EXAM 3 Malaria

Question 1

what is the clinical classification of malignant malaria?

Answer 1

pl. falciparum

Question 2

what is the clinical classification of benign malaria?

Answer 2

• pl. vivax
• pl. ovale
• pl. malariae

Question 3

describe the epidemiology of malaria in the USA

Answer 3

• 1727 cases reporded in 2013
• increasing trend since the 1970s

Question 4

in the USA, ___% of reported malaria cases in 2013 were pl. falciparum

Answer 4

61%

Question 5

in the USA, ___% of reported malaria cases in 2013 were in people from African countries

Answer 5

72%

Question 6

in the USA, ___% of reported malaria cases in 2013 were classified as severe

Answer 6

16%

Question 7

in the USA, ___ deaths as a result of malaria were reported in 2013

Answer 7

10 (1%)

Question 8

who is at risk for death as a result of malaria?

Answer 8

• children 6mo to 6yrs
• non-immune adults
• pregnancy - especially primigravida
• emigrants returning form home visits

Question 9

severe malaria rarely occurs in what populations?

Answer 9

• sickle cell trait in children
• denizens of endemic areas - immune adults

Question 10

what is cerebral malaria

Answer 10

a form of malaria where the patient becomes comotose and is unresponsive; often leads to death

Question 11

what is cerebral malaria with acidosis?

Answer 11

• form of malaria where the patient becomes comatose
• nasal flare and intercostal retractions characteristic of metabolic acidosis

Question 12

what is cerebral malaria with focal seizures and acidosis?

Answer 12

• a form of malaria where the patient becomes comatose
• focal seizures - eyes will flutter
• desperately ill

Question 13

describe a patient who has cerebral malaria and anemia

Answer 13

• severe anemia and coma with eyes open
• severe anemia may lead to heart failure
• blood transfusion needed, but frequently is not available

Question 14

describe the 3 stages of malaria infection transmission

Answer 14

• mosquito stage
  
  • mosquito bites human, infecting with sporozoites (inoculation/infection)
• liver stage
  
  • sporogony
  • sporotoites invade the liver, become merozoites then enter the blood stream
• blood stage
  
  • shizogony
  • asexual cycle and sexual cycle
    
    • sexual cycle produces gametocytes, which are taken up by new mosquitos that bite the human (transmission to mosquito)
    • asexual cycle produces illness when parasite numbers reach 100 million

Question 15

___ has no latent stage in the liver (hypnozoites)

Answer 15

pl. falciparum

Question 16

why are only early stage (ring form) parasites seen in vivo?

Answer 16

because mature forms adhere to the walls of the microvessels in the brain

Question 17

which stages of sporogany are seen in vitro?

Answer 17

all stages

Question 18

what is a thick smear?

Answer 18

• one drop of blood
• RBCs lysed
• fixed and stained with Giemsa

Question 19

what are the benefits (to the parasite) of sequestration?

Answer 19

• evade splenic clearance - free intravascular replication
• post-capillary venule blood pH is low (~7.1) - favors parasite replication
• post-capillary venule pCO2 is high - favors parasite replication
• pl. falciparum infects RBCs of any age
• multiple PfEMP-1 genotypes evade host IR
• all lead to enourmous parasite mass in severe malaria

Question 20

describe the concerns of fever in returning travelers.

Answer 20

• life threatening (immediate) vs. non-emergent diseases
  
  • malaria
  • typhoid fever
  • tuberculosis
  • meningococcol/meningitis (or other serious bacterial infections)
  • viral hemorrhagic fevers

Question 21

how is malaria managed?

Answer 21

• hospital vs. out-patient treatment
• sequestration comes and goes and is a dynamic process
• oral vs. IV prescriptions
  
  • GI absorption, level of consciousness, emesis
• WHO recommended prescription not available in pharmacy
  
  • artemisinin derivatives
  • request through the CDC&P

Question 22

describe the prevention of malaria

Answer 22

• malaria prophylaxis with anti-malarials
  
  • weekly, daily
  • toxicity, side effects
• mosquito repellant - DEET
• permethrin - impregnated bed nets
• permethrin - treated clothing

Question 23

what is the three pronged approach to combating malaria in the world?

Answer 23

1. insecticide impregnated bed nets
2. residual insecticide spraying
3. pre-emptive treatment with ACT

Question 24

what is the cost of combating malaria in the world?

Answer 24

• sustained funding from philanthropic sources
• lack of acquired immunity in increasingly older individuals

Question 25

what stage of pl. falciparum maturation is shown?

Answer 25

ring trophozoites (early)

Question 26

what stage of pl. falciparum maturation is shown?

Answer 26

maturing trophozoites

Question 27

what stage of pl. falciparum maturation is shown?

Answer 27

shizont - early and mature

Question 28

what stage of pl. falciparum maturation is shown?

Answer 28

gametocyte

Question 29

what is the function of knob proteins?

Answer 29

cytoadherence of pl. falciparum to red blood cell membranes