C-8

Question 1

epidemiology

Answer 1

The study of the occurrence and spread of disease and how it can be prevented or limited

Question 2

etiology

Answer 2

The cause of disease or infection

Question 3

incidence

Answer 3

Number of new cases of a disease in a given area/population in a given period of time; tells you what the risk of acquiring the infection is

Question 4

prevalence

Answer 4

Total number of all individuals affected by the disease in an area at a particular time
(includes both new and old cases); tells you how widespread the disease is

Question 5

morbidity

Answer 5

Another term for disease but not deaths (can include incidence and prevalence)

Question 6

mortality

Answer 6

death due to disease

Question 7

endemic

Answer 7

expected disease that normally
occurs at regular intervals at stable incidence within a given population or area (i.e. flu)

Question 8

sporadic

Answer 8

disease with only a few scattered cases within a population or area; occurs
infrequently and irregularly (i.e. rabies)

Question 9

epidemic

Answer 9

disease that occurs at a greater
frequency than is normal/usual for an area or population. Can be endemic!

Question 10

pandemic

Answer 10

if an epidemic occurs
simultaneously worldwide (on multiple continents) (i.e. covid)

Question 11

reservoirs

Answer 11

Sites where pathogens are normally maintained and act as a source of infection

Question 12

portals of entry and exit (skin, mm, placenta)

Answer 12

skin: broken skin, natural openings, hair follicles and sweat glands, insect bites or burrowing

mm: Line the GI, respiratory, urinary, and reproductive
tracts – also line the eyes, nose, and mouth; Thinner and easier to penetrate

placenta: Barrier between fetus and mother – some pathogens can cross

Question 13

direct transmission (contact)

Answer 13

Ex. Handshake, kissing,
intercourse, placenta,
unwashed hand to own mouth

Question 14

indirect transmission (contact)

Answer 14

• Ex. Touching a fomite - toothbrush, drinking glass, money
• Puncture wound

Question 15

droplet transmission (contact)

Answer 15

• Larger droplets from an
  aerosol less than 1 meter away
• Ex. Droplets from sneezing

Question 16

mechanical transmission (vector)

Answer 16

don’t act as hosts for the
pathogens they transmit – only
passively carry pathogens to new hosts on feet or other body parts (flies and cockroaches)

Question 17

biological transmission (vector)

Answer 17

transmit pathogens and serve as hosts for the multiplication of a pathogen during its life cycle (biting - mosquitos, lice, ticks, mites, etc)

Question 18

airborne transmission (vehicle)

Answer 18

Transmitted by the air. Farther distance than droplet transmission; finer aerosolized particles. Ex. fungal spores or measles virus

Question 19

waterborne transmission (vehicle)

Answer 19

Many GI diseases are waterborne caused by fecal
contamination of drinking water (fecal-oral infection).
Ex. cholera

Question 20

foodborne transmission (vehicle)

Answer 20

Similar to waterborne – Ex. produce contaminated with
fecal matter from animals; parasitic worms from undercooked meat

Question 21

bodily fluid transmission (vehicle)

Answer 21

Bodily fluid from infected individuals can also be a
source of transmission.
Ex. semen or blood

Question 22

fomite

Answer 22

inanimate object

Question 23

pathogenicity vs virulence

Answer 23

The ability to cause disease vs The degree of pathogenicity

Question 24

pathogen

Answer 24

microbes that are able to cause disease

Question 25

opportunistic pathogen

Answer 25

microbes that don’t normally cause disease unless an opportunity arises like a compromised immune system or weakened microbiome

Question 26

virulence factor

Answer 26

Characteristics of pathogenic microbes that allow them to be pathogenic/virulent

Question 27

how a capsule affects virulence and survival in the human body

Answer 27

Prevents phagocytes from ingesting/killing pathogenic bacteria

Question 28

how exotoxins and endotoxins affect virulence and survival in the human body

Answer 28

Cytotoxins inhibit protein synthesis and destroy cells (Diptheria toxin) Neurotoxins prevent nerve transmission (Botox) Enterotoxins promote fluid loss from cells (cholera toxin) LPS – pyrogen and can induce inflammation and shock

Question 29

how enzymes (and other extracellular products and components like adhesions) affect virulence and survival in the human body

Answer 29

Help pathogenic bacteria invade deeper tissues and evade immune response

Question 30

Describe how we experimentally determine how something is a virulence factor

Answer 30

need to assess whether it is necessary and/or sufficient for a microbe to cause disease; necessary: make a deletion mutation in that gene and see if the microbe is still able to cause disease sufficient: add that protein into another microbe’s genome and see if that protein is all a microbe needs to cause disease

Question 31

infection vs disease

Answer 31

infection: A progression of contamination – where contaminating microbes have invaded the body, overcome immune defenses, and multiplied disease: When an infection adversely affects the body and health

Question 32

stages of infectious disease

Answer 32

- incubation period (microbes replicating - prodromal period (pathogen multiplying and host feels illness) - period of illness (signs and symptoms most severe) - period of decline (signs and symptoms suppress) - period of convalescence (recovery)

Question 33

signs vs symptoms

Answer 33

signs: Objective manifestations of disease observed or measured by those other than the patient (outside observations) symptoms: Subjective characteristics of a disease that are only felt by the patient

Question 34

HAI

Answer 34

hospital acquired infections (dirty beds, linen, handling patient to patient, etc)

Question 35

how HAI arise

Answer 35

exo: infection acquired form others in health care environment endo: acquired opportunistic infection from hospitalization or chemotherapy

Question 36

prevention and control methods of HAI

Answer 36

* Disinfect surfaces/good housekeeping * Handwashing * Bathing / hygiene * Proper food handling * Aseptic practices in surgery/procedures * Isolation of contagious or vulnerable patients

Question 37

innate (nonspecific) immune

Answer 37

first and second lines of defense

Question 38

phagocytosis

Answer 38

cell eating

Question 39

roles of eosinophils in innate immunity

Answer 39

Phagocyte/Microphage - involved in parasitic infection; Degranulate to secrete antimicrobial chemicals to kill pathogens too big to be ingested

Question 40

roles of neutrophils in innate immunity

Answer 40

Phagocyte/Microphage - releases cytotoxic chemicals like ROS; Degranulate to produce reactive oxygen species (ROS, trigger inflammation, produce NETs

Question 41

roles of NK cells in innate immunity

Answer 41

Degranulate and secrete toxins called perforins and granzymes onto the surfaces of virally infected cells and tumor cells marked for destruction

Question 42

inflammation (How are basophils and molecules like histamines, prostaglandins, and leukotrienes involved? What are the consequences of too much inflammation?)

Answer 42

response to tissue damage and infection; the molecules help stimulate inflammations; HIPER (heat, induration, pain, edema, and redness)

Question 43

complement (opsonization and MAC)

Answer 43

collection of serum proteins that form MAC and do opsonization; MAC= membrane attack complex that punches holes in gm- membranes; opsonization=enhances abilities of antibodies and phagocytes to clear infection

Question 44

interferons (how do they specifically interfere with viral infections)

Answer 44

signaling proteins by host cells infected by viruses to warns other cells that viruses are coming (type 1 and type 2)

Question 45

fever (purpose, pyrogens, too much fever)

Answer 45

fever increases body temp to kill or inhibit microbial growth; pyrogens trigger hypothalamus to reset the body's thermostat to higher temps to enhance inflammation; too much fever=can damage normal, good cells (DNA damage, membrane damage, cellular damage, too much inflammation, bacteria can enter blood stream rather than just exit, losing BP)

Question 46

animal reservoirs

Answer 46

Responsible for spreading zoonoses – diseases that spread from animals to humans

Question 47

human carries

Answer 47

People who incubate the pathogen in their bodies; some become sick and others don’t

Question 48

nonliving reservoirs

Answer 48

Inanimate things like soil, water, food, can harbor pathogens