By Martin Robinson
Last updated at 9:03 PM on 12th October 2011
For decades experts have been prevented from fully understanding the bacteria, which if undetected can make sufferers infertile.
But now researchers in Southampton have made a significant breakthrough in accessing the chlamydial genome and believe it could pave the way for more effective treatment of the disease.
They hope that it could eventually lead to the development of a vaccine.
There are more than 100,000 known cases in Britain each year – many of them involving men and women under 25.
The infection is part of a silent epidemic as most cases do not show symptoms and are left untreated.