Cysticercosis

[BlackPuma]

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If ingested through uncooked pork (taneuim solium), the eggs can get deposited into the intestines and transmitted into the blood. Ok, my question is, and I can't find an answer anywhere, is how on earth do the cysts pass the blood brain barrier where they are deposited all over the brain as shown below!? does anyone know?

 

[rgizmo]

http://www.its.caltech.edu/~sciwrite/journal03/manzo.html


http://www.jimmunol.org/cgi/content/full/162/2/995

 

[Kalel]

Also, remember that even though the exact mechanism may not be understood, T solium enters the CNS when it is in it's larvae stage (when it is only ~40 microns in length), not in it's tape worm stage when it can reach upwards of 10 meters in the human intestine. WBC's which can be ~20 microns in length readily cross the BBB through extravasation, along with many other different types of cells and metastatic and infectious diseases, so I imagine that it just uses some similar mechanism as them. The parasite also secretes various prostaglandins and immunomodulators which probably help it cross as well.

 

[BlackPuma]

thanks guys...the links and info was definitely helpful!

 

[souljah1]

Here's something:

Pigs craze on fields contaminated with T. solium egg-infested feces. These eggs develop into larvae that then take shop in muscle, brain etc. as cysticercus, which is large fluid filled sac with the larvae in the middle. When we eat the pork with the cyticercus, it converts to the adult tape worm in our gut and latches on and winds up releasing eggs in our feces. Eating a cysticercus will not lead to cysticercus formation in us. Humans can only get cysticercus if they ingest eggs, i.e fecal contamination. Hope this helps.

 

[avendesora]

Originally posted by souljah1


Eating a cysticercus will not lead to cysticercus formation in us. Humans can only get cysticercus if they ingest eggs, i.e fecal contamination.

Yah -- this is an important distinction that most of us in the white-bread US lose in the details because we hardly ever see this disorder. When you eat infected meat, you get tapeworms in your gut. To get cysticercosis (larvae in your tissues) you eat feces with eggs in it. It's a two-stage organism.

We just had a case of neurocysticercosis and even my residents were a little foggy on this. Our pharmacy had to get albendazole from another city because they don't stock it -- one of my FMG residents said it's practically OTC where he's from.

 

[BlackPuma]

Originally posted by avendesora
Yah -- this is an important distinction that most of us in the white-bread US lose in the details because we hardly ever see this disorder. When you eat infected meat, you get tapeworms in your gut. To get cysticercosis (larvae in your tissues) you eat feces with eggs in it. It's a two-stage organism.

We just had a case of neurocysticercosis and even my residents were a little foggy on this. Our pharmacy had to get albendazole from another city because they don't stock it -- one of my FMG residents said it's practically OTC where he's from.

hmm, yes that is very true..but you don't have to necessarily eat the feces..if the pork is uncooked or infested with eggs, then you can get neurocysticercosis. Where I'm at, it is quite prevelant in the asian community especially with the vietnamese population...but I'm pretty sure it affects white people especially in the midwest and the south, no?

 

[Kalel]

Originally posted by WatchaMaCallit
hmm, yes that is very true..but you don't have to necessarily eat the feces..if the pork is uncooked or infested with eggs, then you can get neurocysticercosis. Where I'm at, it is quite prevelant in the asian community especially with the vietnamese population...but I'm pretty sure it affects white people especially in the midwest and the south, no?

Based on my readings, it sounds like if you eat uncontaminated raw pork, you will only get the cysts which will become the tape worms. However, from there the tapeworms can have eggs which can then be acquired through fecal oral contamination or reverse intestinal peristalisis (in theory), causing the neurocysticerosis. The other way is that pigs actually secrete the eggs too, which can then either be contaminated into the ground or into the meat itself I suppose. Cysticerosis is not endemic in the US, it's more prevalent in the Latin America, and portions of Asia, Asia and Europe. Most people who have the disease in our country are recent immigrants from those areas.

 

[souljah1]

Originally posted by WatchaMaCallit
hmm, yes that is very true..but you don't have to necessarily eat the feces..if the pork is uncooked or infested with eggs, then you can get neurocysticercosis. Where I'm at, it is quite prevelant in the asian community especially with the vietnamese population...but I'm pretty sure it affects white people especially in the midwest and the south, no?

the only way undercooked pork could be infested with eggs is if you are eating undercooked pork that is contaminated with feces.

 

[avendesora]

Here in the Mid-West it's seen in the migrant worker (Mexican/S.American) populations. It's not that the bug discriminates, just that the lower you sit on the social ladder, the more likely you are to suffer fecal-oral contamination. Or, if you are in a less developed country, there is higher potential for widespread contamination of the water supply, etc.