Posted by Last summer I took my family on a walk through the woodlands that surround the hamlet of Ebernoe, in Sussex. My children clambered on fallen trees, my partner and I hunted for mushrooms, and all the while we were being hunted by creatures more ancient than the last dinosaurs – and so hungry they would have fed on us for days.
In Ebernoe, as across the UK, ticks are on the rise. That day, we came home covered in them. One had sunk its serrated mouthparts into the back of my knee. My wife had one feeding on her flank. Yet another was lodged firmly in the dumpling-smooth skin of my one-year-old’s neck, its rear legs waggling as it sucked.
Until that day, I’d never been bitten by a tick in my life – and I spent much of my childhood bothering bugs – but by the end of that summer I had a small jar full of them. That was also the summer of the great bedbug panic and headlice turned up in record numbers, too. What’s up with bugs?
The UK Health Security Agency (UKHSA) keeps tabs on ticks from a laboratory at Porton Down. Every spring, scientists from its medical entomology team don hiking gear and go on tick hunts, sweeping patches of England and Wales with big white flags, which the ticks latch on to, thinking they’re prey. They also receive ticks in the post from the public. Their data shows a slow but steady increase of 3.2% year on year of tick records in new areas, and in 2023 there were an unusual number of reports of tick infestations, which they are now investigating.
There are 20 different tick species in the UK, most of which are specialist parasites, only capable of taking blood from particular hosts, and therefore are harmless to humans. Ixodes ricinus, also known as the sheep tick or castor bean tick, is a different beast. It’s happy feeding on mice, rats, deer, dogs and humans – often one after the other, which is why it’s the UK’s number one vector of disease. And here’s a disturbing fact about ticks: studies have shown those carrying Borellia, the bacteria that causes Lyme disease, are healthier than those which don’t. Infected ticks have higher fat reserves and are better at surviving extremes of temperature. They’re also more active, so more likely to bite.
“Ticks are out there,” says Arlene Brailey, of the Lyme Resource Centre. “The population of ticks is increasing. We need to be aware of them and we need to know how to protect ourselves. It’s not just hikers who are at risk. It’s any of us that use city parks, country parks, any long grass anywhere. Tuck your trousers into your socks. Wear light-coloured clothing. Use repellent. Always do a tick check. Remove attached ticks carefully using a tick-removal tool. Protection and prevention is the rule.”
While ticks have commonly been associated with hotspots, such as the Highlands, Exmoor and the New Forest, they can be found anywhere there’s sufficient vegetation and mammal hosts – London parks, for example. A single bite can have devastating consequences and, often, an individual won’t realise they’ve been bitten until it’s too late. Brailey’s son, Marcus, was one such case. At 18, having just started university, he collapsed.
“He was bedbound,” says Brailey. “He couldn’t even get up to get meals, showers. He had noise sensitivity. Light sensitivity. Headaches. Upset stomach. Insomnia and fatigue. Floaters in his eyes. Blurred vision. Tremors in his hands. Pains on the soles of his feet whenever he stood up. It goes on and on and on.” After several wrong diagnoses – first of depression, then chronic fatigue – and several years, during which her son’s symptoms worsened, he was eventually diagnosed with Lyme, and several other tick-borne infections, too.
“Early treatment is key,” says Brailey. “You have a window of opportunity of a month or two when antibiotic treatment is likely to be most effective. And if you miss it, Lyme can cause really debilitating disease. It starts to migrate through your system. It hides in the body.”
The early signs to watch out for are a spreading rash, which can appear up to three months after being bitten, although a third of people with Lyme won’t develop a rash; other symptoms may include fatigue, headaches, muscle or joint pain or a feeling of flu. Neurological symptoms, such as facial palsy and heart-related symptoms, may also occur.
“If there’s any indication it could be Lyme disease, then you treat it for three weeks with antibiotics,” says Brailey. “You don’t mess about, because the implications if undertreated, or not treated, are huge. If we always do that, we can prevent people from ending up like Marcus.”
Officially, about 2,000 to 3,000 people are diagnosed with Lyme each year, although this is likely to be a significant underestimate. A study published in the BMJ suggested the actual figure was three times that, and likely to rise. There is also the issue of chronic Lyme, or post-treatment Lyme disease syndrome, a cluster of symptoms that many thousands of sufferers believe is caused by the persistence of the Borrelia bacteria – an organism known to be extremely well-evolved to hide from the immune system in tissues, such as the skin, joints and brain.
Ticks have always been with us. One was found clinging to a dinosaur feather inside a piece of amber that’s almost 100m years old, and Otzi (the 5,300-year-old human corpse discovered in the Alps) had probably been bitten: tell-tale traces of Borrelia bacteria were discovered in his bones. But now, multiple studies suggest, ticks are entering a global golden age. Maps of tick distribution in North America show them surging from south to north, flourishing in regions once considered too cold for them to survive. While in the Netherlands, national surveys conducted between 1995 and 2006 showed a 75% increase in tick bites per capita. Ticks are climbing mountains, prospering at altitudes never seen before, and they’re crossing continents on the backs of migratory birds.
This isn’t just a problem for humans. Swarms of invasive Asian long-horned ticks have been attacking cows in the American midwest, resulting in several deaths by blood loss, while in Canada, forests are haunted by a phenomenon known as “ghost moose”.
Professor Steeve Côté has spent the past three years tracking moose in Quebec. His laboratory at Laval University is filled with antlers and mounted skeletons, and high on a shelf behind him is a stuffed wolf. He began studying the moose because, each year, more “ghost moose” were being discovered: skeletally thin, with large patches of pale skin showing through their fur, and covered in tens of thousands of winter ticks.
“Normally, the climate is too harsh for the ticks to survive,” he tells me over Zoom. “But with climate change the conditions in the spring are much milder and in the fall the conditions are also good, so the infestation rates are increasing. Moose are terrible at grooming. They start to groom when it itches too much, and then it’s too late, because they’re fully infested. They scratch on trees and where the hair is scrubbed off it looks white on the animal. That’s why we call them ghost moose.”
To see exactly what effect the ticks were having on the moose, Côté and his team began capturing their calves and treating half of them with anti-tick chemicals. Almost all the treated calves survived the year. Those left untreated almost all died from blood loss, malnutrition, exhaustion. Does it break his heart, I wonder, to see such majestic creatures dying in this way? “Yes it does,” he says. “I am also a moose hunter. Moose hunting is extremely important in Quebec.”
Lyme is the most famous disease spread to humans by ticks, but it’s not the only one. Last year, the UKHSA issued a warning about tick-borne encephalitis – common in Europe, and now spreading here – and there was a reported case of alpha-gal syndrome in Surrey, a rare condition linked to tick bites, which causes allergic reactions to animal products, from red meat to woollen jumpers to the smell of bacon frying. There’s also tick-borne rickettsiosis, babesiosis, Crimean-Congo haemorrhagic fever, SFTS virus, Powassan virus, Rocky Mountain spotted fever, anaplasmosis and Australian paralysis tick. After mosquitoes, ticks are the biggest vectors of disease in the world.
When I talk to Professor James Logan, a medical entomologist at the London School of Hygiene & Tropical Medicine, he has just returned from the UN climate change conference in Dubai, where he spoke to delegates about the effects climate change is having on vectors, such as ticks and mosquitoes. “My job is not to scaremonger,” he says. “I don’t want to create panic. But one thing is for sure. We know that climate change is affecting vectors. What we’re seeing generally is that with longer spells of warm weather and milder winters, particularly in temperate regions, vectors can live for longer in the year and pathogens tend to develop better in insects when the temperature is higher, so you’ve got a double whammy.”
From a bug’s perspective, this is a rare good news story. While many bumblebees, butterflies, fireflies – in fact, an estimated fifth of all insect species – are at risk of extinction, some bugs are doing extremely well. The kissing bug, famous for sucking blood from the lips of its sleeping victims, is predicted to flourish. So are phlebotomine sandflies, which spread leishmaniasis. The Asian tiger mosquito has already gone global – carrying dengue, chikungunya and Zika with it – and was detected in the UK in 2016, laying eggs at a motorway service station in Kent.
“There’s a whole load of stuff going on at the moment, which means we are kind of living on borrowed time,” says Logan. “This is a bug’s world. It’s their planet. They were here long before we were, and they’ll be there long after we’re gone. So we have to learn to live smarter in their world, essentially. We need better surveillance. We need better modelling of the data, so we can make better predictions about where outbreaks are going to occur and put measures in place.”
Is there anything ticks are good for? “Every single thing we share this rock with is an integral component of the planetary ecosystem,” says entomologist and ecologist Dr Ross Piper, author of How to Read an Insect. “From a purely zoological point of view, ticks are fascinating animals. They are superbly adapted to find, latch on to and take blood from vertebrates. And remember, parasites are extremely important components of all ecosystems. Ticks help regulate the populations of their hosts.”
How to survive on planet parasite? The good news, in the UK at least, is that, according to the UKHSA, only 4% of ticks are believed to carry Lyme and, if removed quickly, it’s unlikely the bacteria will spread. There are many ways to pluck a tick, even without the recommended tick tool. In Australia, they like to freeze them with liquid nitrogen and flick them off. Others fashion a noose from nylon thread, or floss, and tug them out like a tooth. Never try to burn them off, or suffocate them with Vaseline, unless you want them to vomit the contents of their guts into your bloodstream.
But how are you meant to remove one from the back of a toddler’s neck? Mine squirmed and screamed as I went at her with a pair of tweezers, until I had to resort to a lollipop and The Octonauts, a bleak cartoon in which a team of hard-working animals race around the globe cleaning the oceans of plastics and returning invasive species to their natural habitats. In The Octonauts, there are no humans. It’s a vision of nature healing long after we’re gone. My daughter loves it so much that she didn’t even flinch when I broke the tick’s hold and imprisoned it in a bubble of sticky tape, its legs still waggling as it died.