Life Cycle of P. falciparum vs. P. vivax

I am writing this post to help you remember the fundamental differences between the two malarial parasites P. falciparum and P.vivax.

I hope after going through this post, you will discover some fascinating things and their arrangements in the word “FALCIPARUM“. This word will help you can recall or write the life cycle of both P. falciparum and P.vivax individually or even write the most important differences between their life cycle.

Note: To get the best of this blog post: you must have some idea about the general life cycle of the malarial parasite and its stages. Let’s begin with this magic word “FALCIPARUM”. For now, only focus on this word and the alphabets there

Key points regarding P falciparum malaria
  • F:
    • Fatal (Plasmodium falciparum cause most severe (dangerous) or life-threatening types of malaria called “malignant tertian malaria”).
    • Fast: To cause more damage to host cells it must complete each cycle (pre-erythrocytic schizogony and erythrocytic schizogony) faster; faster the life cycle, more will be the parasite… more will be the destruction of blood cells.
  • A/AL:
    • Applique’ or Accole’: These two forms are seen only in falciparum malarial infection. As the parasite attaches itself to the margin or the edge of the host cell, the nucleus and a small part of the cytoplasm remains almost outside giving the characteristics form, “form applique’ or accole’)
    • All: Plasmodium falciparum does not show a special affinity for any particular type of red blood cell but invades both the reticulocytes and erythrocytes (young and old). As both young and old red cells are infected the percentages of infected cells are more (which aids you in the microscopic diagnosis of malaria and differentiation too)
      (Vs. P. vivax: it is known that P. vivax shows a greater tendency to invade younger red blood cells and reticulocytes than mature RBC so the percentage of infected RBC is less, only 1-2% RBC are infected)  
Morphology of the different stages of the Plasmodium falciparum life cycle in thin blood films.
Morphology of the different stages of the Plasmodium falciparum life cycle in thin blood films.

C: “Crescents shaped”:

I: Internal organs:

  • Erythrocytic schizogony of P. falciparum occurs inside the capillaries of the internal organs, hence the only ring forms (not growing trophozoites and schizonts) are found in the peripheral blood.
    (vs. P vivax: The erythrocytic schizogony of P. vivax is completed mainly in the peripheral circulation)

RU: RBC Unaltered:

  • In Plasmodium falciparum infection the infected red blood cells remain unaltered (Vs.in  P. vivax infection RBC enlarges and becomes double in its original size).

M: Multiple and Maurer’s Dot:

  • Multiple infections of the red blood cells are the feature of Plasmodium falciparum infection. i.e. more than one parasite (from 2 to 6) invading a single red blood cell (RBC) is very common with this species(vs. P. vivax: each RBC is generally invaded by a single parasite)
  • Maurer’s dot:  In the erythrocytic schizogony of Plasmodium falciparum the Schuffner’s dots are absent (S alphabet is absent in the above mentioned word), but in their place 6-12 Maurer’s dots of clefts (staining brick-red with Leishman’s stain) are seen. (Vs. vivax Schuffner’s dots present: The portion of cytoplasm unoccupied by the parasite shows a dotted or stippled appearance, called schuffner’s dots)

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References

  1. Arbeitskreis Blut, Untergruppe «Bewertung Blutassoziierter Krankheitserreger» (2009). Malaria. Transfusion medicine and hemotherapy : offizielles Organ der Deutschen Gesellschaft fur Transfusionsmedizin und Immunhamatologie, 36(1), 48–60. https://doi.org/10.1159/000197327
  2. Crutcher JM, Hoffman SL. Malaria. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 83. Available from: https://www.ncbi.nlm.nih.gov/books/NBK8584/
  3. Menkin-Smith L, Winders WT. Plasmodium vivax Malaria. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538333/
  4. Soulard, V., Bosson-Vanga, H., Lorthiois, A., Roucher, C., Franetich, J. F., Zanghi, G., Bordessoulles, M., Tefit, M., Thellier, M., Morosan, S., Le Naour, G., Capron, F., Suemizu, H., Snounou, G., Moreno-Sabater, A., & Mazier, D. (2015). Plasmodium falciparum full life cycle and Plasmodium ovale liver stages in humanized mice. Nature communications, 6, 7690. https://doi.org/10.1038/ncomms8690

Acharya Tankeshwar

Hello, thank you for visiting my blog. I am Tankeshwar Acharya. Blogging is my passion. As an asst. professor, I am teaching microbiology and immunology to medical and nursing students at PAHS, Nepal. I have been working as a microbiologist at Patan hospital for more than 10 years.

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