As used in this article, unless the context requires a different meaning: “Affected area” means any part or the whole of the Commonwealth, which has been identified as where persons reside, or may be located, who are known to have been exposed to or infected with or who are reasonably suspected to have been exposed to or infected with a communicable disease of public health threat. “Affected area” shall include, but not be limited to, cities, counties, towns, and subsections of such areas, public and private property, buildings, and other structures. “Communicable disease of public health threat” means an illness of public health significance, as determined by the State Health Commissioner in accordance with regulations of the Board of Health, caused by a specific or suspected infectious agent that may be reasonably expected or is known to be readily transmitted directly or indirectly from one individual to another and has been found to create a risk of death or significant injury or impairment; this definition shall not, however, be construed to include human immunodeficiency viruses or tuberculosis, unless used as a bioterrorism weapon. “Individual” shall include any companion animal. Further, whenever “person or persons” is used herein it shall be deemed, when the context requires it, to include any individual. “Companion animal” means, consistent with the provisions of § 3.2-6500, any domestic or feral dog, domestic or feral cat, nonhuman primate, guinea pig, hamster, rabbit not raised for human food or fiber, exotic or native animal, reptile, exotic or native bird, or any feral animal or any animal under the care, custody, or ownership of a person or any animal that is bought, sold, traded, or bartered by any person. Agricultural animals, game species, or any animals regulated under federal law as research animals shall not be considered companion animals for the purposes of this article. “Isolation” means the physical separation, including confinement or restriction of movement, of an individual or individuals who are infected with or are reasonably suspected to be infected with a communicable disease of public health threat in order to prevent or limit the transmission of the communicable disease of public health threat to other uninfected and unexposed individuals. “Law-enforcement agency” means any sheriff’s office, police department, adult or youth correctional officer, or other agency or department that employs persons who have law-enforcement authority that is under the direction and control of the Commonwealth or any local governing body. “Law-enforcement agency” shall include, by order of the Governor, the Virginia National Guard. “Quarantine” means the physical separation, including confinement or restriction of movement, of an individual or individuals who are present within an affected area, as defined herein, or who are known to have been exposed or may reasonably be suspected to have been exposed to a communicable disease of public health threat and who do not yet show signs or symptoms of infection with the communicable disease of public health threat in order to prevent or limit the transmission of the communicable disease of public health threat to other unexposed and uninfected individuals.