Plasmodium falciparum: Morphology

---

Navigation
(click blue highlighted text to return to page)

Malaria main index
>Species identification: summary page
>>This page: P.falciparum: morphology

---

The early trophozoite

• 
• 

The earliest growth stage, and often the only form present 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 (signet ring form)
• Parasites may appear on the edge of the red cell and have a flattened appearance (accolé forms)
• Affected red cells have normal size and haemoglobin content

Click for P.falciparum early trophozoite gallery

---

The late trophozoite

• 
• 

The later growth stage:

• Parasites resemble early ring forms, but are thicker and slightly larger
• Additional dots and clefts in cytoplasm when stained correctly (blue and relatively low in number).
• These have a characteristic appearance and are called Maurer's dots and clefts
• Size and shape of infected red cells usually unaffected, but may become crenated
• Look for double chromatin dot, Accolé forms, multiple parasites/cell

---

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 also restricted by the red cell membrane
• They appear as straight rods but frequently curve into a “banana form”
• The residual membrane (empty of haemoglobin) may appear as a "blister" to the side of the parasite
• The single chromatin area is in the centre of the parasite, often pigment overlies or surrounds it
• Gametocytes may not be seen in many cases.

---