Contact-tracing in patients with genital chlamydial infection

Of 2021 men attending a venereal disease clinic during a 20-month period, 527 (26·1%) harboured Chlamydia trachomatis, 310 (15·3%) Neisseria gonorrhoeae, and 94 (4·7%) both organisms. C trachomatis and N gonorrhoeae were isolated in 163 (15·7%) and 141 (13·8%) respectively of 1039 women attending the same clinic over a one-year period; 44 (4·2%) women harboured both organisms.

Contact-tracing was carried out for 112 male and 88 female patients infected with chlamydia, none of whom had gonorrhoea. Of the 144 female contacts, 103 (71·5%) attended for examination and 67 (65%) were found to harbour chlamydia. Of the 103 male contacts, 95 (92·2%) attended for examination and 50 (52·6%) were found to harbour chlamydia. Of the 67 female contacts, about 55% were symptomless as were 50% of the male contacts. Cultures for N gonorrhoeae from the sexual contacts of patients with genital chlamydial infections showed positive results in 37 (18·5%) of the 200 contacts examined.

For comparison the results of contact-tracing in 201 male and 231 female patients with gonorrhoea were analysed. Of the male and female contacts, 64·5% and 66·1% respectively attended the clinic for examination. N gonorrhoeae was isolated from 77·7% of the female and from 85·6% of the male contacts; about 40% and 50% respectively were symptomless.

The high percentage of symptomless carriers of C trachomatis among sexual contacts emphasises the need for tracing contacts of this infection.