Expert outlines ways to reduce tick-borne disease risks

Ticks are particularly numerous this summer, but their health risks can be reduced through precautions, vaccination and biodiversity-friendly gardening, ERR reported in a lecture by Tiina Elvisto, an associate professor of plant ecology at Tallinn University.

Ticks act as vectors for disease-causing viruses and bacteria. According to a 2025 study by the Estonian Health Board, one third of ticks in Estonia carry the bacterium that causes Lyme disease. Its prevalence varies by region, occurring in between a quarter and half of ticks. The tick-borne encephalitis virus is found in less than 1 percent of ticks, but occurs in clusters.

Tick numbers depend on where their host animals move and rest. These include mice, hedgehogs, roe deer, foxes, dogs and cats. Ticks are more numerous in such places.

Biodiversity can also help. Centipedes, ground beetles and various ants, including mound-building and red ants, eat ticks and tick eggs, as well as slugs, snails and their eggs. Elvisto said gardens and parks should preserve habitats for these invertebrates and avoid using poisons.

European garden ecologists recommend leaving about 5 to 10 percent of a garden in a natural state. Suitable habitats can include 2 to 3 square metres of leaf litter, some logs, stones and a few old branches. Mulched areas, perennial beds and spaces beneath shrubs can also support these invertebrates.

Before entering areas where ticks live, people can apply clove, cinnamon or other oils that repel ticks. For protection lasting more than about an hour, pharmacy sprays designed to repel ticks are more suitable, Elvisto said. After spending time outdoors, people should check themselves, their family members and their pets for ticks.

Vaccination against tick-borne encephalitis is essential because the disease can be severe. Estonia recorded more than 200 cases in 2023, according to the Health Statistics and Health Research Database, and almost 150 cases in each of 2024 and 2025.

Elvisto noted that diseases transmitted by ticks can now be treated. She also stressed the need to ensure sufficient resources for developing new vaccines.

Spending time in nature benefits both physical and mental health, she said, expressing hope that people worried about ticks can overcome their fear and continue to enjoy the outdoors.