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 IFU | Low | High | ||
| N=46 | N=23 | N=19 | ||
| 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 IFU | 8 (17.4%) | 3 (13.0%) | 1 (5.3%) | – |
| Low | 3 (6.5%) | 7 (30.4%) | 10 (52.6%) | |
| High | 9 (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.