[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Apicomplexans](https://durgical.com/en/microbiology/groups/apicomplexans/) › Plasmodium malariae and Plasmodium ovale [Microbiology](https://durgical.com/en/microbiology/) · [Apicomplexans](https://durgical.com/en/microbiology/groups/apicomplexans/) # Plasmodium malariae and Plasmodium ovale - Parasite - Exam priority: medium Two less common malaria species: P. malariae gives fever every 72 hours and can harm the kidney; P. ovale forms hypnozoites like vivax. Updated 2026-11-01 Also called: quartan malaria (P. malariae), ovale tertian malaria ## Key points - P. malariae: quartan fever (every 72 hours), band forms, rosettes and nephrotic syndrome. - P. ovale: hypnozoites like P. vivax; oval, fimbriated red cell. - Only P. vivax and P. ovale need anti-relapse treatment. - P. malariae can persist for years at low parasitemia and spread by transfusion. ## At a glance **Shape** P. malariae: band forms and rosette schizont; P. ovale: oval, fimbriated red cell **Family** Plasmodiidae **Type** Intracellular apicomplexan protozoa (liver and red blood cells) **Stain** Giemsa on thick and thin films **Size** P. malariae does not enlarge the cell; P. ovale enlarges it slightly ## Morphology - P. malariae: normal or small red cell, band or basket trophozoites and coarse dark pigment. - P. malariae: schizont with few merozoites arranged in a rosette. - P. ovale: slightly enlarged, oval red cell with fimbriated edges; may show Schüffner's dots. - P. ovale: compact trophozoite with coarser pigment than vivax. ## Transmission - Bite of an infected female Anopheles. - P. malariae can pass through transfusion years after infection because of its low, persistent parasitemia. **Reservoir:** Humans **Vector:** Female Anopheles mosquitoes. ### Isolation precautions What the care team adds to standard precautions. - Standard ## Life cycle - The mosquito injects sporozoites that reach the liver. - In the liver they form schizonts; P. ovale also leaves dormant hypnozoites, P. malariae does not. - Merozoites invade red cells: P. malariae prefers old cells, P. ovale young ones. - The blood cycle lasts about 72 hours in P. malariae and about 48 hours in P. ovale. - Gametocytes form and are taken up by mosquitoes, where the sexual phase produces sporozoites. ## Virulence factors - P. malariae: low parasitemia that can persist for decades without symptoms. - P. malariae: immune-complex deposits in the glomerulus, with nephrotic syndrome in chronic infection. - P. ovale: hypnozoites that cause relapses. ## Diseases it causes - Malaria from P. malariae (quartan) or P. ovale (tertian with relapses). [Malaria →](https://durgical.com/en/conditions/malaria/) - Nephrotic syndrome from chronic or repeated P. malariae infection. ## Clinical picture - P. malariae: fever every third day (every 72 hours), usually mild. - P. ovale: illness similar to vivax, with relapses. - Chronic P. malariae: edema and proteinuria from nephrotic syndrome, especially in children. ## Diagnosis - Giemsa thick and thin films; species are told apart on the thin film. - Band forms and rosette schizonts suggest P. malariae; oval, fimbriated cells suggest P. ovale. - PCR to confirm species, since they are confused with P. vivax or mixed infections. ## Treatment Chloroquine or another blood schizonticide; for P. ovale an 8-aminoquinoline (primaquine or tafenoquine) is added against hypnozoites after G6PD testing. P. malariae needs no anti-relapse treatment. Drug class only; doses and regimens are set by the clinician from the current guideline. ## Prevention - The same anti-Anopheles measures: insecticide-treated nets, repellents and screens. - Blood-donor screening according to each country's rules. - Species diagnosis in travelers returning from Africa, where P. ovale is more common. **Vaccine:** There is no vaccine against these species. ## In Colombia P. malariae is uncommon in Colombia; P. ovale belongs to Africa and appears mainly in travelers. Both are reported to SIVIGILA under the malaria event. ## Memory aid Malariae is the «slow one»: 72 hours per cycle, decades in the blood, and the bill goes to the kidney. Ovale is vivax's «cousin» that also hides in the liver. ## Test yourself Think of the answer, then tap the question to see it. ## Which Plasmodium species causes nephrotic syndrome? P. malariae, through immune-complex deposits in the glomerulus during chronic or repeated infection. ## Which of these two species forms hypnozoites? P. ovale; like P. vivax, it needs an 8-aminoquinoline to prevent relapse. ## Which fever pattern goes with P. malariae? Quartan fever: a paroxysm every 72 hours. ## Which thin-film forms are typical of P. malariae? Band trophozoites stretching across the cell and schizonts with merozoites in a rosette, in red cells that are not enlarged. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/microbiology/plasmodium-malariae-and-plasmodium-ovale/) ## Related - [Plasmodium vivax](https://durgical.com/en/microbiology/plasmodium-vivax/) - [Plasmodium falciparum](https://durgical.com/en/microbiology/plasmodium-falciparum/) ## Related conditions - [Malaria](https://durgical.com/en/conditions/malaria/) ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. [← Back to the group: Apicomplexans](https://durgical.com/en/microbiology/groups/apicomplexans/) Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [CDC - DPDx - Malaria](https://www.cdc.gov/dpdx/malaria/index.html) (CDC, 2024); [Clinical Features of Malaria | Malaria | CDC](https://www.cdc.gov/malaria/hcp/clinical-features/index.html) (CDC, 2024); [Malaria](https://www.who.int/news-room/fact-sheets/detail/malaria) (WHO, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/plasmodium-malariae-and-plasmodium-ovale/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/plasmodium-malariae-and-plasmodium-ovale/