The number of people testing positive for sexually transmitted diseases gonorrhoea, syphilis and chlamydia has risen over the past year, the national health institute RIVM said on Friday.

In total, over 143,000 people were registered at an STD clinic last year, an increase of 5% on 2015. The percentage of this group testing positive for a sexually transmitted infection rose from 17.2% to 18.4%.

The RIVM said the increase could be due to the fact that more people in high risk groups are coming forward for testing.

The number of gonorrhoea cases rose by 13% over the year while syphilis infections were up 30% to a total of 1,223. Cases of chlamydia, the most common STD among heterosexual men and women, rose 11%, as the upward trend first noted in 2013 continued.

However, there was a continuing decline in the number of HIV diagnoses, which reached 285 last year. Of them, 93% involved men who have sex with men,the RIVM said.