The number of young people being tested for chlamydia has risen by 44% in the past year, a report said.
The Health Protection Agency (HPA) said there has been a large upsurge in community-based testing of the infection after a report revealed 1.5 million tests had been taken through a national screening programme and through other community-based tests.
As a result, the number of tests carried out at Genitourinary Medicine Clinics (GUM) dropped between 2008-09/2009-10 as more young people take advantage of screening programmes that are available in their local area.
Community screening programmes have detected 10,200 more cases of the infection - the most commonly diagnosed STI among under-25s in the UK - in the past 12 months, with 90,700 cases detected in young adults in 2009-10.
The HPA said the overall increase could be due to the inclusion of chlamydia testing in the Vital Signs Indicator Framework, which assesses the performance of primary care trusts.
The proportion of people tested for the STI rose from 23.7% in 2008-09 to 29.9% in 2009-10. The HPA said that much of the increase was gained through the success of the national screening programme that has been rolled out to cut the number of cases of chlamydia among young people.