Well, I usually specialize in plotting the demise of Reed Richards, I can dust off one of my old medical textbooks to answer your question.
It seems that they are concerned with testing for Amebiasis, which is caused by the protozoon Entamoeba Histolytica. It's the third leading cause of death from parasites after Malaria and schistosomiasis. I believe most references site 100,000 deaths per 50 million infections every year. Most of these cases occur in countries with poor sanitation but it could theoretically happen anywhere fecal-oral transmission is likely (deviant sexual practices). Here is a link
that has a nice description of the disease with some pictures.
I should warn the more sensitive readers out there that some may find this post a bit, well, gross. But nobody ever said the truth was pretty.
Just to try and put a stop to any unseemly rumors, fecal-oral transmission is far more likely to occur than most people would care to know. Someone like Giambi, Kevin Brown, their wives, or, truth be told, most anyone posting here, are far more likely to contract something transmitted this way by eating out in a restaurant than by engaging in any 'deviant sexual practices'. Let's just say that proper hand-washing etiquette is something that many restaurant employees could learn to do better.
(Not to disparage restaurant employees, of which I used to be one. Honestly though, did you lather up effectively
the last time you took a leak or scratched your a**? Did you turn off the water using a towel, NOT your hands?
Public health measures such as hand-washing, clean water and refrigeration have saved far more lives than any other medical technology. Think about that the next time someone proposes to cut the budget of food or restaurant inspectors. Or the next time your roommate offers to cook dinner.
And while we're talking about parasites, may as well add to the gross-out factor. When my fiancee was in med school, she stopped eating sushi for about two years after studying parasitology. Her friends who specialized in the field will hardly touch fish. This might explain why Giambi et al think Japan was the source of their infection.
"The game has a cleanness. If you do a good job, the numbers say so. You don't have to ask anyone or play politics. You don't have to wait for the reviews." - Sandy Koufax