Lyme disease and you
by Zenah Surani
I decided to write an article about Lyme disease in humans, to build on an article written in a recent Glebe Report by Dr. Michael Mossop on Lyme disease in our pets. Lyme disease is indeed something to watch out for this summer as it is on the rise in Ontario. Because we are getting many more questions about ticks, Lyme disease and insect repellent these days at the pharmacy, I thought it would help to answer some of our frequently asked questions.
What is Lyme disease and why is it more prevalent now?
Lyme disease is caused by a bacterium called Borrelia burgdorferi and is the most common tick-borne infection in North America. In Ontario, Lyme disease is spread through the bites of blacklegged ticks. While not all blacklegged ticks carry Lyme disease, it is possible to encounter an infected one anywhere in the province.
Most commonly, a person who is bitten by an infected tick will experience a red rash and early symptom such as fever, muscle and joint pain, headache and fatigue. The early symptoms usually manifest anywhere between three and 30 days. Sometimes, however, the person may not have any early symptoms at all.
If left untreated, the bacteria will begin to spread throughout the body. As it spreads, the affected person may start to feel weakness and numbness in the limbs. In the long term, Lyme disease can cause damage to the cardiovascular and nervous systems and increased inflammation in the joints.
If someone is aware of a tick bite and recognizes the early symptoms, immediate antibiotic treatment can be effective. Removing a tick (more on this later) within 24 – 36 hours of attachment can also decrease the risk of contracting Lyme disease.
In the early 1990s, only one area in Ontario was known to be at risk, Long Point Provincial Park. One main reason for the increased prevalence of infected ticks is global warming. Warmer overall temperatures mean that ticks have a longer season in which to find hosts to feed on, and a longer season in which to reproduce before the weather turns colder and they die off.
How is it spread?
Lyme disease in humans is caused by a bite from an infected tick. Ticks cannot jump or fly but they can crawl onto us and other mammals when we brush against them, for example, when walking through tall grass, leaf piles or bushes. Ticks thrive in areas that are moist and shaded, like the woods and forest. The bacterium that causes Lyme disease, Borrelia burgdorferi, lives in animals such as mice, chipmunks, deer and birds.
How do I know it’s a tick bite?
Most but not all people who have been bitten by an infected tick will experience a red skin lesion within 3 to 30 days of being bitten. It’s usually greater than 5 cm in diameter and will not be particularly painful or itchy. It will typically slowly grow in size and will commonly take on the appearance of a bull’s eye (a red circular lesion with a red ring around it). It could also take on various shapes.
How I can prevent myself from getting bitten?
If you’re planning to be out in a wooded area, covering the skin with long-sleeved clothing and pants is very important. Tucking your pants into your socks will give you even more protection. Wearing light-coloured clothing can help in spotting ticks to remove them.
Invest in a good quality insect repellent. Ontario Public Health recommends a spray containing DEET (which is very effective but has a bad rep because neurotoxicity can occur with excessive use) or icaridin, which is also effective and safer. Check yourself for ticks after being in an area where blacklegged ticks live (Public Health Ontario’s website has a helpful map that shows at-risk areas).
Pay close attention to skin folds and use a mirror or ask someone to help you to check your back. If you do encounter a tick on your skin, do not use your fingers to remove it. Use fine-tipped tweezers or tick-removal tweezers to grasp it and pull it straight out. Take care to pull the entire tick out, including its head, and try not to crush the tick or any part of its body. Once it’s out, place it in a secure container and contact your public health unit; they can test the tick. If you believe you’ve been bitten by a tick, it’s best to see your doctor as soon as possible because the earlier you receive treatment the less at risk you are for contracting Lyme disease.
Sources:
Ontario Public Health: Lyme Disease
US Pharmacist: Lyme Disease: The Pharmacist’s Role in Prevention and Treatment
Vox Media: “Lyme Explained”
Canadian Pharmacists’ Letter
Zenah Surani is the owner and pharmacist of the Glebe Apothecary.
