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 | *Parasites may have a distinctive [[Double chromatin dot forms|"double dot"]] or signet ring form | ||
*Parasites may appear on the [[Accolé form| | *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 | ||
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*Additional blue/grey dots and clefts are seen in red cell cytoplasm when [[stained correctly]] | *Additional blue/grey dots and clefts are seen in red cell cytoplasm when [[stained correctly]] | ||
*These dots have low number a characteristic "dot" or "line" form [[Maurer's dots and clefts]] | *These dots have low number a characteristic "dot" or "line" form [[Maurer's dots and clefts]] | ||
*[[Red cell size and shape|Size and shape of infected red cells | *[[Red cell size and shape|Size and shape]] of infected red cells is usually unaffected, but may become crenated | ||
*[[Double chromatin dot forms|double | *The [[Double chromatin dot forms|double dot]], [[Accolé form| accolé]], and [[multiple parasites|multiple parasite]] forms remain present | ||
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*'''Do not generally circulate in this species unless overwhelming infection''' | *'''Do not generally circulate in this species unless overwhelming infection''' | ||
*Contain multiple | *Contain multiple (8-16) asexually formed developing parasites known as "merozoites" | ||
*[[ | *[[Schizont Development|Development is progressive]]: first there are multiple chromatin dots, later a distinct nucleus and cytoplasm appears | ||
* | *In this species the loose [[Malaria Pigment|malaria pigment]] may be seen in clumps between the parasites | ||
*Red cell size is generally unaffected but [[haemoglobin | *Red cell size is generally unaffected but [[Haemoglobin Metabolism|haemoglobin is lost]] (metabolised by the parasites) | ||
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*Gametocytes are elongated but are restricted into typical shape by the red cell membrane | *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 gametocyte|"banana" form]]” | *They parasites are rod shaped but the membrane may cause them to curve into a “[[Banana gametocyte|"banana" form]]” | ||
*The residual membrane ( | *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 [[Malaria pigment|pigment]] overlying it | *The single chromatin area is in the centre of the parasite, often has [[Malaria pigment|pigment]] overlying it | ||
*Gametocytes may not be be seen, or may be the only form present (particularly after treatment) | *Gametocytes may not be be seen, or may be the only form present (particularly after treatment) | ||
Revision as of 11:48, 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 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:
- Parasites resemble early ring forms, but are thicker and may be slightly larger
- Additional blue/grey dots and clefts are seen in red cell cytoplasm when stained correctly
- These dots have low number a characteristic "dot" or "line" form Maurer's dots and clefts
- Size and shape of infected red cells is usually unaffected, but may become crenated
- The double dot, accolé, and multiple parasite forms remain present
| The schizont |
The asexual form:
- Do not generally circulate in this species unless overwhelming infection
- Contain multiple (8-16) asexually formed developing parasites known as "merozoites"
- Development is progressive: first there are multiple chromatin dots, later a distinct nucleus and cytoplasm appears
- In this species the loose malaria pigment may be seen in clumps between the parasites
- Red cell size is generally unaffected but haemoglobin is lost (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)