MALARIA

Question 1

What Four Plasmodium species are pathogenic to man ?

Answer 1

1 P. Ovale 2 P. Falciparum 3 P. Vivax 4. P. Malariae

Question 2

Death due to Malaria is usually caused by which species of Plasmodium ?

Answer 2

Plasmodium falciparum.

Question 3

Malaria affects about 350-500 million people per year, with over 1 million deaths each each year. Where is it most common ?

Answer 3

About 70% of cases occur in Sub-Saharan Africa.

Question 4

The infectious stage of the plasmodium parasite, is transported to the host by the bite of the female Anopheles mosquito. What stage is this ?

Answer 4

The Sporozoites.

Question 5

Most cases of severe and complicated malaria are due to which species ?

Answer 5

P. Falciparum

Question 6

What are some clinical features of malaria ?

Answer 6

The onset of the disease is rapid with Fever, headache, lassitude(physical or mental weariness/lack of energy),loss of appetite and pain in the Limbs.

Question 7

What characteristics of fever make malaria a likely diagnosis ?

Answer 7

The fever in malaria in maybe continuous or Remittent for several days before it becomes classically intermittent.

Question 8

Malaria symptoms then progress to a stage of coldness (Chills,Rigors,with headache, Nausea,malaise and Anorexia) True or false ?

Answer 8

True

Question 9

What symptoms are observed in the hot and sweating stages of malaria ?

Answer 9

Hot stage : dry flushed skin,rapid respiration’s,marked thirst. Sweating stage (temperature falls by crisis)

Question 10

On the basis of severity, malaria may be classified as severe/complicated and uncomplicated malaria. What are the clinical findings in severe malaria ?

Answer 10

Presence of any of the following criteria with asexual parasite is (falciparum or Vivax) classifies malaria as severe. Thrombocytopenia alone is not a criteria for the diagnosis. 1. CNS : Loss of consciousness/ unarousable coma , Multiple convulsions (more than 2 in 24 hours ). 2. Somatic : Prostration,generalized weakness, unable to walk or sit by self, failure to feed, Shock/circulatory collapse (systolic < 70 ,adults and < 50 in Children) Respiratory : Deep breathing, respiratory distress, acidotic breathing,Pulmonary edema Metabolism :Hemoglobinuria (black water fever), Clinical jaundice,organ dysfunction Abnormal spontaneous bleeding. Laboratory: Hypoglycemia(< 40mg/dL) Metabolic acidosis (plasma bicarbonate < 15 mEq/L) Severe normocytic anemia (Hb< 5g/dL, PCV < 15%) Hyperparasitemia (> 2% or 100 000/μL in low intensity areas, >5% or 250 000/μL) Hyperlactatemia (lactate > 5mmol/L) Renal impairment (AKI)

Question 11

What is the gold standard diagnostic test in malaria ?

Answer 11

Peripheral blood smear (thick, well prepared). Repeat the smear at least 3 times in 6-8 hourly intervals when the suspicion is likely malaria but initial smear is negative.

Question 12

What does the following image show ?

Answer 12

Red blood cells harboring Plasmodium parasites.

Question 13

Aside from the Peripheral blood smear, what other tests can be done for diagnosis of Malaria ?

Answer 13

1. Rapid diagnostic tests (RDTs) : very useful and simple to use. They distinguish between the plasmodium species. They however cannot be used to monitor progress, no check parasite load, and also are not very sensitive and not cheap.

They detect malarial antigens (PfHRP2/PMA/PLDH/Aldolase)

2. Polymerase Chain Reaction (PCR): highly sensitive and specific. Not available commercially
3. Tests for disease management and severity assessment : FBC, Prothrombin time, Blood glucose, Electrolytes, pH,bicarbonate,CXR,

Question 14

What are the differentials for Malaria ?

Answer 14

Fever in malaria should be distinguished from :

1. Typhoid fever
2. Leptospirosis
3. Dengue fever
4. Viral hepatitis
5. Influenza
6. Chikungunya
7. Rickettsial infections

Cerebral malaria should be distinguished from :

Meningitis,Encephalitis