In the 10 years since 1997, the incidence of Chlamydia has increased by 213% in men and 133% in women.1

The rate of increase has been slowing since a peak in the year 2000. Indeed, in 2006, women showed no increase. However the number of cases reported in men rose by 8%. It is difficult to know whether this is a real increase in the rate of infection in men, or is due to increasing awareness leading to more young men having check-ups.1

There is also a somewhat higher than might be expected rate of increase in both men and women over 45, possibly reflecting a rather incautious approach to sex by those who may no longer be concerned about pregnancy as a risk.1