It is the duty of the local health officers to use every available means to ascertain the existence of cases of infectious venereal diseases within their respective jurisdictions, to investigate all cases that are not, or probably are not, subject to proper control measures approved by the board, to ascertain so far as possible all sources of infection, and to take all measures reasonably necessary to prevent the transmission of infection.
Source:
Section 120575, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=120575..