The infection of a Spanish nurse with the Ebola virus has raised concern in the world, at a time when health authorities, including the World Health Organization, have been providing guidance for weeks in an attempt to contain the epidemic.   The guidelines for preventing Ebola are based on simple measures, such as washing hands with disinfectant liquid, which must be respected with great precision, in addition to monitoring the appearance of symptoms of the disease, such as temperature, in a person suspected of being infected.   The person is not considered contagious as long as he does not show…