A Can of Worms

August 8, 2017 6:08 PM

Do the majority of people in developed countries carry internal parasites? If so, where do they acquire them from? And if they do, are they all 100 percent bad for human health? Sources, other than Google or New Age health books, would be highly appreciated. YANM expert, I am aware. Thanks.

Google yields a wide variety of (conflicting) data on this topic. Some of insists that of course we do (and goes on to promote cleanses that I doubt are truly effective.) Some of it says no, most people don't unless they do things like walk barefoot into an outhouse or visit a country where internal parasites are common.

On a slight tangent, a few years back I heard an episode on radiolab (excerpts here ) discussing how worms might help the immune system. I know, gross, but as someone with easily triggered and severe respiratory allergies, the idea intrigued me. Anyway, just now I got into an argument with a friend about it. She got into google, read about worms and now, utterly convinced, wants to swallow a cleanse product to kill the parasites we "all" have. I have a feeling she will attempt to convince me to take it, and, while I'm 99 percent sure I won't, I am wondering what information and opinions the hivemind may yield and what sources I might consult that I am not thinking of. Thank you.

posted by Crystal Fox to Health & Fitness (10 answers total)

I used to have worms occasionally as a kid (rural, barefoot, etc). It's not the kind of thing you would live with if you had access to regular health care, and we did, in fact, get them regularly dealt with. You might want to read this article: Neglected Parasitic Infections in the United States: Needs and Opportunities which talks sensibly about some of this stuff. The article talks about "neglected" parasitic infections, i.e. those where people live with the parasite and maybe are not aware of it. While it does say that there are more people than you might think living with these parasites, it's definitely not something you'd characterize as a majority. The article, particularly this link, has specifics.
posted by jessamyn at 6:31 PM on August 8, 2017 [7 favorites]

Information from people who are medical doctors:

Dr. Jen Gunter has been taking on some of the parasite nonsense that's currently in wide circulation.

You might also be interested in this Sawbones podcast episode (tl;dr - cleanses are bullshit, and your kidneys and liver do that for you, assuming they're in proper working order).
posted by mandolin conspiracy at 6:46 PM on August 8, 2017 [3 favorites]

Parasites come in an incredible diversity of forms from all over the tree of life. Do not take any product that claims to kill "all parasites" or "all worms". You should research specific parasites if you have some symptom you are concerned about.
posted by dilaudid at 7:00 PM on August 8, 2017

I recommend the book Parasitic Diseases if you want to demystify some of what the word "parasite" conjures up. It's very comprehensive but also very readable.
posted by dilaudid at 7:08 PM on August 8, 2017 [2 favorites]

I found the Parasite Rex interesting and readable; I think it gets at exactly the questions you are wondering about.
posted by Dip Flash at 7:50 PM on August 8, 2017

I'm a little annoyed at Radiolab for not producing a follow-up to that episode. There have been a few controlled studies one the hookworm treatment and none of them has shown a significant effect. I realize it doesn't make a great story, I think that responsible journalism requires it.
posted by All Out of Lulz at 8:19 PM on August 8, 2017 [1 favorite]

I think it's worth noting that a lowball estimate based on the CDC info linked by jessamyn gives 64 million/320 million = 20% of people in the USA currently infected by just one of three parasites (Trypanosoma cruzi, Toxoplasma gondii, Trichomoniasis). Surely if we start adding up all the other common parasites that commonly persist, and add in all the millions of people who will have transient parasites we'd get to higher percentages.

E.g. 30% of adults in the USA have been infected with Cryptosporidium at some point in their life. About 15-20k people get Giardia each year. Another 1k get Babesiosis. Then there's things that can spread via food, like the occasional outbreak of Cyclosporiasis. I'm literally just picking random names from the list of human parasites at the CDC, then checking for prevalence data in the USA. I could go on and on, but most individual parasites are not that prevalent (outside of the top 5).

So no, probably not "most" people in the USA, but easily 1/5 is a lower bound for persistent infection, and if as we add in all the hundreds of less common parasites, all the people fighting things off or being treated, I'd not be surprised if we start to approach 1/4 of people in the USA have some internal parasite on any given day.

(No, you don't need any "cleansing" product. You may well have Toxo but hey, so do 60 million other Americans, you'll be fine)
posted by SaltySalticid at 9:19 PM on August 8, 2017

You may well have Toxo but hey, so do 60 million other Americans, you'll be fine

...bearing in mind that of course that's what Toxo wants you to think.
posted by flabdablet at 9:33 PM on August 8, 2017 [4 favorites]

You might also be interested in Tapeworms, Lice, and Prions: A Compendium of Unpleasant Infections.
posted by hapaxes.legomenon at 10:01 PM on August 8, 2017 [1 favorite]

Response by poster: These are all great answers and are exactly the kind of information I asked for. Thank you all so much.
posted by Crystal Fox at 8:56 AM on August 9, 2017