Transcript (MSM) in Montreal - Ontario HIV Epidemiologic Monitoring Unit

HIV infection in a cohort of
men who have sex with men
(MSM) in Montreal:
Update to February 2001
Robert S, Remis, Michel Alary, Joanne Otis, Benoit Mâsse,
Eric Demers, Jean Vincelette, BrunoTurmel, René Lavoie,
Roger LeClerc, Raymond Parent and the Omega Study
Group
Department of Public Health Sciences, University of Toronto
Group de recherche épidémiologique, CHUQ
Département de sexologie, Université du Québec à Montréal
Département de microbiologie, Pavillon St Luc-CHUM
Département de santé publique, Montréal-Centre
Séro-Zéro, COCQ-sida
Canadian Association of HIV/AIDS Research
Tenth Annual Scientific Conference
Toronto, Ontario, May 31-June 3, 2001
Acknowledgements
•
•
•
•
•
Physicians who helped to recruit subjects
Gay and HIV-related community organizations
Omega Cohort Study Group
Staff, volunteers and Steering Committee members
funding agencies who supported the study including:
• National Health Research and Development Program
• Centre québécois de coordination du sida
• Fonds de la recherche en santé du Québec
• The men who contribute their time and energy by
participating in the study
MOHLTC, Laboratories Branch, IMC – 2001
Background
• MSM in Montreal seriously affected by the HIV
epidemic since it began
• The OMEGA Study is a cohort of 2,000 seronegative
gay men whom we intend to follow to better
understand HIV transmission in Montreal
• First participant recruited in October 1996
MOHLTC, Laboratories Branch, IMC – 2001
Study objectives
• Estimate HIV incidence and identify risk factors
associated with seroconversion among men having
sex with other men (MSM) in Montreal, in particular
among those less than 30 years of age
• Monitor and characterize changes in sexual
behaviour over time
• Facilitate transfer of knowledge to community
groups involved in HIV prevention
MOHLTC, Laboratories Branch, IMC – 2001
Recruitment and follow-up
•
•
•
•
•
MSM HIV negative or unknown serostatus
Recruit from clinical and community sites
Follow-up every 6 months
Subjects lost to follow-up replaced
Recruit marginalized MSM and MSM from ethnic
minorities
MOHLTC, Laboratories Branch, IMC – 2001
Data and specimen collection
• A questionnaire, self-administered and intervieweradministered, on:
• Demographic factors
• Sexual behaviours during lifetime and
previous 6 months
• Psychosocial data
• Subjects tested for HIV and syphilis
MOHLTC, Laboratories Branch, IMC – 2001
Characteristics of participants (n=1,588)
Age
•
•
•
•
•
<20
20-29
30-39
40-49
50+
5%
41%
32%
15%
6%
Education
• None
• High school
• CEGEP
• University
7%
23%
23%
46%
MOHLTC, Laboratories Branch, IMC – 2001
Characteristics of participants (n=1,588)
Residence
• Montreal Island
• Elsewhere
88%
12%
Place of birth
• Quebec
• Canada, elsewhere
• Other country
71%
12%
17%
Language
• French only
• English only
• Both
• Other
78%
12%
9%
1%
MOHLTC, Laboratories Branch, IMC – 2001
Factors associated with
HIV infection at baseline
Age (years)
<25
25 – 34
35 – 44
45+
All
Education
None
DES/DEC
Higher
MOHLTC, Laboratories Branch, IMC – 2001
n
HIV+
p-value
372
596
350
184
1,588
0.54%
1.8%
2.9%
0.54%
1.5%
0.05
109
687
680
6.4%
1.5%
0.9%
<0.0001
Factors associated with
HIV infection at baseline
n
Ethnicity
French-Canadian
1,111
English-Canadian
128
Other
226
Age at first homosexual sex
<15
387
15-20
479
20+
307
MOHLTC, Laboratories Branch, IMC – 2001
HIV+
p-value
1.1%
1.6%
3.5%
0.02
3.4%
1.3%
0.33%
0.006
Factors associated with
HIV infection at baseline
n
Drug use
Yes
No
Injected drugs
Never
Rarely
Sometimes
Fairly often
Very often
MOHLTC, Laboratories Branch, IMC – 2001
HIV+
p-value
1,029
442
2.0%
0.45%
0.04
1,343
28
46
11
45
1.0%
0.0%
6.5%
9.1%
11.1%
<0.0001
Factors associated with
HIV infection at baseline
n
Number of casual partners, lifetime
0-5
306
6-49
603
50+
585
Number of regular partners, lifetime
0
41
6-99
1,427
100+
26
MOHLTC, Laboratories Branch, IMC – 2001
HIV+
p-value
0.65%
1.0%
2.6%
0.03
2.4%
1.4%
7.7%
0.03
Incidence density among subjects
with 2 or more visits (n=1,247)
Age
<30
30+
Seroconversions
9
8
Total
MOHLTC, Laboratories Branch, IMC – 2001
17
Personyears
939
2,087
Incidence density
(95% CI)
0.95 (0.33, 1.6)
0.38 (0.12, 0.64)
3,027
0.56 (0.29, 0.83)
HIV incidence by age and year
1.6
< 30
30+
All a ges
1.4
HI V incidence
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1997
1998
1999
Yea r
MOHLTC, Laboratories Branch, IMC – 2001
2000
HIV incidence (per 100 py) by
rank of follow-up visit and year
Year of visit
1997
1998
1999
2000-01
Total
MOHLTC, Laboratories Branch, IMC – 2001
T2-T4
0.74
0.83
0.56
0.40
0.68
Rank of visit
T5-T9
0.00
0.60
0.31
0.40
Total
0.78
0.65
0.58
0.34
0.56
Factors associated with
HIV seroconversion
n
Age at first homosexual sex
<10 years old
74
10+ years old
876
Drug use, 6m
No
622
Yes
606
Injected drugs, 6m
Never/rarely
1,174
Sometimes+
28
Received $ or drugs for sex, 6m
Never/rarely
1,161
Sometimes+
45
MOHLTC, Laboratories Branch, IMC – 2001
Odds ratio (95% CI)
6.1 (0.97, 29)
4.5 (1.3, 15)
3.07 (0.07, 21)
6.3 (1.7, 23)
Factors associated with
HIV seroconversion
n
UI anal sex other than HIV-neg, 6m
No
963
Yes
170
UR anal sex other than HIV-neg, 6m
No
983
Yes
144
UR oral sex with selected partners, 6m
No
688
Yes
413
MOHLTC, Laboratories Branch, IMC – 2001
Odds ratio (95% CI)
2.9 (0.86, 9.6)
8.3 (2.8, 25)
4.4 (1.5, 13)
Behaviours (previous 6 months) associated
with HIV seroconversion, multivariate model
Adjusted OR (95% CI)
UR anal sex other than HIV-negative
regular partner
Drug use
6.5 (0.82, 52)
UR oral sex with selected partners
8.3 (0.98, 71)
Entered in model but not statistically significant:
Age, injection drug use, gave money or drugs for sex, and
insertive anal sex with other than HIV-negative regular partner
MOHLTC, Laboratories Branch, IMC – 2001
3.8 (1.1, 13)
UR oral sex with selected partners
among those with and without anal
receptive sex with other than
HIV-negative partner
OR
(CI%)
p-value
Among those without UR anal sex
UR oral sex with selected partners
Infinite
Undefined
<0.001
Among those with UR anal sex
UR oral sex with selected partners
1.9
(0.22, 17)
NS (0.48)
MOHLTC, Laboratories Branch, IMC – 2001
Interpretation
• Data on behaviours self-reported and
not independently validated
• Subjects not necessarily representative
of gay men in Montreal
• Selective attrition may introduce bias
• Multivariate model preliminary;
Further analyses are ongoing
MOHLTC, Laboratories Branch, IMC – 2001
Conclusions
• HIV incidence in a cohort of Montreal MSM not increasing
• Trends in incidence different in younger and older MSM
• Young age at first homosexual experience associated with
infection at baseline and new infection (univariate)
• The following appear independently associated with
seroconversion:
• Unprotected receptive anal sex other than with
HIV-negative regular partner
• Drug use
• Unprotected receptive oral sex with high-risk partners
MOHLTC, Laboratories Branch, IMC – 2001