Lecture 17: Epidemiology&Public Health

Question 1

epidemiology

Answer 1

• science that evaluates occurrence, determinants, distribution, and control of health and disease in a human population

Question 2

Epidemiologist

Answer 2

• one who practices epidemiology

Question 3

Centers for disease control and prevention (CDC)

Answer 3

• main epidemiological agency in the US
• develop and carry out disease prevention and control
• environmental health
• health promotion and education activities

Question 4

World health organization (WHO)

Answer 4

• international counterpart, based in Switzerland

Question 5

Sporadic disease

Answer 5

• occurs occasionally or at irregular intervals in human population
• ex. tetanus, rabies, plague

Question 6

Endemic disease

Answer 6

• maintains a steady, low level frequency at a moderately regular interval
• Ex: seasonal cold and flu

Question 7

Hyper-endemic disease

Answer 7

• gradually increase in frequency above endemic level but no to epidemic level
• ex. dengue fever

Question 8

Outbreak

Answer 8

• sudden, unexpected occurrence of disease
• usually in a limited segment of population

Question 9

Epidemic

Answer 9

• outbreak affecting many people at once
• index case

Question 10

Index case

Answer 10

• first person identified in an epidemic

Question 11

Pandemic

Answer 11

• increase in disease occurrence within a large population over at least two countries around the world

Question 12

John Snow

Answer 12

• Father of epidemiology

Question 13

Incidence

Answer 13

• measure occurrence of new cases of a disease during a defined time period

Question 14

Prevalence rate

Answer 14

• total number of individuals infected at any one time

Question 15

Prevalence rate

Answer 15

total # of cases in population/ total population X 100

Question 16

Morbidity rate

Answer 16

of new cases of disease in population/ # of individuals in population

Question 17

Mortality

Answer 17

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

Question 18

Mortality rate

Answer 18

of deaths due to a given disease/ size of total population with the same disease

Question 19

Communicable disease

Answer 19

• can be transmitted from person to person

Question 20

Two types of epidemics

Answer 20

1. common source epidemic
2. Propagated epidemic

Question 21

Common source epidemic

Answer 21

• noncommunicable and results from a single, common source

Question 22

Propagated epidemic

Answer 22

• one infected individual placed into a susceptible population, infection propagated to others

Question 23

Herd immunity

Answer 23

• threshold percentage of the population having immunity so when isolated cases reemerge, there is no escalation of the disease through the population

Question 24

Category A pathogen

Answer 24

• highest threat to public health
• high mortality rate

Question 25

Category B pathogen

Answer 25

- second highest priority - moderate morbidity and low mortality rates

Question 26

Category C pathogen

Answer 26

- third highest priority - emerging pathogens with potential for high morbidity

Question 27

One-health thinking

Answer 27

Focuses on ecological and social factors that influence development of emerging and reemerging diseases

Question 28

Reasons for Emergence

Answer 28

1. World population growth and urbanization 2. Crowded workplaces and public transportation 3. Increased international travel 4. Mass migrations of people 5. Climate change

Question 29

Hospital acquired infections (HAI)

Answer 29

- Nosocomial: associated with healthcare settings - causes by noninvasive bacteria from normal microbiota - many hospital strains are antibiotic resistant

Question 30

Common Hospital acquires infection (HAI)

Answer 30

- Urinary tract infections - surgical site infections - bloodstream infection - Pneumonia

Question 31

Endogenous sources

Answer 31

- Catheter-associated urinary tract infections - surgical site infections - Central line associated bloodstream infections

Question 32

Exogenous sources

Answer 32

- Animate sources: hospital staff, patients, visitors - Inanimate sources: flowers, food, computers

Question 33

two types of prevention and control of epidemics

Answer 33

1. reduce/ eliminate source or reservoir 2. reduce number of susceptible individuals

Question 34

Reduce or eliminate source or reservoir of infection

Answer 34

- Social distancing and isolation of carriers, destruction of animal reservoirs, treatment of water and sewage to reduce contamination.

Question 35

Reduce number of susceptible individuals and raise the general level of herd immunity

Answer 35

Immunizations and prophylactic treatment to prevent infection.

Question 36

Vaccine

Answer 36

- Preparation of one or more microbial antigen that induce protective immunity

Question 37

Immunization

Answer 37

- occurs when host’s immune system has responded to the vaccine

Question 38

Immunize the people

Answer 38

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

Question 39

Inactivated Vacines

Answer 39

- Killed - effective, but less immunogenic - often requires boosters - ex. Polio

Question 40

Attenuated Vaccines

Answer 40

- live but weakened - effective at stimulation both humoral and cell mediated immunity - single dose - can have serious adverse reactions

Question 41

Acellular/ subunit vaccines

Answer 41

- capsular polysaccharides - recombinant surface antigens - inactivated exotoxins (toxoids)

Question 42

Bioterrorism

Answer 42

- intentional use of viruses, bacteria, fungi, or their toxins to produce death or disease in humans, animals, and plants

Question 43

Indicators of Bioterrorism

Answer 43

- Sudden spike in unusual (non-endemic) diseases - sudden increased numbers of zoonoses, diseased animals or vehicle-borne illnesses