Public Health Workforce

communicable disease

a disease due to an organism such as bacteria or a virus that is transmitted person to person or from animals or the physical environment to humans by a variety of routes

pandemic

an epidemic occurring worldwide, or over a very wide area, crossing international boundaries and affecting a large number of people

epidemic

when a disease has increased in frequency in a defined geographic area far above its usual rate

endemic

implies that a disease is present in a community at all times but at a relatively low rate

Koch's postulates

four postulates that together definitely establish a cause and effect for a communicable disease: the organism must be shown to be present in every case of the disease; the organism must not be found in cases of other diseases; once isolated, the organism must be capable of replicating the disease in an experimental animal; and the organism must be recoverable from the animal

modern Koch's postulates

a set of criteria for establishing that an organism is a contributory cause of a disease, requiring evidence of an epidemiological association, isolation, and transmissions

route of transmission

the anatomical and physiological methods for transmission from person to person or from animal species to humans

asymptomatic transmission

the ability to transmit the disease while humans or animals are free of symptoms of the disease

reproduction ratio

the number of new cases one individual with the disease generates on average over the course of the disease's communicable period

chronic carriers

those individuals without symptoms of the disease but with he ability to chronically transmit the disease

immunization

the strengthening of the immune system to prevent or control disease through exposure to antigens or administration of anitbodies

passive immunity

short term protection against a disease provided by administration of antibodies

inactivated vaccines

aka dead; injection of a nonliving organism or antigen from an organism designed to develop antibodies to protect an individual from the disease

live vaccines

aka attenuated; use of a living organism in a vaccine

antibody

a protein produced by the body in response to a foreign antigen that can bind to the antigen and facilitate its elimination

cell mediated immunity

immunological protection that is produced by T-lymphocytes and other white blood cells that combats intracellular pathogens and tumor cells

herd immunity

aka population immunity; protection of an entire population from a communicable disease by obtaining individual immunity through vaccination or natural infections by a large percentage of the population

case finding

an effort to identify and locate contacts of individuals diagnosed with a disease and evaluate them for possible treatment

infectivity

the ability of a pathogen to enter and multiply in a susceptible host

epidemiological treatment

treatment of contacts of an individual with a disease even in the absence of evidence of transmission

ring vaccination

immediate vaccination of populations in surrounding geographic areas after identification of a case of disease

infectious disease

a disease caused by an organism such as bacteria or virus