Blood and Lymphatic System I

Question 1

Yersinia pestis are (G-ve/G+ve) bacilli

Answer 1

Yersinia pestis are G-ve bacilli

Question 2

Yersinia pestis have a ____ appearance due to ____

what stain clearly shows this?

Answer 2

Yersinia pestis have a “safety pin” appearance due to polar bodies

stain = Giemsa, Methylene blue stain

Question 3

list other medically important Yersinia (2)

Answer 3

• Y. enterocolitica
• Y. pseudotuberculosis
• both are zoonotic
• ingestion of contaminated food or water

Question 4

describe the route of acquisition of Yersinia and how it defines clinical presentation

Answer 4

Question 5

plague cases in USA are restricted to _____

Answer 5

plague cases in USA are restricted to rural Western USA

Question 6

describe the pathogenesis of the bubonic form

Answer 6

Question 7

describe the clinical presentation of the bubonic plague

Answer 7

Question 8

if infected with bubonic plague, the draining lymph nodes rapidly become tender and enlarged, called ____

explain where in the body is most common

Answer 8

if infected with bubonic plague, the draining lymph nodes rapidly become tender and enlarged, called “buboes”

most common = femoral and inguinal

tender and firm with surrounding edema and elevation

Question 9

if bubonic plague disseminated to lungs: may result in ______

Answer 9

if bubonic plague disseminated to lungs: may result in secondary pneumonic form

Question 10

describe primary pneumonic plague vs. secondary pneumonic

Answer 10

• primary pneumonic:
  
  • direct inhalation from humans with primary pneumonic or from animals with respiratory infxn
• secondary pneumonic:
  
  • hematogenous spread of Y. pestis from bubo or other foci
  • cough with sputum

Question 11

describe septicemic plague

Answer 11

• sudden high fever
• can develop from bubonic or primary of secondary pneumonic forms
• found mostly in older individuals
• rapidly progressive:
  
  • DIC
  • emboli
    
    • gangrene of extremities: “black death”
  • multiorgan failure

Question 12

describe diagnosis of bubonic plague

Answer 12

• needle aspiration of bubo
  
  • stain and culture on blood agar, chocolate agar or MacConkey’s agar
• serology for titers against F1 antigen
• PCR

Question 13

describe diagnosis of the pneumonic plague

Answer 13

• chest x-ray; rapidly progressing pneumonia
• elevated WBC with immature neutrophils

Question 14

list the 4 diseases associated with Bartonella sp.

Answer 14

• cat scratch disease/fever
• Carrion’s disease
• Bacilliary angiomatosis
• Trench fever

Question 15

Bartonella sp. are intracellular in ____ and ____ cells

Answer 15

Bartonella sp. are intracellular in RBCs and endothelial cells

Question 16

list characteristic of Bartonella sp.

Answer 16

• G-ve
• microaerophilic
• slow-growing
• motile
• physiologically unremarkable; standard biochemical tests are unhelpful

Question 17

describe Bartonella henselae

Answer 17

• Cat-scratch disease
  
  • benign, self-limited
  • erythematous pustule develops within 3-10 days at site of bite or scratch
  • regional lymphadenopathy that may last for months
    
    • can be suppurative and drain
    • accompanying fever, malaise, headache, anorexia
  • primary reservoir is domestic cats, particularly kittens
    
    • mainly occurs in children

Question 18

describe the Sketchy

Answer 18

Question 19

describe the 2 stages of Bartonella bacilliformis

Answer 19

Carrion’s disease

• 2 stages:
  
  • 1. oroya fever: fever and anemia followed by:
  • 2. verruga peruana (weeks to months)
       * multiple nodular hemangiomas skin lesions
       * bacteria invade capillary endothelium → bacteria-filled vacuoles and localized cellular proliferation

Question 20

Bartonella bacilliformis (Carrion’s disease) is geographically restricted to:

Answer 20

Bartonella bacilliformis (Carrion’s disease) is geographically restricted to the mountains of American Andes e.g. Peru

Question 21

Bartonella bacilliformis (Carrion’s disease) is vector-borne and is carried by ____

Answer 21

Bartonella bacilliformis (Carrion’s disease) is vector-borne and is carried by sandflies (dusk and evening feeders)

Question 22

describe baciliiary angiomatosis and name the 2 species that can cause this

Answer 22

• primarily immunocompromised, particulary AIDS
• red “cranberry-like” papules; enlarge and ulcerate
• can occur in all organs
• single or multiple
• can also be due to Bartonella quintana
• caused by:
  
  • B. henselae
  • B. quintana

Question 23

describe Bartonella quintana

Answer 23

Trench fever

• fever, headache with retroorbital pain, restlessness and severe back and shin pain
• periodic, recurring illness every 5-6 days; up to 8 times
  
  • corresponds with release of B. quintana in blood
• primarily associated with culture-negative endocarditis and bacteremia in homeless in USA
• spread by lice

Question 24

describe the pathogenesis of B. bacilliformis

Answer 24

• colonization of entire circulatory system and infxn of erythrocytes
• severe hematocrit reduction (>80%) → acute hemolytic anemia
  
  • 40-80% mortality in absence of antimicrobials

Question 25

name the important virulence factors (for all forms of Bartonellosis)

Answer 25

• Deformin: extracellular factor used for entry
• flagella
• BadA: adhesin

Question 26

describe the diagnosis of the Bartonella infections

Answer 26

Question 27

describe the biology of Filoviridae

Answer 27

• order: mononegavirales
• ebolavirus
  
  • longer than most viruses
• negative sense, ssRNA

Question 28

describe the infectious travel of ebola

Answer 28

Question 29

describe the pathogenesis of Filoviridae

Answer 29

Question 30

describe the clinical presentation of ebola

Answer 30

• incubation period of up to 20 days
• initial, non-specific viral-infection
  
  • fever, headache, muscle aches
  • abdominal pain, nausea, cough, chest pain
  • vomiting and diarrhea
• within few days:
  
  • petechiae
  • ecchymoses
  • bleeding (puncture sites and mucous membranes)
• around day 5: maculopapular rash: mostly trunk

Question 31

describe the basic of CDC algorithm for patients under investigation for EBOV diseases

Answer 31

Question 32

describe diagnostic testing for EBOV

Answer 32

Question 33

describe lymphangitis and etiologic agents

Answer 33

• red, warm and tender streaks to develop at peripheral lesion on extremity and spread to regional lymph nodes
• systemic symptoms: fever, chills, headache
• lymph nodes become enlarged and tender
• etiologic agents:
  
  • group A beta-hemolytic Streptococci
  • S. aureus
  • Pasteurella multocida (dog and cat bites)