# What's the worse a parasite can do? **URL:** \ **Category:** Factual Questions\ **Created:** [September 22, 2006, 5:06pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738 "2006-09-22T17:06:31Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![JustDroppingBy](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@JustDroppingBy](https://boards.straightdope.com/u/JustDroppingBy)\ **Post date:** [September 22, 2006, 5:06pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/1 "2006-09-22T17:06:31Z")
Hi, I’m wondering what’s the worst lice can do to a person in the rare chance that he manages to endure the itch and let the lice roam free and reproduce on his head? and What’s the worse a parasite can do? and is there a record of best survivor of parasitic infestation for the longest duration without treatment or for the worst infestation and still survive? How much at worse can a parasite change a living being especially a human? Are there parasitic infestations that have become so immune to treatment that they become similar to herpes viruses only worse? Are there parasites who kill their hosts? ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [September 22, 2006, 5:18pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/2 "2006-09-22T17:18:36Z")
Parasites certainly can kill their hosts. A good parasite _won’t_ of course, but it’s not like its learned or directed behavior. Parasites that kill off their hosts die when their hosts die, and that’s pretty traumatic for both. But it happens, especially (I imagine) when parasites get introduced to new hosts or ranges. I don’t have any cites, but parasites certainly weaken the host, and a host that’s weakened is more likely yo be done in by disease, old age, or adverse circumstances. ---
**Author:** ![FormerMarineGuy](https://avatars.discourse-cdn.com/v4/letter/f/65b543/32.png) [@FormerMarineGuy](https://boards.straightdope.com/u/FormerMarineGuy)\ **Post date:** [September 22, 2006, 5:21pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/3 "2006-09-22T17:21:58Z")
[This](http://www.stanford.edu/~jansari/leish.JPG) **WARNING-GRAPHIC PICTURES** No, really, I think it depends on the type of parasite you are talking about. We all have parasites in our bodies, and I don’t think we could function normally without them. ---
**Author:** ![Mouse\_Maven](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@Mouse\_Maven](https://boards.straightdope.com/u/Mouse_Maven)\ **Post date:** [September 22, 2006, 5:27pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/4 "2006-09-22T17:27:06Z")
[QUOTE=JustDroppingBy] Hi, I’m wondering what’s the worst lice can do to a person in the rare chance that he manages to endure the itch and let the lice roam free and reproduce on his head? [/QUOTE] I don’t know anything about lice. (Had it a couple of times. If you can cope with the itching, you’re stronger than me.) [QUOTE=JustDroppingBy] What’s the worse a parasite can do? and is there a record of best survivor of parasitic infestation for the longest duration without treatment or for the worst infestation and still survive? How much at worse can a parasite change a living being especially a human? Are there parasitic infestations that have become so immune to treatment that they become similar to herpes viruses only worse? Are there parasites who kill their hosts? [/QUOTE] What do you define as a “_parasite_”? Viruses are parasites because they need living cells to reproduce. Some very nasty diseases are caused by them. Then there multicellular parasites. Tapeworms, roundworms, flukes, etc. All of them can make you’re life really, really miserable. Tapeworms are infamous for making people lose weight. They live in the intestines and absorb nutrients. I have a parasitology text with a picture of a tapeworm that was partially expelled thru a patient’s rectum. The pyshcological horror of that has to be significant There are strains of the organism that causes malaria that have become tolerent to the drugs used to treat the disease. (Mix this with the mosquitoes that carry the disease becoming immune to pesticides and you have a hell of a storm brewing.) I’m at work right now, so I can’t give you all the grizzly details ☹ . if you really want to know, [Parasite Rex](http://www.alibris.com/search/search.cfm) is a great book on the topic. [For a quick resource](http://www.neatorama.com/2006/08/21/six-horrifying-parasites/) ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [September 22, 2006, 5:32pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/5 "2006-09-22T17:32:20Z")
Not to humans, but there’s a kind of wasp, I believe, that attacks a cockroach, controls its mind and _drives it around like a car_, and then lays its eggs in it. When the eggs hatch, of course, the poor roach dies. A two second Google doesn’t give me the name of the thing, but it’s out there. ---
**Author:** ![Mouse\_Maven](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@Mouse\_Maven](https://boards.straightdope.com/u/Mouse_Maven)\ **Post date:** [September 22, 2006, 5:32pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/6 "2006-09-22T17:32:26Z")
[QUOTE=CalMeacham] Parasites certainly can kill their hosts. A good parasite _won’t_ of course, but it’s not like its learned or directed behavior. Parasites that kill off their hosts die when their hosts die, and that’s pretty traumatic for both. But it happens, especially (I imagine) when parasites get introduced to new hosts or ranges. I don’t have any cites, but parasites certainly weaken the host, and a host that’s weakened is more likely yo be done in by disease, old age, or adverse circumstances. [/QUOTE] I respectfully disagree with you. There are several species of parasites that count on their host dying and being eaten as part of their life cycle. The [beef tapeworm](http://www.scientific-art.com/portfolio%20medicine%20pages/tapeworm.htm) for example. ---
**Author:** ![Pazu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pazu/32/15522_2.png) [@Pazu](https://boards.straightdope.com/u/Pazu)\ **Post date:** [September 22, 2006, 5:36pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/7 "2006-09-22T17:36:41Z")
[QUOTE=JustDroppingBy] Hi, I’m wondering what’s the worst lice can do to a person in the rare chance that he manages to endure the itch and let the lice roam free and reproduce on his head? [/quote] Theoretically, head lice could be vectors for several classically louse-borne diseases such as typhus and other rickettsial infections, but I think the jury’s out on whether that actually happens. > [@](#): > > What’s the worse a parasite can do? and is there a record of best survivor of parasitic infestation for the longest duration without treatment or for the worst infestation and still survive? > > How much at worse can a parasite change a living being especially a human? Well, the worst a parasite can do is kill its host, presumably. Keeping it in the realm of human parasites, think of malaria and trypanosomiasis. On the flip side, you can probably survive carrying a fairly heavy load of intestinal helminths (roundworms, tapeworms) indefinitely, assuming you have access to enough food for everyone. There would probably be chronic impairments associated with a heavy parasite load–infestation by fish tapeworm (_Diphyllobothrium latum_) is a known cause of pernicious anemia due to competitive vitamin B12 absorption. How much can a parasite alter a host? In the case of invertebrates, quite extensively–the parasitic barnacle _Sacculina_ pretty much infiltrates the entire body of its host crab and controls it. In the case of humans, there’s some evidence to suggest that certain behavioral changes may be associated with chronic _Toxoplasma_ infection. > [@](#): > > Are there parasitic infestations that have become so immune to treatment that they become similar to herpes viruses only worse? Various species of _Plasmodium_ (malaria) have developed resistance to antimalarials. > [@](#): > > Are there parasites who kill their hosts? See above. Also, pick up a book called _Parasite Rex_ by Carl Zimmer. It’s a fascinating and under-studied field. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [September 22, 2006, 5:39pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/8 "2006-09-22T17:39:39Z")
[QUOTE=FormerMarineGuy] [This](http://www.stanford.edu/~jansari/leish.JPG) **WARNING-GRAPHIC PICTURES** [/quote] Gaah! I clicked on that JUST before you added the warning about the pic, **samclem**. :: shudder :: > [@FormerMarineGuy](#): > > No, really, I think it depends on the type of parasite you are talking about. We all have parasites in our bodies, and I don’t think we could function normally without them. If you need it to survive, it’s not a parasite, it’s a symbiont, isn’t it? Parasites are only destructive from the viewpoint of the host. ---
**Author:** ![Mouse\_Maven](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@Mouse\_Maven](https://boards.straightdope.com/u/Mouse_Maven)\ **Post date:** [September 22, 2006, 5:46pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/9 "2006-09-22T17:46:13Z")
[QUOTE=Sunspace] If you need it to survive, it’s not a parasite, it’s a symbiont, isn’t it? Parasites are only destructive from the viewpoint of the host. [/QUOTE] The definition of parasite is slippery. Currently, we think of them as gross internal worms, etc. I mentioned further up thread that a virus is a parasite. The board definition is an organism that lives off nutrients provided by a host organism. Parasites are everywhere! There are parasitic plants - misletoe. There are is a least one parasitic bony fish - the [Candiru](http://en.wikipedia.org/wiki/Candir%C3%83%C2%BA) I wanted to be a parasitologist. Can you tell? ---
**Author:** ![FormerMarineGuy](https://avatars.discourse-cdn.com/v4/letter/f/65b543/32.png) [@FormerMarineGuy](https://boards.straightdope.com/u/FormerMarineGuy)\ **Post date:** [September 22, 2006, 6:05pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/10 "2006-09-22T18:05:25Z")
[QUOTE=FormerMarineGuy] [This](http://www.stanford.edu/~jansari/leish.JPG) **WARNING-GRAPHIC PICTURES** No, really, I think it depends on the type of parasite you are talking about. We all have parasites in our bodies, and I don’t think we could function normally without them. [/QUOTE] Thanks **Samclem** , sorry about that! Still learning over here. ---
**Author:** ![JustDroppingBy](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@JustDroppingBy](https://boards.straightdope.com/u/JustDroppingBy)\ **Post date:** [September 22, 2006, 6:10pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/11 "2006-09-22T18:10:11Z")
Thanks for the links. It’s scarier than I thought it would be. Sorry if my question wasn’t phrased well. I don’t know about parasites other than the basic perception. I thought that viruses and parasites were different and that some viruses evolved to become parasitic while parasites are well… parasites by nature. This makes me wonder: Can a parasite infest another parasite? or by nature, parasites become immune or hard to target by other parasites? Also in a battle of hosts, are there evidence of which variations of parasites are supposed to be the dominant nutrition taker? Now I’m even more curious of parasite survivors. In particular, I’m curious if it’s possible for a person who has been infested by a candiru to survive without surgery seeing as the candiru quickly dies inside it’s host. ---
**Author:** ![Greenback](https://avatars.discourse-cdn.com/v4/letter/g/2bfe46/32.png) [@Greenback](https://boards.straightdope.com/u/Greenback)\ **Post date:** [September 22, 2006, 6:22pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/12 "2006-09-22T18:22:55Z")
[QUOTE=Zsofia] Not to humans, but there’s a kind of wasp, I believe, that attacks a cockroach, controls its mind and _drives it around like a car_, and then lays its eggs in it. When the eggs hatch, of course, the poor roach dies. A two second Google doesn’t give me the name of the thing, but it’s out there. [/QUOTE] WTF? I, for one, welcome our new mind controlling insect overlords. ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [September 22, 2006, 6:25pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/13 "2006-09-22T18:25:14Z")
I would think that untreated head lice would eventually lead to infection, from all those bites. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [September 22, 2006, 6:25pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/14 "2006-09-22T18:25:21Z")
Speaking personally, I’d say that the worst thing a parasite could do to **me** is eat my brain. [Nongraphic Picture #1](http://www.thamburaj.com/images/other%20infections/parasi1.jpg). [Nongraphic Picture #2](http://www.cdc.gov/ncidod/eid/vol3no3/evans.gif) ---
**Author:** ![JustDroppingBy](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@JustDroppingBy](https://boards.straightdope.com/u/JustDroppingBy)\ **Post date:** [September 22, 2006, 6:35pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/15 "2006-09-22T18:35:04Z")
Oh so brain eating parasites are actually real. I thought it was just a myth. What’s the estimated time before someone dies from having their brain get eaten? ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [September 22, 2006, 6:42pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/16 "2006-09-22T18:42:13Z")
The threat of Guinea Worms is quite real. ---
**Author:** ![FormerMarineGuy](https://avatars.discourse-cdn.com/v4/letter/f/65b543/32.png) [@FormerMarineGuy](https://boards.straightdope.com/u/FormerMarineGuy)\ **Post date:** [September 22, 2006, 6:52pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/17 "2006-09-22T18:52:04Z")
[QUOTE=JustDroppingBy] Oh so brain eating parasites are actually real. I thought it was just a myth. What’s the estimated time before someone dies from having their brain get eaten? [/QUOTE] Not sure, but here is some good information on it: [From pr.caltech.edu](http://pr.caltech.edu/periodicals/eands/articles/LXVI4/brainworms.html) ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [September 22, 2006, 6:52pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/18 "2006-09-22T18:52:47Z")
[QUOTE=JustDroppingBy] Oh so brain eating parasites are actually real. I thought it was just a myth. What’s the estimated time before someone dies from having their brain get eaten? [/QUOTE] I was being a bit facetious. They don’t actually ‘eat’ your brain, but the mere of thought of having anything other than “me” upstairs is quite enough, thanks. The pictures illustrate [neurocysticercocis](http://www.emedicine.com/ped/topic1573.htm), a pretty common disorder in some parts of the world. Believe it or not, it’s actually not (usually) too severe a disease. The link, above, is rather technical, but may be of interest. ---
**Author:** ![Phrontist](https://avatars.discourse-cdn.com/v4/letter/p/839c29/32.png) [@Phrontist](https://boards.straightdope.com/u/Phrontist)\ **Post date:** [September 22, 2006, 7:29pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/19 "2006-09-22T19:29:59Z")
[QUOTE=Zsofia] Not to humans, but there’s a kind of wasp, I believe, that attacks a cockroach, controls its mind and _drives it around like a car_, and then lays its eggs in it. When the eggs hatch, of course, the poor roach dies. A two second Google doesn’t give me the name of the thing, but it’s out there. [/QUOTE] > **[Emerald cockroach wasp](https://en.wikipedia.org/wiki/Emerald_Cockroach_Wasp)** > > The emerald cockroach wasp or jewel wasp (Ampulex compressa) is a solitary wasp of the family Ampulicidae. It is known for its unusual reproductive behavior, which involves leading a cockroach into a dug burrow and using it as a host for its larvae. It thus belongs to the entomophagous parasites. The wasp is mostly found in the tropical regions of Africa, South Asia, Southeast Asia, and the Pacific islands. The flying wasps are more abundant in the warm seasons of the year. A. compressa was int... ---
**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\ **Post date:** [September 22, 2006, 7:31pm UTC](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738/20 "2006-09-22T19:31:57Z")
File for a divorce, then take the house, the car and the children and then demand support on a free meal ticket for life. [Next page](https://boards.straightdope.com/t/whats-the-worse-a-parasite-can-do/373738.md?page=2)