Under the conditions set out in II of article L. 3131-17, the State representative may, by means of a reasoned order, take any individual measure to combat the international spread of disease, in particular the isolation or quarantine of persons suffering from a contagious infection or likely to suffer from such an infection, on the proposal of the Director General of the Regional Health Agency. He shall inform the public prosecutor without delay. A decree in the Conseil d’Etat shall determine the conditions under which the representative of the State may resort to such measures, in particular with regard to the seriousness of the infection and the risks of its transmission.