Blood flukes-
• Schistosoma
Lung flukes-
• Paragonimus westermani
Liver flukes- [UPSC CMS 2024]
• Opisthorchis
• Clonorchis
• Fasciola hepatica and gigantica
Intestinal flukes-
• Fasciolopsis buski
Trematodes | Primary | 1st intermediate | 2nd intermediate |
Schistosoma | Man | Snail | – |
Paragonimus | Man | Snail | Crab / Cray fish |
Opisthorchis | Man | Snail | Fish |
Clonorchis | Man | Snail | Fish |
Fasciola hepatica | Man | Snail | Fresh aquatic plant (Water chestnut plant) |
Fasciolopsis buski | Man | Snail | Fresh aquatic plant (Water chesnut plant) |
Halzoun syndrome-
Caused by the migration of Fasciola hepatica larvae from the digestive tract to the throat.
Symptoms:
• Severe sore throat
• Difficulty swallowing
• Swelling of the throat or even the uvula
• Some cases can cause laryngitis and asphyxia (suffocation) if not treated.
All Trematodes | Schistosoma (Mnemonic: SSSSS) | |
Infective form | Metacercaria larva | S – Cercaria larva |
Mode of infection | Ingestion | S – Skin penetration |
Eggs | Operculated egg | S – Spinous egg |
Hermaphrodites | All | S – Seprate sex (Male & Female) |
DOC | Praziaquantel Exception: F. Hepatica- Triclabendazole | Praziaquantel |
Stages | MCRCM | MC_R_M |
M – Miracidia
C – Cyst
R – Redia
C – Cercaria
M – Metacercaria
Schistosoma haematobium | Schistosoma mansoni | Schistosoma japonicum |
Egg- Terminal spine | Egg- Lateral spine (Mnemonic: MaLa) | Egg- Rudimentary |
Location- Vesical & Pelvic venous plexus | Location- Inferior mesenteric vein (drain from | Location- Superior mesenteric vein (drain from |
– Hematuria – Bladder cancer (Squamous CC > Transitional | Swimmer’s itch | More severe Swimmer’s itch |
Normally, the urinary bladder is lined with transitional epithelium. Schistosoma causes metaplasia, where the transitional epithelium is replaced by squamous epithelium, which can lead to cancer.
Cancer | Cause by |
Cholangiocarcinoma (Bile duct cancer) | – Clonorchis sinensis – Opisthorchis viverrini |
Bladder carcinoma | Schistosoma haematobium |
Gastric cancer | Helicobacter pylori |
Cervical cancer | HPV (Human papilloma virus) |
Liver cancer | Afla toxin (Aspergillosis) |
