Question

How are eggs of taenia species seen under microscope?

Answer 1

Unlike other tapeworms, T. solium infections carry risk for neurocysticercosis. Differential diagnosis of human tapeworm infections relies on morphology of the scolex or proglottids, frequently unavailable. DNA-based assays are poorly available in endemic areas. Ziehl Neelsen staining has been suggested but not tested in controlled designs. We validated whether Ziehl Neelsen staining could differentiate T. solium and T. saginata eggs.

Methods

Tapeworm proglottids (33 specimens, 23 T. solium and 10 T. saginata) and eggs (31 specimens, 13 T. solium and 10 T. saginata) were stained. Four eggs from each sample were measured and average diameters were recorded.

Results

T. saginata eggs stained entirely magenta in seven of 13 cases. T. solium eggs stained entirely blue/purple in 4/18 cases and entirely magenta in one. Eggs of T. saginata were slightly larger and always ovoid, while T. solium eggs were smaller and were mostly spheric.

Conclusions

Ziehl Neelsen staining can occasionally distinguish fully mature T. solium from T. saginata eggs. This distinction is poorly sensitive and not completely specific. Differential staining suggest differences in embryophore components between species, evident along egg maturation. In this small series, egg morphology (shape, maximal diameter) provided appropriate differentiation between T. solium and T. saginata eggs.

Keywords: Taenia, Taenia solium, Taenia saginata, Ziehl Neelsen, cestodes, Perú

Answer 2

Answer:

Taeniidae Egg: Eggs of the family Taeniidae are difficult to identify to species, but all have the characteristic eggs with a striated outer zone (the embryophore).