From the prospect of the regime of data communication (article 11 LOPD), in those cases in which the patient index does not give its consent, the studied legal frame (HIM 3/1986, Law 18/2009 and Law 41/2002, among others), he can fit out to the sanitary administration to communicate to the workplace, the school or third parties the identity of the patient index and the illness in question, in order to carry to term the studies of necessary contacts, to the effects of preventing and minimizing the risk of infection, in the foreseen terms legally. The sanitary authorities will have to consider, in each case, if for the realization of contact studies -or other measures-, it is necessary to identify the patient index, in front of third parties, and they only have to communicate the information at a minimum number of persons who, in the work and school centers, have to have necessarily the information.