Time to clearance of Chlamydia trachomatis RNA and DNA after treatment in patients coinfected with Neisseria gonorrhoeae – a prospective cohort study

Table 2 Behaviour after inclusion and clearance of Chlamydia trachomatis based on RNA and DNA testing, by anatomical site

Characteristics	Total n (%)^a	Urethra n (%)^a	Rectum n (%)^a	Endocervix n (%)^a	P
Patients	23	7 (30.4)	7 (30.4)	9 (39.1)
Behaviour after inclusion
Median no. of samples collected (range)	28 (25–28)	28 (26–28)	28 (26–28)	27 (25–28)	0.01
Patients with missed samples	11 (47.8)	1 (14.3)	2 (28.6)	8 (88.9)	0.009
Median no. of missed samples (IQR)	1 (1–3)	2 (2–2)	1.5 (1–2)	1 (1–3)	0.86
Rectal/vaginal douching	4 (25.0)^g	-	3 (42.9)	1 (11.1)	0.26
Sexual contact	12 (52.2)	3 (42.9)	4 (57.1)	5 (55.6)	1.00
Condomless sex	5 (21.7)	1 (14.3)	2 (28.6)	2 (22.2)	1.00
RNA clearance^b
Clearance during follow-up	23 (100.0)	7 (100.0)	7 (100.0)	9 (100.0)
Day of clearance definable^c	21 (91.3)	7 (100.0)	6 (85.7)	8 (88.9)	1.00
Median time to clearance, days (range)	7 (1–13)	5 (1–13)	6.5 (5–9)	8 (6–13)	0.20
Blips^d
Samples at risk for blip	411	140	126	145
Number of blips	18	0	12	6
Number of patients	8 (34.8)	0 (0.0)	3 (42.9)	5 (55.6)	0.09
Median time to first blip from being at risk, days (range)	1 (1–16)	-	1 (1–2)	4.5 (1–16)	0.61
DNA clearance^b,e
Clearance during follow-up	22 (100.0)	6 (100.0)	7 (100.0)	9 (100.0)
Day of clearance definable^f	21 (95.5)	6 (100.0)	7 (100.0)	8 (88.9)
Median time to clearance, days (range)	6 (1–15)	6 (1–14)	5 (2–9)	7.5 (5–15)	0.08
Blips^f
Samples at risk for blip	403	117	138	144
Number of blips	7	0	0	7
Number of patients	5 (22.7)	0	0	5 (55.6)	0.01
Median time to first blip from being at risk, days (range)	3 (2–8)	-	-	3 (2–8)
Mean Ct-value (range)	38.6 (35.3–41.7)	-	-	38.6 (35.3–41.7)

RNA ribonucleic acid, DNA deoxyribonucleic acid; IQR inter-quartile range; Ct cycle threshold
^aUnless otherwise indicated
^bBased on a definition of 3 consecutive negative tests following a positive test
^cFor 2 patients the exact day of clearance could not be defined due to missing samples in the period of clearance
^dBlip was defined as a positive test following clearance. Samples from all 23 patients were included; for those without an exact day of clearance due to missing samples, all samples after the first three consecutive negative results were considered at risk for blips
^eOne patient was excluded from this analysis because the sample at inclusion was negative for Chlamydia trachomatis DNA
^fFor 1 patient the exact day of clearance could not be defined due to missing samples in the period of clearance
^gRectal/vaginal douching was only reported on by the 16 patients with rectal/endocervical infection

ISSN: 1471-2334