Hotter UK Summers Could Help Disease-Carrying Ticks Survive for Longer

Britain's changing weather patterns could be affecting the way certain ticks survive and develop, with specialists warning that warmer summers may allow some disease-carrying ticks to remain active for longer.

Among the species attracting attention is the Hyalomma tick, a parasite associated with Crimean-Congo haemorrhagic fever. Although cases linked to the disease remain rare in the UK, experts say the changing climate could create conditions that allow these ticks to develop beyond the stage at which they have traditionally been detected.

The issue highlights a broader concern about how warmer temperatures and milder winters could influence the UK's tick population and the diseases associated with ticks.

Why Are Hyalomma Ticks Being Monitored in the UK?

Hyalomma ticks are not traditionally established as a widespread population in Britain. However, immature ticks can occasionally arrive in the UK after attaching themselves to migratory birds travelling from Africa and Mediterranean regions.

These ticks can enter the country during their nymph stage. Historically, cooler British temperatures have generally made it difficult for them to complete their development into adults.

Dr Jolyon Medlock, head of medical entomology at the UK Health Security Agency, explained that ticks arriving on migratory birds would normally fall off before they could moult into their adult stage because conditions were not warm enough.

Recent heatwave years have provided different conditions.

According to Dr Medlock, warmer periods have allowed some of these ticks to progress to the adult stage. This means surveillance teams may increasingly identify adult Hyalomma ticks in the UK.

Records remain uncommon. The specialist indicated that such findings have occurred fewer than five times over approximately the past decade, although researchers and colleagues elsewhere in northern Europe are beginning to observe the phenomenon more closely.

What Is Crimean-Congo Haemorrhagic Fever?

One reason Hyalomma ticks attract public health attention is their role as a vector for Crimean-Congo haemorrhagic fever, often abbreviated to CCHF.

The disease is a viral infection that can cause serious illness. The World Health Organisation identifies Crimean-Congo haemorrhagic fever as endemic in parts of Africa, the Balkans, the Middle East and Asia.

The source article reports that the disease can have a fatality rate of up to 40 per cent. However, the presence of a tick capable of transmitting a virus does not mean that the virus is circulating in the local tick population or that every bite presents an infection risk.

This distinction is important when discussing the potential impact of changing tick populations in Britain.

How Can Crimean-Congo Haemorrhagic Fever Spread?

Crimean-Congo haemorrhagic fever can be transmitted through the bite of an infected tick. It can also spread through contact with infected animal blood or tissues.

The incubation period following a tick bite can range from one to nine days, according to the information reported in the source material.

Symptoms can develop suddenly and may include fever, dizziness, headache, neck pain and sore eyes. Other reported symptoms include nausea, vomiting, mood changes and confusion.

Because the illness can be serious, awareness of tick exposure and appropriate medical advice is important when someone develops concerning symptoms after a relevant exposure.

How Could Climate Change Affect UK Ticks?

The potential development of Hyalomma ticks is part of a wider question surrounding the relationship between weather and tick activity.

Ticks are sensitive to environmental conditions. Milder winters can allow them to remain active for longer periods, while warmer summers can provide conditions that support their development.

Dr Medlock also described a simple method researchers can use to monitor ticks. A blanket can be dragged through vegetation and undergrowth to collect ticks for examination. According to his comments, ticks can be particularly active in hot and humid conditions.

The source also reports that ticks have been observed active at temperatures below the commonly cited threshold of 7C. This suggests that their activity may begin at lower temperatures than some conventional assumptions indicate.

As winters become milder and summers become hotter and drier, specialists expect the seasonal pattern of tick activity to potentially change.

Does Finding a Hyalomma Tick Mean There Is an Immediate Health Risk?

Not necessarily.

This is one of the most important points in understanding the issue. Dr Medlock specifically cautioned that the ability of a Hyalomma tick to reach adulthood in Britain does not automatically mean that it will survive long term or that it represents an infection risk.

The UK has a dedicated tick surveillance programme that was established in 2005. Its purpose includes mapping and monitoring ticks across the country.

Surveillance helps researchers understand which species are being detected, where they are appearing and how environmental changes could affect their distribution. The source article notes that Hyalomma nymphs have been recorded on migratory birds at observatories over several decades.

What Should People Do About Ticks?

For most people, the changing tick situation is a reason to remain aware rather than become alarmed.

Ticks can be encountered outdoors, particularly in areas with vegetation and undergrowth. People spending time in such environments can take sensible precautions, including checking themselves and their clothing for ticks after returning indoors.

Pets can also encounter ticks, so owners should regularly check animals after outdoor activities and follow appropriate veterinary advice about tick prevention.

If a person finds a tick attached to their skin, it should be removed carefully using an appropriate tick-removal technique. Anyone who becomes unwell after a tick bite or develops concerning symptoms should seek medical advice and mention the tick exposure.

What Could Happen Next?

Researchers will continue monitoring tick populations as the UK's climate changes.

The appearance of adult Hyalomma ticks in Britain remains an uncommon observation, and the available evidence described in the source does not establish that these ticks have become a widespread established population in the UK.

However, the findings demonstrate why continued surveillance matters. Changes in temperature can influence the survival, development and seasonal activity of ticks, potentially affecting the geographical patterns of some tick-related diseases.

For now, specialists are watching these developments closely. The key message is that warmer weather may be creating opportunities for certain ticks to develop further than they could in the past, but that should not be confused with evidence of widespread disease transmission in Britain.

Disclaimer

This article is provided for general information only and is not medical advice. Information about ticks, infectious diseases and health risks can change as new evidence becomes available. If you have been bitten by a tick, develop symptoms after possible tick exposure, or are concerned about your health, consult a qualified healthcare professional or an appropriate public health service.