Any parent or other person having custody of a minor child which child shows evidence of need for medical attention as the result of physical injury inflicted by an act of any member of the household, whether the injury was intentional or unintentional, who knowingly fails or refuses to secure prompt and adequate medical attention, or who conspires to prevent the securing of such attention, for such minor child, shall be guilty of a Class 1 misdemeanor; provided, however, that any parent or other person having custody of a minor child that is being furnished Christian Science treatment by a duly accredited Christian Science practitioner shall not, for that reason alone, be considered in violation of this section.