The first indication I’d picked up a tick-borne disease three years ago was the excruciating arthritic pain in my feet as I hobbled to a dinner party at a neighbour’s house in Jerusalem.
Later that night I experienced flu-like symptoms, including a raging fever that, even with antibiotics, would last for more than a week.
It was my wife who noticed the rash spreading across my back, which, with the black halo around the bite on my ankle, was the give-away. It was a form of spotted fever caught from an infected dog tick in the Palestinian territories.
The infectious agent is a bacteria called Rickettsia – identical in transmission and very similar in symptoms to Lyme disease and Rocky Mountain fever. I had caught the Mediterranean cousin, which is known variously as tick typhus or Boutonneuse fever and whose defining feature, in addition to the symptoms shared with Lyme disease, is a vicious rash.
This week tick-borne diseases – specifically Lyme disease – were catapulted into the headlines because of claims in a book, championed by a US congressman, that the current incidence in the US, where tens of thousands of cases of Lyme disease a year are being identified, may have been caused by a shadowy US bioweapons programme that deliberately infected ticks.
What is Lyme disease?
How common is Lyme disease?
According to Public Health England, no more than 10% of the ticks in question have the bacteria that can then cause Lyme disease. The organisation estimates 3,000 people contract the disease a year in the UK. Diagnoses in the US are much more common, at more than 300,000 a year.
How do the ticks spread the disease?
The ticks cling to grasses or other plants in relatively moist areas (Lyme disease cases have been recorded in all parts of Britain) after hitching rides on deer or other animals. They lie in wait for animal flesh to brush past. When it does, they make the leap, swelling up to the size of a pea as they feast on blood. Doctors advise anyone to check their skin for ticks by sight and by hand and remove them carefully without squeezing their bodies. Only see a GP if a rash or flu-like symptoms then develop – and be sure to mention the bite.
How dangerous is Lyme disease?
Left untreated by antibiotics, the bacteria can spread around the body with various effects including the heart condition Lyme carditis. Deaths are rarer still; a 2011 review of 114 deaths supposedly caused by Lyme disease in the US between 1999 and 2003 concluded that only one could be attributed solely to the effects of the disease.
How do you remove a tick?
Once you find a tick, the key is to remove it as quickly as possible. Use specially made very fine tweezers or you can buy claw-shaped tick-removal tools in pharmacies, outdoor pursuit shops and online. If using tweezers, pull the tick directly upwards – do not twist it – and grab it as close to the skin as possible, to ensure you remove the head and mouth.
The story, picked up around the world and shared virally on social media, has given credence to the book and its author, Kris Newby, who had been struggling to gain recognition for her theory amid a smattering of largely sceptical reviews.
Those reviews noted the thinness of the evidence of her central claim.
Others have noted the improbability of creating a bioweapon out of a slow-moving tick confined to specific habitats and using a disease that takes time to develop and is easily treated with antibiotics.
Vice News called it a “conspiracy theory”. Phil Baker, executive director of the American Lyme Disease Foundation, told the news site: “There’s evidence in the US that Lyme disease was here before Columbus came around. Plus, Lyme disease isn’t life-threatening, so it’s not a good candidate for a biological weapon.”
A colleague of Willy Burgdorfer, who first identified the organism responsible for Lyme disease and is accused of weaponising it, was equally damning in the Washington Post. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told the paper: “This is again another one of those unfortunate situations where the science fiction of these issues overwhelms the truth.”
The reality, as experts make clear, is that variants of tick-borne infections such as Lyme disease are a global problem. The World Health Organization makes clear that they spread from forested areas of Asia, north-western, central and eastern Europe, as well as the US.
The highly contentious debate – both among scientists and a wider public – over the nature of Lyme disease and its treatment is, however, specific to the US. At times it has lurched into wild and cranky speculation.
If Lyme disease is spreading, it is almost certainly nothing to do with mysterious US bioweapons programmes but instead more mundane human impacts on, and interaction with, the environment.
In the US that includes the continuing sprawl of suburbs and exurbs into places where infected ticks, and disease hosts such as chipmunks and deer, are still common. This is the explanation of the US Centers for Disease Prevention and Control.
Another explanation for the believed spread of the disease since the 1930s – even before Burgdorfer had identified and named it – is the large increase in the population of deer, one of the key hosts of the disease, in the northeastern US after the Depression.
All of which, as argued recently by Katharine Walter who has been studying ticks at Yale University, may have been exacerbated by the climate crisis. Her genome research suggests that Lyme disease has been present in the US for more than 60,000 years.
“Warmer winters and longer summers let more ticks survive and thrive further north each year,” she says. “Tick eggs hatch sooner and ticks spend more time questing for blood, and so are increasingly likely to feast on a human and pass on a disease-causing pathogen. Because more ticks survive and mature more quickly, diseases can be transmitted faster.”
None of which, needless to say, is garnering social media shares in the tens of thousands.
As I write this, I am heading to the vast forests and lakes of Minnesota’s Boundary Waters region where Lyme-infected deer ticks are commonplace.
I’ll be doing what I should have done on the West Bank when I got bitten three years ago. I’ll be tucking long trousers into socks, spraying my trouser legs with tick repellent, zipping up my tent, and checking clothes and what little hair I have left for any ticks.
Because, in the final analysis, it is humans venturing where ticks live that is the most likely cause of the spread of these diseases, combined with global heating. And that last point is sinister enough without adding bioweapons to the mix.
• Peter Beaumont is a senior reporter on the Guardian’s Global Development desk