Pharyngeal Flora in a Sexually Active Population

During a 7-week period 1141 patients attending the Genitourinary Clinic at Charing Cross Hospital completed a brief questionnaire and had pharyngeal swabs cultured for Neisseria spp, β-haemolytic streptococci, corynebacterium and yeasts. The study included 397 heterosexual men, 492 heterosexual women, 189 homosexuals, 41 lesbians and 22 bisexual men and women. Four hundred and sixty patients (40%) admitted oro-genital contact in the preceding 2 weeks.

The meningococcal carriage rate was 11.6%. Homosexuals had the highest carriage 23.8% and heterosexual females the lowest 5.9%. Significant differences in carriage rates were found between homosexual and heterosexual men (P<0.0001), heterosexual men and women (P<0.005) and between lesbian and heterosexual women (P< 0.025). Recent oro-anal contact significantly increased meningococcal isolation (P<0.001).

A significant association between β-haemolytic streptococci and concomitant meningococcal carriage was also found (P<0.01).

Sexual orientation and oro-genital contact influences both meningococcal and pharyngeal yeast isolation and should be considered when interpreting pharyngeal culture results.