Lyme Disease and Tick Bites

Lyme Disease and Tick Bites

5/1/13

It is spring and the flowers, black flies and ticks are blooming! Flowers and black flies rarely cause significant health problems, but deer ticks can. They can transmit Lyme disease by transmitting Lyme bacteria when they attach to their victim. They can also transmit the rarer diseases called ehrlichiosis, babesiosis and, even more rarely, tularemia and Lyme variants, recently reported to cause a dementing illness especially in the elderly. Our region used to be on the edge of the deer tick/Lyme disease infestation area, which was the southern New England states and southern Maine. But with long term warming and less winter kill of ticks, the population has increased substantially so that it is now much more common to see tick bites and consequently increased Lyme disease incidence.

There are two common types of ticks locally, the benign common dog tick (apple seed-sized), and deer ticks, which are sometimes (not always) carriers of Lyme and other diseases. Deer ticks are half the size of dog ticks, and lack the latters” white "racing stripes" down the back. But the deer tick nymphs, more common this time of year, are as small as poppy seeds, that is until they attach to people or animals and fill with blood to 10 times that size over several days. The longer a deer tick stays on a person, the more likely they are to contract Lyme disease, if the tick is a carrier. If the tick is attached for less than 24 hours, disease rarely follows; most patients with Lyme disease have had a tick on for over a week.

The disease itself usually causes a circular (usually over 3 inches in diameter), non-tender rash, called erythema chronicum migrans, which looks like a red "ringworm" rash around a bite site or a bulls eye and follows the bite one to several weeks later. Fever in 60% of patients, aching body and joints (90+%), and headache (65%) also occur as the rash reaches its peak and begins to fade. If not treated, later complications involving heart, nerves, brain, and joints can occur weeks and months later. But don’t be alarmed about the small mosquito bite-like red spot appearing at the site of the bite itself within a day or two; it just reflects the bite injury, not a Lyme infection.

 

So how can you avoid these troubles without moving to Northern Canada? First the most important thing to do is use DEET-containing bug dope to discourage their climbing on you. Secondly, you should check yourself and your children for ticks every day in the spring and summer after being outside. This can be hard in difficult places to see, like the back side of your knees or trunk. I thought I'd grown a big skin tag behind my knee for several days until I looked with a mirror and saw it was an engorged (swollen) tick. And wash, or at least heat in a dryer, clothes worn outside that may or do have ticks on them.

If you find a tick, and it's not swollen, and you are pretty sure it hasn't been on for more than a couple days, there is no need to submit it to the state lab; just remove it and your chances of developing disease are very small. Slow steady pressure to pull it off usually works. Don't try to burn it off. Use tweezers or a leatherman to pull steadily but gently for the several minutes it takes to get the tick to release. Breaking the head off in the bite leaves some, though substantially less, risk of infection.

If the tick is engorged and may have been on for several days, then taking a single preventive dose of doxycycline, a prescription you can call and ask your doctor for, will reduce your chances of getting Lyme from 3% to 0.6%, if the tick was infected.

If you develop a ring rash around the bite site weeks later, or in a place where you weren't aware you'd been bitten, then you should be given a course of antibiotics for 2-3 weeks, doxycycline/tetracycline for most, amoxicillin or cefuroxime for pregnant women and children, in whom the tetracyclines are not safe. The downside of the latter alternative antibiotics is that they don't also cover the rare co-infections with ehrlichiosis and babesiosis. You will probably need to see a doctor to evaluate any such rash, but ask for an urgent appointment. The rare late complications are also treated with antibiotics after being proven due to Lyme by blood test immune titers.

So use bug dope. Check yourself and the kids. Pull ticks off before they get engorged. And get antibiotics if you develop the characteristic rash or other symptoms.

For more information, check out these websites:

www.mmcri.org/lyme/lymehome.html

•http://www.maine.gov/dhhs/mecdc/infectious-disease/epi/vector-borne/lyme/index.shtml

•http://www.cdc.gov/lyme/.

Dan Onion, MD, MPH

Mt. Vernon/Vienna Health Officer

293-2076, dkonion@gmail.com

Maine CDC just sent out this message about Lyme disease on the Health Alert Network (HAN):

Lyme disease is a bacterial infection that is carried by Ixodes scapularis (the deer tick). Cases have been increasing each year in Maine, and occur in all 16 counties. Over 1,100 cases of Lyme disease were reported statewide in 2012, a record high for Maine. Lyme disease is most common among school age children, middle aged adults and adults over the age of 65. Most infections occur during the summer months, and as the weather continues to warm up, more ticks will be out in the open, and we are likely to see more cases of Lyme disease. Cases have already been reported in 2013, and the number will rise as we enter the summer months. * A full version of this advisory can be downloaded from the Maine CDC website as a Microsoft Word document (.doc) or Adobe PDF (.pdf) by clicking www.mainepublichealth.gov and looking under the Recent Health Advisories section of the page that loads. Please contact the MaineHAN Helpdesk at HAN@maine.gov if you have trouble accessing this document.


Web links:

Maine CDC page Lyme Disease

Resources for Maine Residents

∙         Lyme Fact Sheet (Word* | also in PDF*)

∙         Tick Identification

∙         Distribution of Deer Ticks in Maine 2008 (PDF*)

∙         Prevention of Tick-Borne Diseases

∙         Lyme Disease Q&A

∙         Lyme Disease Awareness and Prevention Movie

Maine CDC Surveillance report Lyme Disease - 2012  Tick Borne Diseases - 2011

Maine CDC Tracking Network – Lyme Disease  Maine Tracking Network: Lyme Disease

Maine CDC Vector-Borne Disease Website: http://www.maine.gov/dhhs/mecdc/infectious-disease/epi/vector-borne/index.shtml

Disease.reporting@maine.gov

Phone numbers:

Maine CDC disease reporting and consultation line:    1-800-821-5821

Maine Medical Center Research Institute – Vector-borne Disease Lab:   662-7142

& to find out where ticks are most prevalent, take a look at these geographic distribution maps

 

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