Lecture 14

Question 1

Epidemiology

Answer 1

The study of the frequency and distribution of disease

Question 2

Father of epidemiology

Answer 2

John snow famous for determining the cause of the 1854 cholera outbreak in London

Question 3

Surveillance

Answer 3

Collecting, analyzing, and reporting data on rates of occurrence, mortality, morbidity and transmission of infections

Question 4

Who does surveillance

Answer 4

In US CDC
Worldwide WHO

Question 5

Prevalence

Answer 5

Accumulated total of existing cases with respect to the entire population

Question 6

Prevalence formula

Answer 6

Total number of cases in population/ total number of persons in population
x100

Question 7

Incidence

Answer 7

Number of new cases over a certain time period as compared with the general healthy population

Question 8

Incidence formula

Answer 8

Number of new cases/ total number of susceptible persons
x100

Question 9

Mortality rate

Answer 9

Total number of deaths in a population due to a certain disease
Mortality from infectious diseases have dropped over past century

Question 10

Morbidity rate

Answer 10

Measures total number of persons afflicted with an infectious disease
Rate has remained high over past century

Question 11

Endemic

Answer 11

An infectious disease that exhibits a relatively steady frequency over a long time period in a particular geographic locale

Question 12

Endemic disease examples

Answer 12

Valley river in Southwestern US

Lyme disease in certain areas of the US like northeast

Question 13

Sporadic

Answer 13

Infrequent or irregular cases of an infectious disease outbreak that occur randomly over a wide area

Question 14

Sporadic disease examples

Answer 14

Measles and typhoid fever

Question 15

Epidemic

Answer 15

An increased number of cases beyond expected levels that appear in geographic clusters

Question 16

Epidemic examples

Answer 16

Syphilis and STDs
Foodborne
Influenza

Question 17

Pandemic

Answer 17

The spread of an epidemic across continents

Question 18

Pandemic examples

Answer 18

HIV/AIDS
COVID-19

Question 19

Determining transmission

Answer 19

Ask about patient background
Locations frequented or traveled
Possible contacts
Habits
Food
Sexual partners

Question 20

Transmission

Answer 20

Exchange of the pathogen from an infected individual to uninflected hosts

Question 21

Direct transmission

Answer 21

Kissing, sex, biological vectors, large droplets

Question 22

Indirect transmission

Answer 22

Airborne droplet nuclei, fomites, food

Question 23

Reservoir

Answer 23

Primary habitat in the natural world from which a pathogen originates

Question 24

Living reservoir

Answer 24

May or may not have symptoms, members of a host population or carriers, animals

Question 25

Non-living reservoir

Answer 25

Soil and water for pathogenic fungi, bacterial endospores, parasite cysts ova and larvae

Question 26

Asymptomatic carrier

Answer 26

Infected without symptoms, a living reservoir

Question 27

Incubation, convalescent, and chronic carriers

Answer 27

Can transmit the infection either before or after the period of symptoms

Question 28

Vectors

Answer 28

Live animal that transmits the infectious agent from one host to another

Question 29

Biological vector

Answer 29

Actively participates in a pathogen's life cycle, serving as a site for multiplication or completion of life cycle like anopheles mosquito

Question 30

Mechanical vector

Answer 30

Not necessary to the life cycle of a pathogen only transports it without being infected like flies carrying bacteria

Question 31

Zoonosis

Answer 31

Infection indigenous to animals but naturally transmissible to humans like west Nile and birds, human may be dead end host don't contribute to persistence of microbe

Question 32

Zoonoses

Answer 32

70% of all new emerging diseases worldwide

Question 33

Common zoonotic infections

Answer 33

Rabies in mammals, west nile virus birds and mosquitoes, salmonellosis in chicken and swines, influenza in chicken and swine, anthrax in domestic farm animals

Question 34

Nosocomial infections

Answer 34

Infectious diseases acquired or developed during a hospital stay, 0.1-20% of all admitted patients

Question 35

CDC nosocomial infections

Answer 35

1.7 million each year 99,000 deaths per year

Question 36

Common nosocomial infections

Answer 36

Urinary tract from catheters and being unable to stand, respiratory tract from breathing machines, surgical incision infections

Question 37

Applying epidemiological info

Answer 37

Determine recommendations for individuals, determine recommendations for public health policy, predict future of disease, suggest ways to stop/slow disease spread

Question 38

Etiological agent

Answer 38

Causative agent of infection or disease

Question 39

Robert Koch

Answer 39

Laid foundation for determining the etiological agent for many infections and a standard for determining causation, developed pure culture methods, identified etiological agent of anthrax, TB, and cholera

Question 40

Koch's postulates

Answer 40

Show that a specific microorganism is responsible for a particular disease

Question 41

Postulate 1

Answer 41

Correlate every case of disease with the presence of a certain microbe

Question 42

Postulate 2

Answer 42

Isolate that microbe from an infected subject, cultivate it in a pure culture in the lab and identify it

Question 43

Postulate 3

Answer 43

Inoculate a susceptible healthy subject with the laboratory isolate and observe the resultant disease

Question 44

Postulate 4

Answer 44

Re-isolate the agent from this subject in Pure culture and prove its the same microbe that you inoculated

Question 45

"Gold standard"

Answer 45

Koch'S postulates for identifying etiological agent of infections helped determine the cause of TB, diphtheria, and plague

Question 46

Postulates don't work for

Answer 46

Viral infections, obligate intracellular bacteria, microbes that cause multiple diseases Modified for these pathogens