In the first half of 2007 252 new cases of HIV were reported to the Swedish Institute for Infectious Disease Control (Smittskyddsinstitutet). That is the highest half-year figure since reporting began 20 years ago.
Anders Blaxhult, deputy state epidemiologist at the institute, told The Local that it was notable that the number of cases in all categories - that is to say heterosexual, homosexual and intravenous transmission - have risen.
One of the main reasons for the increase is rising immigration. According to Blaxhult, just over half of the reported cases of HIV infection were 'imported'.
"But what's most remarkable is that there is an increase in the number of people who contracted HIV in Sweden," he said.
In total, 7,700 cases of HIV have been reported in Sweden. Of those, around 4,000 are still living with the disease.
In the last six months, 60 percent of the new cases were men and a quarter of the new cases were contracted through homosexual intercourse. Heterosexual intercourse was behind 42 percent of the cases, and of those, two thirds of those were women. 70% of them were infected with the disease before they arrived in Sweden.
But Anders Blaxhult pointed to changing attitudes towards sex as being another contributing factor.
"Unsafe sex is more common and we also see that with more cases of chlamydia," he said.
"Awareness was higher ten to fifteen years ago. Many people are quite unaware of HIV being present in our society, or they've heard that there are drugs so maybe it's not so serious any more."
The fastest-growing category, however, was those who became HIV positive through intravenous drug use. There were 29 reported cases in the first half of 2007, almost three times the number reported in the same period last year.