<unk>  <unk>  is the title used in many countries for the senior government official designated head of<unk>  services, sometimes at the national level. The post is held by a physician who serves to advise and lead a team of<unk>  experts on matters of public health importance. The post of<unk>  dates back to Victorian times. The equivalent title may go under different names across countries, for example, the Surgeon General in the United States and the<unk>  Public Health<unk>  in Canada. By extension,<unk>  is also used as a job title, for the physician who is the professional lead of all physicians at a hospital.
Chief medical officer
Independent safety officer
Biological pharmacist
Assistant doctor 
Clinical officer
Clinician
Surgical technologist
Aviation medical examiner