[Last Modified: ]

January 2002
Answer to Case 76
This was a case of giardiasis.  Only cysts of the parasite were observed in this specimen.  The key microscopic diagnostic features were:

• Oval (sometimes round) smooth-walled cyst measuring 11 to 14 µm in length and 7 to 10 µm in width.
• Presence of 2 to 4 nuclei in cysts.  All 4 nuclei are rarely visible in a single focal plane.
• Presence of a longitudinal axostyle.