Lyme Disease

This tiny little tick is the one responsible for spreading Lyme disease.  It is called the blacklegged tick, and is also known as the Lyme disease tick, by virtue of being the carrier of this disease. As can be seen from the photo of the black legged tick below, its markings are quite obvious.

However, the lyme disease tick in the USA comprises two ticks:

The Ixodes scapularis tick of the Eastern USA, and the Ixodes pacificus tick of the western USA.

Both these lyme disease ticks look pretty much the same and are both called the blacklegged tick.

Although popularly referred to as insects, the lyme disease tick has 8 legs, and is therefore an arachnid, like a spider is.

So, how do you know if the tick that bit you is a lyme disease tick?

It’s size, but mostly it’s appearance is the big give away:

The lyme disease tick has a pronounced darker area around the top half or more of it’s body, the other two ticks do not.

The Life Cycle of the Lyme disease tick:

AS you can see from this lovely picture of the lyme disease tick lifecycle, the eggs and larva are not considered to be greatly  infectious for lyme disease.  Rather, it is only when the lyme disease tick is in the nymph stage that they pose the greatest real risk to humans – presumably because, as adults, it is no longer feeding to grow.

Essentially any animal can act as a host for the lyme disease tick, including robbins, deer, foxes, mice … Come autumn and winter, and the lyme disease tick poses little risk of infection.

How do you remove a tick?

Carefully, as you don’t want to leave the head attached into your skin, which can easily happen if you yank on the body.

So, with a pair of fine, pointy tweezers, you grasp the tick around the head region, and lift it up off the skin steadily. This can be a bit of a challenge given the small size of a lyme disease tick, and the way it sticks its head into your skin.

Should we coat the tick with vaseline or try burning it or do something else to it? The CDC says not to do anything to the tick prior to its removal, as you could cause the tick to inject more saliva into you, thereby increasing your risk of catching lyme disease etc.

Why is the removal of the head from the skin so important?

I believe it is because that when a tick feeds, it does so by a tube it inserts into the skin, and the blood then flows up the tube into its body.  The problem is that blood animals have blood that coagulates to seal off breaks in the blood vessels and capilleries. So, the blood coagulates to prevent the tick from from taking the blood.  In order to get round this, the tick automatically excretes it’s saliva into the blood vessel to prevent the blood from coagulating at that point.  It is believed, that via this saliva,  the lyme disease is carried into the human body.  So, if you remove the tick body and leave the head, the first thing your leaving there is the tube and head that are responsible for the saliva being pumped in in the first place.

Secondly, infection can set in where the tick head is left behind.

Thirdly, if you grasp the tick round the body, your likely to force more saliva from the tick into you, and increase the risk of catching lyme disease from it, if the tick is likewise infected.

Maps, diagrams, drawings  and photos courtesy of www.cdc.com.  You may also find http://www.anaes.med.usyd.edu.au/venom/spiders.html a useful page on tick removal.

What some of you may not be aware of is that their is a vaccine that has been made and tested, and found to be effective against Lyme disease.

The Lyme disease vaccine is called LYMErix and is made by TM SmithKline Beecham Pharmaceuticals.  It is available to residents of the USA aged 15 to 70 years.

Clinical trials have been fruitful and the side effects rather few, and I will describe those side effects in another post to come.

This post is to describe the results and recommendations made in relation to this Lyme disease vaccine, by a document appearing on the CDC web site (originally posted in 1999).

Firstly, the Lyme disease vaccine requires you to have three vaccinations with LYMErix:

With 2 vaccinations you have a 49% chance of being protected against the Lyme disease YOU HAVE ALREADY CAUGHT; with 3 vaccinations that climbs to 76% chance that the Lyme disease YOU HAVE ALREADY CAUGHT will be defeated.

Although no stats are obviously apparent, the value of the Lyme disease vaccine for non-infected persons is determined by the density of  Lyme disease carrying ticks in the environment  and the amount of contact the person is likely to have in the area where those ticks are.   The medical opinion of that document is one of cost analysis to a large degree, but I would argue that the human suffering of those who do become infected, warrants a wider group of people having access to the vaccine than would otherwise be recommended medically speaking.

Specifically these learned people argue that the vaccine is NOT recommended for those in low risk groups, whereas this should be for the person to decide.  As Katelyn, the previous author of LymeAdvocate.com found, the family dog was considered to have negligible risk of catching Lyme disease, because it was a house dog, not an outdoors dog.  Well, the dog went outside, got bitten by a lyme carrying tick, and later died.  Although I am not talking about pets on this page as such, the juxtaposition of pet dog and human is very worthwhile mentioning and pointing out, for the same goes for people in low risk groups – they are still open to becoming infected by Lyme disease infected ticks.

The Maryland lyme disease map, shows the distribution of reported Lyme disease cases throughout Maryland – map courtesy of the CDC

The map regrettably does not give the color coding for incidence of lyme disease, and this is a problem with the actual CDC map of Maryland.  I suspect that the darker the color, the higher the incidence of lyme disease for that Maryland zipcode.

The Lyme disease distribution map for California – again, courtesy of the CDC, and again only refers to the reported number of cases – the unreported/undiagnosed ones obviously are not included in these California Lyme Disease map statistics.

Lyme disease map of the USA shows the incidence level of lyme disease across the United Stated.  It needs to be pointed out that the Lyme Disease map refers to the cases reported by doctors to the CDC – Centers for Disease Control and Prevention.  Most Lyme disease maps come from the CDC, as do the following Lyme disease maps:

Take heart, the transmission of the Lyme disease bacteria normally occurs after the tick has attached itself to the host for around 24 hours. So if the tick has been attached for much less time, there is every reason to feel a bit more safe about not having caught it.

The prevention of Lyme disease is primarily achieved by:

1… by avoiding tick infested locations,

2… by avoiding tick bites through the application of repellents,

3… by dressing in light colored clothing. The light colored clothing is to make it easier to see a tick, should one get on the clothes – obviously, if you see the tick, you should remove and dispose of it quickly.

Antibiotics to Prevent Lyme Disease 

Antibiotic use to try and prevent Lyme disease appears to have little value, and is therefore apparently not considered worthwhile at this time.

Lyme Disease Vaccine

Vaccines for Lyme disease are continuing to be researched, but no vaccine yet is cost effective enough to be used by the entire populace.

So, I have now discovered three different articles in farm journals by people who have free roaming chickens, turkeys, ducks and/or guineas and they all say the same thing. Those little birds love to eat ticks and they have many fewer ticks in their yards than their neighbors do. Hmm. If Avian Flu wasn’t a possible concern, I’d say that Cecil County needs to institute a chicken or guinea hen release program.

If that won’t work, maybe one of the other organic tick control methods researchers are working on will control the population around here. The USDA has an older report on some different methods being researched that makes for interesting reading. I’ve got some nematodes to spread in my yard and have that chore on this week’s to do list.

I debated for a long time this year over whether I was going to garden at all. I considered options like getting a huge load of green concrete in and covering the whole yard with it, but in the end, I decided that the pleasure of gardening outweighs the risks. Besides, one of the feral cats probably delivered the tick that infected me to my door.

I could get a relapse of Lyme disease. Or catch West Nile Virus. Or receive a bite from one of the poisonous baby snakes that enjoy the rock wall. I could also get hit by a falling ceiling fan in the house. So, I’m gardening cautiously. Very cautiously. I’m doing my best to alleviate risks with:

• Light colored clothing with long sleeves
• Hat
• Off sprayed on my shoes

And I’m enjoying my time in the garden, even if it is a bit painful because of the joint pain and I can’t do the more strenuous activities I used to handle easily. The bulbs are blooming and the veggie garden (Freshly tilled thanks to my brother.) is partially planted.

I love spring, even it means a legion of infectious deer ticks are being hatched.

Well, I think I’m doing much better lately. I don’t suddenly lose words like I was doing. Do you know how annoying it is to suddenly forget the word for fridge in the middle of a conversation when you’re trying to sound intelligent?

“I’m just going to run and stick my lunch in…uh…that white box thing that keeps food cold and I’ll be right back to help you set up, ok?”

“You know, I think I’ve got it covered. Are you sure you can handle working today? Maybe you need to go home and rest.”

“No, no, I’m fine. Just forgot the word for fridge for a second there.”

I still tire out really easily, but something reconnected in my brain and on top of losing words less often, I am no longer taking an hour to compose a single paragraph. Yahoo!

I’ve been thinking, though. If I knew I’d get Lyme disease, would I have avoided gardening and hiking and feeding feral cats? I don’t think so. I still do some of those things, although I am a little weird about it.

“Here, kitty, kitty. I’ll just stand three feet away so I don’t startle him, wait til his head is in the bowl and stretch over with the treatment tube… Ah, ha! You’re good for another month, buddy.”

It isn’t cheap treating every stray I still haven’t managed to trap and place in a new home, but it is worth avoiding having them drag ticks near the house.

And gardening – well, I like to do that when temps are well below freezing and hide indoors when it is nice. I’m certainly not doing much, either. Walking across the yard wears me out. Digging and transplanting -forget it.

Hiking is still really important to me, too, but I haven’t gotten the nerve or the stamina to venture back out there.

So, what about you? Would you have still done things that could result in a tick bite? Are you still doing that kind of stuff? I really want to know.

From Newsday.com:

A coalition of several Fairfield County towns and cities is proposing a reduction in the deer population as the only sure way to reduce the number of cases of Lyme disease.

With the news about mice being the big carriers, they may be planning to hunt the wrong four legged critter.  However, I’m sure that overcrowded deer populations do account for at least part of the Lyme disease problem. If they don’t have enough food in the wild, they are more likely to go into people’s gardens to forage and can very easily leave behind infected ticks.