Plasmodium spp. I

Question 1

What are the four major plasmodium spp.?

Answer 1

• falciparum
• vivax
• ovale
• malariae

*knowlesi also reported in southeast asia

Question 2

Plasmodium spp. are found in tropics and subtropics worldwide, which species is confined to western Africa?

Answer 2

P. ovale

Question 3

How are ALL malaria species transmitted?

Answer 3

Anopheles mosquitos

-Females

Question 4

What is the mechanisms of infections following mosquito bite (anopheles, female)? (3)

Answer 4

1. Sporozoites injected into blood stream and go to liver and proliferate (Exoerythrocytic schizogony)
2. Schizonts rupture and release merozoites into bloodstream
3. Merozoites infect RBCs to initiate erythrocytic schizogony

Question 5

In endemic areas who is at greatest risk of death?

Answer 5

Pregnant and Young children
-Relative immunity develops in those who survive childhood

*outside of endemic areas, all age groups are equally susceptible

Question 6

After inoculation, when does malaria usually present?

Answer 6

1-4 weeks

Question 7

What are the initial symptoms?

Answer 7

• 1st week asymptomatic

- initial stages of erythrocytic schizogony produce disorganized and vague symptoms

Question 8

What happens within weeks of infection?

Answer 8

Schizogony becomes synchronized and produce fever cycles

Question 9

What does full blown malaria look like?

Answer 9

• Symptoms are paroxysmal, lasting 6-12 hours

- Intermittent intravascular hemolysis

Question 10

Species specific clinical features:

-Fever spikes every 48 hours (3)

Answer 10

• P. ovale
• P. vivax
• P. falciparum

Question 11

Species specific clinical features:

-Most lethal

Answer 11

P. falciparum

-“malignant tertian malaria”

Question 12

Species specific clinical features:

-Fever spikes every 72 hours

Answer 12

P. malariae

-quartan fever)

Question 13

Species specific clinical features:

-Nephrotic syndrome

Answer 13

P. malariae

Question 14

Species specific clinical features:

-CNS involvement

Answer 14

P. falciparum

Question 15

Species specific clinical features:

-Hemosiderinuria, hemoglobinuria, and renal failure

Answer 15

P. falciparum (“blackwater fever”)

Question 16

Species specific clinical features:

-True relapse/recurrence

Answer 16

P. vivax, P. ovale
-Reinvasion of RBCs by liver merozoites (from hypnozoites), after complete clearing of the blood stream by therapy or immunity

Question 17

Species specific clinical features:

-Infection of Young RBCs

Answer 17

• P. vivax

- P. ovale

Question 18

Species specific clinical features:

-Infection of Old RBCs

Answer 18

-P. malariae

Question 19

Species specific clinical features:

-Infection of ALL RBCs

Answer 19

-P. falciparum

Question 20

Effect of inherited Red Cell Anomalies:

-Hemoglobin S

Answer 20

P. falciparum protection

Question 21

Effect of inherited Red Cell Anomalies:

-General protection (4)

Answer 21

• Thalassemia
• HbC
• HbE
• Hereditary persistence of HbF

Question 22

Effect of inherited Red Cell Anomalies:

-Duffy negative blood type

Answer 22

P. vivax protection

Question 23

Effect of inherited Red Cell Anomalies:

-G6PD deficiency

Answer 23

Protective against all species

Question 24

Effect of inherited Red Cell Anomalies:

-Hereditary ovalocytosis

Answer 24

Cerebral malaria protection

Question 25

Laboratory Diagnosis - Detection:

-stains (3)

Answer 25

• Wright stains
• Acridine orange*
• Rhodamine 123*

*Fluorescent stains

Question 26

Laboratory Diagnosis - Detection:

-Screening

Answer 26

Thick blood films

Question 27

Laboratory Diagnosis - Detection:

-Species identification

Answer 27

Thin blood films

Question 28

When is the ideal time to obtain blood specimen?

Answer 28

Preceding the next anticipated fever spike

Question 29

Examination of at least ____ oil immersion Thick Film fields or ____ thin film fiels is required to achieve the reported sensitivity (5 parasites/uL).

Answer 29

• 100 oil immersion Thick Film fields

- 300 Thin Film fields