chpt 18 definitions

Question 1

disease

Answer 1

disturbance in the normal functioning of an organism

Question 2

infectious diseases

Answer 2

disease caused by a microbe that can be transmitted from host to host

Question 3

zoonotic diseases

Answer 3

infectious disease of animals that can cause disease when transmitted to humans

Question 4

symptoms

Answer 4

subjective disease state such as muscle aches

Question 5

pathogens

Answer 5

a microbe that routinely causes disease

Question 6

pathogenesis

Answer 6

process by which a pathogen causes disease

Question 7

infection

Answer 7

successful colonization and invasion by a pathogen of a host

Question 8

primary pathogens

Answer 8

microbe that causes disease in otherwise healthy hosts

Question 9

opportunistic pathogens

Answer 9

microbe that causes disease only when a host has been compromised

Question 10

virulence

Answer 10

degree of severity of disease a pathogen is capable of causing

Question 11

case-to-case infection ratio (CI ratio)

Answer 11

proportion of infected individuals who develop disease

Question 12

attenuation

Answer 12

regulatory mechanism that occurs after the initiation of transcription but before transcription of the operon is complete; decrease in virulence

Question 13

vaccines

Answer 13

preparation containing antigens used to immunize against disease

Question 14

carriers

Answer 14

asymptomatic host that can transmit an infectious agent to others

Question 15

host range

Answer 15

the diversity of cells that can be infected by a pathogen or support the replication of a virus or plasmid

Question 16

antigenic variation

Answer 16

change in molecules on the surface of a pathogen to which the immune system responds; can allow pathogen to avoid immune detection

Question 17

latency

Answer 17

infection characterized by a delay or cessation of disease; in viral disease, characterized by limited transcription of the viral genome; results in reduced immune response

Question 18

Reactivation

Answer 18

resumption of disease after a latent period; can occur due to cellular stress i the hose; in viruses, resumption of transcription of a previously latent viral genome

Question 19

toxins

Answer 19

substance of biological origin that damages a host

Question 20

apoptosis

Answer 20

cell death accomplished through a highly ordered and tightly controlled cascade of chemical signaling events within the cell that results in its destruction without the release of damaging cell constituents or triggering of inflammation

Question 21

transmission

Answer 21

spread of an infectious agent from one host to another or from its source

Question 22

reservoir

Answer 22

source of an infectious agent

Question 23

direct contact transmission

Answer 23

spread of an infectious agent that occurs via physical contact between an infected person and a susceptible person

Question 24

indirect contact transmission

Answer 24

spread of an infectious agent that occurs from one person to another via an inanimate object or a vector

Question 25

fomite

Answer 25

inanimate object via which pathogens may be transferred to a susceptible host

Question 26

fecal-oral transmittion

Answer 26

spread of an infectious agent that is eliminated in the feces of one individual and then ingested by another individual

Question 27

respiratory transmittion

Answer 27

spread of an infectious agent that replicates in the respiratory tract and leaves the infected host as an aerosol during coughing, sneezing, laughing, or similar activities

Question 28

vector-borne transmittion

Answer 28

spread of an infectious agent from an infected individual to another organism such as an insect that then transmits the infectious agent to a different susceptible host

Question 29

sexual transmittion

Answer 29

spread of an infectious agent that occurs during vaginal, anal, or oral sex

Question 30

sexually transmitted infections (STIs)

Answer 30

infectious disease that is spread sexually through vaginal, anal, or oral sex

Question 31

vertical transmission

Answer 31

spread of an infectious agent from part to child

Question 32

horizontal transmittion

Answer 32

spread of an infectious agent between members of a species that are not parent and offspring

Question 33

zoonotic transfer

Answer 33

spread of pathogen from its natural animal host to a human

Question 34

reservoir host

Answer 34

natural host that supports replication of a pathogen

Question 35

dead-end host

Answer 35

individual in which a pathogen may replicate and cause disease but int transferred efficiently to another individual; also called incidental host

Question 36

epidemiology

Answer 36

study of patterns of disease within populations

Question 37

morbidity rate

Answer 37

rate of disease

Question 38

mortality rate

Answer 38

rate of death associated with disease

Question 39

incidence

Answer 39

number of new cases of a disease appearing in a population during a specific time period

Question 40

prevalence

Answer 40

total number of cases of a disease in a population at a particular time or during a particular time period

Question 41

emerging diseases

Answer 41

disease that was previously unknown or that shows a significant increase in incidence

Question 42

endemic diseases

Answer 42

disease that is normally present in a population

Question 43

epidemic

Answer 43

significant rise in incidence of a disease above that normally expected in a population

Question 44

pandemic

Answer 44

global epidemic, usually on ore than one continent

Question 45

outbreak

Answer 45

cluster of cases appearing within a short period of time in a localized population

Question 46

common-source epidemic

Answer 46

an outbreak that results from exposure to a single source of infection

Question 47

incubation period

Answer 47

time between entry of a pathogen into a host and appearance of illness

Question 48

propagated epiemics

Answer 48

pattern of disease characterized by infection passing from one host to another, either directly or indirectly

Question 49

koch's postulates

Answer 49

guidelines for demonstrating that a specific microbe causes a specific disease

Question 50

molecular kock's postulates

Answer 50

guidelines for using molecular tools to demonstrate that a specific microbial product is a virulence factor

Question 51

pathogenicity islands (PAIs)

Answer 51

region of a chromosome containing multiple virulence factor genes

Question 52

signs

Answer 52

objective disease state that can be readily observed or measured, such as a rash or a fever