Screening of different populations, usually female, for infection with Chlamydia trachomatis has been commonplace since cheap and reliable, if not initially sensitive, tests became available. Most screening was of women who conveniently presented themselves at well-woman clinics or for contraception or cervical cytology.

There is, on the other hand, a dearth of prevalence studies on gonorrhoea, largely because of the historical lack of suitable, practical and cheap diagnostic tools outside specialist centres. The KC60 returns from GUM clinics reflect incidence rather than prevalence. The advent of nucleic acid amplification tests (NAATs) has made available a convenient, reliable and reproducible instrument for use in other settings. The study by Rao and others in this issue1 is thus a welcome step forward in description of the …