Micro Chapter 14: Disease & Infection

Front 1

2 reasons antibiotic misuse is of great concern

Back 1

1. Generating resistance ("selecting for resistance")

2. Killing off natural microbiota

Front 2

Pathology vs. Etiology

Back 2

Pathology = study of the structural and functional changes to the body caused by disease

Etiology = study of the cause of disease

Front 3

Infection

Back 3

Invasion of the body by pathogens (can exist in the absence of a detectable disease)

Front 4

Disease

Back 4

When an infection results in a change to the state of the patient's health

Front 5

Signs vs. Symptoms

Back 5

Signs: objective (physician can observe and measure)

Symptoms: subjective (observer cannot see them)

Front 6

Pathogenesis

Back 6

Progression of disease

Front 7

4 types of disease

Back 7

1. Acute (short-term)

2. Chronic (long-term)

3. Subacute (between acute and chronic)

4. Latent (inactive)

Front 8

Permanent vs. Transient Microbiota

Back 8

Permanent = normal microbiota

Transient = present for days, weeks, or months

Front 9

Locations of normal microbiota

Back 9

*skin

*eyes

*nose

*throat

*mouth

*lg. intestine

*urinary system

*reproductive system

Front 10

Normal microbiota are not present during ________________ development because the environment is ________________. Microbiota are acquired after birth through ____________________ and ________________. If we lose microbiota to disease, we can take __________________.

Back 10

*embryonic / fetal

*sterile

*human contact and food

*probiotics

Front 11

Human Microbiome Project (2007)

Back 11

Analyze microbial communities (microbiomes) on healthy and sick volunteers to determine a relationship between changes in the human microbiome and changes in health.

Front 12

Microbes can colonize only those body sites that can supply the appropriate __________________.

Back 12

Nutrients

Front 13

Microbial antagonism/competitive exclusion

Back 13

Normal microbiota prevents overgrowth of harmful microbiota by outcompeting them for the same resources

Front 14

Symbiosis

Back 14

One organism is dependent on another

Front 15

Commensalism

Back 15

1 organism benefits, the other is unaffected

Front 16

Mutualism

Back 16

Both organisms benefit (ex: bacteria in the large intestine make vitamin K & vitamin B. Bacteria get nutrients, humans get vitamins.)

Front 17

Parasitism

Back 17

One organism benefits at the expense of the other

Front 18

Opportunistic infections

Back 18

Do not cause disease in normal habitat, but may in a different environment or if they are allowed to overpopulate.

Ex: E. coli, Candida albicans

(Immunosuppression causes secondary infections in AIDS patients)

Front 19

Etiology with Koch's postulates

Back 19

1. Microorganisms are isolated from a diseased or dead animal.

2. The microorganisms are grown in pure culture and identified.

3. The microorganisms are injected into a healthy laboratory animal.

4. The disease is reproduced in the lab animal; microorganisms are isolated from this animal.

Front 20

Poorly defined etiology: Some diseases are caused by _________________________________, and some pathogens cause _______________________.

Back 20

*more than one pathogen

*more than one disease (ex: pneumonia, meningitis, peritonitis)

Front 21

If a pathogen won't grow in pure culture media, a _________________________ or _________________________________ can be used

Back 21

*guinea pig

*chicken embryo

Front 22

Communicable

Back 22

Spread host-to-host, directly or indirectly

(AIDS is communicable, but not contagious.)

Front 23

Contagious

Back 23

EASILY spread host to host (airborne droplets)

(Ex: chicken pox, measles)

Front 24

Noncommunicable

Back 24

Not spread from host to host; can be caused by microbes getting in (ex: tetanus)

Front 25

Local vs. Systemic Infection

Back 25

Ex: skin rash vs in bloodstream

Front 26

Focal infection

Back 26

When a local infection travels and infects another specific area of body (ex: tooth, tonsil and sinus infections can lead to systemic infections by traveling via blood/lymph)

Front 27

Sepsis vs. Septicemia

Back 27

Sepsis = toxic inflammatory condition from an infection site; an immune response to a local infection

Septicemia = systemic infection of pathogens spreading in blood (entire circulatory system)

Front 28

3 types of pathogens in blood

Back 28

*bacteremia

*toxemia

*viremia

Front 29

Incidence vs. Prevalence

Back 29

Incidence = number who develop a disease in a specific time frame (ex: # of cases per year)

Prevalence = number of people in a population with disease, regardless of time of onset (both old and new cases)

Front 30

Frequency of occurrence of disease in a population (4)

Back 30

Sporadic (occasional)

Endemic (consistently present)

Epidemic (high number infected at once)

Pandemic (global high number infected at once) Ex: bubonic plague

Front 31

Predisposing factors for disease

Back 31

*Gender

*Age

*Genetics

*Nutrition

*Climate

*Lifestyle

*Occupation

*Preexisting conditions

*Chemo

Front 32

Five Stages of Disease

Back 32

1. Incubation period- from infection to first signs/symptoms

2. Prodomal period-mild signs/symptoms

3. Period of illness-most severe. Overt signs/symptoms, WBC increase, immune system overcome. Must recover or die

4. Period of decline- malaise; vulnerable to secondary infections

5. Period of convalescence- resting and recovering to full strength

Front 33

Reservoirs of disease

Back 33

*humans

*animals

*nonliving (soil, water)

Front 34

Three Routes of Disease Transmission

Back 34

1. Direct contact: person to person (AIDS)

2. Indirect contact: fomites-objects or surfaces capable of carrying infectious organisms (ex: gas pumps, door handles. Diseases: colds, MRSA)

3. Droplet transmission: sneezes, coughs (ex: pertussis, influenza, tuberculosis)

Front 35

Vehicles of transmission (3)

Back 35

1. Airborne (differs from droplet in that it travels more than 1 meter from host)

2. Waterborne (improperly treated sewage)

3. Foodborne (improperly prepared foods)

Front 36

Vectors (transmission by biological agents)

Back 36

1. Mechanical transmission (passive transport--flies, roaches)

2. Biological transmission (active transport--bite)

Front 37

Nosocomial infections are the _______th leading cause of death in the US, with 5% to ________% of hospital patients acquiring them. They have ______________ in incidence in the last 20 years and the strains are ____________________ and

_________________________.

Back 37

*8th

*15%

*increased

*resistant

*opportunistic

Front 38

3 factors in nosocomial infections

Back 38

1. Microorganisms in hospital environment

2. Compromised / weakened status of host

3. Chain of transmission in hospital (Drs moving from patient to patient without washing)

Front 39

Nosocomial pathogens by decade

Back 39

1940s-50s: Gram positive (S. aureus)

1970s: Gram negative (E. coli, P. aeruginosa)

1980s: Resistant strains (S. aureus, Enterococcus)

1990s & 2000s: Antibiotic resistant strains (Gram positive = 34%; Gram negative = 32%)

Front 40

EIDs are diseases that are new or ____________,

showing an _____________ in incidence, or have potential to _____________ in future.

Back 40

*changing

*increase
*increase

Front 41

3 types of Epidemiology

Back 41

1. Descriptive (John Snow looked at incidence of London cholera outbreak and traced it to a single water pump)

2. Experimental (Semmelweis recorded maternity births/deaths, introduced sanitation and mortality dropped to 2%)

3. Analytical (Florence Nightingale drew connection between poor military living conditions and increase in risk of typhus by looking at data)

Front 42

What are the five stages of disease?

Back 42

*incubation

*prodomal

*period of illness

*period of decline

*convalescence

Front 43

Why is it important to control nosocomial infections?

Back 43

*hospitalized people already have weakened immune systems

*avoid lawsuits

*avoid outbreak