[Incorporating molecular tests into the practice of public health]

Public Health has evolved in accordance with basic scientific and technologic advances. Molecular biology has provided sophisticated laboratory techniques and fine diagnostic tools that are being exploited in the area of Public Health in order to deepen our knowledge of the natural history of diseases, identify populations at risk, diagnose infectious process and different pathologies in the early stages of the illness and limit the damage produced by a late diagnosis. The modern molecular techniques provide a promising insight into the identification and measurement of molecular structures linked to the pathological process, the genotypic identification of infectious agents, the level of exposure and the susceptibility at individual as well as population levels. This paper describes its applications in the area of Public Health and highlights its limits and potential risks.