Quantitative culture of Chlamydia trachomatis: Relationship of inclusion-forming units produced in culture to clinical manifestations and acute inflammation in urogenital disease

The relationship of Chlamydia trachomatis inclusion-forming units in quanti tative culture to clinical manifestations and inflammation in urogenital di sease was assessed in 1179 patients attending a sexually transmitted diseas es clinic. In women, greater inclusion-forming unit counts were associated with cervical mucopus (3000 vs. 450 ifu), amount and character of cervical discharge, greater than or equal to 30 polymorphonuclear cells (PMNL) per h igh-power field (hpf) on Gram stain (2050 vs. 320 ifu), and diagnoses of mu copurulent cervicitis (MPC; 2550 vs. 300 ifu) and pelvic inflammatory disea se (PID; 3000 vs. 578 ifu). In men, greater inclusion-forming unit counts w ere associated with urethral discharge (85 vs. 44 ifu), amount and characte r of discharge, and greater than or equal to 10 PMNL/hpf (95 vs. 50 ifu). T hese associations persisted on multivariate analysis. Thus, chlamydial repl ication is associated with MPC and PID in women, urethritis in men, and inf lammation in both. Since infections with high inclusion counts may be the m ost transmissible, identification and treatment of patients with these chla mydia-associated syndromes is important in control programs.