Chlamydia is the most common STI in all parts of the United Kingdom.1,2

It affects predominantly women and the young, with a peak incidence in the 20-24 age group.1,2

Undiagnosed Chlamydia infection may cause serious sequelae, such as pelvic inflammatory disease and infertility in women. Due to the amount of infection which remains undiagnosed, the true rates of Chlamydia infections are likely to be higher than reported in the official statistics.2

Trends in reported cases from GUM clinics may also be affected by:

• increased rates of testing for Chlamydia infection following the Department of Health’s introduction of the National Chlamydia Screening Programme
• increased opportunistic screening for Chlamydia infection
• modernisation of GUM services
• enhancements to laboratory capacity for more sensitive testing methods