The stomach flu outbreak in Pyynikki was caused by norovirus

According to the information collected, the cause of the stomach outbreak in Pyynikki is a small-scale outbreak of norovirus.

The authorities have been investigating the underlying factors that led to the outbreak. Although the authorities have a firm understanding of the sequence of events, it is not possible to comment further on the details of the stomach virus outbreak in order to protect individual information and confidential health data.

– The authorities know the background and the source of the outbreak has been identified. For confidential health reasons, we cannot say more, says Merja Bojang, Chair of the Epidemic Investigation Team.

Authorities thank respondents for their proactive approach and remind people to practice good hand hygiene

The survey on the causes of the outbreak received around 600 responses, of which just over 500 were reported sick. The authorities thank those who responded and answered for the survey.

– We thank all those who reported their illness and those who responded to the outbreak survey, tells Bojang.

The epidemic peaked between 27 and 28 April 2025, after which there have been few new cases. Investigations found no evidence of food or waterborne transmission of the outbreak. The main symptoms were severe vomiting, diarrhoea and fever.

– Noroviruses may continue to be shed in faeces for some time after symptoms have resolved. It is also common for symptoms to worsen again for a while after they seem to have subsided. Good hand and toilet hygiene is important to prevent the spread of infection, says Sirpa Räsänen, an epidemiologist in the Pirkanmaa Welfare Region.

Tampere City Environmental Health and Pirha Communicable Disease Control investigated the causes of the stomach flu outbreak in cooperation with health protection, food and health authorities.

Proper handwashing techniques

• Remove rings, jewellery and watches while washing and cooking
• Wet your hands with warm water
• Use liquid soap on your hands
• Rub palms together for about 20 seconds
• Also wash the backs of the hands, sides, wrists, between the fingers and the bases of nails and rings thoroughly
• Rinse hands clean
• Dry hands thoroughly on a clean disposable hand towel or cloth towel
• Close the tap so that you protect clean hands, for example with a hand towel If necessary, use a hand sanitiser after washing