Giardia sp

Trophozoites

These are bilaterally symmetrical, pear-shaped protozoa with lateral and caudal lagella, longitudinal ventral groove and two prominent nuclei (as though it is staring back at you).

• usually only recovered from freshly passed diarrhoea
• 10 - 15 µm long

Cysts

• 6 - 10µm long and 4 - 6 µm wide
• Elliptical with a thin, smooth wall and containing 2 to 4 nuclei, 2 slender, linear intracytoplasmic fibrils and 2 thick, comma-shaped median bodies
• Use zinc sulphate floatation (centrifugation)