chlamydia trachomatis infection is the most commonly-diagnosed STI in the South East, accounting for 83 per cent of laboratory-confirmed STIs in 2010.
Surveillance scientist Dr Marrita Mahon and specialist in public health medicine Dr Sarah Doyle - both in the Department of Public Health, HSE South East - said chlamydia was the only laboratory-confirmed STI that had an increase in notifications, from 657 to 685, compared to the previous year.
The other laboratory-confirmed STIs decreased in 2010 compared to 2009: gonorrhoea from 67 to 66; herpes simplex (genital) from 41 to 38; trichomoniasis from 30 to 29; and syphilis from 30 to 29.
Notifications of ano-genital warts, the only clinically-confirmed STI, increased from 389 in 2009 to 412 in 2010.
There were 685 cases of chlamydia reported in 2010, comprising 258 males and 427 (62 per cent) females. Of those with recorded data, 401 (59 per cent) were GP patients and 267 (39 per cent) were hospital outpatients, almost all of whom attended the STI clinic. More than two-thirds of cases (461) were in those aged 20-29 years.
Dr Mahon and Dr Doyle said trachomatis and another species of chlamydia, lymphogranuloma venereum (LGV), tend to be tropical diseases, although an upsurge of LGV had been seen in Europe in recent years, largely in men who have sex with men (MSM).
They advised doctors to take a rectal chlamydial swab using a proctoscope if a patient (especially MSM) presents with proctitis.
"Genital chlamydial infection is important from a public health and clinical perspective as it is common, often asymptomatic, there are important complications and it is easily treatable," they said.
They said testing men for trachomatis was now much easier with the adoption of nucleic acid amplification tests and investigation should be with a first void urine in men and with a cervical swab or patient-taken vulvo-vaginal swab in women.
Treatment of uncomplicated infection was by azithromycin or doxycycline (contraindicated in pregnancy) and patients should avoid sexual intercourse even with a condom, including oral sex, until completing treatment or for a week, if on azithromycin.
Treatment in pregnancy or at risk of pregnancy was by erythromycin or amoxycillin, although testing of cure was necessary before resuming intercourse.
Patients should also be screened for other STIs, including HIV and, where indicated, hepatitis B, while partners should be notified and also offered tests, Dr Mahon and Dr Dolan added.
