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Say Hello to Helminths !. Helminths. Multicellular invertebrate worms; typically macroscopic as adults; may be parasitic/infectious or neutral heterotrophs found in soil a nd water of virtually all environments Contaminate food, water, air, feces, pets, wild animals, and various surfaces
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Helminths • Multicellular invertebrate worms; typically macroscopic as adults; may be parasitic/infectious or neutral heterotrophs found in soil and water of virtually all environments • Contaminate food, water, air, feces, pets, wild animals, and various surfaces • Prevention: • Frequent hand washing • Frequent cleaning of bathrooms and kitchens • Thorough cooking of beef, pork, sausage, and game meat
Common helminths • Roundworms aka Nematodes • Parasitic nematodes - hatch/live in intestines • Symptoms • fatigue • Weight loss • Irritability • Poor appetite • Abdominal pain • Diarrhea • Untreated • Anemia • malnutrition • - about 1 million species
Common helminths in meat • Trichina spiralis (trichinosis) • Ingested via undercooked pork, sausage, or game meat – especially bear meat (responsible for 1/3 of the 100,000 cases of trichinosis in the US per year) • Spread throughout bloodstream and lymphatic system • Symptoms of infection • First stage – Vomiting, diarrhea, muscle cramps, fever, sweating • Untreated – Second stage • Penetration of muscles, heart, and brain – intense muscle and joint pain, shortness of breath • Symptoms usually subside, but there is no cure for the infection once the larvae are encysted in muscles and may lead to death
Common helminths • Tapeworms (cestodes) • Ingested via undercooked beef or sometimes raw pork • Live in intestines – up to 25 M long – absorbs nutrients through its body • Symptoms • Usually absent • May include abdominal pain, fatigue, weight loss, diarrhea
Pinworms • AKA: seatworms or threadworms • Most common worm infection in the US • Ingested in contaminated food or drink, or by hand – self inoculation is common • Embryonated eggs are on clothes, bedding, bathroom fixtures or dust • 42 million people infected globally • Mostly children aged 5-14 years • Commonly institutional settings such as child care facilities, hospitals, or family members • Only helminthic infection with approved OTC treatment • Symptoms – itching, sleep disruption, sometimes nausea, abdominal pain and diarrhea
Pinworm lifecycle 1. Adult males and females inhabit ileocecum. 2. Female migrates out of anus and deposits eggs in perianal region then dies. 3. Eggs hatch within a few hours and larvae return to large intestine via anus (retroinfection), crawl into genitourinary tract, or eggs are reingested by the host.