Infectious Diseases Flashcards Preview

Path Exam 2 > Infectious Diseases > Flashcards

Flashcards in Infectious Diseases Deck (60):
1

describe the etiology of the disease seen in the image

  • etiology:
    • inhalation of spores in bird and bat droppings (caves)
      • Ohio, Appalachia, Mississippi River Valley

2

describe the most specific test for the condition seen in the image

latex agglutination test using antibodies = most specific

3

____ causes the disease seen in the image

Streptococcal pneumonia causes lobar pneumonia in healthy young adults exposed to cold, strain, exhaustion 

4

describe the populations most at risk for the disease seen in the image

children, elderly, bedridden, immunocompromised, hospitalized

5

describe the investigations for the disease seen in the image

  • investigation:
    • histoplasma antigens in blood and urine by PCR
    • biopsy: intracellular organism
      • acute = in PMNs
      • chronic = budding yeast in macrophages (increased pH to survive)

6

describe the pathogenesis of the disease seen in the image

  • pathogenesis: 
    • inhalation of spores → tropism for endothelial cells of blood vessels → angio-invasive → disseminated → endothelial damage → thrombosis → ischemia → hypoxia
      • most common in cerebral hemispheres: red infarct
      • lung, GI, sinuses

7

describe the etiology of the image

  • etiology: S. aureus and S. pyogenes
    • contact with fomites, patients with poor hygiene 

8

describe the etiology of the disease seen in the image

Rocky Mountain Spotted fever (viral)

  • etiology: Rickettsia rickettsii (obligate intracellular bacteria)
    • transmitted by tick bites (seen mainly in campers/hikers)
    • predilection for endothelial cells and smooth muscles of arterioles
    • perivascular inflammatory infiltrate: macrophages, lymphocytes and plasma cells

9

describe the pathogenesis of the disease seen in the image

10

describe the immune cells found in the disease seen in the image

  • infiltration of PMNs + lymphocytes + monocytes + giant cells (mixture of acute + chronic in all fungi)

11

describe the images seen

12

describe the complications of the disease seen in the image

  • may lead to abscesses, empyema 
    • caused by Klebsiella followed by S. aureus 
  • complications: sepsis, DIC, lung abscess, empyema, pleural fibrosis

13

describe the location on the body of the disease seen in the image

  • oral thrush: gray-white, dirty gray pseudomembrane
  • esophagitis: seen in AIDS and hematolymphoid malignancies
  • vaginitis: seen in diabetes, pregnancy, oral contraceptive pills
    • itching, soreness, redness, thick (creamy cheese) discharge
  • skin infxn: onychomycosis, paronychia, folliculitis, balanitis, diaper rash

14

describe the acute vs chronic form of the disease seen in the image

  • acute: in immunocompromised patients
    • contained in the lungs; see PMNs
    • asymptomatic or flu-like
  • chronic: presents exactly like TB
    • fever, weight loss, cough with hemoptysis
    • immunocompetent: caseating granuloma (like TB) mostly in upper lobe
      • difference on CXR = multiple foci (buckshot dystrophic calcification)
      • TB only has one focus but x-ray is identical to that of miliary TB
    • immunocompromised pts: disseminated bc cannot form a granuloma to contain it in the lungs
      • go to cells of RES → lymphadenopathy, splenomegaly, hepatomegaly, bone marrow suppression (pancytopenia)

15

describe the prognosis of the disease seen in the image

  • prognosis: based on site of bite (distance from bite site to brain determines prognosis)
    • leg bite has better prognosis than neck bite

16

describe the etiology of the disease seen in the image

  • etiology: RNA virus → bite by bat, dogs, raccoons, foxes, skunks

17

which cells are found in the locations affected with the disease seen in the image?

PMNs + lymphocytes + monocytes + giant cells (mixture of acute + chronic in all fungal infxns)

18

impetigo causes direct damage via enzymes _____ and spreads by _____

impetigo causes direct damage via enzymes hyaluronidase and collagenase and spreads by fomites

19

the proclivity of ___ to invade the ___ directly sets it apart from other fungi which reach the ___ by hematogenous dissemination from distant sites

the proclivity of Mucor to invade the brain directly sets it apart from other fungi which reach the brain by hematogenous dissemination from distant sites

  • Mucor may spread to the brain through vascular invasion or by direct extension through the cribriform plate

20

describe the organs affected by the disease seen in the image

  • most common CMV in AIDS patients: retinitis (CMV retinitis) → cotton wool appearance
    • can also affect lungs (interstitial "atypical" pneumonia), GI (esophagitis), gastritis, duodenitis, colitis
    • most common complication of CMV in organ transplant or kidney/liver → CMV nephritis/hepatitis

21

describe the presentation of the disease seen in the image

  • presentation: loss of consciousness/stupor, hydrophobia, spasms of pharyngeal muscles, respiratory failure (#1 cause of death bc it interferes with respiratory areas in brainstem)

22

describe the etiology of the disease seen in the image

Coxsackie A or B (virus)

23

describe the etiology of the disease seen in in the image

  • Zygomycetes: Mucor, Rhizopus, Absidia
    • opportunistic fungi in all immunocompromised
    • prevalent in pts with DKA bc low pH favors growth of organism & availability of glucose

24

describe the investigations for the disease seen in the image

  • investigation: Tzanck smear = scrape vesicle and stain with Giemsa to visualize Tzanck cells (multinucleated giant cells) in syncytia formation
    • intranuclear eosinophil inclusions = Cowdry type A

25

describe the investigation for the disease seen in the image

  • investigation:
    • bronchoalveolar lavage & stain with silver stain
      • black cup-shaped cyst

26

describe the investigation for the disease seen in the image

  • urine sample, PCR for virus DNA, antibody titers
    • cytopathic effects (inclusions): cytomegaly (enlarged cell and nucleus), formation of intranuclear basophilic inclusions (Owl's eyes), intracytoplasmic inclusions which are mostly basophilic

27

describe the complications for the diease seen in the image

  • complication:
    • dilated cardiomyopathy = swollen and can't pump blood
    • arrhythmias and heart failure if affects conduction fibers

28

describe the pathogenesis of the disease seen in the image

  • no ischemia
  • combination of direct damage by virus and damage via immune response/lymphocytic infiltration
    • more damage done by immune system (indirect damage, CTL cells)

29

describe the investigation for the disease seen in the image

  • investigation: PCR (virus) after endomyocardial biopsy
    • note: PCR almost always best for viruses

30

describe the presentation of the disease seen in the image

  • presentation (1 week after bite): fever, headache, myalgia and vasculitic rash (starts from extremities and moves inward/proximal)
    • can go to lung or brain and cause endothelial damage → thrombus
    • skin: hypoxia → ischemia → gangrene
    • brain: stroke/red infarct
    • lung: red infarct

31

describe the pathogenesis of the disease seen in the image

  • inhalation of respiratory droplets → chicken pox → varicella zoster dormant in DRG → activates when immunocompromised
    • unilateral painful vesicles which follow a single dermatome

32

which patients are most at risk for the disease shown in the image?

  • opportunistic: diabetic pts, immunocompromised (AIDS) and patients on broad-spectrum antibiotics
    • invasive form can disseminate → abscesses

33

describe the pathogenesis of the disease seen in the image

  • pathogenesis:
    • spores in pigeon droppings → inhalation → granulomas with giant cells
      • usually involve lungs and brains
      • inflammatory reaction is absent due to inert capsule
      • if disseminated → meningitis
        • NO fever or neck stiffness (bc no inflammation) but WILL see headache, increased intracranial pressure, projective vomiting, photophobia 

34

describe the presentation of disease in the image 

  • presentation:  honey-colored crusts on face

35

describe the spread of the disease seen in the image

  • contracted via body fluids (transplacental, saliva, urine, breast milk, blood transfusion) and organ transplant or vertically transmitted 

36

describe the presentation for the disease seen in the image

  • presentation:
    • sero-sangrenous nasal discharge, fever, pain and headache & rhino-facial-palatal necrosis

37

describe the presentation of the disease seen in the image

  • fever, pleuritic chest pain worse on inspiration, dyspnea, productive cough with bloody sputum 

38

describe diagnostic tests for the disease seen in the images

39

describe a differential for the disease seen in the image

  • R. prowazeki: causes epidemic typhus (via lice)
    • loves endothelial cells and causes thrombosis 
    • difference in rash; starts from trunk and spreads out
  • Coxiella Burnetti (Q-fever): Negative Weil-Felix test but immunofluorescent
    • no skin rash & ring granuloma on liver biopsy (fat surrounded by epithelioid cells)

40

describe the etiology of the disease seen in the image

  • inhalation of aspergillus (mycelial form)
    • no effect in immunocompetent
    • A. flavus = aflatoxin & A. fumigatus = gliotoxin

41

describe the presentation and outcome of the disease seen in the image 

  • presentation: flu-like or asymptomatic
  • common outcome: complete resolution

42

describe the course of the disease shown in the picture

  • superficial skin infxn affecting only epidermis → complete resoultion (no fibrosis)
    • S. pyogenes impetigo: 2 weeks after can have hematuria and decreased urinary output (oliguria) → post-streptococcal glomerulonephritis 

43

describe the presentation of the disease seen in the image

44

describe the definitive diagnosis of the disease seen in the image

  • definitive diagnosis: made on autopsy (Negri bodies - intracytoplasmic eosinophilic inclusions found in neurons)
    • not PCR because the virus is found in the neurons

45

describe the image seen

46

describe the presentation of the disease seen in the image

  • depends on organ (transplant affects organ, AIDS patient effects retina more often)
    • tropism for endothelial cells
    • intracranial calcifications
    • polyclonal B cell activator
    • immunocompetent: infectious mononucleosis 

47

the disease seen in the image is caused by _____

lobular bronchopneumonia is caused by Klebsiella, E. coli, Pseudomonas, Staph

48

describe diagnosis of the disease seen in the image

  • squamous epithelium → stain with PAS, silver stain, mucicarmine
    • budding yeast with pseudohyphae (Chinese letter appearance)

49

describe the pathogenesis of the disease seen in the image

  • URT infxn → acute bronchitis → spread of inflammatory exudate to adjacent alveoli → destruction of bronchioles & alveoli 
    • no macrophages in bronchioles to clean up the debris → scarring

50

the disease shown in the image mainly affects ___

the disease shown in the image mainly affects AIDS patients (CD4 <200)

51

describe the pathogenesis of the disease seen in the image

  • pathogenesis:
    • aspergilloma (fungal ball): colonize a pre-existing cavity from TB or lung abscess (pneumonia)
    • allergic bronchopulmonary aspergillosis: type I and type III hypersensitivity
      • seen in pts with bronchial asthma → inhale → colonizes → causes wheezing, dyspnea, productive cough and fever → exacerbation of asthma
    • disseminated aspergillosis: angio-invasive → ONLY in immunocompromised
      • invades blood vessel wall → thrombosis → coagulative necrosis
      • most common organs = brain and lung → stroke and necrotizing pneumonia

52

describe the locations where the disease in the image can be found

  • GOAT regions: Georgia, Oklahoma, Alabama, Tennessee

53

describe the images seen 

54

summarize the differences between lobar pneumonia and bronchopneumonia

55

describe the spread of the disease seen in the image within the body

  • virus spreads from PNS to CNS via retrograde axonal transport

56

describe investigations for the disease seen in the image

  • Best investigation = skin biopsy with immunofluorescent staining
  • 2nd best = Positive Weil-Felix test (latex agglutination test)
    • indirect test → looks for antibodies 

57

describe investigations for the disease seen in the image

  • investigation:
    • stain with PAS, silver, mucicarmine
      • slender organisms, septate hyphae that branch at acute angles

58

describe the immune cells found in the disease seen in the image

infiltration of PMNs + lymphocytes + monocytes + giant cells (mixture of acute + chronic in all fungi)

59

describe the etiology of the disease seen in the image

  • etiology:
    • found in spores in pigeon droppings → opportunistic infxn in immunocompromised HIV patients (CD4 <100)

60

describe the presentation of the disease seen in the image

  • presentation:
    • fever, dyspnea on exertion, dry cough (because produces "cotton candy" exudate in alveolar space → not able to produce sputum) & interstitial pneumonia → inflammation and thickening of alveolar wall w/ sparse mononuclear infiltrate