Infectious Diseases Flashcards Preview

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Flashcards in Infectious Diseases Deck (63)
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1
Q

Infections

A

A disease caused by microorganisms, especially those that release toxins or invade body tissues

2
Q

Colonization

A

Harmless inhabitation by microbes in the body

3
Q

Virus

A

a pathogen made of a nucleic acid inside a protein shell

4
Q

Bacteria

A

a unicellular organism without a true nucleus or organelles

5
Q

Helminthes

A

worms

6
Q

Mycobacteria

A

A type of bacteria with fungal-type properties

7
Q

Prions

A

A small proteinaceous infectious particle.

8
Q

Routes of infection

A
Contact
Airbourne
Droplet
Vehicle (common source -- i.e. food, water)
Vector (carried by intermediate source)
9
Q

Pathogenicity

A

The number of organisms and amount of time required to start a new infectious process

10
Q

Chain of Transmission

A
Pathogen or Agent
Reservoir
Portal of Exit
Transmission
Modes of entry
Susceptible host
11
Q

What are the lines of defence?

A

First: mechanical barriers
Second: inflammation
Third: acquired immune response

12
Q

Defence against infection relies on what two thing?

A
  1. Mechanical integrity of epithelial surfaces

2. Decontamination (removal of pathogen)

13
Q

Three patterns of infections

A
  1. Local damage (wart)
  2. Toxic to host (botulism)
  3. Widespread effects (HIV)
14
Q

How does infection spread within a host?

A
  1. Directly
  2. Via natural channels (membranes, vessels)
  3. Through nerves or phagocytes
15
Q

Pathogen’s Mode of Action

A

How the organism produces a pathologic process

16
Q

What factors affect the occurrence and spread of infection?

A
  1. Pathogenic factors

2. Host factors

17
Q

Pathogen factors affecting occurrence and spread

A
  1. Virulence (degree of pathogenicity)
  2. Dose
  3. Site of infection
  4. Synergy between different pathogens
18
Q

Host factors affecting occurrence and spread of infection.

A

Resistance to infection
Immune competency
Leukocyte count
Necrosis/Ischemia of tissue

19
Q

Opportunistic infection

A

Takes advantage of compromised/defective immune system

20
Q

Staphylococcal Infections

A

One of the most common bacteria to reside on the skin

Over 30 subtypes

Leading cause of nosocomial and community acquired infections.

21
Q

S. aureus

A

Staphyloccus aureus
Most common staph infection

Nonmotile, anaerobic, hardy. Includes MSRA

Infection can result in: osteomyelitis, respiratory tract infection, infectious arthritis, septicemia, endocarditis, TSS, cellulitis, mastitis

22
Q

S. pyogenes

A

Streptococcal pyogenes

One of the most common bacterial pathogens.
Suppurative and non-suppurative

Transmission: contact, droplets, foodborne

23
Q

Strep throat

A

Caused by S. pyogenes
Common cause of sore throat.
Pustulant

24
Q

Scarlet fever

A

Caused by S. pyogenes

Usually follows untreated strep throat

25
Q

Impetigo

A

Caused by S. pyogenes

Skin infection. Usually in children, in hot weather.

26
Q

Cellulitis

A

Caused by S. pyogenes

Acute skin infection

27
Q

S. agalactiae

A

Streptococcus agalactiae
Normal part of GI flora

Leading cause of neonatal pneumonia, meningitis, sepsis

Infrequent cause of pyrogenic (purulent – pus – but not related to S. pyogenes. sigh) disease in adults

Pregnant women routinely screened.

28
Q

Necrotizing fasciitis

A

Caused by S. pyogenes

Serious, potential fatal, spreads quickly along fascial lines.

29
Q

Pneumococcal infections

A

Streptococcus pneumonia

Can cause pneumonia, sepsis, otitis media, meningitis

Most common cause of community acquired pneumonia, and of bacterial meningitis

30
Q

Meningococcal Infections

A

Can cause meningitis and septicaemia

31
Q

Anaerobic infections

A

Not big oxygen fans. Suppurative.

32
Q

Diptheria

A

C. diphteria.
Anaerobic

Pseudomembranous pharyngitis

33
Q

Plague

A

Y. pestis
Anaerobic

Severe pneumonia, massive lymphadenopathy, high fever –> can progress to septicaemia

34
Q

Buboes

A

Enlarges lymph nodes; pathognomic for plague

35
Q

Botulism

A

C. botulinum (spore)
Anaerobic

Food borne or wound borne
Interferes with release of ACh at peripheral nerve endings

36
Q

Spore

A

Cell produced by bacillus to withstand extreme conditions. Can remain viable for decades

37
Q

Cholera

A

V. cholerae
Anaerobic

Diarrhea –> dehydration, oliguria, shock

38
Q

Spirochete

A

Slender, spiral, motile bacteria that lives off dead and decaying matter in soil and water.

Ex. Lyme disease, syphylis

39
Q

Lyme disease

A

B. burgdorferi

Vector borne disease (deer tick).
Bull’s eye rash (erythemia migrans), nausea, vomiting, neurological and arthritis-type symptoms

40
Q

Mycobacteria

A

Small, slow growing aerobic bacteria
Complex lipid-rich envelope

Tuberculosis
Leprosy

41
Q

Tuberculosis

A

Mycobacterium tuberculosis

Leading infectious disease cause of death
1/3 world’s preventable deaths

Systemic, inflammatory
Affects lungs and may disseminate to lymph nodes and other organs.

Characterized by granulomas and then casseous necrosis

42
Q

Virus

A

Smallest microorganism
Always pathogenic
Can only reproduce in host cells.

Protein cover.

43
Q

Herpes virus

A

Family of virus that can cause

Herpes Simplex 1
Herpes Simplex 2
Varicella-zoster virus 
Epstein-Barr
Cytomegalovirus
44
Q

Herpes Simplex

A

HSV 1 – typically oral

HSV 2 – genital

45
Q

Varicella-Zoster Virus

A

Causes chicken pox and shingles

Can develop into life threatening pneumonia or encephalitis

46
Q

Herpes Zoster

A

Shingles

47
Q

Epstein-Barr Virus

A

Infectious mononucleosis

48
Q

Cytomegalovirus

A

CMV
Symptoms similar to mono

Can cross placenta and cause congenital defects

49
Q

Enterovirus

A

Member of picornavirus (small RNA virus)

Includes hand/foot/mouth, poliomyelitis

50
Q

Post polio syndrome

A

In 25-50% of people who have had polio, 15-30 years later.

Symptoms like chronic fatigue but progressive

51
Q

Influenza

A

Fever, cough, headache. Possibly fatal

52
Q

Rhinovirus

A

Common cold
URTA
Acute, afebrile, self-limiting

53
Q

Mycosis

A

Any disease caused by fungus

Can be superficial or systemic

54
Q

Fungal pneumonia

A

Pneumocystis carinii or jirovecli

Extremely serious form of pneumonia

55
Q

Yeast infections

A

Candida albicans

GI tract, mouth (thrush), genitals (candidiasis)

56
Q

Genital warts

A

Human papillovirus

Higher incidence of cervical, anorectal and bladder cancers.

57
Q

Chlamydia

A

Chlamydia trachomatus

3 million new cases/year

Most common bacterial STI

No symptoms, or pain with intercourse, dysuria, bleeding

58
Q

Gonorrhea

A

Neisseria gonorrhoeae

650,000 new cases/year

In men: urethritis, urgency, paining
In women: no symptoms, or slight pain with urination, intercourse

59
Q

Hepatitis B

A

Hep B Virus

Can be passed through breastfeeding

77,000 new cases/year
Jaundice, arthralgias, rash, dark urine, anorexia …

Can relapse at the end of treatment.
Cannot be eliminated.

60
Q

Syphillis

A

70,000 new cases a year

Treponema pallidum

Unprotected sexual contact, contact with skin and mucous membranes, transplancental, blood transfusions

61
Q

Primary, secondary and tertiary syphilis

A

Primary: Chancre at site of infections
3-8 weeks after

Secondary: flu like symptoms and rash 6 weeks to 2 years

Tertiary: severe, CV and CNS up to 20 years later.

62
Q

Vaccination

A

Any suspension containing antigenic molecules derived from microorganism given to stimulate an immune response to infectious disease.

63
Q

Most common cause of bacterial meningitis is non-teens.

A

Pneumococcus infection.