1. Nematodes (Roundworms):
Nematodes are cylindrical worms that are typically found in the intestines or tissues of the host.
Common Nematode Infections:
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Ascaris lumbricoides (Giant roundworm):
- Disease: Ascariasis
- Transmission: Ingestion of eggs from contaminated food, water, or soil.
- Symptoms: Abdominal pain, coughing, or wheezing when larvae migrate through the lungs.
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Enterobius vermicularis (Pinworm):
- Disease: Enterobiasis
- Transmission: Fecal-oral route, often through contaminated bedding or surfaces.
- Symptoms: Itching around the anus, especially at night.
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Trichuris trichiura (Whipworm):
- Disease: Trichuriasis
- Transmission: Ingestion of eggs from contaminated food or water.
- Symptoms: Abdominal pain, diarrhea, and in severe cases, rectal prolapse.
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Strongyloides stercoralis (Threadworm):
- Disease: Strongyloidiasis
- Transmission: Skin contact with contaminated soil.
- Symptoms: Abdominal pain, itching, and in severe cases, systemic infection.
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Ancylostoma duodenale / Necator americanus (Hookworms):
- Disease: Hookworm infection
- Transmission: Skin penetration by larvae from contaminated soil.
- Symptoms: Abdominal pain, anemia, fatigue.
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Wuchereria bancrofti / Brugia malayi (Filariasis):
- Disease: Lymphatic filariasis (elephantiasis)
- Transmission: Mosquito bites that introduce larvae into the bloodstream.
- Symptoms: Swelling and thickening of skin, particularly in the limbs and genitals.
2. Trematodes (Flukes):
Trematodes are flat, leaf-shaped parasitic worms that can infect various organs in the body, including the liver, lungs, intestines, and blood vessels.
Common Trematode Infections:
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Schistosoma species (Blood flukes):
- Disease: Schistosomiasis
- Transmission: Contact with contaminated freshwater, where larvae penetrate the skin.
- Symptoms: Abdominal pain, blood in urine or stool, liver damage, and possible neurological complications.
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Fasciola hepatica (Liver fluke):
- Disease: Fascioliasis
- Transmission: Ingestion of contaminated water plants or undercooked aquatic animals.
- Symptoms: Fever, abdominal pain, jaundice, and liver inflammation.
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Clonorchis sinensis (Chinese liver fluke):
- Disease: Clonorchiasis
- Transmission: Ingestion of undercooked fish infected with larvae.
- Symptoms: Abdominal pain, jaundice, and increased risk of liver cancer.
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Paragonimus westermani (Lung fluke):
- Disease: Paragonimiasis
- Transmission: Eating undercooked freshwater crustaceans.
- Symptoms: Cough, chest pain, and in severe cases, hemoptysis (coughing up blood).
3. Cestodes (Tapeworms):
Cestodes are flat, segmented worms that can live in the intestines of their hosts, and they can grow to great lengths.
Common Cestode Infections:
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Taenia solium (Pork tapeworm):
- Disease: Taeniasis, cysticercosis
- Transmission: Ingestion of undercooked pork containing cysts, or ingestion of tapeworm eggs from contaminated food or water.
- Symptoms: Abdominal discomfort, weight loss, and in the case of cysticercosis, neurological symptoms if larvae invade tissues.
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Taenia saginata (Beef tapeworm):
- Disease: Taeniasis
- Transmission: Ingestion of undercooked beef containing cysts.
- Symptoms: Abdominal pain, nausea, and possible weight loss.
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Diphyllobothrium latum (Fish tapeworm):
- Disease: Diphyllobothriasis
- Transmission: Ingestion of undercooked freshwater fish.
- Symptoms: Abdominal discomfort, weight loss, and possibly B12 deficiency leading to anemia.
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Echinococcus is a cestode (tapeworm) from the Taeniidae family. It is a parasitic flatworm that causes echinococcosis (hydatid disease) in humans