Detection of shigella in lettuce by the use of a rapid molecular assay with increased sensitivity

artículo (arbitrado)--Universidad de Costa Rica.Instituto de Investigaciones en Salud, 2010A Multiplex Polymerase Chain Reaction (PCR) assay to be used as an alternative to the conventional culture method in detecting Shigella and enteroinvasive Escherichia coli (EIEC) virulence genes ipaH and ial in lettuce was developed. Efficacy and rapidity of the molecular method were determined as compared to the conventional culture. Lettuce samples were inoculated with different Shigella flexneri concentrations (from 10 CFU/ml to 107 CFU/ml). DNA was extracted directly from lettuce after inoculation (direct-PCR) and after an enrichment step (enrichment PCR). Multiplex PCR detection limit was 104 CFU/ml, diagnostic sensitivity and specificity were 100% accurate. An internal amplification control (IAC) of 100 bp was used in order to avoid false negative results. This method produced results in 1 to 2 days while the conventional culture method required 5 to 6 days. Also, the culture method detection limit was 106 CFU/ml, diagnostic sensitivity was 53% and diagnostic specificity was 100%. In this study a Multiplex PCR method for detection of virulence genes in Shigella and EIEC was shown to be effective in terms of diagnostic sensitivity, detection limit and amount of time as compared to Shigella conventional culture.Universidad de Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Compliance to Bleach Disinfection Protocols among Injecting Drug Users in Miami

Bleach cleansing of injection equipment has been recommended to reduce the risk of human immunodeficiency virus (HIV) transmission associated with the reuse of injection equipment by injecting drug users (IDUs). We evaluated the recall and performance of the most commonly recommended bleach cleansing procedure of two complete fillings of the syringe with bleach, followed by two complete fillings with rinse water, and not putting used bleach and water back into source containers. IDUs were taught this procedure on enrollment in an HIV prevention demonstration project in Dade County, Florida. During follow-up session 6-12 months after initial training, the knowledge and ability of IDUs to perform bleach cleansing were assessed by trained observers using a standardized method. In 1988-90, we assessed the knowledge and ability of 450 IDUs to perform the bleach cleansing procedure taught at enrollment. More than 90% of IDUs assessed performed the basic steps. However, only 43.1% completely filled the syringe with bleach and only 35.8% completely filled the syringe with bleach at least twice. Substantial proportions of IDUs did not perform all the steps of the previously taught bleach cleansing procedure. Compliance decreased as the number of steps required was increased. This limited compliance may make bleach cleansing less effective and suggests that some IDUs may fail to adequately disinfect injection equipment and therefore sterile needles and syringes are safer than bleach-cleansed ones. Compliance testing can help assess the effectiveness of HIV prevention programs. © 1994 Raven Press, Ltd., New York

Prácticas sexuales y conocimiento sobre el VIH/ sida entre usuarios de drogas en una comunidad urbana de bajos ingresos en Costa Rica

artículo -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 2014HIV/AIDS transmission among drug users is associated with education, sex practices and substance use. This study examined 159 drugs users’ knowledge, beliefs and sex behavior related to HIV/AIDS risk in Costa Rica. Results showed considerable use of marihuana, alcohol, crack and cocaine and a very low lifetime incidence of other drugs. All substance use patterns were higher than national averages. Respondents showed a high level of knowledge about HIV/AIDS transmission and prevention. However, there did not seem to be a relationship between knowledge and practice. Unprotected sex was common and having an HIV/AIDS test was not a regular practice. Knowledge about HIV/AIDS is not a determinant factor for condom use among this group. It is concluded that having the proper knowledge about transmission and prevention does not guarantee safe sex practices. Further research and public health evidence based practices for HIV/AIDS prevention should target drug user population.La transmisión del VIH/SIDA entre consumidores de drogas se asocia con factores como, educación, prácticas sexuales y consumo de sustancias. Este estudio examinó los conocimientos 159 usuarios de drogas, las creencias y el comportamiento sexual relacionado con el riesgo de VIH / SIDA en Costa Rica. Los resultados mostraron un uso considerable de marihuana, alcohol, crack y cocaína y una incidencia muy baja de otras drogas. Todos los patrones de consumo de sustancias fueron más altos que los promedios nacionales. Los encuestados mostraron un alto nivel de conocimiento sobre la transmisión y prevención del VIH/SIDA. Se concluye que el tener el conocimiento adecuado sobre la transmisión y prevención no garantiza las prácticas de sexo seguro. Nuevas investigaciones y prácticas basadas en la evidencia de salud pública para la prevención del VIH / SIDA deben dirigirse población de usuarios de drogasInstituto de investigaciones en Salud Universidad de Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Effectiveness of HIV Interventions Among Women Drug Users

A prospective cohort study was conducted among chronic injecting and crack cocaine drug using women. The hypothesis tested was that participation in a standard-plus-innovative intervention was more likely to produce behavior change than participation in a standard intervention. Standardized intervention protocols and corresponding instruments were designed. Data were collected on drug and sex risk behaviors at baseline and six-month follow-up intervals. The level of behavioral change in two intervention arms-standard and a standard-plus-innovative intervention-was measured by composite sex risk and drug risk scores using the generalized estimating equation approach. The results show that on four risk measures the enhanced intervention was significantly associated with positive change in both drug use and sexual behavior: less frequent drug use, less drug use during sex, and more frequent condom use during particular frequencies for specific types of sexual activities. Public health interventions are effective when targeting specific risk behaviors through interventions tailored to prevent HIV and reduce risk behaviors among specific cultural and gender groups