The number of reported cases of gonorrhea in Sweden rose from 951 in 2011 to 1,098 last year - a rise of 16 percent, according to new statistics from the Swedish Institute for Communicable Disease Control (Smittskyddsinstitutet, SMI).
The disease, transmitted sexually and caused by the bacterium Neisseria gonorrhoeae, has been on the rise in Sweden since the middle of the nineties.
"Now we've reached a quite large figure, and this is a worrying development," Inga Velicko, epidemiologist at SMI, told the TT news agency.
The infection is more than twice as common among men, largely due to the fact that the infection is spread more among men who are having sexual relations with other men. But the SMI has also seen an increase among heterosexual couples.
The infection can lead to sterility if not treated, and is difficult especially for women to notice, as many women don't see any symptoms from the infection.
Gonorrhea can be treated with anti-biotics, however researchers are concerned that the bacteria is getting stronger and that anti-biotics may not be effective in the future.
Magnus Unemo, lecturer in microbioliogy at Örebro Univerity and director of the World Health Organization (WHO) Collaborating Centre (CC) for Gonorrhoea and Other Sexually Transmitted Infections, said the rise was part of a global phenomenon that's been happened for around five years.
"The concern has only grown since then, and this has led to international recommendations for treatment with two separate kinds of antibiotics," he said.
There are an estimated 106 million cases of gonorrhea in the world, according to WHO's latest estimation.
Citing figures from an online UK health clinic, The Daily Mail last week reported that Swedes were found to be more likely than their European counterparts to seek treatment for diseases such chlamydia and gonorrhea, dubbing Sweden Europe's "sexually transmitted disease capital".