Chlamydia is known as the 'silent' infection due to its lack of noticeable symptoms
Government missed an opportunity to slash chlamydia rates in England by a botched attempt at screening for the sexually transmitted disease, say MPs.
The Public Accounts Committee says there was a lack of urgency in trying to reach the high volume of testing needed to curb the spread of infection.
As a result, more young people than necessary are still being infected, it says in a report.
Ministers said the English programme would take time to perfect.
In 2008, almost 210,000 people were diagnosed with chlamydia.
It is known as the 'silent' infection due to its lack of noticeable symptoms.
Left untreated, chlamydia can cause severe health complications and infertility in women, but it is easy to detect.
This was the point of the national screening programme, but it has come under repeated criticism, most recently by the National Audit Office and now by the committee that oversees government spending.
Although £100 million has been spent on screening in England since 2003, it is not yet known what effect, if any, this has had, says the cross-party group of MPs.
When the screening was first introduced, testing was not compulsory.
During the financial year 2007-08, five years after the programme's launch, only 5% of 15 to 24 year-olds were tested, against a target of 15%.
According to the committee report, when it became clear that very little was happening government introduced a new requirement for trusts to test 17% of their 15-24 year-old population, which drove the testing rate up to around 16% in 2008-09.
But the programme has not yet reached the level of activity where models predict that the spread of chlamydia will be significantly reduced, it says.
Edward Leigh, chairman of the committee, said: "This is a classic example of what can happen when the responsibility for delivering a national initiative is pushed down to local level, with little thought about the mechanisms and interventions needed at national and regional level to maintain efficiency and momentum."
He says government needs to make the screening programme a national response to a national problem.
To do this, it should identify the most cost-effective local delivery strategies, establish regional or national commissioning arrangements and increase testing numbers.
Not only should this cut infection rates, but improving efficiency could save £40 million a year, he says.
Simon Blake, of Brook, the sexual health charity for young people, agreed with the criticisms.
He added: "There has been duplication of effort. The programme has not always been as efficient or effective as possible."
But public health minister Gillian Merron said the programme was improving.
"An ambitious new programme on this scale takes time to perfect and improve," she said.