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Plasmodium

Epidemiology: 1) Plasmodia undergo a sexual phase (sporogony) in Anopheles mosquitoes & an asexual phase (schizogony) in humans 2) sporogony (in mosquitoes) results in formation of infectious sporozoites 3) schizogony within the vertebrate host results in formation of schizonts & merozoites 4) within female Anopheles mosquitoes a) gametocytes form macrogametes & microgametes within the stomach of the mosquito b) fusion of a microgamete with a macrogamete results in formation of a motile ookinete c) the ookinete migrates outside the stomach wall & forms an oocyst d) within the oocyst, numerous sporozoites are formed e) the mature oocyst ruptures into the body cavity releasing sporozoites f) sporozoites migrate throught the tissues to the salivary glands g) sporozoites are injected through the saliva into the vertebrate host h) development within the mosquito ranges from 8-21 days 5) within the vertebrate host a) sporozoites injected into the vertebrate host invade hepatocytes b) schizogony within hepatocytes begins within minutes c) release of merozoites from ruptured hepatic schizonts initiates bloodstream infection d) merozoites penetrate erythrocytes to form trophozoites (ring forms) which mature to form mature trophozoites (growing form) e) schizogony within erythrocytes occurs with schizont (dividing) forms & results in release of merozoites with rupture of the host erythrocyte to re-initiate the cycle f) some merozyoites eventually develop into gametocytes g) gametocytes are ingested by female Anopheles mosquitoes Laboratory: - Plasmodium identified in blood by light microscopy - Plasmodium serology - Plasmodium antigen in blood - Plasmodium lactate dehydrogenase in blood - Plasmodium DNA - see ARUP consult [3]

Related

malaria

Specific

Plasmodium falciparum Plasmodium knowlesi Plasmodium malariae Plasmodium ovale Plasmodium vivax

General

Coccidia

Properties

KINGDOM: animal PHYLUM: protozoa

References

  1. Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996, pg 1260-64
  2. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 1180-89
  3. ARUP Consult: Plasmodium Species - Malaria The Physician's Guide to Laboratory Test Selection & Interpretation https://www.arupconsult.com/content/plasmodium-species