Efecto del cambio de la terapia antirretroviral en la falla virológica en una cohorte de pacientes que conviven con el VIH en Medellín, Antioquia, Colombia / Effect of the change in antirretroviral therapy on virological failure in a cohort of patients living with HIV in Medellín, Antioquia, Colombia

Objetivo: determinar el efecto del cambio en la terapia antirretroviral sobre el control virológico en una cohorte de pacientes VIH positivos de una institución prestadora de servicios de salud en Medellín, Antioquia (Colombia) en el año 2017. Materiales y métodos: estudio observacional analítico transversal, comparativo entre pacientes que cambiaron y no cambiaron el esquema inicial de terapia antirretroviral. Se realizó en una cohorte de 1245 pacientes que conviven con el VIH. Resultados: un total de 322 pacientes fueron evaluados. El principal motivo de cambio fue la presencia de efectos adversos a la terapia antirretroviral, seguido de la falla virológica sin genotipo e intolerancia a la terapia antirretroviral. La falla virológica, RP 1,4 IC95% (1,2-1,6, p0,00), el tener genotipo, RP 1,2 IC95% (1,1-1,3, p 0,00) y el padecer una infección oportunista, RP 1,3 IC95% (1,0-1,6, p 0,03), se asociaron a mayor número de cambios a la TAR. La adherencia a la terapia antirretroviral, RP 0,18 IC95% (0,1-0,3, p 0,00) y la toma de otros medicamentos no relacionados al VIH (RP 0,6, IC95% 0,4-0,8, p 0,005) se asociaron a menor frecuencia de cambio de la terapia antirretroviral. El cambio de la terapia antirretroviral (OR ajustado 3,4, IC 95% (2,0-5,8), continúa siendo el factor pronóstico más importante para falla virológica. Conclusión: el cambio de la terapia antirretroviral, definida en este estudio como la principal variable de exposición, representa el principal factor de riesgo para falla virológica, incluso cuando fue ajustado por otras variables..Au

Objective: to determine the effect of the change in antiretroviral therapy on virological control in a cohort of HIV positive patients corresponding to a healthcare institution in Medellín, Antioquia (Colombia) in 2017. Materials and methods: cross-sectional,comparative analytical observational study. It was performed in a cohort of 1245 patients living with HIV. Results: a total of 322 patients were evaluated. The main reason for change was the presence of adverse effects to antiretroviral therapy, followed by virological failure without genotype and antiretroviral therapy intolerance. Virological failure, PR 1.4 95% CI (1.2-1.6, p 0,00), having genotype, PR 1.2 95% CI (1.1-1.3, p0,00 ) and suffering from an opportunistic infection, PR 1.3 95% CI (1.0-1.6, p 0,03),were associated with a greater number of changes to antiretroviral therapy. Adherence to antiretroviral therapy, PR 0.18 95% CI (0.1-0.3, p 0,00) and taking other non-HIVrelated medications (PR 0.6, 95% CI 0.4-0 , 8, p 0,005) were associated with a lower frequency of change of antiretroviral therapy. The change in antiretroviral therapy (adjusted OR 3.4, 95% CI (2.0-5.8)) remains the most important prognostic factor for virological failure. Conclusion: the change in antirretroviral therapy, defined in this study as the main exposure variable, represents the main risk factor for virological failure, even when was adjusted for other variables..Au

Alluvial and gypsum karst geological transition favors spreading arsenic contamination in Matehuala, Mexico.

Arsenic transport in alluvial aquifers is usually constrained due to arsenic adsorption on iron oxides. In karstic aquifers, however, arsenic contamination may spread to further extensions mainly due to favorable hydrogeochemical conditions. In this study, we i) determined the spatial and temporal behavior of arsenic in water in an alluvial-karstic geological setting using field and literature data, ii) established whether a contaminated aquifer exists using field and literature piezometric data and geophysical analysis, iii) studied the local geology and associated arsenic contaminated water sources to specific aquifers, iv) revealed and modeled subsoil stratigraphy, and v) established the extent of arsenic exposure to the population. We found arsenic contamination (up to 91.51 mg/l) in surface and shallow groundwater (<15 m), where water flows from west to east through a shallow aquifer, paleochannels and a qanat within an alluvial-karst transition that favors the spreading and transport of arsenic along 8 km as well as the increase of arsenic exposure to the population (up to 3.6 mgAs/kghair). Results from this study contribute to understanding arsenic transport in semi-arid, mining-metallurgical, and urban environments, where the presence of karst could favor arsenic transport to remote places and exacerbate arsenic exposure and impact in the future.