Karin Markhede from Sahlgrenska Hospital told TT that they could not say how the woman was infected.
On Wednesday, Sweden confirmed its first death of a coronavirus patient. The patient was being treated at the intensive care ward at the Karolinska University Hospital in Huddinge when they were diagnosed with the coronavirus. Stockholm health officials said the patient had underlying health conditions.
The Public Health Agency reported on Saturday that there are now 924 people in Sweden infected by the coronavirus.
It says the majority of people have been infected abroad or through someone in the area who has come home from a foreign trip. 341 cases have been found in the Stockholm region.