V
- Vaccinia
- A viral disease of cattle commonly known as cowpox. When transmitted to man, usually by vaccination, it confers immunity to smallpox. Introduction of vaccinia virus for the purpose of immunization against smallpox results in a local reaction of a single lesion at the sight of the injection.
- Vaccination
- A process by which small amounts of infective material, or material similar to that which is infective, is introduced into individuals to increase their resistance to disease. Sometimes, it is used in the general sense to refer to the process of immunization.
- Vaccine
- A killed or attenuated bacterial product that can be used to immunize against disease in an effort to promote protective immunity.
- Valley Fever (coccidioidomycosis)
- A disease produced by inhaling spores of the fungus Coccidioides immitis, affecting the lungs, skin, brain, and bones.
- Valve of the heart
- Include: aortic, the valve between the left ventricle and the aorta that prevents the blood being pumped out of the heart from falling back into the left ventricle; mitral, the valve between the right ventricle and the pulmonary artery that prevents the blood being pumped to the lungs from falling back into the right ventricle; tricuspid, the heart valve between the right atrium and the right ventricle that prevents the blood being pumped to the lungs from being ejected backwards into the right atrium.
- Varicella virus (VZV)
- A herpes virus responsible for chicken pox and shingles.
- Varioliform
- Resembling smallpox.
- Vectors
- Carriers, especially an animal (usually an arthropod), in whose body a pathogenic organism develops and multiplies before being transmitted to the next host.
- Vegetations
- Collections of blood proteins and platelets that adhere to heart valves containing infecting microorganisms that cause the disease of infectious endocarditis.
- Vehicle
- A nonliving source of pathogens, which are used to infect large numbers of individuals, for example, food and water.
- Venereal disease
- Any infectious social disease transmitted by sexual contact.
- Vermicide
- A chemical agent that kills parasitic worms in the intestine.
- Vermifuge
- A chemical agent used to expel parasites from the intestine; also called anthelmintic.
- Vermiculous
- Wormlike or infected with worms.
- Verruca
- Another name for a wart, usually caused by a virus; example is a plantar's wart found on feet.
- Vesicle
- A small skin blister containing clear fluid.
- Viable
- Alive and able to reproduce. Viable count is the measurement of the concentration of live cells in a microbial population.
- Viremia
- The presence of viruses in the blood.
- Virion
- A complete infective virus particle comprised of a nucleic acid surrounded by a protein coat and, in some cases, other material. Two substructures of viruses are viroids and prions.
- Viroid
- A small RNA molecule with viruslike properties.
- Virologist
- A microbiologist specializing in virology or the study of viruses.
- Virology
- The study of viruses.
- Virucide
- An agent that neutralizes or kills viruses.
- Viruria
- The presence of viruses in the urine.
- Virulence
- The degree of pathogenicity of an organism.
- Virulence factor
- A structure or attribute of a microbe that enhances its capacity to produce symptoms of disease in an infected host.
- Virus
- A genetic element containing either DNA or RNA that is able to alternate between intracellular and extracellular states, the latter being the infectious state; but all viruses are obligate intracellular parasites.
