Introduction and Approach to studying ID

Question 1

What are three ways vaccinations are made?

Answer 1

produced from inactivated microbial strains
produced from live viruses
produced from viral particles

Question 2

Chemotherapeutic agents are used for?

Answer 2

used to treat infectious disease can be synthetic drugs or antibiotics.

Question 3

Antibiotics are used for?

Answer 3

are chemicals produced by bacteria and fungi that inhibit or kill other microbes.

Question 4

Quinine is used for?

Answer 4

from tree bark was long used to treat malaria.

Question 5

Biological stains for bacteria?

Answer 5

gram stains

Question 6

Fungi stains?

4

Answer 6

KOH, lactophenol blue, India ink, silver stains in tissue

Question 7

Mycobacteria stains? (TB)

Answer 7

acid fast stains

Question 8

Parasite stains?

2

Answer 8

trichrome stain, Wright’s stain

Question 9

Virus stains?

Answer 9

Viruses—antibody conjugated dyes

Question 10

Disease definition?

Answer 10

an upset in the homeostasis of the host, resulting in generation of observable changes

Question 11

Whats the normal host-parasite relationship?

Answer 11

Carrier state

Question 12

Factors that influence infection multifactorial?

5

Answer 12

Host Factors		
Site specific Infections
Virulence Factors
Degree of Pathogenicity
Toxin Production

Question 13

A compromised immune system, however, presents an “opportunity” for the pathogen to infect
Common ones?
4

Answer 13

Pneumocystis
Candida
Disseminated HSV
TB

Question 14

Factors Required for Infection to Occur

5

Answer 14

Contact the host - be transmissible
Colonize the host - adhere to and grow or multiply on host surfaces
Infect the host - proliferate in host cells or tissues
Evade the host defense system - by avoiding contact that will damage it
Damage host tissues - by physical (mechanical) or chemical means

Question 15

Pathogenesis of Infection
has a consistant pattern. Describe it?
4

Answer 15

Consistent pattern:

1. parasite enters body
2. organisms adhere to site specific target tissue
3. organisms multiply establishing local or primary lesions
4. spread
   - -fascial planes
   - -tubular structures (bronchus/ureter)
   - -hematogeneous/lymphatic

Question 16

Whats the incubation period?

What can the length of the incubation period be affected by/dependant on?

Answer 16

Pathogen replicates without any recognizable symptoms

Length may be affected by the general health of host, portal of entry, infectious dose of the pathogen and the virulence of the organism

Question 17

Describe the prodromal stage?

3

Answer 17

1. Initial appearance of symptoms in host
2. Clinical presentation may be VERY vague (general malaise)
3. Fever, myalgia, headache and fatigue may be present but are very non-specific

Question 18

Describe the acute stage?

3

Answer 18

1. Host experiences maximum impact due to rapid proliferation and dissemination of pathogen
2. Toxic byproducts of microbial metabolism, cell lysis, and immune response combine to produce tissue damage and inflammation
3. Symptoms are usually more pronounced and focused than during prodrome pointing to site and possible pathogen

Question 19

Describe the convalescent stage?

3

Answer 19

1. Containment of infection, progressive elimination of pathogen, repair of damaged tissue, and resolution of associated symptoms
2. Length is variable depending on host and pathogen (days to months)
3. Total elimination of pathogen from the body without residual signs or symptoms of disease

Question 20

What kind of infectious diseases have a protracted/irregular course?

Answer 20

Chronic infectious diseases

Question 21

WHat are Subclinical or Subacute illness?

Answer 21

progresses from infection → resolution without symptoms

Question 22

The prodromal period is lengthy?

Answer 22

Insidious

Question 23

Abrupt onset of symptoms with little or no prodrome?

Answer 23

Fulminant

Question 24

Portal of entry types?

Answer 24

Penetration
Direct contact
Ingestion
Inhalation
Port of entry does NOT mean that is final site of infection

Question 25

What are the sources of infection? | 4

Answer 25

1. Endogenous = from patient’s own normal flora 2. Exogenous = From outside source 3. Zoonoses = diseases passed from other animals to humans 4. Nosocomial = hospital acquired infections (pneumomias are more pathogenic these types) Community Acquired

Question 26

Source can also refer to the body substance that was the most likely vehicle for transmission. Examples?

Answer 26

feces, urine, sputum, blood, body fluids

Question 27

What is the collection of signs and symptoms expressed by the host during the disease process?

Answer 27

Symptomatology aka “clinical picture” or “disease presentation"

Question 28

What is the outward expression of the struggle between invading organisms and the retaliatory inflammatory and immune responses of the host?

Answer 28

Symptoms

Question 29

Describe how different symtpoms prevent? | 4

Answer 29

May be specific and show site of infection (diarrhea) May be non-specific and reflect overall battle (fever) May be overt (chickenpox lesions) or hidden (elevated WBC count)

Question 30

Cinical features suggestive of infection? | 6

Answer 30

``` Fever/Chills/Rigors Myalgia/Fatigue Lymphadenopathy Splenomegaly (mono) GI Upset (gram neg) Leukocytosis/Leukopenia (overwhelming infection) ```

Question 31

GI upset is often precent with what kind of bacteria?

Answer 31

Gram Neg

Question 32

Common Community Acquired Infections | 13

Answer 32

``` Skin Sinusitis Pharyngitis Otitis Pneumonia Meningitis Encephalitis ``` ``` Gastroenteritis Urethritis Cystitis Prostatitis PID Osteomyelitis ```

Question 33

Common Hospital Acquired Infections (Nosocomial)? 8

Answer 33

``` Bacteria: Staph Strep group E. coli Klebsiella Proteus Psuedomonas Serratia Candida ```

Question 34

Diagnosis of Infectious Disease Direct Microscopic evaluation types? 5 Indirect evidence of infection? 3

Answer 34

``` Gram Stain Wet Mounts KOH Culture Electron Microscopy ``` Agglutination Electrophoresis RIA

Question 35

What factors do we look at when deciding on epidemiology? | 5

Answer 35

1. Incidence = the number of new cases of an infectious disease that occur within a defined population over time (1:100,000 per year) 2. Disease prevalence = number of active cases at any given time 3. Endemic = disease numbers in a geographical area if the incidence and prevalence are expected and relatively stable 4. Epidemic = An abrupt and unexpected increase in the incidence over endemic rates 5. Pandemic = Spread of disease beyond continental boundaries