Table 1. Comparisons of baseline characteristics between the IDUs and the non-IDU group.
| Characteristica | IDUs (n=423) | Non-IDU (n=194) | P |
|---|---|---|---|
| Male, N (%) | 372 (87.9%) | 194 (100%) | <0.01 |
| Age (year) | 32.2 (26.7–38.3) | 28.5 (23.9–33.0) | <0.01 |
| CD4 cell counts (cells/mm3) | 481 (388–629) | 404 (317–557) | <0.01 |
| PVL (log10 copies/mL) | 3.99 (3.47–4.39) | 5.17 (4.52–5.88) | <0.01 |
| Subtype, N (%) | <0.01 | ||
| B | 2/213 (0.9%) | 144/157 (91.7%) | |
| CRF07_BC | 199/213 (93.4%) | 0/157 (0) | |
| CRF01_AE | 9/213 (4.2%) | 4/157 (2.5%) | |
| Others | 3/213 (1.4%) | 9/157 (5.7%) | |
| Coreceptor tropismb, N (%) | |||
| CCR5-tropic only | 121/128 (94.5%) | 123/142 (86.6%) | 0.03 |
| Risk factor, N (%) | <0.01 | ||
| MSM/bisexual | 0 (0) | 188 (96.9%) | |
| Heterosexual | 0 (0) | 6 (3.1%) | |
| IDU | 423 (100%) | 0 (0) | |
| HBsAg (+), N (%) | 76/368 (20.7%) | 21/183 (11.5%) | 0.01 |
| Anti-HCV (+), N (%) | 363/370 (98.1%) | 6/184 (3.3%) | <0.01 |
| Year of diagnosis | <0.01 | ||
| 1997–2003 | 2 (0.5%) | 20 (10.3%) | |
| 2004–2007 | 403 (95.3%) | 53 (27.3%) | |
| 2008–2011 | 18 (4.2%) | 121 (62.3%) | |
| Number of CD4 cell measurements per patient | 4 (3–6) | 4 (3–8) | 0.64 |
Abbreviations: HBsAg, hepatitis B surface antigen; HCV, hepatitis C virus; IDU, injecting drug users; MSM, men who have sex with men; PVL, plasma HIV RNA load.
a
Data are median (interquartile range) for continuous variables.
b
Genotypic tropism analysis was conducted to determine the coreceptor usage using the protocol developed by Dr PR Harrigan of the BC Centre for Excellence in HIV/AIDS laboratory.22 A 10% false positive rate (FPR) was used in the G2P algorithm. The accession numbers of submitted sequences are KC787218–KC787345.