High incidence of diagnosis with syphilis co-infection among men who have sex with men in an HIV cohort in Ontario, Canada

Table 1 Characteristics of HIV-positive MSM included in the analysis, OHTN Cohort Study, 2006–2010

	Analysis of first syphilis diagnosis		Analysis of syphilis re-diagnosis		Combined analysis of new syphilis diagnosis
	n	%	n	%	n	%
Total N	1799	100	586	100	2271	100
Mean age at baseline (SD) (a)	45.2	9.2	47.1	10.5	45.9	9.5
Sexual orientation
Gay	1360	75.6	493	84.1	1752	77.1
Bisexual	129	7.2	27	4.6	151	6.6
Heterosexual	75	4.2	7	1.2	81	3.6
Unknown (b)	235	13.1	59	10.1	287	12.6
Race
White	1311	72.9	423	72.2	1654	72.8
Black/African	54	3	27	4.6	77	3.4
Multiple	138	7.7	52	8.9	177	7.8
Indigenous	111	6.2	20	3.4	126	5.5
Other	116	6.4	51	8.7	157	6.9
Unknown	69	3.8	13	2.2	80	3.5
Education (c)
High school or less	395	22	111	18.9	493	21.7
Trade school or college	498	27.7	179	30.5	633	27.9
University	680	37.8	242	41.3	871	38.4
Unknown (b)	226	12.6	54	9.2	274	12.1
Annual personal income (c)
Less than $20,000 CDN	565	31.4	188	32.1	716	31.5
$20,000 to $59,999 CDN	631	35.1	213	36.3	799	35.2
$60,000 CDN or more	353	19.6	122	20.8	452	19.9
Unknown (b)	250	13.9	63	10.8	304	13.4
Region where receiving HIV care
Toronto	1224	68	474	80.9	1598	70.4
Ottawa	193	10.7	50	8.5	237	10.4
Elsewhere in Ontario	382	21.2	62	10.6	436	19.2
Year of HIV diagnosis
Median (IQR)	1997	(91,03)	1997	(91,03)	1996	(91,03)
Diagnosed in 2006–09	177	9.8	56	9.6	214	9.4
Clinical status at baseline (a)
Initiated antiretroviral treatment	1952	86.0	1546	85.9	491	83.8
Mean CD4 cell count/mm³ (SD)	497.1	261.6	491.3	252.4	497.1	261.6
Undetectable viral load (d)	1173	65.2	363	61.9	1473	64.9

MSM Men who have sex with men, SD Standard deviation, IQR Interquartile range
(a) Baseline was the later of January 1, 2006 or the date of enrolment in the cohort
(b) Unknowns include men who were not interviewed
(c) As reported at the participant’s first interview in 2007–2010, available for 1967/2271 men
(d) Undetectable viral load defined as <50 copies/mL in 2006–2009 and <40 copies/mL in 2010

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