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Parasitology/Virology > Malaria > Flashcards

Flashcards in Malaria Deck (22):
1

What are the 4 major species of malaria?

Plasmodium falciparum, P. vivax, P. ovale, P. malariae

2

What is the vector of malaria?

Female Anophales mosquito

3

Describe the life cycle of malaria

- Sporozoites transmitted from anophales mosquito during blood meal
- Sporozoites invade hepatocytes and multiply into merozoites
- Merozoites invade erythrocytes and mature into trophozoite (ring form)
- Trophozoite divide into multi-nucleated shizont
- Shizont bursts releasing new merozoites, can either go through asexual cycle again or can differentiate into male and female gametocytes
- Gametocytes are taken up by mosquito and progress through stages to become sporozoites in the proboscis

4

Which stages of the life cycle cause disease?

Asexual blood stages (destruction of erythrocytes)

5

What makes P. falciprum more severe?

Var genes encode protein expressed on infected erythrocytes surface that causes endothelial adhesion and microvascular obstruction in brain and other organs (cerebral malaria)

6

What species of malaria cause uncomplicated malarial disease?

Any four species

7

What species of malaria cause the most severe malarial disease?

Plasmodium falciparum

8

What is the clinical presentation of uncomplicated malaria?

- Periodic fever paroxysms every 48 hours
- Headache, myalgia, backache, cough, diarrhea, abdominal pain
- Anemia, hepatomegaly, jaundice

9

What are lab signs of uncomplicated malaria?

Anemia, thrombocytopenia, normal to low white blood cell count

10

What is the clinical presentation of severe malaria due to P. falciprum?

Cerebral malaria (altered consciousness, seizures common, rapid onset)
Severe anemia (hemoglobin <5 gm/dL)

11

What is the clinical presentation of severe malaria due to P. vivax?

Splenic rupture, chronic anemia
Mostly SE Asia, West Pacific, and South America (African lack Duffy antigen to allow P. vivax invasion)
Ability to relapse, no sequestration

12

What is the clinical presentation of severe malaria due to P. malariae?

Nephrotic syndrome in African children

13

Which species of malaria remain dormant in the liver and can reactivate?

P. vivax and P. ovale (OVer and OVer)

14

How is the diagnosis of malaria made?

- Giemsa stained blood smear
- Rapid antigen test

15

What is the function of thin smear v. thick smear?

Thick smear - detects malaria
Thin smear - determines species based on morphology

16

What are downsides to the rapid antigen tests?

- Sensitivity decreases with low parasitemia and non-falciparum infection
- Can't differentiate P. falciparum from mixed infections
- May remain positive after treatment

17

What are major clinical clues to suspect malaria?

Any fever in potentially exposed person (travel to malaria endemic country recently)
- Incubation usually 1-4 weeks

18

Signs of severe malaria

Mental status altered
Acidotic breathing
Renal, hepatic, cardiac dysfunction, shock
Anemia
Hypoglycemia

19

Treatment for uncomplicated P. falciparum malaria

Artemether-lumefantrine
Atovaquone-proguanil (Malarone)
Mefloquine
Chloroquine

20

Treatment for P. vivax, ovale and malariae

Primaquine (make sure G6PD activity is good) to treat hypnozoites in liver
Chloroquine for shizonts in blood

21

Treatment for severe malaria

IV quinine or quinidine
Supportive care
- Treat hypoglycemia
- Monitor anemia and cardiac-respiratory status
- Antipyretics
- Anticonvulsants if needed

22

Is malarial anemia due to iron deficiency?

NO, do not give iron!
Due to peripheral hemolysis, bone marrow suppression, inflammation.