Malaria case studies

Question 1

List the common presenting signs and symptoms of malaria

Answer 1

-periodic and paroxysmal fever
Chills and rigors
Fever spikes to 40oC (104oF)
Profuse sweating
Extreme fatigue and sleep
Lasts several hours
Recurs at regular intervals (sometimes)
-non specific symptoms:HA, lassitude, fatigue, abdominal discomfort, myalgias, arthralgias
Fever, chills, perspiration, anorexia, nausea, worsening malaise
Physical exam findings: anemia, palpable spleen sometimes, fever

Question 2

discuss appropriate diagnostic testing for malaria

Answer 2

-Lab findings: usually mild anemia, severe anemia only with P. falciparum due to hyperparasitemia 
Normal white blood cell count
Thrombocytopenia
Elevated acute phase proteins
Elevated bilirubin, liver enzymes
-clinical
-light microscopy: thick and thin smear, for 3 days
-fluorescence microscopy
-Rapid diagnostic tests

Question 3

Describe malaria caused by Plasmodium vivax/ovale.

Answer 3

-Rarely causing serious illness
-Parasitemia usually <1%
-Resistance uncommon
-Clinical Problem: likelihood of recurrence even if patient receives standard therapy of chloroquin
-Very common
-Different geographic distribution
Both found worldwide, but…
-P. ovale found in sub-Saharan Africa
-P. vivax other areas

Question 4

Discuss the appropriate prophylactic measures to be used by an individual traveling in a malarious area.

Answer 4

-Malarone
Atovaquone/proguanil
Preferred by many travelers because of lack of adverse effects
One tablet (250/100) daily
Start 1-2 d before and for 7 d after
Disadvantages
Daily v. once a week
Expensive
-Mefloquine
Drug of choice in most areas
250 mg taken once a week
Start 1 week before exposure
Continue 4 weeks after exposure
Side effects include CNS complications
-Doxycycline
Effective in areas of high resistance
Must be taken daily

Question 5

Identify the appropriate therapy for infection with uncomplicated malaria via plasmodium falciparum

Answer 5

-ACT for 3 days
Sulfadoxine/pyrimethamine + amodiaquine
Not as effective as ACT
Atovaquone-proguanil (Malarone)
Safe and effective; not included in recommendations because of high cost
Halofantrine
Not evaluated as part of ACT; not included because of safety concerns

Question 6

Describe Plasmodium Falciparum malaria

Answer 6

Infects erythrocytes of all ages
Leads to high parasite burden
Able to sequester in the deep venous microvasculature, avoiding destruction by spleen
Binds to endothelium with P. falciparum erythrocyte membrane protein 1 (PfEMP1)
Seen in all areas of the world
Worst type (only type to lead to death)
Complications include cerebral malaria, severe anemia, respiratory failure, renal failure, hypoglycemia
Causes acute disease and then resolves
No recurrences without reinfection
Drug resistance a major problem

Question 7

What diseases give resistance to malaria?

Answer 7

• sickle cell
• thalassemias
• G6PD deficiency

Question 8

What are some of the symptoms of severe malaria?

Answer 8

Coma, metabolic acidosis, severe anemia, hypoglycemia, acute renal failure, pulmonary edema
Renal failure (Blackwater fever)
Pulmonary edema or ARDS
Circulatory collapse or shock
Mortality: 80%
Spontaneous bleeding (DIC)
Acidemia (arterial pH < 7.25)
Macroscopic hematuria

Question 9

Identify the appropriate therapy for infection with uncomplicated malaria via plasmodium ovale or vivax

Answer 9

-Chloraquine
In chloraquine sensitive areas
-[Amodiaquine]
In resistant areas
Not licensed in the US
-Patients with P. vivax or P. ovale at risk for recurrence from exoerythrocytic (liver) parasites
Chloroquine must be followed by 14 days of primaquine