Epidemiology

Question 1

What is the epidemiology?

Answer 1

Science that evaluates occurrence, determinants, distribution, and control of health and disease in a defined human population.

Question 2

Who was the first epidemiologist?

Answer 2

John Snow

studied Cholera in London

Question 3

What did Florence Nightingale show in 1858?

Answer 3

Showed that improved sanitation decreased the incidence of epidemic typhus.

Question 4

What does the Centers for Disease control and Prevention (CDC) do?

Answer 4

Functions as national focus for developing and applying disease prevention and control, environmental health, and health promotion and health education activities designed to improve the health of the people.

Question 5

What do epidemiologist determine in their research of disease?

Answer 5

> causative agent
source and/or reservoir of disease agent
mechanism of transmission
host and environmental factors that facilitate development of disease within a defined population
best control measures

Question 6

What is the definition of sporadic disease?

Answer 6

Occurs occasionally and at irregular intervals.

Question 7

What is the definition of endemic disease?

Answer 7

Maintains a relatively steady low-level frequency at a moderately regular interval.

Question 8

What is the definition of hyperendemic disease?

Answer 8

Gradually increase in occurrence frequency above endemic level but not to epidemic level.

Question 9

What is the definition of epidemic?

Answer 9

> Sudden increase in frequency above expected number.

> Index case - first case in an epidemic.

Question 10

What is the definition of pandemic?

Answer 10

Increase in disease occurrence within large population over wide region (usually worldwide).

Question 11

What is the definition of outbreak?

Answer 11

> Sudden, unexpected occurrence of disease.

> Usually focal or in a limited segment of population.

Question 12

What are the methods that epidemiologist use to look at disease?

Answer 12

> Public Health Surveillance
Remote Sensing
Geographic Information Systems - charting infectious disease.

Question 13

What are the three important statistical measures of disease frequency?

Answer 13

> morbidity rate (incidence rate)
prevalence rate
mortality rate

Question 14

How do you calculate morbidity rate?

Answer 14

number of new cases in a specific time period / number of individuals in population

Question 15

How do you calculate prevalence rate?

Answer 15

total # of cases in population / total population X 100

Question 16

What does prevalence rate measure?

Answer 16

> total number of individuals infected at any one time

> depends both on incidence rate and duration of illness

Question 17

How do you calculate mortality rate?

Answer 17

deaths due to given disease / size of total population with disease

Question 18

What does mortality rate measure?

Answer 18

Number of deaths from a disease per number of cases of the disease

Question 19

What does the morbidity rate tell you?

Answer 19

> an incidence rate

> number of new cases in a specific time period per unit of population

Question 20

What is an infectious disease?

Answer 20

Disease resulting from an infection by microbial agents such as viruses, bacteria, fungi, protozoa, and helminths.

Question 21

What is a communicable disease?

Answer 21

Can be transmitted from one host to another.

Question 22

What is a contagious disease?

Answer 22

A disease that is easily spread from one host to another.

Question 23

What is a noncommunicable disease?

Answer 23

A disease that is not transmitted from one host to another.

Question 24

What is an acute disease?

Answer 24

Symptoms develop rapidly.

Question 25

What is a chronic disease?

Answer 25

Disease develops slowly.

Question 26

What is a subacute disease?

Answer 26

Symptoms between acute and chronic.

Question 27

What is a latent disease?

Answer 27

Disease with a period of no symptoms when the causative agent is inactive.

Question 28

What are the two types of epidemics?

Answer 28

> common source epidemic (e.g., food) | > propagated epidemic (e.g., strep throat)

Question 29

What is herd immunity?

Answer 29

Resistance of a population to infection and to spread of an infectious organism because of the immunity of a large percentage of the population. > level can be altered by introduction of new susceptible individuals into population > level can be altered by changes in pathogen - antigenic shift (major change in antigenic character of pathogen) - antigenic drift (smaller antigenic changes)

Question 30

What is systematic epidemiology?

Answer 30

Focuses on ecological and social factors that influence development and spread of emerging and reemerging disease. ``` Reasons: > world population growth > increased international travel > habitat disruption > microbial evolution and development of resistance > inadequate public infrastructures ```

Question 31

What is a nosocomial infection?

Answer 31

Hospital-acquired infection. > from pathogens within a hospital or other clinical care facility, acquired by patients in the facility > 10% of all hospital patients acquire a nosocomial infection > often caused by bacteria that are members of normal microbiota > many hospital strains are antibiotic-resistant

Question 32

Sources of Nosocomial infections?

Answer 32

> endogenous pathogen (brought into hospital by patient or acquired when patient is colonized after admission) > exogenous pathogen (microbiota other than the patient's) > autogenous infection (caused by an agent derived from microbiota of patient despite whether it became part of patient's microbiota following admission)

Question 33

What are the three types of control measures of epidemics?

Answer 33

> reduce or eliminate source or reservoir of infection > break connection between source and susceptible individual > reduce number of susceptible individuals

Question 34

What is immunization?

Answer 34

Result obtained when vaccine stimulates immunity.

Question 35

What is the goal of vaccines given to an individual?

Answer 35

Vaccines attempt to induce antibodies and activated T cells to protect host from future infection.

Question 36

What is vaccinomics?

Answer 36

The application of genomics and bioinformatics to vaccine development.

Question 37

What is a adjuvant?

Answer 37

Are mixed with antigens in vaccines to enhance the rate and degree of immunization. > Can be any nontoxic material that prolongs antigen interaction with immune cells and stimulates the immune response to the antigen.

Question 38

What are whole cell vaccines?

Answer 38

> most current vaccines active against bacteria and viruses consist of two microbes that are either inactivated (killed) or attenuated (live but avirulent). > considered gold-standard but may be problematic: - may not protect - immunosuppressed at risk of getting disease - attenuated may revert to virulent

Question 39

What is a acellular or subunit vaccine?

Answer 39

Use of purified molecules from microbes avoids some of the risks of whole-cell vaccines. > Forms of subunit vaccines: - capsular polysaccharides - recombinant surface antigens - inactivated exotoxins (toxoids)

Question 40

What is a recombinant-vetor vaccine?

Answer 40

Pathogen genes that encode major antigens inserted into nonvirulent viruses or bacteria which serve as vectors and express the inserted gene. > released gene products (antigens) can elicit cellular and humoral immunity.

Question 41

What are DNA vaccines?

Answer 41

DNA directly introduced into host cell via air pressure or gene gun. > DNA taken into nucleus and pathogen's DNA fragment is expressed. - host immune system responds to foreign proteins produced > Many DNA vaccine trials are currently being run.

Question 42

What is the role of the public health system?

Answer 42

Network of health professionals involved in surveillance, diagnosis, and control of epidemics. Form count, regional, state, national, and international public health organizations.

Question 43

What is bioterrorism?

Answer 43

intentional or threatened use of viruses, bacteria, fungi, or toxins from living organisms to produce death or disease in humans, animals, and plants

Question 44

What are the key indicators of a bioterrorism event?

Answer 44

> sudden increased numbers of sick people, espcially with unusual diseases for that place and/or time of year. > sudden increased numbers of zoonoses, diseased animals, or vehicle-borne illnesses.