Lecture 7: Principles of Infectious Disease

Question 1

Normal Microbiota

Answer 1

Sum of microorganisms that colonize the body’s surface without normally causing disease

Question 2

Resident Microbiota

Answer 2

• part of normal microbiota throughout life
• usually commensal
• upper respiratory tract, digestive tract, urinary tract

Question 3

Transient Microbiota

Answer 3

may be present for only hours to months and are found in same regions as resident microbiota, but cannot persist in the body

Question 4

Acquisition of Normal Microbiota

Answer 4

• Development in the womb is free of microbiota (Axenic)
• Microbiota begins to develop during the birthing process
• much of ones resident microbiota is established during the first months of life

Question 5

Opportunistic Pathogens

Answer 5

• part of normal microbiota that can cause disease under certain conditions:
• Immune suppression
• Changes in the normal microbitoa
• introduction of normal microbiota into unusual sites of the body

Question 6

Periotinitis

Answer 6

• Microbes in an unusual body site

- when the appendix bursts and bacteria gets into the system

Question 7

Disease

Answer 7

Abnormal medical condition associated with specific symptoms and signs

Question 8

Infection

Answer 8

Invasion and colonization of a host organisms body by a pathogen
-Inf diseases result only if the invading pathogen alters the normal functions of the body

Question 9

Pathology

Answer 9

study of disease

Question 10

Etiology

Answer 10

study of the cause of disease

Question 11

Pathogenesis

Answer 11

development of disease

Question 12

Categories of Disease

Answer 12

Hereditary, Congenital, Degenerative, Nutritional

Question 13

Symptom

Answer 13

• Change in body function that is felt by a patient as a result of disease
• Subjective manifestation
• Headache, Pain

Question 14

Sign

Answer 14

• Change in a body that can be measured or observed as a result of disease
• Objective manifestation
• Rash or Swelling

Question 15

Syndrome

Answer 15

Specific group of signs and symptoms that accompany a disease

Question 16

Germ Theory of Disease

Answer 16

Claims that disease can be caused by infections of pathogenic microorgansims

Question 17

Koch Postulates

Answer 17

To prove a specific microbe causes a specific disease:

1. suspected germ must be present in every case of the disease
2. germ must be isolated and grown in pure culture
3. cultured form must cause the disease when its inolculated into healthy experimental host
4. Same germ must be reisolated from the diseased experimental host

Question 18

Infectious Diseases can be classified by:

Answer 18

• Taxonomic groups of the causative agent
• Severity and duration (chronic vs. acute)
• How they spread to their host
• Systemic vs. local
• effects they have on populations

Question 19

Stages of Infectious Diseases

Answer 19

1. Incubation Period- No signs or Symptoms
2. Prodromal Period- Vague, genreal Symptoms
3. Illness- most severe signs, symptoms
4. Decline- declining signs and symptoms
5. Convalescence: no signs or symptoms

Question 20

Disease can be distinguished as:

Answer 20

Acute, Chronic, Subacute, Latent, Asymptomatic

Question 21

Reservoires

Answer 21

sites at which infectious agents remain viable and from which infection of individuals can occur
-most pathogens can’t survive for long outside of their host

Question 22

3 general types of carriers

Answer 22

Human (Active or healthy) Carriers, Animals, Nonliving matter

Question 23

Human carriers

Answer 23

Active: individuals who have an infectious disease
Healthy: asymptomatic themselves, but infective to others

Question 24

Animal Carriers

Answer 24

Zoonosies
Zoonotic disease aquired through direct contact with animals or their waste, eating animals, blood sucking arthropods
-reverse zoonosis (humans back to animals) has been seen, but more rare

Question 25

Nonliving matter Reservours

Answer 25

some organisms are able to survive and multiply in non living environments like food, water, and soil
-spore formers (liek clostridia) survive for many years in soil

Question 26

3 Modes of Transmission

Answer 26

1. Contact (droplet)
2. Vehicle (airborne)
3. Vector (mechanical or biological)
   - communicable disease
   - not spread these ways = noncommunicable disease
   - contagious disease =easily spread

Question 27

Focal infection:

Answer 27

local infection that serves as a source of pathogen at other sites of the body

Question 28

Primary infection

Answer 28

acute infection that causes initial illness

Question 29

secondary infection

Answer 29

opportunistic infection following a primary infection