Micro Ch 13 Epidemiology

Front 1

Disease

Back 1

Change in state of health

Front 2

Symptoms

Back 2

Changes in body function

Not visible to observer

(Pain, malaise)

Front 3

Signs

Back 3

Visible changes in body function

See the sign!

(Fever, bleeding)

Front 4

Epidemiology

Back 4

Study of disease:

Patterns of disease Statistics

Agents,

Spread,

SnS,

Prevention & Treatment,

In a population

Front 5

Etiology

Back 5

Causal agents

Cause of disease

Front 6

Pathogen

Back 6

Any disease causing agent

Front 7

Contamination

Back 7

Incoming microbes on host surface

Front 8

Infection

Back 8

Invasion of tissues

Front 9

Etiological agent

Back 9

Specific name of the pathogen

Front 10

Symbiosis

Back 10

Living together

Front 11

Mutualism

Back 11

Mutually beneficial

++

Front 12

Commensalism

Back 12

One benefits, no affect on other

+0

Front 13

Commensalism

Back 13

One benefits, no affect on other

+0

Front 14

Parasitism

Back 14

1 benefits at cost to other +-

Front 15

Opportunist

Back 15

Normally harmless

Does not cause disease, under normal conditions

Front 16

Microbial antagonist

Back 16

Battle it out

Front 17

Benefits of resident microbiota

Back 17

Stimulate: immune and other systems

Defense: create environment unfavorable to pathogens

Prevent: overgrowth of opportunists

Required: normal intestinal development

Produce: micronutrients (Vit K & B)

Front 18

Adverse effects of resident microbiota

Back 18

Endogenous infection: opportunists multiply, disrupt tissue

Reservoirs

Carriers

Front 19

Microbiota cell amount

Back 19

1 x 10^14

(1 × 10^13 body cells)

Front 20

G.I tract is

Back 20

25-35 feet long

Anaerobic

Front 21

Vaginal tract microflora

Back 21

pH 3.5- 4.5

Anaerobic

Beneficial flora

Lactobacilli

E. coli from gut is bad here

Front 22

Where flora comes from

Back 22

In utero: microbe-free

Lactobacilli: multiply in vag. tract before birth

(prominent, produce H2O2)

Different flora: vag. Birth vs C-section, breast vs bottle

Environment

Flora stabilizes

Front 23

Where flora comes from

Back 23

In utero: microbe-free

Lactobacilli: multiply in vag. tract before birth

(prominent, produce H2O2)

Different flora: vag. Birth vs C-section, breast vs bottle

Environment

Flora stabilizes

Front 24

Where flora comes from

Back 24

In utero: microbe-free

Lactobacilli: multiply in vag. tract before birth

(prominent, produce H2O2)

Different flora: vag. Birth vs C-section, breast vs bottle

Environment

Flora stabilizes

Front 25

Koch's postulates

Back 25

Presence of pathogen

Isolation

Inoculate

Disease

Isolate original organism

Front 26

Why can't Koch' s postulates be used for every etiological agent/pathogen?

Back 26

Unethical

Many microbes cause same disease/SnS

Front 27

Frequency

Back 27

Endemic

Epidemic

Pandemic

Sporadic

Front 28

Frequency

Back 28

Endemic

Epidemic

Pandemic

Sporadic

Front 29

Endemic

Back 29

Constantly present

Front 30

Epidemic

Back 30

Sudden, Higher than normal incidence

Front 31

Pandemic

Back 31

Spreads worldwide

Front 32

Sporadic

Back 32

Appears randomly, unpredictably

Front 33

Disease cycle

Back 33

Survival outside host (reservoir)

Transmission to host

Portal of Entry

----------------------------------------

Attachment to target tissue

Colonization

Host damage

Portal of exit

Front 34

When does disease start during disease cycle?

Back 34

Attachment

Front 35

Reservoir

Back 35

Primary habitat

Where pathogen originates

Front 36

Reservoir

Back 36

Primary habitat

Where pathogen originates

Front 37

Endogenous infection

Back 37

Caused by hosts own opportunists

Front 38

Endogenous infection

Back 38

Caused by hosts own opportunists

Front 39

Exogenous infections

Back 39

Enter host from environment

Front 40

Exogenous infections

Back 40

Enter host from environment

Front 41

Human reservoirs

Back 41

Asymptomatic: seem healthy

Symptomatic

Front 42

Zoonoses

Back 42

Diseases transmitted from animals to humans

(Directly or indirectly)

Both source & spread/transmission

Front 43

Animal reservoirs

Back 43

150+ pathogens infect both animals and humans

Front 44

Nonliving reservoirs

Back 44

Inert environment

Soil

Water

Food

Front 45

Soil

Back 45

Clostridium tetani

C. Botulinum

Fungi (ringworm)

Front 46

Water

Back 46

Vibrio cholerae

Salmonella typhi

Giardia

Front 47

Food

Back 47

Staphylococcus toxins

Salmonella

Front 48

Nosocomial infections

Back 48

Disease acquired during hospital/health facility stay

10% of admitted patients acquire infection

UTIs 40%

Surgical wounds 19%

Respiratory 15%

Front 49

Universal precautions

Back 49

Guidelines established by CDC to reduce risks of disease transmission in health care settings

Front 50

Communicable diseases

Back 50

Can spread from living to living hosts

Directly or indirectly

Not all are communicable, but transmission can still occur

Front 51

Non-communicable disease

Back 51

Picked up from environment but not passed to another living host.

Front 52

Contact transmission

Back 52

Direct

Indirect

Direct Droplet

Front 53

Direct contact transmission

Back 53

Body contact

w/in a meter

Nothing between

Horizontal/vertical transmission

Front 54

Indirect transmission

Back 54

Requires fomite

(Involves object)

Nonliving to living

Front 55

Direct Droplet transmission

Back 55

Cough

Sneeze

Dried mucous

Travels less than 1 meter

Front 56

Transmission groups

Back 56

Contact

Vehicle

Vector

Front 57

Vehicle transmission

Back 57

Non-living carrier to living

Over 1 meter

(Indirect host-host transmission)

Water: oral-fecal

Air: long-distance droplets

Food: hamburgers

Front 58

Vector transmission

Back 58

Living organisms transmit disease from one host to another

Front 59

Vector transmission

Back 59

Living organisms transmit disease from one host to another

Front 60

Mechanical vectors

Back 60

On insect body

Picked up on surface

Surface carried

Front 61

Biological vectors

Back 61

Internally carried

Front 62

Control of transmission

Back 62

Isolation

Quarantine

Immunization

Vector control

Front 63

Isolation

Back 63

Patient has communicable disease

Front 64

Quarantine

Back 64

Separates "healthy" person exposed to communicable disease

Front 65

Vector control

Back 65

Pesticide

Insecticide

Mosquito net

Clean up food

No swimming dogs: Leptospira spirochetes

Front 66

Portals of entry

Back 66

Skin

Resp. & dig. tracts

Genitals, urinary tracts

Mucous membranes

Placental

+ more

Front 67

Pathogenicity

Back 67

Ability to cause disease in host

(Easy to catch, fewer cells needed)

Front 68

Virulence

Back 68

Degree of severity

How evil?

Death?

Front 69

Portal of entry applies to

Back 69

Pathogenicity

Front 70

Penetration/adhesion applies to

Back 70

Pathogenicity

Front 71

Evasion of host defences applies to

Back 71

Pathogenicity

Virulence

Front 72

Damage to host cells applies to

Back 72

Virulency

Hint 72

Cytopathic effects

Front 73

Portal of exit applies to

Back 73

Pathogenicity

Front 74

Infectious dose

Back 74

# of cells needed to cause 50% of healthy hosts to become infected

(Pathogenicity)

Front 75

Lethal dose

Back 75

# of cells or toxin potency to kill 50% of inoculated hosts

(Virulence)

Front 76

Factors affecting disease process

Back 76

Numbers of microbes

Attachment

Phagocytosis avoidance

Extracellular enzymes

Exotoxins

Endotoxins

Front 77

Avoidance of phagocytosis

Back 77

Capsule- slippery

Special proteins

Wax

Leukociden- destroys neutrophils & macrophages

Front 78

Production of extracellular enzymes

Back 78

Digestion, destruction of tissues:

Collagenase

Keratinase

Hyaluronidase

Streptokinase (dissolves clot)

Coagulase

Mucinase

Hemolysin

Front 79

Species-specific Exotoxins

Back 79

Diptheria- inhibits protein synth.

Erythrotoxin- from Streptococcus pyogenes

Vibrio Enterotoxin- (cholera) affects G.I cells

Botulinum & Tetanus neurotoxins- nerves

Front 80

Attachment (how)

Back 80

Fimbrae- fringe

Glycocalyx- sticky, sugary crown

Adhesin- ligands, bind to host receptors (glue)

Biofilms- living cells bind together and adhere to a surface

Front 81

Evasion of host defences (immune system)

Back 81

Antigenic variation

Pathogen keeps changing

Many variants may be present in one host

Front 82

Exotoxin production

Back 82

Proteins produced inside

Especially gram +

Species-specific

Heat-labile

Front 83

Antitoxins

Back 83

Antibodies

Produced by WBCs

Combat exotoxins

Front 84

Toxoids

Back 84

Altered exotoxins

Induce immunity

Injected

Front 85

Endotoxin production

Back 85

Lipids in Gram - cell wall

Released by dead pathogens

Effects: fever, aching, weakness, TSS

Front 86

Gram + pathogens

Back 86

Some produce exotoxins

Protein by-products

No fever

Neutralized by antitoxin

Small lethal dose

Front 87

Gram + pathogens

Back 87

Some produce exotoxins

Protein by-products

No fever

Neutralized by antitoxin

Small lethal dose

Front 88

Gram - pathogens

Back 88

Endotoxins in LPS

Lipid

Fever

Not neutralized by antitoxin

Relatively large lethal dose

Front 89

Portals of Exit

Back 89

How infectious agents exit host

So they can enter new host

Body fluids

Feces

Front 90

Portals of Exit

Back 90

How infectious agents exit host

So they can enter new host

Body fluids

Feces

Front 91

Disease stages

Back 91

IPIDC:

Incubation

Prodromal

Illness

Decline

Convalescence

Front 92

Incubation

Back 92

Variable

2-3 days, most diseases

No SnS

Front 93

Prodromal stage

Back 93

Mild SnS

Malaise

Variable

Front 94

Illness stage

Back 94

Max SnS

Immune system activated

If fails= patient death

Front 95

Decline stage

Back 95

SnS decrease

Fever departs

Vulnerable to 2° infection

Front 96

Convalescence stage

Back 96

Body repairs

Returning to normal

Front 97

Localized

Back 97

Still where it got in at

Front 98

Systemic

Back 98

System-wide

Front 99

Focal

Back 99

Went somewhere specific

Front 100

Acute

Back 100

Quick

Short

Front 101

Chronic

Back 101

Long time to develop or go away

Front 102

-itis

Back 102

Inflammation

Swollen, heated, painful

Front 103

-emia

Back 103

Blood

Front 104

-osis/iasis

Back 104

Disease from pathogen

(Tuberculosis)

Front 105

-oma

Back 105

Tumor

Cancer

Front 106

Disease frequency

Back 106

Incidence

Prevalence

Morbidity

Mortality

Front 107

Incidence

Back 107

Number of new cases

Front 108

Prevalence

Back 108

Number of infected people

Any given time

Front 109

Morbidity

Back 109

Number of disease cases

In a specific time period

With respect to the population

Front 110

Mortality rate

Back 110

Number of disease deaths during specific with respect to total population.

(Deaths per 100,000 people per year)

Front 111

Mortality rate

Back 111

Number of disease deaths during specific with respect to total population.

(Deaths per 100,000 people per year)

Front 112

Mortality rate

Back 112

Number of disease deaths during specific with respect to total population.

(Deaths per 100,000 people per year)

Front 113

Notifiable

Back 113

Agencies required by law to collect data

Front 114

Contagious

Back 114

Easy host to host transmission

Front 115

Communicable

Back 115

Host to host transmission

Front 116

Non-communicable

Back 116

Not host to host transmission

Front 117

Correlation

Back 117

One factor assumed to be related to another

Front 118

Cause and effect

Back 118

One factor is proven to cause measurable change in another