The Rest of the Story on the Real Life Cycle of SI

The real life cycle is between birds and snails. People just happen to swim in the middle of the life cycle of the cercariae who try to penetrate our skin, thinking, of course, that we are a bird, and will help them complete their cycle.

So here is Harvey's letter to me that thoroughly explains every aspect of the swimmer's itch life cycle, and thus really helps me to understand what is really going on. If you are a biology major, as I was, this is easy to follow.


Carolyn:

Obviously, people are not getting the life cycle.  Adult schistosome worms live in the mesenteric veins of the bird.  These threadlike adult worms produce eggs that make their way from the veins of birds intestine, to the lumen of the intestine.  The eggs exit with the bird fecal material.  Once in the water, stimiluated by a change in osmolarity pressure and the exposue to light, the miracidium hatches out of the egg and begins swimming.  The miracidia are positively geotaxic (this means that they go toward gravity or to the bottom of the lake) where they are most likely to come in contact with the right species of snail (not just any snail).  For most species, the miracidium penetrates into the tegument of the snail and migrates to the hepatopancreas (in snails this organ is the liver and the pancreas combined).  At this site, it begins reproducing at an incredible rate.

After about a month, the tube factories in the hepatopancreas of the liver, produce cercariae (up to 2,000 per day).  Keyed by light again, these larvae (called cercariae), exit the snail every day.  Unlike the miracdia, the cercariae are positively phototaxic and so they move toward the surface where they are more likely to encounter the next host, a specific species of bird.  In the Midwest, they birds are most often common mergansers. How they enter the bird is a mystery.  They may go in the mouth and enter the epidermis of the mouth, pharynx, etc. or they may enter through skin on the feet or under the feathers.  

In about a month, these cercariae become adult worms again in the veins of the duck.  It takes about two months for the whole cycle to be completed in snails and birds.  There is a day on both sides of these hosts where the parasite is aquatic.  Finally, if the cercariae come in contact with people, they often mistake it for a bird, try to enter the skin but only can make it through the epidermis and then die.  They do not have the right enzymes to go through human skin.  In the right bird, they would enter the skin, go in a blood vessel, migrate to the heart, liver and then mesenteric veins of the bird where they become adult worms.

Incidentally, once they enter the skin (usually in the water), there is no amount of toweling or showering that will remove them. Some people believe that they can go into the water with the swimmer's itch parasites and that they will not get it if they shower or towel down. That is not correct.  I get a lot of contacts about that.   ....


Harvey Blakespoor, PhD

Watch the Life Cycle of Swimmer's Itch

Dr. Harvey Blankespoor suggests that everyone read his website for additional information. I agree. He has an animated life cycle of SI. To quote him:  "The animated part with the life cycle is about as simple as one could make it." Harvey:

http://swimmersitch.org/flash/itch3.swf

website: swimmersitch.org

Be sure to fill out his survey, please, if you have SI.

Thank you,

Carolyn Bates

Swimmer's Itch Guard: How to Properly Use it

This is from a pdf sent to me by the manufacturers of Swimmer's Itch Guard. Please read it thoroughly to properly use their product and be protected from Swimmer's Itch.

2011 Directions for Use
Before entering the water, apply to all uncovered skin and skin at the openings of loose fitting bottoms and tops that will be under water continuously for 5 minutes or longer. Apply liberally and evenly. Reapply after 90 minutes of water activity or taking a shower or hot-tub.

Additional Tips
To be safe, always apply before entering the water. Our experience is that it takes about 5minutes (sometimes less, sometimes more) for the parasite to penetrate the skin. Once it penetrates, there is no amount of toweling off or showering or anything that you can do to prevent getting those itchy red bumps. Swimmer’s Itch Guard prevents the parasite from penetrating so always apply before entering the water.

Applying to uncovered skin is obvious, but what about skin covered by swimsuits and swim shirts? If the suit or shirt is snug fitting at the openings, then apply to only a couple of inches of skin underneath the suit or shirt at the openings. The reason for a couple of inches of skin is that the suit or shirt will move and leave untreated skin exposed. If the suit or shirt is loose fitting, apply to several more inches of skin underneath the suit or shirt. If possible, tuck in the swim shirt and then no application is needed in that area. Loose fitting bottoms and tops allow water and the parasite to flow freely to untreated skin.

Application to the face is not necessary unless snorkeling or swimming with face in and out of the water (crawl) for more than 5 minutes. Be sure to apply to the necks of children since they are up to their necks often!

Apply liberally and evenly. Swimmer’s Itch Guard spreads easily so by applying liberally and evenly, you assure complete coverage. A missed spot might become an itchy spot! Don’t forget to apply to feet and between toes.

Remember to reapply after 90 minutes of water activity or taking a shower or hot tub if planning to go back in the water. A safe rule with water loving kids and grandkids is “Apply in the Morning and Reapply in the Afternoon!”

Now enjoy the water again!


Questions

Please contact Bud Mixon
Swimmer’s Itch Guard
Bud Mixon
651-636-7503

Harvey D. Blankespoor Ph.D. Letter

Dr Blankespoor recently sent this letter to me. It has updated information on Swimmer's Itch, and the url for his survey which I hope everyone will use to tell him about their experiences with SI, and the new SI Guard: survey: http://www.swimmersitch.org/report.html
Swimmer's Itch Guard: http://www.SwimmersItchGuard.com

Hi carolyn,


This email is an update for those who completed the Swimmer’s Itch Questionnaire during the last 8 years. Thanks again for taking time to do that.

Our intent is to provide answers to three common questions:
1. Is there anything we can do to prevent Swimmer’s Itch?
2. Where is Swimmer’s Itch Found in North America?
3. Can you send me any of your published information?

As I reported in the last email, there appears to be a topical cream that prevents Swimmer’s Itch. It is called Swimmers Itch Guard, and it is available online and at many local stores with pharmacies. You can learn more at www.SwimmersItchGuard.com.

Based on six trials, nobody got Swimmer’s Itch (not even one papule) on the leg that had the Guard. Several students got papules on the leg that had no Guard.

This summer, I will do additional testing of the effectiveness of this cream at the Univ. of Michigan Biological Station. I also plan to test if Swimmers Itch Guard prevents leeches from attaching. As soon as the results of this summer’s testing are compiled, I will forward them to you.

If you, other family members, or friends don't use the Guard and get swimmers itch, I am still interested in getting the information listed on the questionnaire. Thanks in advance for taking the time and interest in getting your data to me.

Several people asked where swimmers itch is found in North America. It is found where birds such as Mergansers and certain snail species live. I can report that Michigan had the most reported cases, followed by Wisconsin, Minnesota and Washington. Ontario and British Columbia were the two Canadian provinces where Swimmer’s Itch was the worst. I hope to have a paper published on the latest results sometime this year.

Finally, our research has been published in a book entitled “The Changing Environment of Northern Michigan” and is published by the University of Michigan Press. Incidentally, if you would like an electronic copy of Chapter 16: “Swimmer’s Itch: Misguided Flatworms”, email me and I will send you a copy.

Thank you again for your participation and feel free to contact me if you have any questions.

Sincerely,

Harvey D. Blankespoor Ph.D.
Professor Emeritus of Biology
Hope College
Holland, MI 49423
blankespoor@hope.edu
616-395-7279
www.SwimmersItch.org

Swimmers Itch Guard

Wouldn't it be wonderful if this will really work to prevent getting swimmer's itch when swimming.!!

It is called SwimmersItchGuard Please send us your comments on this blog after using this product.

Thank you

Carolyn Bates

SwimmersItchGuard has been endorsed by Dr. Harvey Blankenspoor, the leading Swimmers Itch expert.

Here is an except from his letter he recently sent to me, via email. As well as the story behind the making of this "potion."

"First, many of you asked me what you or your lake association can do to prevent Swimmer’s Itch. I am happy to inform you that there is a new product that you can use to prevent Swimmer’s Itch. It is called Swimmer’s Itch Guard; you can get more information by going online to: www.SwimmersItchGuard.com. "

Thank you for participating in our research, and if you or your loved ones want to enjoy the water without the misery or aggravation of Swimmer's Itch, I hope you find that Swimmer's Itch Guard helps. www.SwimmersItchGuard.com

Sincerely,

Harvey D. Blankespoor Ph.D.

blankespoor@hope.edu
616-395-7279
www.SwimmersItch.org

Here is the story of how this cream was produced: www.SwimmersItchGuard.com:

Family Declares Victory Over Swimmer's Itch published in the 2010 Michigan Riparian Special Edition Vol. 44 No.4

Our story begins in the summer of 1973 when our contractor completed construction of our cabin on Webb Lake in northwestern Wisconsin. It was that summer when our family of Bud, Karen, Tucker 9, Tim 4, Katie 4 months, and Pepper our black lab, began to enjoy and appreciate cabin and lake life every weekend from June to September.

Karen and I loved it and our kids and their friends loved it. And so, they grew up going to the cabin most every weekend – at least during the summer. Today, 37 summers later, we are still going to the cabin on Webb Lake. Our family has changed from 5 and 1 lab to 16 and 2 labs! Now the 8 grandchildren love it too. We have always been an active family, enjoying water sports such as swimming, tubing, water skiing etc. and so we spend a lot of time in the lake and at our sandy beach.

Several years ago, we began to notice more ducks and geese on the lake. Next, we began to notice more snails in the lake. And finally, we began to see red bumps appearing on our skin and especially on the younger grandkids. Those red bumps are itchy! What was going on? We had never experienced this in all the years. Well, you probably know the answer.

Those itchy red bumps are called Swimmer’s Itch. Overnight, our water fun was threatened. What could we do to prevent Swimmer’s Itch? We read and studied most of the information available, talked with DNR officials, and tried many things but nothing really prevented it. Our grandkids were scratching and itching to the point of not sleeping well and neither were their parents or grandparents!

Then, during the summer of 2009, we tried mixing a chemical “block“ with a 30SPF sunscreen. It worked! No swimmer’s itch! Well, let me qualify that. It worked as long as mom or dad applied the lotion to the child. Yes, we had a few red bumps but that was a result of the little ones getting into the water before they had their “lotion” on. Yes, it did work and we gave it a good test. We had a total of approximately 240 grandkid days at the cabin this summer (same as 8 grandkids for 30 days) and they were in the water at least 90% of the days.

When applied and applied properly, there was no swimmer’s itch! It worked on children from 4 to 12 and on adults from 18 to 66. We were thrilled with our success. It was another great summer at the cabin. One last word, during the summer, my grandson, TC, after spending 10 days with us at the cabin, said to me, “Ba, since the ‘lotion’ works, why don’t you sell it?” I said “TC, I think that is a good idea.

Posters for your Beaches are Ready to Order

It is time to alert not only residents but the public that Swimmer's Itch is present occasionally on our beaches. The signage enables people to adequately protect themselves before swimming through the most up-to-date information we have.

The aluminum signs, are double sided, 2 ft. by 3 ft. in white wood framing and double posts. Smaller signs may be put in bulletin board cases. The red signs are laminated, double sided, 13 in. by 19 in. on metal stakes, and are posted for 24 hours after the swimming area has been raked. These signs are available at BaySide Printing, Inc. and can be adapted with your own local information. BaySide Printing, Inc., P.O. Box 1124, 515 Main Street, Frankfort, MI 49635. (231) 352-4440. mmcnabb@baysideprintinginc.com.

The Crystal Lake Swimmer's Itch Partnership and the Crystal Lake and Watershed Association near Frankfort, Michigan, designed these signs and will be putting them up next summer on several beaches around the lake. We thank them for the time it took to do the designs and to find someone willing to print them. Please call BaySide Printing to have them make a custom sign for your beach. Thank you Meredith McNabb.

Posted by Carolyn Bates from email sent from Meredith.

Products That May Prevent Swimmers Itch

Lifeguard-Alcohol based waterproof sunscreen. Non skin drying. Liquid. Fast drying. Easy to apply. Place in small hand pump sprayer. Seems to work without citronella oil. If you do add Citronella Oil only add 3 drops to an 8 oz bottle. Questproducts.com

Citronella Oil-natural plant insect repellent. Use in waterproof lotion sunscreen. A little goes a long way. 1 drop in a whole palm full or 3 drops in a 8 oz bottle.

Using too much citronella may discolor towels or showers.

Waterproof sunscreen with insect repellent-Bug and Sun(with DEET) and DEET Free BullFrog. There are special precautions for the use of chemical insect repellent sunscreens on children and adults. Read manufacturer directions carefully.

If you contract Swimmers Itch ask your pharmacist about effectice anti-itch lotions and Benedryl.

Some users have reported success with these products. Scientific testing is not available at this time and the products are not endorsed by the Swimmers Itch Task Force. Follow manufacturer's instructions.

Jana B. Way SI Task Force Crystal Lake MI tomway@comcast.net