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16 Cards in this Set
- Front
- Back
Filariae
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- Blood and tissue namatodes
- long, slender roundworms - may live 10-15 years and they release microfilariae which live in the blood or skin and are the infective stage for the insect intermediate host |
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Wuchereria bancrofti Basic Info
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- elephantiasis or Lymphatic filariasis - gross swelling of limbs - lymphatic ducts/nodes blocked and scarred
- develops after years of chronic and repeated infection -in africa, asia, latin america, caribbean |
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Wuchereria bancrofti Infection
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- Adult worms live in lymphatics and microfilariae in blood are ingested by the mosquito
- mature in mosquito and microfilariae can be transmitted - do nocturnal periodicity, where they circulate at night, when vector is active, and remain in lung caps in day - south pacific has "day-biters" - Travelers may have rapid progression and tropical pulmonary eosinophilia w/ fever, eosinophilia, respiratory symptoms but no microfilaremia - prevent w/ mosquito abatement and early treatment |
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Wuchereria bancrofti Disease
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- chronic, cumulative disease w/ few symptoms at first
- damage from inflam which varies among individuals - microfilariae can be detected in blood at night when asymptomatic - After 8 to 16 months, painful lymphangitis, esp in groin w/ recurring fever - Also eosinophilia - can lead to swelling of limbs or scrotum(hydrocoele), complete blockage - if elephantiasis no circulating microfilariae |
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Onchocerca volvulus Basic Info
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- tissue nematode, river blindness
- Adults live in nodules under the skin, make microfilariae that migrate in skin - micros transmitted by bite of black fly that cant fly far from fast-flowing water - tropical Africa,Central/south America |
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Onchocerca volvulus Infection
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- Micro migrating in skin ->
intense itching -> 2o inf - months to years, then skin atrophy and degeneration (pachydermia) - may get eye -> blindness |
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Onchocerca volvulus Diagnosis and Treatment
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- taking superficial skin snips,
place in water, and examine for motile micros - If nodules, biopsy or nodulectomy - control w/ Ivermectin |
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Taenia saginata
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- Cestodes or tapeworms
- adults live in human GI - eggs from feces may be ingested by cow, hatch in their intestine and migrate to muscle to form cysticerci (larval tapeworm in fluid sac - ingest undercooked meat and cysticercus elongates into adult w/ segments - Eggs form in post proglottids, detach, then passed w/ feces |
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Taenia solium
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- Cestodes or tapeworms
- adults live in human GI - eggs from feces may be ingested by pig, hatch in their intestine and migrate to muscle to form cysticerci (larval tapeworm in fluid sac - ingest undercooked meat and cysticercus elongates into adult w/ segments - Eggs form in post proglottids, detach, then passed w/ feces - can cause cysticercosis in humans - in muscles its ok, in brain heart lungs eye its not - human to human transmission also possible(fecal-oral) |
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Tapeworms
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- rarly cause symptoms
- no gut or digestive enzymes - absorb nutrients from host - may be noticed if a proglottid is passed in the feces - Diagnosis w/ feces for eggs and if proglottid, inject uterus with India ink to show the uterine branches (fewer in solium) - The scolex (“head”) of solium has armed rostellum (circle of hooks) in addition to the four suckers |
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Cysticercosis
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- severe tapeworm disease
- can cause seizures, even w/out an adult tapeworm - symptoms may appear long after exposure to the eggs - diagnose w/ Abs in the blood or CSF - cysticerci are seldom found, but in muscle there are calcium deposits(seen in radiograph) - pork tapeworm most common in Mexico, Chile, E Europe, S Africa, China, and Indonesia - Control by sanitary sewage, thorough cooking & inspection |
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trematodes
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- flukes - flatworms
- live in GI, bile ducts, lungs, BVs - complicated life cycles - asexual in snail and sexual in humans |
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Schistosomes Basic info
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- bloodfluke (trematodes)
- mansoni cuases intestinal infection - in Africa, South America, and Caribbean - japonicum causes intestinal infection - in Far East - hematobium causes urinary infections in Africa |
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Schistosomes Infection
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- live 10 yrs, male and female permanently coupled in veins of the GI or bladder
- pass lots of spined eggs -> tissue damage and symptoms - eggs get into the feces or urine and hatch to release a motile miracidium when released - must infect correct snail ->(asexual) makes free-swimming cercariae than can penetrate human skin causin swimmer’s itch - developing larvae migrate via lymphatics and lungs to the venules and grow to adults |
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Schistosomes Disease
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- mainly in rural areas where sewage enters water (snail can meet poop)
- Light infections may be asymptomatic after swimmer’s itch - sometimes fever - heavy/repeat infection-lots of eggs-> granulomatous rxn and fibrosis - w/ mansoni, periportal fibrosis in the liver -> portal hypertension - may have distension of esophagus veins - w/ hematobium, obstruction of the ureters and 2o UTI, granulomas in the bladder, or bladder carcinoma. |
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Schistosomes Diagnosis and Treatment
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- detecting eggs in the feces or urine
- If found early and the patient, the chronic stages are avoided - Control via sanitation, look out for snails in waterways, treat infected persons |