Ticks are a vector for a great number of diseases, the most well-known of which is Lyme disease. Ticks transmit bacteria and other pathogens through their bite, which is typically painless, meaning that it often goes unnoticed. What can we do to prevent ticks from biting and how do we remove them if they do bite?
Lyme disease is a reportable disease, with the latest figures showing over 27,000 confirmed cases in the US in 2013; the actual number of cases is thought to be considerably higher, around 300,000, as many cases go undiagnosed, are misdiagnoses or are not reported.1,10
Other tickborne diseases include relapsing fever, Crimean-Congo hemorrhagic fever, human babesiosis, Texas cattle fever and Rocky Mountain spotted fever.
Most ticks do not carry bacteria that cause diseases, but the rates of infection vary considerably between different states and from year to year. For example, between 2009 and 2011 in the Black Forest in Wisconsin, the average proportion of ticks infected with Borrelia burgdorferi, the bacteria responsible for Lyme disease, ranged from 11% to 35%.11
In a 2010 paper, researchers revealed that 71% of ticks tested in two counties in New York State carried at least one organism responsible for disease in humans, with 30% carrying multiple organisms.12
Rates of infection with disease-causing pathogens vary considerably, but infection in humans is thought to have increased overall in recent years, in part due to climate change and the encroachment of humans into the territory of animals that act as a host reservoir for tickborne diseases.
If you, your family or your pets spend significant amounts of time in nature, it is essential to know how to minimize the likelihood of being bitten by a tick, to know how to spot them and how to deal with ticks if you or a loved one have been bitten. Many tick bites actually occur in our backyards, rather than as a result of back country rambles and camping trips, so it is also important to take preventative measures at home and to stay watchful.
This article aims to give you the basics you need to know to avoid getting bitten in the first place and what to do if you are bitten.
Contents of this article:
Fast facts on ticks
Here are some key points about ticks and their removal. More detail and supporting information is in the main article.
- Ticks are related to spiders, scorpions and mites.
- When a tick bites a host, it releases a cement-like compound into the skin to aid its attachment.
- Prompt removal of a tick is preferable as most pathogens are not transmitted until the tick has been attached for 24 hours (transmission can occur earlier, however).
- As many as 30,000 new cases of Lyme disease are reported each year in the US, with estimates of 300,000 cases in total.
- Ticks will take blood from most warm-blooded animals (and some lizards) they come into contact with.
- There are almost 900 species of tick (more than 90 of which live in the US).
- Ticks find their hosts by detecting breath and body odors, or by sensing body heat, moisture, vibrations and even shadows.
What are ticks?
Ticks are widely distributed across the world and are responsible for spreading numerous diseases.
Ticks are small, bloodsucking arthropods that are related to spiders, scorpions and mites (the Acaridae family). Most ticks have a preferred host at different stages of their lives - deer or mice, for instance - but many will bite a human or dog if the opportunity arises.
The tick is widely distributed throughout the world and often thrives. They have very few parasites or predators, a high reproductive potential, can live for years and have a wide variety of host animals.2
Ticks have four stages in their life-cycle: egg, larva, nymph and adult. It is the nymph stage that is most likely to bite; at this point in their lives, some species can be as small as the full stops on this page.3
Where are ticks most likely to be found?
Ticks need moisture in the air to complete their life cycle, so water is an essential part of their environment. They also favor warmer regions because cold inhibits their change from egg to larva. This is why the changing climate means that many northern regions previously uninhabited by ticks are now developing tick infestations.
In short, all the tick requires to flourish is warm moist air and an animal to feed on. Any wooded area with a wealth of plants and animals is likely to be a hot spot for ticks.
How to prevent tick bitesAvoid initial contact:
- Avoid wooded areas with large amounts of leaf litter
- Stick to the center of paths
- Wear long trousers tucked into your boots and a long sleeved top
- Keep gardens neat (avoid log-piles and long grass) and stay watchful at home.
- Use repellents that contain 20-30% DEET (N, N-diethyl-m-toluamide) on any exposed skin (avoid getting repellent in the mouth or eyes)
- Clothing and camping equipment can be treated with permethrin to offer a long-lasting repellent
- Citronella may be a useful additional protective agent to be used in conjunction with other products.4
DEET is often recommended as a tick repellent, but there is some evidence that it is not as effective as permethrin or other agents. Field research by the Minnesota Insect-Borne Disease Education Council found that spraying shoes with Duranon (a 0.5% permethrin solution) led to the deaths of most ticks coming into contact with the shoe even 3 weeks later. In contrast, ticks continued to walk unimpeded over shoes recently sprayed with 35% DEET.15
There is little, if any, evidence that vitamin B1 (thiamine) or garlic have any effect as tick repellents. Some natural compounds, such as alpha-pinene, limonene, citronellol, citronellal, camphor and thymol have shown some benefits against arthropod vectors, but specific tests on ticks have not yet been performed.14
One study in Maine has revealed that a botanical compound containing 10% rosemary oil and called IC2 (classified as minimal-risk (25B)) was as effective as a commonly used synthetic product, bifenthrin, in grid tests. Bifenthrin was more effective longer term, but IC2 poses fewer threats to health than the synthetic repellent.13
How to check for ticks
The following procedure is best practice after time spent outdoors in areas popular with ticks (which may include your back yard or garden):
- Bathe or shower as soon as you get in - this will help wash off any less securely bonded ticks and help you spot any others
- After showering, stand in front of a mirror and conduct a whole body search (you can use a magnifying glass to help you spot small ticks)
- Closely investigate pets and children, and also check any outdoor gear you were using
- Place your clothing in a dryer on a high heat for an hour to destroy any remaining ticks. 5
On the next page, we look at how to remove ticks and the tools that can be used in the process.