Tuesday, February 13, 2007

House and the Fish Tapeworm



Anybody watch Dr. House pull that nice long cestode out of the girls abdomen last night? As soon as I heard them mention vitamin B12 I thought of diphyllobothriasis. It also seems that they really like parasitic diseases on that show. Diphyllobothriasis is a disease that is caused by infection with the fish tapeworm Diphyllobothrium latum and you get it by eating poorly cooked fish. These tapeworms live in the small intestine and get to be up to 10 meters long.



The eggs of this cestode are easy to identify. They have a "hatch" or operculum at the top and a knob at the bottom of the egg (not easy to see in this picture).



The proglottids (segments) have a characteristically shaped uterus and the segments are wider than they are long.

The most important pathological effect of diphyllobothriasis is anemia caused by the competitive uptake of vitamin B12 by the worm. D. latum absorbs 80-100% of radioactive B12 added to an infected persons diet.

The plerocercoid larvae in fish are killed by freezing, even if frozen for only 15 min.

3 comments:

B-Wizz said...

I was in the other room and only got to hear the wife's reaction. Yes they do seem to like their parasites on that show.

Don and Sher said...

Eating lunch today and reading your post at the same time was probably not a good idea

Unknown said...

Suddenly feeling converted to frozen fish.

Regards - Shinga