Differences Between Plasmodium falciparum and Plasmodium vivax

Malaria parasites are sporozoans and belongs to order Haemosporida. The genus Plasmodium has been subdivided into nine subgenera, of which three are found in mammals, four in birds and two in lizards. According to the classification, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae belong to the subgenus Plasmodium, and Plasmodium falciparum belongs to the subgenera Laverania.

Differences Between Plasmodium falciparum and Plasmodium vivax with characters are given below:

Characteristics	P. faciparum	P. vivax
Duration of asexual phase in man	36-48 hrs Usually 48 hrs	48 hrs
Duration of sporogony in mosquito	22-23 days at 20°C 10-12 days at 27°C	30 days at 17.5°C 10 days at 25-30°C
Duration of intrahepatic phase	5.5 days	8 days
Duration of Schizogony	12 days	14 days
Forms found in the smear	Rings and banana shaped gametocytes	Trophozoites, schizonts and gametocytes
Level of usual maximum parasitemia	May exceed 200,000/µl, commonly 50,000/µl	Up to 30,000/µl of blood
No. of merozoites released per infected hepatocyte	30,000	10,000
Red cell preference	Younger cells (but can invade cells of all ages)	Reticulocytes and red cells up to 2 weeks old
Parasitized Red cells	Not enlarge. Coarse stippling (Maurer’s clefts)	Enlarged, pale. Fine stippling (Schuffner’s dots)
Pigment Color	Black and Dark Brown	Yellow or Golden Brown
Ability to cause relapses	No	Yes
Ring Stage Trophozoite	Small rings (1/5 red cell diameter). Often two granules. Multiple rings common.	Large rings (1/3 to 1/2 diameter). Single chromatin granule. Two rings in one cell.
Pigment in developing trophozoites	Coarse, black, few clumps	Fine, Light brown, scattered
Late Trophozoite	Compact Medium Sized Rarely amoeboid Vacuole inconspicuous.	Pleomorphic Large Markedly amoeboid Vacuole prominent.
Schizont	Small, compact, Single pigmented mass Seldom seen in the peripheral blood smear	Large, amoeboid, Pigments coarse Can be seen in the blood smear
Mature Schizont (segmenters)	8-16 (Usually 8-18).	12-14 (Usually 12-18)
Microgametocytes	Kidney-shaped with blunt round ends. Cytoplasm stains pale blue. Nucleus large. Chromatin diffuse. Granules fine, scattered.	Spherical, compact. Cytoplasm stains pale light blue. Chromatin undivided. Granules abundant.
Macrogametocytes	Crescentic. Cytoplasm stains dark blue. Nucleus compact. Chromatin central. Pigment more compact.	Spherical. Cytoplasm stains dark blue. Nucleus small. Pigment diffuse ecoarse.
Disease	Malignant tertian malaria	Benign tertian malaria