(1) Use every available means to ascertain the existence of, and to investigate all cases of sexually transmitted disease coming within their respective jurisdictions and, when it is necessary, have all cases treated, if they are not already under treatment;
(2) To ascertain the sources and transmission of the infection; and
(3) To institute measures for the protection of other persons from infection by the infected person, or from persons reasonably suspected of being so infected, and for the protection of the public health at all times.
(b) A municipal health officer may designate any member of the city police or health department to make any investigation required by the provisions of this section. A county health officer may designate any discreet person to make any investigation required by the provisions of this section. Any person conducting an investigation has all authority necessary for the purpose, the same as the health officer.