Plasmodium ovale is an important human cause of malaria, generally causing moderate disease after a 7 to 28 day incubation period. It has a tertan (two-day cycle) life cycle. Like P. vivax it can become latent in the liver, but primaquine is effective in preventing the spread of the parasite into the bloodstream. Without such treatment the parasite may become active and spread into the bloodstream from the liver causing the patient to have a relapse of malaria and this occurs in about 20% of patients.
- Superkingdom Eukaryota