(a) provide for care and isolation of cases of communicable disease in a hospital or elsewhere when necessary for protection of the public health and,
(b) subject to the provisions of the sanitary code, prohibit and prevent all intercourse and communication with or use of infected premises, places and things, and require, and if necessary, provide the means for the thorough purification and cleansing of the same before general intercourse with the same or use thereof shall be allowed.