Protozoa--hematologic infections

Question 1

Plasmodium: P. vivax/ovale, P. falciparum, P. malariae–disease

Answer 1

• Malaria
  
  • fever
  • headache
  • anemia
  • splenomegaly

Question 2

P. vivax/ovale–disease

Answer 2

• 48 hour cycle (tertian; includes fever on first day and thrd day–thus fevers are actually 48 hours apart)
• dormant form (hypnozite) in liver

Question 3

P. falciparum–disease

Answer 3

• severe
• irregular fever patterns
• parasitized RBCs occlude capillaries in brain (cerebral malaria), kidneys, lungs

Question 4

P. malariae–disease

Answer 4

• 72 hour cycle (quartan)

Question 5

Plasmodium–transmission

Answer 5

• Anopheles mosquito

Question 6

Plasmodium–diagnosis

Answer 6

• blood smear:
  
  • trophozoite ring form wihtin RBC (A)
  • schizont containing merozoites
  • red granules (Schuffner stippling) (B) throughout RBC cytoplasm seen with P. vivax/ovale

Question 7

Plasmodium–treatment

Answer 7

• chloroquine (for sensitive species) which blocks Plasmodium heme polymerase
  
  • if resistant, use mefloquine or atovaquone/proguanil
• if life threatening, use IV quinidine or artesunate (test for G6PD deficiency)
• for P. vivax/ovale: add primaquine for hypnozoite (test for G6PD deficiency)

Question 8

Babesia–disease

Answer 8

• Babesiosis
  
  • fever and hemolytic anemia
  • predominantly in northeastern US
  • asplenia inc risk of severe disease

Question 9

Babesia–transmission

Answer 9

• Ixodes tick (same as Borrelia burgdorferi for Lyme dz; may often coinfect humans)

Question 10

Babesia–diagnosis

Answer 10

• blood smear
  
  • ring form (C1)
  • “maltese cross” (C2)
• PCR

Question 11

Babesia–treatment

Answer 11

• atovaquone + azithromycin