There is an error in table 3 of the paper by Pimenta et al (J M Pimenta, M Catchpole, P A Rogers, J Hopwood, S Randall, H Mallinson, E Perkins, N Jackson, C Carlisle, G Hewitt, G Underhill, T Gleave, L McLean, A Ghosh, J Tobin, V Harindra. Opportunistic screening for genital chlamydial infection. II: Prevalence among healthcare attenders, outcome, and evaluation of positive cases. Sex Transm Inf, 2003;79:22–27).

The statistical calculation of this table combined all women, regardless of age. The authors have recalculated this table, and the revised version is available on the website (http://sti.bmjjournals.com/cgi/data/79/1/22/DC1/1 with the correct age restriction —female participants 16 to 24 years only, as originally specified. The majority of these data (general practice, family planning, and youth clinics) have only changed marginally; the main differences lie within the GUM clinics, due to the wider age of women tested at this setting. The conclusions, however, are unaffected by this error. The authors stand by their assertion that prevalence tends to be higher in those reporting and attending with symptoms than those screened opportunistically.