Health authorities see record number of tick bites during June heatwave

Dutch health authorities recorded an unprecedented level of tick bites during a late-June heat wave. More than 30 percent of respondents to a national monitoring survey reported a tick bite for the first time since the system launched in 2022.

The National Institute for Public Health and the Environment (RIVM) said more than 30 percent of the 673 people who responded to its weekly Tekenradar survey reported a tick bite, marking the highest share since the monitoring system began. Researcher Kees van den Wijngaard said such a result had never occurred before.

The RIVM surveys more than 700 people each week about recent tick bites. During the same hot period, members of the public separately reported another 800 tick bites through the Tekenradar platform.

"Normally, we also see a peak in this period, which has to do, among other things, with the weather conditions and that many people go on vacation. This is how ticks and people come into contact with each other earlier," van den Wijngaard told RTL.

Nationwide so far this year, 34 percent of tick bites occurred in gardens and 47 percent in forests. Regional patterns varied. More than 40 percent of bites in Drenthe, Groningen, and Zeeland occurred in gardens. In Noord-Holland, Utrecht, and Noord-Brabant, garden bites accounted for less than 30 percent of cases. The RIVM said it could not explain the differences.

Warm weather has continued to drive high numbers of bites in recent days, van den Wijngaard said. However, if conditions become extremely hot and dry without rainfall, it could become too dry for ticks. "They cannot handle the heat well," he said.

Authorities urge people to remove ticks as soon as possible. About 20 percent of ticks carry the bacteria that can cause Lyme disease, although only about two out of every 100 people bitten develop the illness.

In 47 percent of reported bites, the tick remained attached for more than 12 hours. The longer a tick stays attached, the greater the risk of transmitting disease.