Swedish health authorities say they have identified the first domestic case of infection in the E. coli outbreak that has killed 48 people in Europe.

The Swedish Institute for Communicable Disease Control says it's the first case in Sweden without any direct link to Germany.

It said it remains unclear how the patient was infected.

Sweden has previously reported 53 cases of the infection, including 18 cases of the complication that can lead to kidney failure. All were linked to Germany.

Karin Tegmark-Wisell, a senior physician at the institute, said the patient in southern Sweden had not traveled abroad and does not have any direct links to neither Germany or France.

The agency has now started an investigation to trace the source of the infection, which is also known as EHEC.

Also Tuesday, Danish health authorities said 23 people in Denmark have been infected, including a 24-year-old who had no direct link to Germany. The case was reported last month and it remained unclear how the patient was infected.

The agency said Tuesday it remains unclear how the patient was infected.

Sweden has previously reported 53 cases of the infection, including 18 cases of the complication that can lead to kidney failure. All were linked to Germany.

Outbreak deaths and illnesses

The Robert Koch Institute, Germany's disease control center,said 47 deaths have now been reported in the country. One person has died in Sweden and officials say one death in the U.S. may be linked to the outbreak.

The disease control center says 3,901 people have been reported sick in Germany — including 838 suffering from the kidney-related complication. A further 142 cases have been reported in 15 other countries. New infections have declined significantly over recent weeks but overall numbers are still rising due to delays in notification.

The source has been traced to a sprout farm in northern Germany.

It's unclear how the sprouts were contaminated.

Meanwhile, Russia said Tuesday it is ending a blanket ban on vegetable imports from the European Union put in place over fears of E. coli infection, starting with the Netherlands and Belgium, the country's top consumer watchdog said.