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Tick activity rising in south, set to fade after Midsummer in Oulu region

A website offered by the University of Turku indicates which municipalities in Finland have the highest concentrations of ticks – and of the tick-borne illness TBE.

More than 36,000 tick observations have been reported so far this year in Finland (file photo). Image: Yle / Sara Vertanen

During the spring and early summer, more than 36,000 tick observations have been reported to the University of Turku's Punkkilive (siirryt toiseen palveluun) website. These indicate particularly high concentrations of the parasitic arachnids along the south coast, along with many observations from the Oulu region.

"In Oulu, the predominant species is taiga, which makes up about 98 percent of the region's ticks," according to Jani Sormunen, a postdoctoral researcher at the University of Turku's Biodiversity Unit.

This hard-bodied species begin to move around earlier in the spring than those found in the south, he said, adding that the cold spring probably affected their start-up less than that of the sheep or castor bean tick (known in Finnish as puutiainen or the more general term punkki).

"Besides, virtually all taiga ticks that attach themselves to humans and pets are adults, which are easier to detect," he said.

According to Sormunen, the activity of taiga mites largely ceases by Midsummer, after which they are mostly shelter in soil or ground debris. Observations of them are rare later in the summer. In contrast, in the south, August to September is often the worst tick season.

'Punkkilive' indicates TBE hotspots

It will soon be possible to view municipality-specific data on the prevalence of ticks on the Punkkilive observation map. The data is based on findings reported in 2021, adjusted in relation to the population of each municipality. Last year, nearly 80,000 tick observations were reported to Punkkilive by members of the public.

The app, developed jointly by the University of Turku and Pfizer, is aimed at collecting data for university research on tick distribution in Finland.

The site also compares observations with data from the Finnish Institute for Health and Welfare (THL) on cases of tick-borne encephalitis (TBE) reported in the municipality over the past five years.

According to the European Centre for Disease Prevention and Control (ECDC), this viral infection can initially cause fever, fatigue, headache, muscular ache and nausea. A second phase of the illness can involve the neurological system with symptoms of meningitis and/or encephalitis.

"Like other tick-borne infectious diseases, the risk from TBE can be reduced by using insect repellents and protective clothing to prevent tick bites," says the ECDC.

There is also a vaccine, which is offered free to permanent and summer residents of regions included in the national vaccination programme (siirryt toiseen palveluun). These range from parts of Kemi, north of Oulu, to the Åland Islands. parts of Uusimaa and the Kotka Archipelago of southeast Finland.

Ticks in Finland can also transmit Lyme disease, a bacterial infection also known as Lyme borreliosis.