This means that 31 people in the country have now been infected in the measles outbreak, which started at the festival in Västernorrland at the turn of July and August.
The new case on Tuesday is reported from Region Gotland.
Most of those infected in the outbreak are under 18 years of age and were unvaccinated against measles.
Measles has now been reported in a total of nine regions, with the most cases in Stockholm.
