Ticks in your neighborhood? No need to panic!

In 2015, the University of Turku tick project launched a massive crowdsourcing campaign, with the aim of collecting tick samples from all over Finland. The campaign was a success, with nearly 7000 letters received, containing roughly 20 000 individual ticks from all around Finland.

After this campaign concluded, our efforts have been focused on analyzing the collected data, particularly focusing on the pathogens that ticks carry. Once these analyses are ready, we will have knowledge of the prevalence – that is, the percentage of ticks that have been found to harbor the pathogen in question, in relation to the total number of ticks studied – of current medically relevant tick-borne pathogens in different areas in Finland.

One of the major aims of our project has, from the very beginning, been to increase awareness regarding ticks and tick-borne disease. As such, our aim is to make the data produced available to everyone once it has been peer-reviewed. However, there are some problems that have to be addressed when publishing this kind of data. One such problem is the possible hysteria arising when people learn that ticks carry certain pathogens in their neighborhood.

In particular, people need to understand the difference between the prevalence of a pathogen in a tick population and the actual chance to get infected by ticks from said population. Indeed, the prevalence of a pathogen in ticks does not depict the chance of acquiring the pathogen through tick bite – many factors affect the chances of a pathogen successfully infecting a human. Let us consider Borrelia bacteria for example: some analyses made from existing medical data estimate that only 4% of Borrelia harboring ticks feeding on humans usually cause an infection leading to disease. So, while prevalence estimates for the pathogens can get quite high, up to 20-50% regarding Borrelia, just keep in mind that prevalence does not equal the chance to get infected.

While our efforts to uncover tick-borne disease foci in Finland continue, we encourage citizens to keep on (or start!) doing tick searches after outdoor activities. In addition to avoiding ticks, the best way to prevent Lyme disease is to remove attached ticks as soon as possible. By doing a tick search and removal after outdoor activities, you effectively prevent infection by Borrelia spirochetes – just be sure to check your body with adequate precision.

Jani Sormunen
Doctoral candidate, University of Turku tick project
Ecology