Worms #2.

Roundworms - Ascaris
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These are some of the critters commonly found in dog FECES. (That word should make HP feel more comfortable). Remember, 20 - 30 cm is about 8 - 12 inches.
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Causal Agent: Ascaris lumbricoides is the largest nematode (roundworm) parasitizing the human intestine. (Adult females: 20 to 35 cm; adult male: 15 to 30 cm.)

Life Cycle: Adult worms [1] live in the lumen of the small intestine. A female may produce approximately 200,000 eggs per day, which are passed with the feces [2] . Unfertilized eggs may be ingested but are not infective. Fertile eggs embryonate and become infective after 18 days to several weeks [3] , depending on the environmental conditions (optimum: moist, warm, shaded soil). After infective eggs are swallowed [4] , the larvae hatch [5] , invade the intestinal mucosa, and are carried via the portal, then systemic circulation to the lungs [6] . The larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed [7] . Upon reaching the small intestine, they develop into adult worms [1] . Between 2 and 3 months are required from ingestion of the infective eggs to oviposition by the adult female. Adult worms can live 1 to 2 years.

Geographic Distribution: The most common human helminthic infection. Worldwide distribution. Highest prevalence in tropical and subtropical regions, and areas with inadequate sanitation. Occurs in rural areas of the southeastern United States.(Above courtesy of Centers for Disease Control)

Note from the above -- when in doubt, it is safer to spit than to swallow.

Gruesome Photos: Too gruesome. I won't post them here, but you can see them at :

http://curezone.com/image_gallery/parasites/infected/default.asp?i=0&n=15

and

http://curezone.com/image_gallery/parasites/infected/default.asp?i=15&n=15

Complications : Complications related to typical ascariasis are rare. However, potentially dangerous complications can develop if you have a heavy infestation.

• Nutritional deficiencies. Children with ascariasis are especially at risk of nutritional deficiencies. Loss of appetite and insufficient absorption of digested foods can occur as a large number of parasites take nourishment from the host's body.
  
• Intestinal blockage and perforation. In heavy ascariasis infestation, a mass of worms can block a portion of the intestine, causing severe abdominal cramping and vomiting. The blockage can even perforate the intestinal wall or appendix, causing hemorrhage or appendicitis.
  
• Allergic reactions. Some people develop allergic reactions to the ascaris worm's metabolic excretions and secretions, or to dead and dying worms. These reactions can cause signs and symptoms such as asthma, insomnia, eye pain and rashes.

(Courtesy of MayoClinic.com)

Worms #1.

Pinworms
Causal Agent: The nematode (roundworm) Enterobius vermicularis (previously Oxyuris vermicularis) also called human pinworm. (Adult females: 8 to 13 mm, adult male: 2 to 5 mm.) Humans are considered to be the only hosts of E. vermicularis. A second species, Enterobius gregorii, has been described and reported from Europe, Africa, and Asia. For all practical purposes, the morphology, life cycle, clinical presentation, and treatment of E. gregorii is identical to E. vermicularis.

Eggs are deposited on perianal folds [1] . Self-infection occurs by transferring infective eggs to the mouth with hands that have scratched the perianal area [2]. Person-to-person transmission can also occur through handling of contaminated clothes or bed linens. Enterobiasis may also be acquired through surfaces in the environment that are contaminated with pinworm eggs (e.g., curtains, carpeting). Some small number of eggs may become airborne and inhaled. These would be swallowed and follow the same development as ingested eggs. Following ingestion of infective eggs, the larvae hatch in the small intestine [3] and the adults establish themselves in the colon [4]. The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. The life span of the adults is about two months. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area [5]. The larvae contained inside the eggs develop (the eggs become infective) in 4 to 6 hours under optimal conditions [1]. Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur but the frequency with which this happens is unknown.

Geographic Distribution: Worldwide, with infections more frequent in school- or preschool- children and in crowded conditions. Enterobiasis appears to be more common in temperate than tropical countries. The most common helminthic infection in the United States (an estimated 40 million persons infected). (Above courtesy of Centers for Disease Control)

Pinworm. Adult female worms of Enterobius vermicularis collected from a 2-year-old girl in a Korean orphanage after treatment with pyrantel pamoate 10 mg/kg, November 24, 1975.
(Courtesy of www.emedicine.com/med/topic1837.htm).

Complications : Typical pinworm infections don't cause serious problems. In rare circumstances, complications can develop from a heavy infection, including:

• Urinary tract infection. More common in females, urinary tract infections sometimes are caused by heavy pinworm infestation. The parasite can also migrate to the bladder, causing cystitis.
  
• Infection of the peritoneal cavity. In women or girls, the parasite may travel from the anal area up the vagina to the uterus, fallopian tubes and the area around the pelvic organs. This can cause vaginitis, endometritis or other problems.
  
• Dientamoeba fragilis infection. This parasite, which lives in human intestines, is often spread through contaminated food or water. Although scientists are not sure, it appears that you also may be able to contract this parasite by swallowing pinworm eggs — which may contain the fragile parasite. Signs and symptoms include diarrhea, abdominal cramping, weight loss, loss of appetite and fatigue. You can prevent pinworm-related infection by washing your hands frequently and thoroughly to make sure you don't swallow pinworm eggs that may be on your hands.
  
• Weight loss. When a large number of adult pinworms are living in your intestine, they can cause enough abdominal pain and take enough nutrients that you will lose weight.

(Courtesy of MayoClinic.com)

How to Be Hated (just say what nobody wants to hear)

So here I am, back in my Biology teacher outfit...

I have been mocked and called a killjoy for my phobia regarding dirt and bugs in food (and in contact with the skin, for that matter). My insistence that animals belong out-of-doors has made me persona non grata in some homes (and in others, depending on the circumstances, the home is locus non grata to me!). All this because I have had the opportunity to study pathological organisms up close and in real-time. OK, folks, here's another goodie to make you dislike my depressing attitude.

It seems that the Pharisees might have had some good points with respect to their frequent washing. Remember -- Jesus' words were to do as they said and not as they did. Here is a cute little article, an interview with a leading wormologist, Dr. Peter Hotez :

http://usinfo.state.gov/journals/itgic/0307/ijge/hall.htm

following this Christmas present of an article via Reuters :

http://news.yahoo.com/s/nm/20071226/hl_nm/diseases_neglected_usa_dc

My children (the older ones) had plenty of opportunity to observe roundworms and tapeworms in dogshit when we lived in Northern Saskatchewan. The educational value of steaming piles with wriggling critters is enormous. Just because the ascarids and fish tapeworms were in the local dogs did not mean they were not ready to take up residence in a careless person. The article above provides a wake-up call :

"I feel strongly that this is such an important health issue and yet because it only affects the poor it has been ignored," Hotez said via e-mail.

He said the United States spent hundreds of millions of dollars to defend against bio-terrorism threats like anthrax or smallpox or avian flu, which were more a theoretical concern than a real threat at present.

"And yet we have a devastating parasitic disease burden among the American poor, right under our nose," Hotez said.

He noted a recent study by the Centers for Disease Control and Prevention, presented in November, found that almost 14 percent of the U.S. population is infected with Toxocara roundworms, which dogs and cats can pass to people.

"Urban playgrounds in the United States have recently been shown to be a particularly rich source of Toxocara eggs and inner-city children are at high risk of acquiring the infection," Hotez wrote, adding that this might be partly behind the rise in asthma cases in the country. Up to 23 percent of urban black children may be infected, he said.

"Because of its possible links to asthma, it would be important to determine whether covert toxocariasis is a basis for the rise of asthma among inner-city children in the northeastern United States," he added.

"Cysticercosis is another very serious parasitic worm infection ... caused by the tapeworm Taenia solium, that results in seizures and other neurological manifestations," Hotez wrote.

He said up to 2,000 new cases of neurological disease caused by tapeworms are diagnosed every year in the United States. More than 2 percent of adult Latinos may be infected, and with 35 million Hispanics in the United States, this could add up to tens of thousands of cases, Hotez said.

"In the hospitals of Los Angeles, California, neurocysticercosis currently accounts for 10 percent of all seizures presenting to some emergency departments," he wrote.

Ummm... Taenia solium... that is the pork tapeworm. ["Neurological disease" (transl.) tapeworm cysts in the brain.] Also, I would dispute that it "only affects the poor"; rather, it tends to affect the ignorant, regardless their economic status. (His slanting it toward the "poor" may be a pitch for increased government funding).

The solution to the problem -- prevention -- does not require massive amounts of taxpayer funding. It starts with a few fundamental principles of hygiene :

1. WASH YOUR HANDS before eating.

2. WASH YOUR FOOD before eating raw fruit and veggies. A huge amount of our produce is imported from Mexico and points south, as well as that nice fruit that comes here from southern Europe, the Middle East, Africa, and the Orient. Countries that fertilize their soil with human shit are allowed to export the produce to us. Aside from any bacteria or protozoa that might be there, you could also swallow cestodes, trematodes, and helminthes in the form of eggs or cysts.

3. STOP EATING SUSHI. Don't believe me? Try :

http://www.cfsan.fda.gov/~mow/chap25.html

or for the REAL gory details, try :

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=358121

(I got a kick out of this part -- "Thorough heating of the fish dish is essential, since anisakid nematodes are reported to have survived after fish was prepared in a microwave oven. Alternatively, seafoods should be frozen at -20C (temperature of most home freezers) for 3 days; a whole fish weighing 4 to 8 pounds should be frozen at -20C for at least 5 days. At room temperature, Anisakis larvae can survive for up to 6 days in 10% Formalin, 112 days in 1% HCl, 51 days in vinegar, 1 day in soy sauce, and 1 day in Worcestershire sauce.")

4. COOK PORK THOROUGHLY. I saw a recent article that said trichinosis was extinct in the USA, to which I would have to say, that is a stupid statement.

4. Keep Fido, KiKi, and their associates out-of-doors. Yeah, they are cuddly and intelligent and good companions. They also lick the hind ends of their fellow four-legged friends, and eat raw critters they find when they go for a walk. For good measure, wash your hands after you pet them, since parasite eggs are frequently disseminated attached to fur.

5. Look back before you flush. I got that tip from the guy I did my student teaching with. He was an amateur parasitologist; he had quite a collection of worms from road kill or otherwise deceased wild animals. One of his more impressive exhibits was a 2-foot long tapeworm he extracted from the intestines of a dead sparrow. A quick peek in the bowl may be the best shot you have at early diagnosis.

I won't say here what you should do if your butt itches. Suffice it to say that ascarids (pinworms, notoriously) crawl out at night to lay their eggs around the anal opening and reinfection can occur when hand-to-mouth interfaces take place (see also my comment about Fido's proclivity towards the anal inspections of his friends).

Maybe I should do a series on lifecycles of the critters most animal-lovers never think about.

Steppin' Right Along

Ho, me boyos, time to announce the completion of the bottom rung!

One of the problems with making a silk purse from a sow's ear is collecting enough pig skin. When a ready-made double ended starting step from L. J. Smith costs almost $400 (and that is for a 48" unit, and what the project calls for is a custom made 60" unit) desperate measures are prescribed. We start by gluing together some of those scrap pieces of oak that so many people have been telling me to throw away.

Because the scrap is only 3/4" thick and we need a net 1" thickness, it has to be glued in two layers, and there must be controls to keep the piece from warping while the glue sets.

When the clamps are off, the back side looks really ugly, but we don't care because this stuff has merely been added to generate thickness.

The top side looks prettier... but not by much.

Also, it would be nice to hide the joint in the head-on view, so an additional piece is glued on as a nosing.

Once the stock is planed down to the 5/4 thickness, the step blank must be fitted to the base.

Like so.

Then it is necessary to mark where the radius will be cut. We begin where nobody will ever see it under normal conditions.

Finding the center of the radius...

is a multi-step (ha! a pun!) process...

using such exotic tools as a sheet of paper...

and skill at Origami.

The paper is folded to the step width, then folded in half to find the centerline...

and quartered to find the center of the radius.

We mark the center with a punch. The process is repeated at the other end.

Using a makeshift compass to scribe the outer edge of the radius...

we rough out the cut with the sabre saw.

A custom router plate is required. The distance from the edge of the router blade to the center of the radius is laid out, and a hole drilled to fit a nail as a trammel point.

We are ready to cut...

and so far it looks OK...

but there are some minor items to touch up with the block plane.

Then the edge is rounded over, and the tread is ready to be sanded.

One last check on the custom fit before we sand, stain, and urethane (3 coats).

C'est fini. The tread has been glued to the riser structure with subfloor adhesive. Lots of time and labor invested, but I figure that, had I bought this thing ready made, it would have cost about 500 bucks. Now all I need to do is finish the rest of the stairway!!

Let's riser and shine!

Custom stair parts are fun. They just take time. When you have a rib that designs stuff and you have to figure out how to make her designs work, you have to get creative. The problem at hand is the double ended bottom stair unit. It has to be custom built so that it fits a retro stairway and can take volutes at both sides. After several failures -- bending oak in a tight radius can be tricky -- I hit on the idea of using oak plywood for the riser, and kurfing it to allow for a smooth bend.

I began by setting up the Sawbuck. Removing the 8" blade and inserting a 7-1/4" blade raises it above the table, but a shim has to be used to get the right depth.

In this case, a slab of OSB was run through the planer to the correct thickness.

Then came the layout...

and the distance from the end of the workpiece to the beginning of the radius at the front of the step...

and we are ready to begin cutting.

This takes some patience, and care that chunks are not knocked out each time the blade slides back.

You can see that the thickness of the shim is critical to making sure you have just enough wood left to make a smooth bend and keep the piece from breaking.

There is no sense in making more cuts than you actually need...

and the result is quite flimsy, so be careful moving it.

Now to create the form for the riser. The end pieces will be part of the step; the rest is simply to be the place to rest Archimede's lever.

Here we go...

The kurfs are filled with subfloor adhesive. This will give a solid end, without voids.

Here is a close-up of the end. The excess glue will be trimmed off later, and so will the extra wood. When it has set, we remove the riser from the form, trim off the excess wood, and install the riser around the bottom of the rough framed stairway. (I should have taken more pix!) Then comes the problem of the tread.

Three Dozen Today

Thirty and six years have now gone by since I plucked a lovely Violet and rode off into the future with her. GOD has blessed us in many ways, too many to count. I thank HIM that my Violet still blooms, and I pray that her seedlings also enjoy long and full lives with their spouses.

Oh. Yeah. I did have some hair back in those days.