Section 7. If smallpox or any other contagious or infectious disease declared by the department to be dangerous to the public health exists or is likely to exist in any place within the commonwealth, the department shall make an investigation thereof and of the means of preventing the spread of the disease, and shall consult thereon with the local authorities. It shall have co-ordinate powers as a board of health, in every town, with the board of health thereof. It may require the officers in charge of any city or state institution, charitable institution, public or private hospital, dispensary or maternity hospital, or any board of health, or the physicians in any town to give notice of cases of any disease declared by the said department to be dangerous to the public health. Such notice shall be given in such manner as the department may deem advisable. If any such officer, board or physician refuses or neglects to give such notice, he or they shall forfeit not less than fifty nor more than two hundred dollars.