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Plasmodium falciparum: Morphology: Difference between revisions

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*[[Ring forms]] that are fine and delicate
*[[Ring forms]] that are fine and delicate
*Frequently the red cells contain [[multiple parasites]]  
*Frequently the red cells contain [[multiple parasites]]  
*Parasites may have a distinctive [[Double chromatin dot forms|double chromatin dot]] (signet ring form)
*Parasites may have a distinctive [[Double dot|double chromatin dot]] or signet ring form
*Parasites may appear on the [[Accolé form|accolé forms]] that appear flattened against the cell membrane
*Parasites may appear on the [[Accolé form|accolé forms]] that appear flattened against the cell membrane
*Affected red cells have normal size and haemoglobin content
*Affected red cells have normal size and haemoglobin content

Revision as of 11:31, 25 March 2024


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The early trophozoite




The earliest growth stage, and may be the only form seen in this species:

  • Ring forms that are fine and delicate
  • Frequently the red cells contain multiple parasites
  • Parasites may have a distinctive double chromatin dot or signet ring form
  • Parasites may appear on the accolé forms that appear flattened against the cell membrane
  • Affected red cells have normal size and haemoglobin content





The late trophozoite




The later growth stage:




The schizont



The asexual form:

  • Do not generally circulate in this species unless overwhelming infection
  • Contain multiple asexually formed developing parasites (most frequently 8-16)
  • Development is progressive: first there are multiple chromatin dots, later a distinct nucleus and cytoplasm appears
  • Loose pigment may be seen in clumps between the parasites
  • Red cell size is generally unaffected but haemoglobin will largely be absent (metabolised by the parasites)




The gametocyte

The gametocyte




The sexual replication form (very distinctive).

  • Gametocytes are elongated but are restricted into typical shape by the red cell membrane
  • They parasites are rod shaped but the membrane may cause them to curve into a “"banana" form
  • The residual membrane (empty of haemoglobin) is often seen as a "blister" to the side of the parasite
  • The single chromatin area is in the centre of the parasite, often has pigment overlying it
  • Gametocytes may not be be seen, or may be the only form present (particularly after treatment)