Just FTR, I’ve been trying to get Cecil to do a column on Guinea Worms for over a year. I love crap like this. Maybe we just haven’t received the right question yet…
OK, I’ll throw in this little bon mot that was in my college undergrad Parasitology textbook:
Parasitologist - someone who sits on one stool gazing at another (through a microsope). Hahahaha!
It’s not easy finding a parasite egg inside all the detritus you can see in a prepared slide of feces. Of course, we had the joy of bringing in a sample of our own to prepare in class. One lady who had gotten sick in Mexico was asked to bring enough for all the other students.
Aiiiiiiiiiieeeeeeeeeeee!!!
Please forgive me if I’m repeating myself.
Yeah, Coll. Not in that lecture, though. We call it schistosomiasis here, and we mainly learn about it with its relationship with the Aswan Dam, its snail host, and its chronic infection leading to squamous cell bladder cancer. Not a pretty disease by any stretch of the imagination, but at least it doesn’t involve squirmy things (except its snail host). In many ways, though, it is far worse than the worm diseases, as it predisposes to cancer and liver failure…
And DSYoungEsq, you know the obvious answer to this. When I entered medical school, they made us sign the pledge. You know the McCarthy holdover, “I am not and have never been a member of the legal profession.” Or something like that. And I’ll take intestine sucking roundworms over blood sucking leeches any day. Do I need to even type “duck and run” now? Or will I just get the subpoenea automatically?
Oh yes. Imagine my joy in being offered a glass of nile water.
Collounsbury: Wouldn’t worry too much about the Schistosomiasis. My understanding is the systemic problems generally only result from years of constant exposure and reinfection. And I don’t have my old Parasitology text handy, but I seem to recall it either being a transitory disease or at least an easily treatable one. Also you should know when you get it - I believe painful, bloody urination is one of the most common symptoms 
.
Old acquaintance of mine who used to run the local Peace Corps recruiting office and who did two tours in Africa ( one in West, one in East ) said the bilharzia was only an uncomfortable annoyance. Malaria ( Plasmodium falciparum - the nasty one ) was what really made him want to off himself to escape the misery. Course I can’t really recall if the species of Schistosoma ( I think there’s 4 biggies ) in the Nile are the same as the one(s) found in sub-Saharan Africa. I’ll look it up if you like.
- Tamerlane
Ah this does sound better. No symptoms quite as yet. I was getting a little antsy you know. (and wondering why I get these assignments… hmmm.)
Now of course if you have the refs on hand it would be nice to know if the Nile version is the same as the little boys in East Africa, but don’t trouble yourself.
Collounsbury: Not a problem at all - I never throw away useful reference material 
.
And oh, joy. Seems Egypt has two of the three ( not four like I originally thought ) most medically important species :rolleyes: . So herein follows the good news and the bad:
1.) If you aren’t bathing in the Nile, I wouldn’t worry a lot. These critters are both visible to the naked eye ( just barely - at least the non-infective species I saw in lab was - 170 to 240 micrometers long - Can’t recall the size of the species I saw in the lab ) ) as little swimming wrigglers and they typically need about 10 seconds or more to bore into the surface of the epidermis and 30 minutes to penetrate it completely. Also these are parasites of the circulatory system ( despite the fact that their eggs somehow get into the gut and bladder to be excreted - a process which is apparently still slightly mysterious ). I doubt any would survive being ingested directly after drinking.
2.) Worm load matters. Even if you were infected by drinking, you likely didn’t get many. And if you stay away from further chances of infection, you won’t get any more. These are two host parasites ( the other part of the life-cycle takes place in snails ), so they’re not going to multiply inside you. Any pathology you get, if any, would probably be very mild. Also some protective immunity to superinfection seems to acquired during infection as part of an immune response ( which may help this disease from being a worse scourge than it already is ). Eventually the damn things will expire of old age.
3.) There are typically three stages of infection.
a.) An initial phase 4 - 10 weeks after infection which is similar for all species. Intermittent fever, skin rashes, abdominal pain, bronchitis, diarrhea, and sometimes ( severe cases, I’m assuming ) enlargement of the liver and spleen.
b.) The next two stage differs a bit ( and ranges anywhere from 2.5 months to a few years in developing ):
In Scistosoma mansoni the large intestine is the most heavily affected, especially the sigmoid colon and rectum. The eggs lodged in the venules and submucosa elicit an immune response. Inflammation is followed by leukocytic, then fibroblastic infiltration that finally result in the formation of fibrous nodules. This results in micro-abscesses, necrosis and ulceration from occluded blood vessels. The resulting clinical symptoms include abdominal pain and diarrhea with blood, mucous, and pus. Meanwhile many eggs are swept back into the liver causing similar reactions. The spleen enlarges both from eggs and because of chronic congestion of the liver. Continue the process and some eggs will get past the liver into the lungs, nervous system, etc. Ick. Ick. Ick.
In Schistosoma haemotobium( the most common and widespread of these species ) it is a little less serious. These congregate chiefly in the venules of the urinary bladder. This is the one with the painful, bloody urination. Apparently the bloody urine starts out minor and worsens as the bladder wall ulcerates. The pain is apparently most intense at the end of urination. Chronic cases lead to kidney and urethra complications.
4.) Treatment is apparently more difficult than I thought ( at least as of 1985 ) with only fairly toxic organic trivalent antimonials being effective. They’re sufficiently potentially dangerous that administrating them must be very carefully monitored over several weeks. Not a problem for you, I would imagine. But of course not possible for most folks in Third World countries.
5.) But I was right that it is a transitory disease in that constant reinfection is the problem. The chronic problems result from ever-increasing worm loads from daily reexposure. Avoid reinfecting yourself and increasing your parasite load and you should be just jim-dandy .
- Tamerlane
“Last was Loa loa, which besides having a cool name, causes Cecil’s continuously burrowing 4 cm worm in the soft tissues.”- -edwino
Sorry for the way i quoted you, I dont’ post much
I believe, though Loa loa may be possible, that Cecil is actually describing Dracunculis Medinensis, or guinea worm, or as it is sometimes called “the fiery serpent”, which is extracted by the gradual rolling up on a peg method.
Parasitologists have a theory regarding the origins of the recognised symbol for medicine and surgery - the caduceus. In biblical times (and before), infection by Guinea Worm was widespread throughout the Mediterranean and Middle East. It is likely that the surgeons and other health professionals were kept busy removing this particular worm. Since the majority of people in those days were illiterate, it would make sense that a professional advertised their business by supplying a picture of what they did - cobblers showed images of shoes, smiths a forge, and surgeons had pictures of worms being wrapped around sticks. Well, it’s a good story anyway.
Some scholars even believe that the serpent which struck the Jewish people as they wandered in the wilderness as related biblically in Numbers 21:6.
Most recently, the worm has seen a slight upsurge in India due to the practice of abulations in water that is also used for drinking.
P.S.- X-rays of the calcified worms in people look really cool.
I saw a news program on the guinea worm in Africa. They were discussing teaching the people cleanliness techniques like running the water through a cloth to filter out the bugs. Then they showed a guinea worm infection. We’re talking meter long worms through the body, wriggling under the skin. The extraction method is as described. You get the end and pull out about an inch at a time. Then wait until the next day, and retract another inch. The slow going is to pull it out intact and prevent breaking it. It looked pleasant. :rolleyes:
Dammit, man! I want pictures! Anyone got some?
Ok, I got a minute to do some searching. And . . . man are them things deeeeeesgusting.
http://www.cartercenter.org/guineawormprogram.html
http://www.who.int/ctd/dracun/disease.htm
and the reigning champion pics:
http://www.biosci.ohio-state.edu/~parasite/dracunculus.html
and not to be missed is the very bizarre Save the Guinea Worm Foundation.
Eeesh.
Well, what I’d like to know is whether folk in developed countries with clean water supplies have a hig infestation rate of parasites. Does anyone know? Does it matter? Is there a way to get rid of them or is worth the effort?
Some months ago I got a junk mail offer for a “worm cure” that had plenty to say about parasite infection in the general population and its supposed effects on overall health. I chalked it up to some serious cure-selling propaganda, but I remain curious.
Save the Guinea Worm? That’s just freaky. I respect the world’s biodiversity, but come on.
From the site:
chuckle I needed a good laugh.
That’s right, you too can volunteer to host your very own Guinea worms. You have the opportunity to drink infected water and spend months gestating your own parasitic growth, and let the worms crawl their way through your body. You too can get a painful blister, degenerated joint tissue, risk infection, all for the low cost of $19.95.
Okay, I made up the cost part.
I think I’ll start a new awareness campaign - Save Ebola!
Irishman, I’m pretty sure that the site is supposed to be humorous. Why don’t you volunteer to be a guinea worm preserver and find out for us if they’re really serious?
Hmmm, Tamerlane, I hate to say this but your post was much less reassuring than I was hoping for as (a) some of these symptoms are a bit… familiar. (b) sloshing through irrigation ditches full of Nile water has been known to happen.
Oh dear, I think my hypochondria is going to send me to a doctor.
By the way Arnold, you know my boss is Swiss? You bastards, you dirty ever-so-pleasant neutralish seeming bastards.
Does any of the literature mention large amounts of alcohol consumption as a cure?
Well, Cranky, the answer is yes and no. Public health measures in countries like the U.S. have made prevention the norm, and nasty parasites fairly rare. If you do get infected your doctor can prescribe better medicines than you’d get mail-order without a prescription anyway.
The Center for Disease Control has some good population infection data on their website.
On the otherhand, yes, one parasitic round worm in particular has a VERY high rate of infestation - it is Pinworm.
Almost every human…including you, has had or will probably get Pinworm in their life span, and usually more than once, and usually as a child.
People usually get Pinworm like this: First grader Johnny scratches his itchy backside (or fails to wash after the loo) and later touches Suzy, transfering the eggs. Suzy picks up the eggs on her hands and eats lunch, ingesting the eggs (hand to mouth). Suzy comes home touches more objects, including parents. Now Suzy’s whole family has Pinworm. Yea!
Pinworm is almost always harmless, causing only mild irritation of the perianal area as the females lay their eggs around the anal opening at night while the human host sleeps. The worms are very small, measuring only a fraction of a centimeter. Irritation is often so mild it goes unnoticed by the host in many cases. The infestation usually runs it’s course without any treatment needed. Should you discover you or your child has pinworm, recommended action is to:
- Be sure everyone always washes their hands, and keep your hands away from your face
- Launder all bedding and clothing, removing bedding carefully without shaking out the bedding. Shaking will cause the microscopic eggs in the bedding to be launched into the air where you could (gasp) inhale and swallow them. Dry articles in the sun…UV radiation will kill almost any roundworm.
(edwino mentioned in a post above the traditional scotch-tape method used to collect the worm for differential diagnosis. Many school nurses know how to do this.)
I love this stuff…
Collounsbury: Well large amounts of alcohol will temporarily cure the hypochondria, if nothing else 
.
See, now, I hesitate too even mention the following to a self-confessed hypochondriac. But in the interest of full disclosure and wanting you to watch your health, I will. Irrigation ditches in Egypt are, in the context of Schistosomiasis, not good places to be. The snails that host the other part of the life cycle love them. My strong advice is that when you’re out in the field that you take a pair of Wellington’s or even hip-waders with you for just such an emergency. The locals will think you’re insane. But then they probably do already 
.
Now, that said - Don’t sweat it that much.
1.) Occasional contact does not necessarily = deabilitating infection. It’s a common pest, but not universal in the waterways. And the titer of the infective cercaria in any given body of water will probably vary greatly.
2.) Those symptoms are mighty general ( unless you have the bloody stool/urine one - In which case I would imagine you would have already rushed to see a doctor ) and could be anything.
3.) If you do get it, it sucks. But it is treatable and almost never a threat to life or generally a long-term health problem ( for properly treated Westerners ). Like I said, I know folks ( not just the one ) that have had multiple bouts and just treated it as a nasty, but not overwhelming, occupational hazard. They’re all fine today.
Get checked if you’re feeling ill. Then have a drink and relax . And remember to wear your rubbers ( always good advice 
).
- Tamerlane
Cecil mentioned the subject book in the worm article. It is indeed an excellent reference to have around the house, if you can speak medicalese. It is an annual publication. I have been buying it for years and I am not a physician. I stumbled on it in Austria when I was there for an extended assignment and was sub-letting an apartment that belonged to a young physician who was doing her residency in New York. The only English-language publications in the place were medical texts, magazines and books, CMDT among them. Naturally, I came down with every disease known to man.
Anyway, it costs $56. The upside is you can sell last year’s edition on E Bay for $40 or more.
If anyone’s still interested in the subject, the newest Discover Magazine has an article in it about an Air Force pilot suffering from schistosomiasis.
I think one of the more interesting quotes from the story is that the worms “copulate nonstop” once they have entered the human body, with the female only stopping to actually lay the eggs. Anyway, the article is in the “Vital Signs” section (though they haven’t updated it yet, so the current issue might not be put on up on their site for a few more days).