When a health officer has been appointed under the provisions of N.H. Rev. Stat. § 128:1, such officer may, subject to the approval of the selectmen and the commissioner of the department of health and human services, appoint a deputy health officer or officers who shall be empowered to enforce public health laws and regulations and make such sanitation investigations as the health officer may direct or as may be required by the department of health and human services. The term of the deputy health officer shall expire with that of the health officer, or may be extended with the approval of the board of selectmen, in consultation with the commissioner of the department of health and human services or designee, until the health officer vacancy is filled. The deputy health officer shall receive such compensation from the town as the selectmen of the town shall fix.