Table 3 will help to identify the eggs of the other flukes, Paraganimus and the Schistosoma spp. Note that S. mansoni and S. intercalatum are similar except for size. The same can be said of S. japonicum and S. mekongi.
Table 3. Flukes Living in the Veins Located Near the Intestines or Bladder and those Living in the LungsSpecies and Description | Image | Geographic Location | Means of Infection |
Schistosoma mansoni 114-180 x 45-70 µm Note lateral spine | (12) | Areas in Africa, South America, Arabian peninsula | Skin penetration by cerceriae |
Schistosoma intercalatum 140-240 x 40-70 µm Note terminal spine and elongated shape | (13) | Democratic Republic of the Congo | Skin penetration by cerceriae |
Schistosoma japonicum 70-100 x 55-64 µm Red arrow shows very small spine | (14) | China, Philippines, Sulawawesi | Skin penetration by cerceriae |
Schistosoma mekongi 50-80 x 40-65 µm Red arrow shows small lateral spine | (15) | Cambodia and Laos | Skin penetration by cerceriae |
Schistosoma haematobium 110-170 x 40-70 µm Note terminal spine | (16) | Africa, Middle East | Skin penetration by cerceriae |
Paragonimus westermani 80-120 x 45-70 µm Egg has operculum at one end and a barely perceptible knob at one end | (17) | Southeast Asia and Japan | Consuming undercooked crustaceans containing metacercariae |
12. DPDx. "Schistosomiasis - Figure C: Egg of S. mansoni in an unstained wet mount. Images courtesy of the Missouri State Public Health Laboratory." CDC.gov, 14 Aug 2019, https://www.cdc.gov/dpdx/schistosomiasis/index.html
13. DPDx. "Schistosomiasis - Figure B: Egg ofS. intercalatumin a wet mount." CDC.gov, 14 Aug 2019, https://www.cdc.gov/dpdx/schistosomiasis/index.html
14. DPDx. "Schistosomiasis - Figure A: Egg ofS. japonicumin an unstained wet mount. Note the small, inconspicuous spines (red arrows)." CDC.gov, 14 Aug 2019, https://www.cdc.gov/dpdx/schistosomiasis/index.html
15. DPDx. "Schistosomiasis - Figure A: Egg ofS. mekongi. Note the inconspicuous spine (red arrow)." CDC.gov, 14 Aug 2019, https://www.cdc.gov/dpdx/schistosomiasis/index.html
16. DPDx. "Schistosomiasis - Figure C: Egg ofS. haematobiumin a wet mount of a urine concentrate." CDC.gov, 14 Aug 2019, https://www.cdc.gov/dpdx/schistosomiasis/index.html
17. DPDx. "Paragonimiasis - Figure A: Egg ofP. westermaniin an unstained wet mount." CDC.gov, 2 Nov 2020, https://www.cdc.gov/dpdx/paragonimiasis/index.html