Plasmodium falciparum | Plasmodium vivax | Plasmodium ovale | Plasmodium malariae | Plasmodium knowlesi[1-7] | |
Geography | Tropical, temperate zones | Tropical, temperate zones, absent from West Africa | Tropical, endemic in West Africa, present in Philippines, Indonesia, and Papua New Guinea | Tropical, isolated pockets | Southeast Asia |
RBC preference | RBCs of all ages | Young RBCs (reticulocytes) | Young RBCs (reticulocytes) | Older RBCs | RBCs of all ages |
Infected RBC diameter | Normal | Larger than normal | Larger than normal | Normal or smaller than normal | Normal |
Ameboid trophozoites | No | Yes | Yes | No | No |
Band forms | No | No | No | Yes | Yes |
Schizont* | 16 to 20 merozoites; very rare in peripheral circulation | 20 to 24 merozoites | 4 to 16 merozoites (8 typical) | 6 to 12 merozoites (8 or 10 typical) | 8 to 16 merozoites (10 typical) |
Parasitemia | Can be very high | Usually <2% | Usually <2% | Usually very low | Usually low, can be high |
Disease severity | End organ damage and death can occur | End organ damage and death less common than P. falciparum but can occur | Severe disease uncommon | Severe disease rare | Severe disease can occur |
Chloroquine resistance | Yes | Yes | No | Rare | No |
Relapses from liver | No | Yes | Yes | No | No |
Incubation period | 12 days (8 to 25) | 14 days (8 to 25; occasionally months) | 15 days (9 to 17) | 18 days (15 to 30; occasionally months to years) | 11 days (9 to 12) |
Prepatent period¶ | 11 days | 12 daysΔ | 12 days | 32 days | Uncertain in naturally infected humans |
Cycle in red cell | 48 hours | 48 hours | 48 hours | 72 hours | 24 hours |
RBC: red blood cell.
* Identification of a schizont with >12 merozoites in the peripheral circulation is an important diagnostic clue for P. vivax. In general, schizonts of P. falciparum are very rarely seen in blood films; they occur only in the setting of severe disease with hyperparasitemia.
¶ The prepatent period is the time from mosquito bite to the first appearance of parasites in the peripheral blood (as detected by microscopy).
Δ The latency period of vivax is typically longer than falciparum (refer to UpToDate table summarizing time to symptoms for each species).Do you want to add Medilib to your home screen?