Turku University Hospital (Tyks) said a child infected with measles visited the hospital's pediatric unit on Thursday, potentially exposing 100-150 people in different areas of the building.
Possible exposure zones include the pediatric reception area on Thursday (19.8) between 12.15pm and 2.15pm as well as the Mäntymäen health clinic for infectious diseases on Wednesday (18.8) from 10am to noon.
Tyks said it would contact individuals it deemed at risk. Those concerned about a potential exposure can also call the hospital at 02 313 0263.
Transmitted via respiratory droplets, measles is a highly contagious viral disease and spreads through the air when an infected person coughs or sneezes. Symptoms include sore eyes and sensitivity to light, high fever and a rash.
In 2020, public health institute THL said 96 percent of infants in Finland had had the MMR vaccine protecting against measles, mumps and rubella, with three out of five municipalities reaching the 95-percent coverage rate critical for herd immunity.
Measles symptoms usually begin about nine to 11 days after infection, according to the THL.
Finland considers almost all of those born in or after 1975 to have received the MMR vaccination at a child health clinic or school. People born before 1965 are assumed to have had the disease.