected to be anti-HCV-positive in the country. Conclusions The large estimated absolute numbers of infected individuals reveals the burden of the disease in the near future, giving rise to costs for the health care system and society at large. The known risk factors explain less than 50% of the infected cases, limiting the prevention strategies. Our findings regarding risk behaviors associated with HCV infection showed that there is still room for improving strategies for reducing transmission among drug users and nosocomial infection, as well as a need for specific prevention and control strategies targeting individuals living in poverty.

Adverse Drug Events Leading Children to Hospital Emergency Care

To determine the incidence of adverse drug events (ADE) that resulted in the need for children's emergency care, a total of 23,286 pediatric emergency case notes were analyzed. They were selected on the basis of the ICD code indicating a possible ADE. ADEs were found in 13 case notes (0.06%), predominantly among girls and mainly in the 1 to 5 year age group. About half of the observed events occurred as a result of accidental ingestion, 27.3% were suicide attempts, and 27.3% arose due to the discontinuation of treatment. Antiepileptic drugs were those most often involved. Three (23%) were serious. The results suggest that children have easy access to medications and are involved in the majority of accidental occurrences. Using drugs involves risks, and drawing attention to such risks while prescribing and dispensing them fosters the sharing of responsibility and the empowerment of the users, measures necessary to health promotion.

Concurrent crack and powder cocaine users from Sao Paulo: Do they represent a different group?

Abstract Background Cocaine abuse is a serious and socially damaging illegal drug problem. Different routes of administration are associated with a specific progression of use, different degrees of abuse liability, propensity for dependence and treatment response. There have been relatively few studies comparing different cocaine users groups and no studies into the characterization of the group of individuals reporting concurrent use of powder cocaine and crack cocaine. Methods Six hundred and ninety-nine cocaine users were assessed during the period August 1997 to October 1998 in one outpatient and six inpatient clinics located in the São Paulo, Brazil. Patients were interviewed using a structured questionnaire schedule in Portuguese, designed specifically for the Brazilian population. The statistical analyses were performed using either ANOVA or a chi-squared test and focusing on their preferred form of use/route of administration and other variables. Results For 83% of the variables tested in this study, the Dual Users subgroup (using both powder and crack cocaine) demonstrated statistical differences from the single drug user subgroups. Those differences include the initiation of cocaine, the abuse of other illicit drugs, and rates of criminal history. Conclusion These data suggest cocaine-dependent individuals who report use of both powder and crack cocaine are an at least partially, distinct subgroup. However, further studies will be necessary to confirm this and to determine if they also show a different treatment response.