New cases of stomach flu have been reported along the Karhunkierros Trail in Oulanka National Park. Metsähallitus Parks & Wildlife is aware of around twenty hiking groups, in each of which at least one member has fallen ill. To prevent the illness from spreading further, Metsähallitus is closing the wilderness huts and toilets along the Karhunkierros Trail until further notice. The cause of the illness is not yet known.
Stomach flu (a stomach bug causing vomiting and diarrhea) is spreading along the Karhunkierros Trail in Oulanka National Park. Metsähallitus Parks & Wildlife is aware of around twenty hiking groups, in each of which at least one member has become ill.
To prevent the number of cases from increasing, the wilderness huts and toilets on the Karhunkierros Trail are out of service until further notice. Metsähallitus is also urging hikers not to set out on the Karhunkierros Trail at all for the time being.
“With these measures, we want to ensure the illness is brought under control. It is difficult to maintain hygiene in outdoor conditions, and accessing medical care can be challenging,” says Airi Kallunki, Outdoor Recreation Specialist at Metsähallitus Parks & Wildlife.
Metsähallitus has delivered signage about the illness and the recommendation to avoid the area to locations such as Hautajärvi, Ristikallio, and the starting points of the Small Karhunkierros Trail.
Only the door of the Siilastupa wilderness hut has been physically closed with boarding. Not all huts can be shut in this way. A responsible hiker avoids using the huts and toilets even if their doors have not been boarded shut.
The cause of the illness is not known – the virus may survive on surfaces for several days
The cause of the illness is not yet known. However, gastrointestinal illnesses are not uncommon on popular hiking trails and may occur both in winter and during the snow-free season.
According to the wellbeing services county of North Ostrobothnia (Pohde), most cases of stomach flu are short-term illnesses lasting a day or two and resolve on their own. Rest and maintaining proper hydration – in other words, drinking enough fluids – is important during illness. The online Omaolo symptom checker can help determine when a person with diarrhea should contact emergency services.
If symptoms are severe or prolonged, the person affected can contact the health and social services centres or the digital health centre of Pohde. When health and social services centres are closed, those who are ill can call the medical helpline at 116 117.
Pohde reminds that the pathogen may remain on surfaces for several days. Norovirus, for example, can survive on surfaces for over a week.
Pohde reminds that the pathogen may remain on surfaces for several days. Norovirus, for example, can survive on surfaces for over a week.
Metsähallitus still hopes to receive reports of stomach flu symptoms
Hikers can report symptoms of stomach flu at luontoon.fi/palaute. For any personal health concerns, it is advisable to contact a doctor.
“It is very important that cases are reported to us. This helps us gain a better overall picture of the situation and enables us to share information through our channels. So, thank you to everyone who has reported their symptoms,” says Kallunki.
The Luontoon.fi website provides guidance on drinking water hygiene, general outdoor hygiene, what to do when toilets are unavailable, and how to act if stomach flu strikes during a hike.
Metsähallitus will issue a separate announcement when it is again safe to hike the Karhunkierros Trail without concern for stomach flu.
Further information
Airi Kallunki, Outdoor Recreation Specialist, Metsähallitus Parks & Wildlife
+358 40 4829 750, airi.kallunki@metsa.fi
Available until 5 p.m. on Friday 6 June 2025
During the weekend, Metsähallitus will not issue any new updates on the situation. Reports of cases received over the weekend will be reviewed on Monday.