Scotland could face an infestation of TICKS thanks to climate change: Numbers of the pests will double if temperatures rise by just 4°C, study warns

  • Computer models predict how numbers of ticks will change in Scotland by 2080
  • An increase in ticks could also spark a surge in cases of Lyme disease 

Scotland could face an infestation of ticks - with climate change to blame.

That's according to scientists from the University of Stirling, who have used computer modelling to predict how numbers of the pests will change by 2080.

Under the most optimistic climate change scenario, in which global temperatures rise by 1°C, they predict that the prevalence of ticks in Scotland will increase by a quarter.

However, if temperatures rise by just 4°C, numbers will almost double, according to the team.

Worryingly, an increase of ticks could also spark a surge in cases of Lyme disease – a bacterial infection that can be spread to humans by infected ticks.

Scotland could face an infestation of ticks - with climate change to blame (stock image)

Scotland could face an infestation of ticks - with climate change to blame (stock image) 

The team developed a model which predicts tick density by 2080 under varying climate change scenarios ¿ including no change in temperature (top left), and a global temperature rise of 1°C (top right), 2°C (bottom left), or 4°C (bottom right)

The team developed a model which predicts tick density by 2080 under varying climate change scenarios – including no change in temperature (top left), and a global temperature rise of 1°C (top right), 2°C (bottom left), or 4°C (bottom right)

Measuring just 1cm long, adult ticks are about the same size as an apple seed.

But despite their diminutive size, ticks can transmit nasty viral and bacterial infections to both animals and humans – including Lyme disease.

'Ticks that may cause Lyme disease are found all over the UK, but high-risk places include grassy and wooded areas in southern and northern England and the Scottish Highlands,' the NHS explains.

In their new study, the researchers set out to understand how numbers of ticks in Scotland could change as temperatures continue to rise.

The team developed a model which predicts tick density by 2080 under varying climate change scenarios – including no change in temperature, and a global temperature rise of 1°C, 2°C, or 4°C.

The results suggest that, if global temperatures rise by 1°C, the prevalence of ticks will increase by 26 per cent.

But if global temperatures rise by 4°C, the prevalence of ticks will increase by 99 per cent.

In terms of the locations that could be affected, the researchers warn that under the most extreme scenario, only the highest peaks in Scotland will remain tick-free.

Worryingly, an increase of ticks could also spark a surge in cases of Lyme disease ¿ a bacterial infection that can be spread to humans by infected ticks

Worryingly, an increase of ticks could also spark a surge in cases of Lyme disease – a bacterial infection that can be spread to humans by infected ticks

'The strength of these predicted increases in tick density varied depending on the habitat,' said Professor Rachel Norman, who led the study.

'While woodland habitats were predicted to experience the highest absolute increases, the largest proportional increases were predicted for the slopes of mountains, known as montane habitats.

'Many of these areas that were predicted to be tick-free under recent climatic conditions were predicted to become warm enough to allow sustained tick populations by 2080.'

While this study focused on ticks in Scotland, the researchers say that their model could be applied to other countries, or even other vector species. 

'While we developed the approach to predict tick densities over Scotland, it could be easily used for other areas and other vector species, and pathogens could be added to the model, enabling predictions of disease risk,' Professor Norman added.

'Indeed, this methodology could be used more broadly to understand the dynamic response of populations over time to a variety of environmental changes and provides a neat new method in the modelling toolbox for researchers to choose from.'

WHAT IS LYME DISEASE?

Lyme disease is caused by a bacteria that is transmitted to humans through the bite of infected black-legged ticks.

The most common symptoms of the disease are fever, headache, fatigue and a skin rash called erythema migrans.

The disease can typically be treated by several weeks of oral antibiotics.

But if left untreated, the infection can spread to the joints, heart and nervous symptoms and be deadly.  

WHAT HAPPENS WHEN YOU ARE INFECTED?

During the first three to 30 days of infection, these symptoms may occur:

  • Fever
  • Chills
  • Headache
  • Fatigue
  • Muscle and joint aches
  • Swollen lymph nodes
  • Erythema migrans (EM) rash 

The rash occurs in approximately 80 per cent of infected people.

It can expand to up to 12 inches (30 cm), eventually clearing and giving off the appearance of a target or a 'bull's-eye'.

Later symptoms of Lyme disease include:

  • Severe headaches and neck stiffness
  • Additional rashes
  • Arthritis with joint pain and swelling
  • Facial or Bell's palsy
  • Heart palpitations
  • Problems with short-term memory
  • Nerve pain 

Source: CDC