1. The gentle parasite and not always our foe.
Recently it has been found that certain parasites confer resistance upon the host. It is hypothesized that the immune system response fights off unrelated and much worse conditions than the infestation. Testing has been going on using worm infestations to reduce symptoms of asthma, allergies and ulcerative colitis. We are seething masses of symbiotes but its one thing knowing it and another having it shoved in your face.
That image from Alien of the phallic eruption from the middle of the chest is what we imagine when we think of these things. Or Robert Heinlein’s The Body Snatchers where we become unwilling passengers in our own vehicles. The following examples are not happy family stories but they are intriguing. Like most parasites they infect but do not kill. But in some cases, its not that comforting.
We have that visceral response to unwanted creatures even if they don’t hurt us. The unfortunate dust mite (not that its losing sleep over this) has been blamed for most of our pillow weight. There was a little witch hunt on these previously unregistered residents fueling new improved vacuum cleaners because in the old ones they just flew through the bags because they were so small. They lived on dead human skin. Sounds useful to me. Anyway, they look like little chunky insectoid tanks and we have the technology to see them so see them we did and spread those pictures around like bad gossip. My own theory at the time was that these might be what holds everything together and to really clean house might leave nothing standing.
2. From the classic New Guinea Tapeworms and Jewish Grandmothers. Read this years ago, so forgive me if I get a couple of things wrong.
Turns out that Jewish grandmothers in Wisconsin and Minnesota were coming down with tapeworms at a worrying rate. Apparently these were transported into the area by newly emigrating Norwegian fisherman infected back home, and having the predilection, the tradition, of defecating over the side of the boat.
Fish got into that and in turn were infected. The fish were caught, “cleaned” and sold. Jewish grandmothers made gefilte fish, a dish which features fish “just done”, and the way to do it well is to taste it for doneness.
Before done, is before the parasites are killed and presto, infected grandmothers.
3. This is the one that has really filled me with awe. The lancet fluke.
It is not unique but it is highly unusual. In this case, cows are infected with the eggs of this parasite. They defecate and this is eaten by snails. The snails eject the mutating creatures, now worms, in slime balls. These slime balls are tasty to ants. When the ants eat the slime, some of the flukes form cysts in the stomach and others invade the ants head and cause the ant, at the end of the day when the temperature drops, to climb a stalk of grass and wait there quietly. If by the warming of next morning nothing has happened they go back to being normal ants, until nightfall, when they once again climb the grass. Some of them will be eaten by grazing cows and so the circle is formed.
It astounds me in two ways. First of all, the brain control. Zombie ants at night. And the fact that it switches on and off controlled by the temperature. Second, how did this very complicated sequence come about?
4. The grossest for last. I wanted to end on something more transcendent like the last wonder of nature but thought some might not make it past the image that follows this. Keep in mind that the fish you see if being held in the palm of the hand so the tenant is quite small. (Also keep in mind that I could’ve discussed elephantiasis and would then have to have posted some really disturbing pictures; you can find them quite easily).
Ran across this one in the book Parasite Rex by Carl Zimmer. Fascinating book and this particular one had little explanation but a horrible little picture and I have found even a worse one.
This bug invades the mouth of the fish, eats its tongue and then fixes itself to the base, and then feeds itself with the morsels that go flying by when the fish feeds. This makes me so glad I am not a fish. My nightmare would be that there was a human version of this.