It shall be the duty of the health officer:
(A) To enforce and observe all rules, regulations, and orders of the Illinois Department of Public Health, and all state laws pertaining to the preservation of the health of the people within the city.
(B) To execute and enforce all ordinances of the city relating to nuisances, public health, and sanitation.
(C) To investigate the existence of any contagious or infectious disease within the city, and to report the same promptly to the city council and to the department of health of the state, and to act without delay in carrying out measures for arresting the progress of the same as either or both of said bodies shall adopt.
(D) To make all necessary sanitation and health investigations and inspections within the city.
('69 Code, § 15-35)