Demographic and epidemiological characteristics of HIV-infected men with and without incident syphilis who attended the national referral centre for HIV in Singapore, 2006–2017
| Characteristic | All | Incident syphilis | No incident syphilis | P value |
| n (%) | n (%) | n (%) | ||
| All | 1069 (100.0) | 266 (100.0) | 803 (100.0) | |
| Age at HIV diagnosis (years) | <0.0005 | |||
| 15—24 | 177 (16.6) | 65 (24.4) | 112 (13.9) | |
| 25—34 | 306 (28.6) | 95 (35.7) | 211 (26.3) | |
| 35—44 | 281 (26.3) | 71 (26.7) | 210 (26.2) | |
| 45—54 | 205 (19.2) | 25 (9.4) | 180 (22.4) | |
| 55—64 | 81 (7.6) | 8 (3.0) | 73 (9.1) | |
| 65+ | 19 (1.8) | 2 (0.8) | 17 (2.1) | |
| Ethnic group | 0.055 | |||
| Chinese | 809 (75.7) | 205 (77.1) | 604 (75.2) | |
| Malay | 171 (16) | 49 (18.4) | 122 (15.2) | |
| Indian | 51 (4.8) | 7 (2.6) | 44 (5.5) | |
| Others | 38 (3.6) | 5 (1.9) | 33 (4.1) | |
| Marital status | <0.0005 | |||
| Never married | 670 (62.7) | 188 (70.7) | 482 (60.0) | |
| Married | 182 (17.0) | 19 (7.1) | 163 (20.3) | |
| Separated/divorced/widowed | 66 (6.2) | 3 (1.1) | 63 (7.8) | |
| Unknown | 151 (14.1) | 56 (21.1) | 95 (11.8) | |
| HIV transmission risk group | <0.0005 | |||
| Heterosexual | 374 (35.0) | 34 (12.8) | 340 (42.3) | |
| Homosexual | 496 (46.4) | 173 (65.0) | 323 (40.2) | |
| Bisexual | 130 (12.2) | 50 (18.8) | 80 (10.0) | |
| IDU | 5 (0.5) | 1 (0.4) | 4 (0.5) | |
| IDU and sexual | 34 (3.2) | 4 (1.5) | 30 (3.7) | |
| Others and unknown | 30 (2.8) | 4 (1.5) | 26 (3.2) | |
| Period of HIV diagnosis | 0.277 | |||
| 2006–2008 | 301 (28.2) | 72 (27.1) | 229 (28.5) | |
| 2009–2011 | 376 (35.2) | 100 (37.6) | 276 (34.4) | |
| 2012–2014 | 272 (25.4) | 72 (27.1) | 200 (24.9) | |
| 2015–2017 | 120 (11.2) | 22 (8.3) | 98 (12.2) | |
| Prior AIDS diagnosis | 0.217 | |||
| No | 808 (75.6) | 209 (78.6) | 599 (74.6) | |
| Yes | 261 (24.4) | 57 (21.4) | 204 (25.4) | |
| Ever on ART | 1.000 | |||
| Yes | 1051 (98.3) | 262 (98.5) | 789 (98.3) | |
| No | 18 (1.7) | 4 (1.5) | 14 (1.7) | |
| Ever used recreational or illicit drugs* | 0.242 | |||
| No | 231 (21.6) | 62 (23.3) | 169 (21.0) | |
| Yes | 136 (12.7) | 40 (15.0) | 96 (12.0) | |
| Unknown | 702 (65.7) | 164 (61.7) | 538 (67.0) | |
| CD4 (cells/mm3 at HIV diagnosis† | <0.0005 | |||
| ≤200 | 419 (39.2) | 69 (25.9) | 350 (43.6) | |
| 201–350 | 251 (23.5) | 82 (30.8) | 169 (21.0) | |
| >350 | 339 (31.7) | 96 (36.1) | 243 (30.3) | |
| Not available | 60 (5.6) | 19 (7.1) | 41 (5.1) | |
| Viral load (copies/mL) at diagnosis† | 0.113 | |||
| >200 | 668 (62.5) | 180 (67.7) | 488 (60.8) | |
| ≤200 | 24 (2.2) | 4 (1.5) | 20 (2.5) | |
| Not available | 377 (35.3) | 82 (30.8) | 295 (36.7) |
*Includes ecstasy, insufflated amyl nitrites or 'poppers', erectile dysfunction medications like sildenafil, amphetamines, cannabis, heroin, cocaine, barbiturates/benzodiazepines, opium, psychedelic psilocybin mushrooms, solvents, lysergic acid diethylamide).
†Within ±6 months of HIV diagnosis.
ART, antiretroviral therapy; IDU, intravenous drug use.