Table 3

Chlamydial DNA concentration in initial and follow-up pharyngeal Chlamydia trachomatis positive samples and association with spontaneous clearance of pharyngeal chlamydia in 88 patients, STI clinic, Public Health Service of Amsterdam, 2011–2012

 Chlamydial DNA concentration* in initial pharyngeal chlamydia samples†
Undetectable IFULowHigh
n (%)n (%)n (%)p Value‡
Pharyngeal chlamydia in follow-up sample
 Cleared (N=35)26 (56.5%)7 (30.4%)2 (10.5%)0.001
 Not cleared (N=53)20 (43.5%)16 (69.6%)17 (89.5%)
Chlamydial DNA concentration* follow-up PhCT samples†
 Undetectable IFU8 (17.4%)3 (13.0%)1 (5.3%)
 Low3 (6.5%)7 (30.4%)10 (52.6%)
 High9 (19.6%)6 (26.1%)6 (31.6%)
  • *Chlamydial DNA concentration defined as; low: equal or lower than median (3.4 log IFU/100 million HLA copies); high: higher than median (3.4 log IFU/100 million HLA copies); undetectable IFU: IFU undetectable.

  • †This analysis included all patients who had a C. trachomatis-positive initial result, who also provided a pharyngeal sample at follow-up, and in whose samples (both initial and follow-up) HLA could be detected.

  • ‡p Value calculated with χ2 test; chlamydial DNA concentration of initial PhCT samples in those who cleared PhCT compared with those who did not clear PhCT.

  • HLA, human leucocyte antigen; IFU, inclusion forming units; PhCT, pharyngeal C. trachomatis; STI, sexually transmitted infection.