Chapter 9: Principles of Infectious Disease and Epidemiology

Question 1

Define: pathogen

Answer 1

-cause disease (viruses, prions, protozoans, fungi, helminths, bacteria)

Question 2

Define: opportunistic pathogen

Answer 2

-pathogens that cause disease in a weakend host (weak immune system/HIV/AIDS)

Question 3

Define: endemic

Answer 3

• an infection that is routinely detected in a population or region (common cold)

Question 4

Define: epidemic

Answer 4

-widespread disease outbreak in a particular region during a specific timeframe

Question 5

Define: pandemic

Answer 5

-epidemic spreads to numerous countries or througout the world

Question 6

Define: emerging pathogen

Answer 6

-newly identified agents/pathogens that previously only caused sporadic diseases

Question 7

Define: reemerging pathogen

Answer 7

-infectious agent that was once under control but is now resurfacing (antibiotic resistant bacteria)

Question 8

Define: zoonotic disease

Answer 8

-diseases spread from animals to humans

Question 9

Define: noncommunicable

Answer 9

-do not spread from human to human

Question 10

Define: communicable

Answer 10

-spread from human to human

Question 11

Define: contagious

Answer 11

-easily transmitted from one host to the next

Question 12

Define: signs

Answer 12

-objective indicators of disease that can be measured or verified (fever, rash, blood in stool)

Question 13

Define: symptoms

Answer 13

-sensed by the patient rather than precisely measurable (pain, fatigue, nausea)

Question 14

Define: latent disease

Answer 14

-asymptomatic

Question 15

Define: chronic disease

Answer 15

-slow onset and progression

Question 16

Define: acute disease

Answer 16

-rapid onset and progression (quick resolution)

Question 17

Define: noninfectious disease

Answer 17

-illnesses not directly caused by pathogens

Question 18

Define: infectious disease

Answer 18

-illnesses caused by pathogens

Question 19

Define: susceptible host

Answer 19

-host that can develop a disease in question

Question 20

Define: obligate intracellular pathogen

Answer 20

-pathogens that only replicate inside a host cell and therefore cannot be grown as independent pure cultures

(viruses, certain bacteria, protozoans)

Question 21

Define: reservoir

Answer 21

-animate or inanimate habitat where a pathogen is naturally found

Question 22

Define: source

Answer 22

• disseminate infectious agent from the reservoir to new hosts

Question 23

Define: endogenous source

Answer 23

-pathogen came from hosts own body

Question 24

Define: exogenous

Answer 24

-pathogen is from external to host

Question 25

Define: vector

Answer 25

-organisms such as arthropods and rodents that spread infectious agents to other susceptible hosts

Question 26

Define: morbidity

Answer 26

-existence of disease in a population

Question 27

Define: prevalence rate

Answer 27

-morbidity in a given population during a specified time

Question 28

Define: incidence rate

Answer 28

-number of new cases in a defined population during a defined time frame

Question 29

Define: duration

Answer 29

-how long the infection lasts

Question 30

Define: epidemiology

Answer 30

-monitoring and controlling disease occurrence to promote public health

Question 31

Define: HAI

Answer 31

-healthcare acquired infection

Question 32

Define: localized infection

Answer 32

-infection restricted to a specific part of the body

Question 33

Define: systemic infection

Answer 33

-infection widespread throughout the body

Question 34

Define: virulence factor

Answer 34

-ways pathogens overcome our defenses

Question 35

Kochs Postulates

Answer 35

1. the same organism must be present in every case of disease
2. the organism must be isolated from the diseased host and grown as a pure culture
3. the isolated organism should cause the disease in question when it is inoculated into a susceptible host
4. the organism must then be re-isolated from the inoculated, diseased animal

Question 36

Infectious Disease Transmission (know mechanisms)

Know figure 9.1

Answer 36

Question 37

5 stages of infectious disease

Answer 37

incubation period: time between infection and the development of disease symptoms

prodromal phase: patient has mild symptoms

acute phase: patient experiences full blown symptoms

period of decline: pathogen replication decreases

convalescent period: elimination of the pathogen from the hosts body

Question 38

Know the epidemiological triangle(what can be done to stop the spread of infection?)

Answer 38

• education
• quarantine
• vector control

Question 39

Importance of CDC and WHO?

Answer 39

• the CDC is a federal health agency that serves as a central source of epidemiological information
• the WHO is importance for the global governance of health and disease

Question 40

What is the MMWR?

Answer 40

• MORBIDITY AND MORTALITY WEEKLY REPORT
• updates health officials and care providers on U.S. health issues
• provides summaries of health watches and a running report for selected notifiable diseases

Question 41

What is an HAI (nosocomial)? Why are they a problem?

Most common HAIs?

Prevention?

Answer 41

• HAIs are healthcare acquired infections
• 1 in 25 hospitalized patients develop an HAI

Prevention

• hand washing
• personal protective gear
• environmental sanitation
• equipment sterilization
• limiting patient transport
• patient isolation

Question 42

What is the NNDS?

Answer 42

-surveillance for nationally notifiable diseases

Question 43

Examples of vaccine preventable diseases:

Answer 43