Diagnostic egg morphology difference between Schistosoma mansoni and Schistosoma haematobium?

Diagnostic egg morphology difference between Schistosoma mansoni and Schistosoma haematobium?

• A. Terminal spine: Schistosoma mansoni; lateral spine: Schistosoma haematobium
• B. Lateral spine: Schistosoma mansoni; terminal spine: Schistosoma haematobium
• C. Lateral spine: Schistosoma haematobium; terminal spine: Schistosoma mansoni
• D. No spines on either egg

Answer: (C)

The distinguishing feature here is where the spine sits on the egg. Schistosoma mansoni eggs have a large spine on the side (a lateral spine), which is characteristic when you’re looking at eggs from fecal samples. Schistosoma haematobium eggs, on the other hand, have a spine at the tip of the egg (a terminal spine), a hallmark seen in eggs from urine samples. This difference in spine position is the key microscopic clue used to tell these two species apart.

The distinguishing feature here is where the spine sits on the egg. Schistosoma mansoni eggs have a large spine on the side (a lateral spine), which is characteristic when you’re looking at eggs from fecal samples. Schistosoma haematobium eggs, on the other hand, have a spine at the tip of the egg (a terminal spine), a hallmark seen in eggs from urine samples. This difference in spine position is the key microscopic clue used to tell these two species apart.