Table 3.
Factors associated with a repeat positive rectal chlamydia diagnosis, treatment failure and reinfection*
| Repeat positive (n = 64) | Treatment failure (n = 29) | Reinfection (n = 35) | |||||
|---|---|---|---|---|---|---|---|
| Characteristic | n (%) | Unadjusted OR (95% CI) | Adjusted OR (95% CI) | n (%) | Unadjusted OR (95% CI) | n (%) | Unadjusted OR (95%CI) |
| Age (years) | |||||||
| ⩽29 | 38 (59·4) | Ref. | Ref. | 18 (62·1) | Ref. | 20 (57·1) | Ref. |
| 30–39 | 16 (25·0) | 0·9 (0·4–1·7) | 0·9 (0·4–2·1) | 8 (27·6) | 0·9 (0·4–2·2) | 8 (22·9) | 0·8 (0·3–2·0) |
| ⩾40 | 10 (15·6) | 0·7 (0·3–1·8) | 0·7 (0·3–1·8) | 3 (10·3) | 0·4 (0·1–1·6) | 7 (20·0) | 0·9 (0·4–2·4) |
| Organism load in index cases (log10 copies/ml) | Median 5·0 | 1·8 (1·4–2·3)† | 1·7 (1·4–2·2)† | Median 5·2 | 2·0 (1·4–2·7)† | Median 4·7 | 1·6 (1·2–2·2)† |
| Time between treatment and diagnosis (days) | Median 54 | 1·0 (0·9–1·1) | 1·0 (0·9–1·1) | Median 55 | 1·0 (0·9–1·2) | Median 50 | 1·1 (0·9–1·2) |
| Concurrent co-infections with other STI (excluding HIV) | |||||||
| Yes | 15 (23·4) | 0·7 (0·3–1·3) | Excluded | 6 (20·7) | 0·6 (0·2–1·5) | 9 (25·7) | 0·7 (0·3–1·7) |
| No | 49 (76·6) | Ref. | 23 (79·3) | Ref. | 26 (74·3) | Ref. | |
| Ever had chlamydia in past | |||||||
| Yes | 11 (17·2) | 1·7 (0·7–3·8) | Excluded | 4 (13·8) | 1·3 (0·4–4·1) | 7 (20·0) | 2·0 (0·8–5·3) |
| No | 53 (82·8) | Ref. | 25 (86·2) | Ref. | 28 (80·0) | Ref. | |
| HIV status | |||||||
| Positive | 13 (20·3) | 1·0 (0·5–2·2) | 2·0 (0·7–5·2) | 6 (20·7) | 1·1 (0·4–2·8) | 7 (20·0) | 1·0 (0·4–2·6) |
| Negative | 51 (79·7) | Ref. | Ref. | 23 (79·3) | Ref. | 28 (80·0) | Ref. |
| No. of male partners last 3 months | |||||||
| 0–1 | 16 (25·0) | Ref. | Ref. | 8 (27·6) | Ref. | 8 (22·9) | Ref. |
| ⩾2 | 48 (75·0) | 1·9 (1·0–3·6) | 2·5 (1·1–5·8)† | 21 (72·4) | 1·7 (0·7–4·0) | 27 (77·1) | 2·1 (0·9–5·0) |
| No. of male partners last 12 months | |||||||
| 0–1 | 12 (18·8) | Ref. | Excluded | 6 (20·7) | Ref. | 6 (17·1) | Ref. |
| 2–5 | 17 (26·6) | 1·7 (0·7–4·1) | 6 (20·7) | 1·2 (0·4–4·1) | 11 (31·4) | 2·3 (0·8–6·6) | |
| ⩾6 | 35 (54·7) | 1·8 (0·9–3·9) | 17 (58·6) | 1·8 (0·7–4·9) | 18 (51·4) | 1·9 (0·7–5·1) | |
| Condom use with male partner, receptive anal intercourse, last 3 months | |||||||
| Always | 16 (28·1) | Ref. | Excluded | 6 (21·4) | Ref. | 10 (34·5) | Ref. |
| Never/sometimes | 16 (28·1) | 1·0 (0·4–2·3) | 8 (28·6) | 1·3 (0·5–3·1) | 8 (27·6) | 1·2 (0·5–2·9) | |
| Missing/not applicable | 25 (43·9) | 0·7 (0·3–1·5) | 14 (50·0) | − | 11 (37·9) | − | |
| Genovar by OMP classification | |||||||
| B complex (B, D, E, L2) | 30 (52·6) | Ref. | Excluded | 13 (50·0) | Ref. | 17 (57·8) | Ref. |
| Intermediate group (F, G) | 19 (33·3) | 0·7 (0·4–1·4) | 12 (46·2) | 1·1 (0·5–2·5) | 7 (22·6) | 0·5 (0·2–1·2) | |
| C complex (J) | 8 (14·0) | 0·7 (0·3–1·7) | 1 (3·9) | 0·2 (0·1–0·3) | 7 (22·6) | 1·1 (0·1–0·4) | |
OR, Odds ratio; CI, confidence interval.
*
Treatment success is the reference group (n = 163); Excluded = excluded from multivariate analysis.
†
P < 0·05.