Plasmodium falciparum

Question 1

Classification

Answer 1

Protozoa

Question 2

Indirect or direct

Hosts

Answer 2

Indirect life cycle

Mosquito is final host
Human is intermediate host

Question 3

Transmission and life cycle

Answer 3

The mosquito releases sporozoites during a blood meal. These sporozoites travel to the liver and infect hepatocytes.

Here they mature and develop to schizonts. They undergo schizogony and form merozoites. These merozoites are being released from the hepatocytes and rupture the cells.

Then they infect erythrocytes and again undergo schizogony. Again rupturing the erythrocytes and being released.

Some parasites differentiate to gametocytes (micro and macrogametes). These gametocytes are then picked up by a mosquito during a blood meal.

The parasites’ multiplication in the mosquito is known as the sporogonic cycle. In the mosquitos stomach, the gametocytes undergo sexual multiplication vorming oocysts.

These oocysts grow, rupture and release sporozoites which travel to the mosquitos salivary glands and doing the cycle all over again.

Question 4

Diagnosis

Answer 4

Microscopy
Thick smear to detect presence of parasite. Thin smear to differentiate between plasmodium species.

Molecular:
PCR for DNA detection. Very helpful when the parasitemia is too low to be able to detect with microscopy.

Serology:
Antibody detection not very helpful because it takes time to develop antibodies and by the time a person has developed them, the person might have already died.

Antigen detection:
In addition to microscopy and molecular methods.