| Identification key Group | Size of helminth eggs | ||
|---|---|---|---|
| < 40 µm | 41~80 µm | > 81 µm | |
| Group I | |||
| Embryo (+) | Opisthorchiid, Heterophyid & Gymnophaliid flukes | Dicrocoeliid fluke | |
| Operculum (+) | |||
| Group II | |||
| Embryo (−) | Diphyllobothriid & Spirometrid tapeworms | Echinostomatid, Paragonimus Neodiplostomum, Fasciola spp. Fasciolopsis | |
| Group III | |||
| Embryo (+) | Cyclophyllidean tapeworm* | Schistosoma spp. | |
| Operculum (−) | |||
| Group IV | |||
| Embryo (−) | Nematodes† | Nametodes‡ | |
*Taenia spp. and Hymenolepis spp.; †Ascaris lumbricoides (F), Trichuris trichiura and hookworms; ‡Ascaris lumbricoides (U) and Trichostrongylus orientalis.