Normal Microbiota, Pathogenesis, and Epidemiology

Question 1

Importance of normal microbiota (5)

Answer 1

1. stimulate immune system
2. colinization resistance
3. excrete waste products
4. aid in digestion
5. produce essential nutrients

Question 2

4 major areas where they are found

Answer 2

1. GI tract
2. Integument
3. Upper respiratory tract
4. External genito-urinary tract

Question 3

Requirement for growth of microbiota

Answer 3

1. Nutrients
2. Water
3. Warm temp (35-37C)
4. Neutral pH
5. Proper atmosphere

Question 4

Pathogenesis

Answer 4

series of events that lead to development of disease

Question 5

Source

Answer 5

bug/microorganism

Question 6

Types of human reservoirs (4 types)

Answer 6

1. human cases - obvious, spread can be stopped
2. colonized cases -capable of spreading before developing disease
   a. Incubation
   b. Podromal
   c. Convalescent
   or. ..
   d. Sub clinically infected - colonized, but no symptoms

4.Latent cases - reactivation/re-ocurrance

Question 7

Types of carriers

Answer 7

1. Active - sick, recover, never get sick again, organism still grows (Typhoid Mary)
2. Passive (most common)
   a. Never get sick, organism in body
   b. Chronic infection - remain well, infection, eventually sicken and succumb

Question 8

Animal reservoirs

Answer 8

Zoonoses - animal disease transmitted to people

Question 9

Common Zoonoses

Answer 9

Rabies
Pasteurella
Toxoplasmosis
Salmonella
CJD
Lyme disease
Rocky Mountain Spotted Fever

Question 10

Non-living reservoirs

Answer 10

1. Environmental
   a. Air droplets
   b. Dust containing spores
   c. Soil containing spores
   d. Food and milk
   e. Fecal matter

2.Inanimate objects - fomites

Question 11

Factors needed for pathogenesis (4)

Answer 11

1. virulence factors
2. attachment factors
   a. adhesin protein
   b. bacterial pili/fimbriae
3. replication, invasion, and evasion of immune system
   a. capsules
   b. intracellular
   c. flagella
   d. destructive enzymes
   e. biofilm
   f. camouflage
4. toxin production

Question 12

Communicable vs. Contagious

Answer 12

Gonorrhea vs. influenza

Question 13

Incidence

Answer 13

New cases in pop over a specific period of time

Question 14

Morbidity

Answer 14

New cases per x number of people

Question 15

Prevalence

Answer 15

Total number of cases in pop over a specified period of time

Question 16

Mortality rate

Answer 16

ratio for number of people who died of a particular disease

Question 17

Endemic vs. Epidemic vs. Pandemic

Answer 17

Endemic: within a population at all times - flu, chicken pox, STDs, etc
Epidemic: above usual incidence in a region - ebola
Pandemic: epidemic proportions in many countries at same time - plague