Walkers are being urged to check for tick bites after the public health agency RIVM reported an upsurge in incidents in recent weeks.

Most tick bites are harmless, but around 27,000 people a year develop Lyme disease, which can lead to swollen joints and tissues, stiffness, and in the worst cases strokes and blindness. One in 27 sufferers have long-term complications.

The disease is caused by a bacteria carried by the bloodsucking insect. A common early symptom is a rash that spreads out from the bite in the shape of a target.

The RIVM said the number of reports so far this year is 39% lower than average, probably because of the wet spring weather deterring people from going outside.

But as the peak season for both walking and tick activity approaches, the agency is calling for people to check for bites after spending time outdoors.

Anyone who discovers a tick bite can ask their doctor for an antibody test to check for Lyme disease. Home testing kits are available online for about €20, but the RIVM has warned that these are not reliable.