Pathogenesis (disease development)
Pathogenesis depends on the type of pathogen: usually, the pathogen is transmitted as follows: see below.
Etiology (causes)
Cestodes (tapeworms)
Cyclophyllidae
- Raw beef, pork
Echinococcus [Echinococcosis]
- Oral ingestion of eggs from dog/fox/cat feces: ingestion of contaminated food (e.g., wild berries, etc.).
Hymenoleptidae
- Oral intake of eggs directly
- Oral ingestion of larvae in infections via cereals, cornflakes, etc.
Pseudophyllidae
- Insufficiently cooked freshwater fish.
Nematodes (threadworms)
Ancylostomatidae (hookworms
- Percutaneous (through the skin) ingestion of larvae (in soil).
- Oral (if applicable) through contaminated food
Anisakis
- Raw/insufficiently salted or smoked fish (e.g., sushi or sashimi dishes; matje herring).
Angiostrongylidae
- Raw/undercooked snails, crabs or shrimp.
- Water or vegetables containing larvae
Ascarididae (roundworms)
- Fecal-oral transmission, classically via fertilized vegetables / lettuce (egg-containing soil).
Enterobius [oxyuriasis; pinworms/ pinworm]
- Human-to-human transmission; fecal-oral (ages 4-11; uncontrolled anus–finger–mouth contact, nail-biting (onychophagy/perionychophagy)), low hand hygiene compliance, and unsupervised personal hygiene).
- Transmission via commodities, toys, etc. possible.
- Spread mostly through close social contacts in kindergarten or elementary school
- Egg shell is softened in the stomach of the host organism, the pinworm larva subsequently hatches in the small intestine; circa 2 to 6 weeks pass from ingestion of infectious eggs to oviposition by adult female pinworms; oviposition occurs mainly at night in the anal region.
Filiariidae (nematode)
- Transmission by blood-sucking arthropods.
Rhabditidae
- Percutaneous (through the skin) uptake of larvae.
Spiruridae
- Ingestion of infected small crustaceans in drinking water.
Toxocara canis/-cati
- Transmission through dog/cat feces
Trichinella (trichinosis) [trichinellosis].
- Raw/insufficiently heated meat, usually pork.
Trichuridae (whipworms).
- Fecal-oral
Trematodes (sucking worms)
Intestinal fluke
- Transmission via aquatic plants such as water nut, cress, consumed raw or insufficiently cooked
- Raw / insufficiently cooked fish
Liver fluke
- Raw/insufficiently cooked fish
- Ants (e.g., in lettuce)
- Consumption of contaminated aquatic plants such as watercress.
Lung fluke
- Ingestion of raw or undercooked freshwater crustaceans (raw crab meat) and consumption of animals that eat crustaceans (e.g., wild boar)
Schistosoma [schistosomiasis; bilharzia]
