Final Exam - Helminths Flashcards
Nemattode general characteristics
bisexual, cylindrical, inhabit intestinal sites, occasionally pass through intestinal mucosa or skin into lung and liver.
Enterobius vermicularis
(CNs+SSS+Notes)
Common names: pinworms or enterobiasis.
Nematode type
SSS: perianal itching, esp. at night, sometimes abdominal pain and anorexia.
Notes: Female worms lay eggs at night in the perianal area of the rectum
Ascaris lumbricoides
(CNs+SSS+Notes)
Common Names: Roundworms or ascariasis
Nematode type
SSS:
Light loads - asymptomatic
Heavy Loads - abdominal discomfort, diarrhea, malnutrition.
Rare - abdominal obstruction
Notes: May migrate to liver or lungs. One billion infections per year worldwide in tropical areas. Up to 30 cm long.
Trichuris trichuria
(CNs+SSS+Notes)
Common Names: Trichuriasis, whipworms
Nematode type
SSS: diarrhea, abdominal pain, anemia, and weight loss. If untreated, may lead to stunted growth and clubbing of fingers in children.
Notes: 600-800mil infected worldwide in tropics. Up to 4 cm long
Necator americanus
(CNs+SSS+Notes)
Common name: Hookworms
Nematode type
SSS: Enter skin via feet to cause ground itch, esp. in area where human feces used as fertilizer.
Intestinal infection - anorexia, diarrhea, weight loss, anemia.
Lung infections - pneumonitis, cough, dyspnea
Notes: Closely related to Ancylostoma duodenale. 9-13 mm long.
Ancylostoma duodenale
(CNs+SSS+Notes)
Common name: Hookworms
Nematode type
SSS: Enter skin via feet to cause ground itch, esp. in area where human feces used as fertilizer.
Intestinal infection - anorexia, diarrhea, weight loss, anemia.
Lung infections - pneumonitis, cough, dyspnea
Notes: Closely related to Necator americanus. 9-13 mm long.
Trichinella spiralis (or murelli)
(CNs+SSS+Mech+Notes)
Common names: Trichonellosis or trichinosis
Nematode type
SSS: Diarrhea, abdominal pain, nausea, muscle pain, periorbital edema, rash, CNS involvement.
Mechanism: Cysts containing larvae are ingested and attach to small intestine, where they mature and migrate to skeletal muscle via blood or lymphatic system.
Notes: Typically obtained by eating uncooked meat like pork and wild game (boar and bears)
Cestodes General Info
Also known as tapeworms
Anatomy: flat, elongated shape consisting of segments called proglottids. from 2 mm to 10 meters long. Anatomically have scolex (head), a neck, and a chain of segments. Cysts form in striated muscle. May cause seizures or other CNS symptoms.
Notes: Infections occur by eating uncooked beef, pork, or fish. Adult worms in intestine, larvae may locate to extracellular sites to form cysts. Rare in the USA
Taenia solium and asiatica
(CNs+Notes)
Common name: pork tapeworm
Notes: 3 meters in length
Taenia saginata
(CNs+Notes)
Common name: beef tapeworm
Notes: 10 meters in length
Diphyllobothrium latum
(CNs+Notes)
Common Names: fish or broad tapeworm
Notes: largest human tapeworm, up to 10 meters. 3000 proglottids and lay up to 1 mill eggs per day
Echinococcus granulosis
(CNs+SSS+Notes)
Common Name: Dog tapeworm
SSS: Hydatid cyst disease in liver, lung, heart, and brain.
Notes: contracted from sheep, dog, and wolf feces
Trematodes (flukes) general information
Contracted from free-swimming larvae given off from infected snails.
Penetrate through skin or by ingestion.
Adult flukes are leaf shaped flatworms
Rare in US, but common worldwide
Schistosoma diseases
(Flukes)
Schistosomal dermatitis
Acute schistosomiasis
Chronic schistosomiasis
Schistosomal dermatitis
(Flukes)
Itchy rash near penetration site of skin “swimmers itch”
