Plasmodium falciparum: Morphology: Difference between revisions
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The earliest growth stage, and may be the only form seen in this species: | The earliest growth stage, this is characterised by fine ring forms and few other changes, this may be the only form seen in this species: | ||
*[[Ring forms]] that are fine and delicate | *[[Ring forms]] that are fine and delicate | ||
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The later growth stage: | The later growth stage where parasites begin to modify the erythrocyte, causing characteristic changes with added dots and minr changes to red cell form: | ||
*Parasites resemble early ring forms, but are thicker and may be slightly larger | *Parasites resemble early ring forms, but are thicker and may be slightly larger | ||
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The asexual form: | The schizont is the asexual form of the malaria parasite in blood - for a detailed description see the "Biology of malaria" section in the main menu: | ||
*'''Do not generally circulate in this species unless overwhelming infection''' | *'''Do not generally circulate in this species unless overwhelming infection''' | ||
*The | *The merozoites cluster "untidily" as they develop | ||
*[[ | *[[Biology of the schizont|Schizonts]] develop progressively to form 8-16 merozoites when mature | ||
*In this species the loose [[Malaria pigment|malaria pigment]] may be seen in clumps between the parasites | *In this species the loose [[Malaria pigment|malaria pigment]] may be seen in clumps between the parasites | ||
*Red cell size is generally unaffected but | *Red cell size is generally unaffected but red cells become pale as haemoglobin is metabolised by the parasites | ||
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The sexual replication form (very distinctive). | The sexual replication form (very distinctive). | ||
* | *male and femaie [[Gametocyte develpment|gametocytes]] are elongated and have the appearance of rods | ||
*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 (empty of haemoglobin) is often seen as a "blister" to the side of the parasite | *The residual membrane (empty of haemoglobin) is often seen as a "blister" to the side of the parasite |
Latest revision as of 11:59, 7 May 2024
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The early trophozoite |
The earliest growth stage, this is characterised by fine ring forms and few other changes, this 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 where parasites begin to modify the erythrocyte, causing characteristic changes with added dots and minr changes to red cell form:
- 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 schizont is the asexual form of the malaria parasite in blood - for a detailed description see the "Biology of malaria" section in the main menu:
- Do not generally circulate in this species unless overwhelming infection
- The merozoites cluster "untidily" as they develop
- Schizonts develop progressively to form 8-16 merozoites when mature
- In this species the loose malaria pigment may be seen in clumps between the parasites
- Red cell size is generally unaffected but red cells become pale as haemoglobin is metabolised by the parasites
The gametocyte
The gametocyte |
The sexual replication form (very distinctive).
- male and femaie gametocytes are elongated and have the appearance of rods
- 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)