As far as arachnid superorders go, ticks are highly successful in terms of evolution. They have existed in various forms for at least 100 million years and have developed a remarkable ability to feed on a wide range of animals in diverse environments. However, it is important to consider the potential concerns they pose in the UK. While you may not notice the blood they extract, ticks can cause various unpleasant conditions in the animals they feed on, and there is evidence suggesting that their population is increasing.
To provide some context, there are currently over 900 species of ticks found across every continent, each targeting different hosts such as seabirds, lizards, cattle, or dogs. Ticks have the ability to sense vibrations and body heat, allowing them to locate a suitable place to wait for a host. Once located, they attach themselves by latching onto a patch of skin where blood vessels are close to the surface and are difficult to scratch away. They insert their barbed, tubular mouthparts, sometimes secreting a form of “cement” to make removal more challenging. While feeding, ticks inject saliva into the wound, which contains a protein that prevents the host’s blood from clotting.
It is this saliva that causes many issues related to ticks, not just through the transmission of pathogens but also by counteracting the host’s natural bodily responses in potentially harmful ways. For example, ticks can inhibit pain receptors and suppress the immune system, which is advantageous for the ticks but can lead to serious problems for the host. Lyme disease is perhaps the most well-known condition associated with ticks, and it is a bacterial infection that affects around 5,000 people in the UK each year. Symptoms typically include a spreading rash at the site of the tick bite, flu-like illness, facial drooping, nerve pain, and numbness or tingling in the hands or feet.
More recently, ticks found in the UK have been discovered to carry tick-borne encephalitis (TBE), which can cause a range of diseases from asymptomatic infection or mild flu-like illness to severe infections in the central nervous system, such as meningitis or brain swelling. Additional information on symptoms can be found on the NHS website. While TBE is prevalent in many parts of the world, including several European countries, it was only detected in ticks in England in 2019, and human cases in the UK have been fortunately rare.
In 2017, former England rugby captain Matt Dawson had to undergo heart surgery after being bitten by a tick. So, is there a growing cause for concern now? It is difficult to say. “Since data collection began in 2005, there has been a general trend of increasing cases of laboratory-confirmed Lyme disease,” says Dr. Tim Brooks, head of the Rare and Imported Pathogens Laboratory (RIPL). “This rise could be attributed to a combination of increased awareness, improved surveillance, and better access to diagnostics. However, it could also be related to increased encounters with ticks due to changes in wildlife populations and habitat modifications that may have altered tick distribution across the country.”
On the positive side, ticks do not move around extensively on their own, which benefits individuals seeking to avoid them. According to Brooks, the most common tick species in the UK, known as deer/sheep ticks, can survive in various habitats but prefer moist areas with dense ground-level vegetation typically found in woodlands, grasslands, moorlands, heathlands, and some urban parks and gardens. Ticks do not fly or jump; instead, they wait on vegetation for a suitable host to pass by, and then they climb on. Therefore, when walking in green spaces, it is advisable to wear clothing that covers the skin to make it more challenging for ticks to access a biting spot, use insect repellent such as DEET, and opt for light-colored clothing to aid in spotting and removing ticks.
If a tick manages to attach itself to you, it is not necessarily a disaster. “On average, approximately 4% of ticks in England and Wales are infected with the bacteria that can cause Lyme disease,” says Brooks. “However, the presence of bacteria in a tick does not automatically mean the person will be infected, especially if the tick is promptly removed.”
After spending time outdoors, it is worth thoroughly checking yourself, your pets, or your children for ticks. Data from the UK Health Security Agency’s Tick Surveillance Scheme shows that adults are commonly bitten on the legs, while children are commonly bitten around the head or neck. If you find a tick, using a tick removal tool or fine-tipped tweezers can reduce the risk of infection. If you experience symptoms, remember that a rash only occurs in approximately two-thirds of Lyme disease cases. In such instances, it is important to contact your GP for antibiotics to prevent the development of further complications.
Despite the presence of ticks, it is important not to let that deter you from exploring nature. Research suggests that spending time outdoors, particularly in forests, can have enormous benefits, including alleviating anxiety and depression. While ticks may have utilized their evolutionary success by simply snacking most of the time, you don’t have to follow suit.