Presentation on theme: "Nematodes, Cestodes, Trematodes Slackers Facts by Mike Ori."— Presentation transcript:
Nematodes, Cestodes, Trematodes Slackers Facts by Mike Ori
Disclaimer The information represents my understanding only so errors and omissions are probably rampant. It has not been vetted or reviewed by faculty. The source is our class notes. The document can mostly be used forward and backward. I tried to mark questionable stuff with (?). If you want it to look pretty, steal some crayons and go to town. Finally… If you’re a gunner, buck up and do your own work.
1.Ingestion of embryonated eggs from contaminated dirt. 2.Larva hatch in small intestine 3.Adults mature in colon where they burrow into the surface 4.Eggs are passed in the feces 5.Egg embryonate in the soil over 2-4 weeks
What is the lifecycle for Ascaris lumbricoides?
1.Ingestion of embryonated eggs which hatch in intestines 2.Larva migrate to alveoli 3.L3 larva break through into the alveolar spaces 4.Larva migrate up trachea and are swallowed 5.Adults mature in small intestines 6.Eggs pass in feces 7.Embryonate in soil for 2-4 weeks
1.Eggs hatch in the soil and larvate 2.L3 larva directly penetrate the skin 3.Larva migrate to the lungs and pass through to the alveolar space 4.They are regurgitated and swallowed 5.Adults mature in the small intestines 6.Eggs pass in the feces
How dow Necator and Ancylostoma vary in their paths of infection?
Ancylostoma infection can also occur by direct ingestion of eggs in a manner akin to Ascaris. Wakana’s disease relates to ancylostoma infection by ingestion
1.L3 larva penetrate skin 2.Larva migrate to lungs and break out of alveoli 3.Larva migrate up trachea and are swallowed 4.Adults mature in the small intestines 5.Eggs ebryonate and hatch in the host 6.L2 larva pass in feces 7.L3 larva reinfect host
How does Strongyloides infection differ from that of other intestinal worms?
Strongyloides eggs hatch within the host resulting in the potential for autoinfection.
1.Eggs hatch in fresh water to form miracidia 2.Miracidia pentrate snails and mature to cercariae 3.Cercariae leave snail and penetrate host. 4.Migrate to lungs and liver and mature to adults 5.Adults mate and migrate to venous plexus of mesentery or urinary tract. 6.Eggs are deposited into epithelium where they burrow through to the epithelium to pass
What is the origin of granulomatous disease in schistosomiasis
Eggs float to the liver instead of passing into the epithelium. In the liver they elicit a strong immune response that results in granuloma formation.
What are the time course of the diseases caused by schistosomiasis
Swimmers itch lasting a 2 days Katayama fever beginning 2-3 weeks after exposure Chronic schistosomiasis beginning 2+ years
1. Ingested eggs hatch in cattle 2. Larva hatch in small intestines 3. Larva penetrate intestinal epithelium 4. Larva migrate to the skeletal muscle to encyst and develop to cystecerci 5. Encysted meat is improperly cooked and ingested. 6. Unencyst and develop into adults 7. Proglottids containing eggs break up and eggs pass in feces
Describe the clinical disease caused by the adult tapeworm
Usually only one worm present so there is no clinical disease. PT may notice proglottids in stool.