Epidemiology

Question 1

What is a disease?

Answer 1

a pathological condition of body parts or tissues characterized by an identifiable group of signs or symptoms

Question 2

Infectious Disease

Answer 2

A disease caused by an infectious agent such as a bacterium, virus, protozoan, or fungus that can be passed on to others.

Question 3

What is an infection?

Answer 3

occurs when an infectious agent enters the body and begins to reproduce; may or may not lead to disease

Question 4

Host

Answer 4

an organism infected by another organism

Question 5

Pathogen

Answer 5

an infectious agent that causes disease

Question 6

What are some types of pathogens?

Answer 6

-virus
-bacterium
-fungi
-metazoa
-prions
-protazoa

Question 7

What are emerging diseases?

Answer 7

-diseases that have recently appeared within a population or whose incidence or geographic range is increasing rapidly.

Question 8

What causes a disease to emerge or re-emerge?

Answer 8

¤ appearance of a previously unknown agent.
¤ evolution of a new infectious agent.
¤ spread of an infectious agent to a new host.
¤ spread of an infectious agent to new locations.
¤ acquisition of resistance to anti-microbial drugs.
¤ deliberate introduction into a population.

Question 9

Endemic/enzootic

Answer 9

-constantly present in a certain population or region with relatively low spread

Question 10

Epidemic/epizootic

Answer 10

when there is a sudden increase in cases spreading through a large population like a country

Question 11

Pandemic/Panzootic

Answer 11

when there is sudden increase in cases spreading through several countries

Question 12

What makes up the epidiomelogical triangle?

Answer 12

Host, environment, vector

Question 13

Outcomes of exposure

Answer 13

-No infection

-Subclinical Infection–> immunity, carrier state ,no immunity

-Clinical–> no immunity= death

Question 14

Incubation period

Answer 14

time between infection and the appearance of signs and symptoms.

Question 15

Signs

Answer 15

are the physical manifestation of disease or injury that are measurable and reproducible and that can be recognized by any observer,
usually a health practitioner.

Question 16

Symptoms

Answer 16

are clinical manifestations of a disorder of organs or systems
that can be recognized or perceived only by patients.

Question 17

Prodromal phase

Answer 17

mild, nonspecific symptoms that signal onset of some diseases.

Question 18

clinical Phase

Answer 18

a person experiences typical signs and symptoms of disease

Question 19

Decline phase

Answer 19

Subsidence of symptoms

Question 20

Recovery Phase

Answer 20

symptoms have disappeared, tissues heal, and the body regains strength

Question 21

Mechanism of Disease

Answer 21

microbes cause disease in the course of stealing space, nutrients, and or living tissue from their symbiotic hosts

Question 22

How do microbes cause disease?

Answer 22

– Gain access to the host (contamination)
– Adhere to the host (adherence)
– Replicate on the host (colonization)
– Invade tissues (invasion)
– Produce toxins or other agents that cause host harm (damage)

Question 23

What is infectivity?

Answer 23

The ability to infect the host

Question 24

What is pathogenicity?

Answer 24

the ability to cause disease in the host

Question 25

Virulence

Answer 25

the ability to cause severe disease in the host

Question 26

Immunogenicity

Answer 26

the ability to induce an immune response in the host

Question 27

Modes of transmission; Indirect contact

Answer 27

¤ Via vector (an organism that carries disease-causing micro- organisms, such as mosquito) ¤ Via dust particles, air, food, water, blood, tissues, organs, fomites (inanimate objects that can carry disease-causing micro-organisms—e.g., toothbrush, cutting board, toys, etc. ¤ Diseases that are commonly spread by means of fomites include the common cold, cold sores, conjunctivitis, coxsackievirus (hand-foot- mouth disease), croup, E. coli infection, Giardia infection, influenza, lice, meningitis, rotavirus diarrhea, RSV, and strep

Question 28

Modes of transmission; direct contact

Answer 28

¤ Direct contact (person-to-person) ¤ Skin, saliva via kissing, sexual contact, aerosol from sneezing or coughing (e.g. .Polio, hepatitis, HIV, influenza)

Question 29

Modes of transmission; vertical transmission

Answer 29

-transmission of disease from mother to child -just before or just after birth -through placenta or breast milk

Question 30

Modes of transmission; horizontal transmission

Answer 30

all other transmission person to person

Question 31

What is epidemiology?

Answer 31

the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems (CDC).

Question 32

Ratio

Answer 32

is the relative magnitude of two quantities or a comparison of any two values. The numerator and denominator need not be related. Therefore, one could compare any two events

Question 33

Proportion

Answer 33

is the comparison of a part to the whole. It is a type of ratio in which the numerator is included in the denominator. A proportion may be expressed as a decimal, a fraction, or a percentage.

Question 34

Rate

Answer 34

-is a measure of the frequency with which an event occurs in a defined population over a specified period of time. Ex. Number of COVID test in CA last week: 516,536 Number of positive tests last week: 21,843 Calculate the positivity rate for last week:

Question 35

What is prevalence?

Answer 35

The number of persons with a specific disease at a specific time point

Question 36

Incidence

Answer 36

number of proportion of persons developing a specific disease during a time period

Question 37

Morbidity

Answer 37

refers to the number of persons that are ill

Question 38

Mortality

Answer 38

Number or proportion of persons dying during a time period

Question 39

Fatality rate

Answer 39

-Proportion of persons dying from a specific disease among all persons with the disease.

Question 40

Attack rate

Answer 40

-proportion of cases developing the disease among all persons who were exposed to the disease

Question 41

Herd Immunity

Answer 41

Herd immunity is the resistance of a group to attack from a disease to which a large portion of members are immune, thus lessening the likelihood of a patient with a disease coming into contact with a susceptible individual.