Study 1: TasP

Study 1: TasP

• BC Centre for Excellence in HIV/AIDS
• Vancouver resource rich
  • Free treatment by universally accessible health care
  • centralized laboratory monitoring
• For every 1% increase in number of individuals on suppressed HAART, HIV incidence rate decreased by 1%
• Declining trend in new HIV diagnosis in BC unique in Canada
• TasP favourable cost-benefit ratio

Study 1: TasP

Choose parameters to fit Vancouver MSM:

• Infection rate    <--> Prevalence
• Testing rate       <--> HIV awareness
• Treatment rate <--> Treatment percentage

Study 2: Acute infection

• Infectiousness correlates with viral load
• Viral load very high shortly after exposure
• How much of the epidemic is driven by acute infections?

Study 2: Acute infection

• Pooled NAAT tests at HIV testing clinics
• Recruitment between April 2009 and June 2012
• Very difficult to catch early infections:
  • 13 participants with acute infection
  • 12 with early infection
• Questionnaires on sexual activity, number of partners, use of condoms, etc.

Goal: Find acute/early infections in Vancouver

Study 2: Acute infection

Findings:

• 64% were not expecting a positive result
• Likelihood of "risky sex" decreased for first 3 months after diagnosis, remained low during follow-up, but increased over time
• All participants eventually resumed sexual activity, 92% resumed anal sex
• The 25 cases would not have been detected otherwise, hence prevented secondary cases.

Study 2: Acute infection

Study 2: Acute infection

Choose parameters to fit Vancouver MSM:

• # acute infections found

Study 2: Acute infection

Choose parameters to fit Vancouver MSM:

• Effect of recent diagnosis

• Difficult to find early infections
• Are there any differences between the infected and non-infected group?

Study 3: Negative cohort

Why study HIV negative cohort?

• 166 HIV- MSM (tested at health clinic in Vancouver)
• 1 year follow-up with 4 questionnaires
• Questions similar to positive cohort
• 33 men reporting risky sex in the past 6 months, those invited to interview.

Study design

Study 3: Negative cohort

1. Have you had a HIV test in the LAST 5 months?
2. How many men have you had anal sex with in the LAST 3 months?
3. How often do you use condoms when you are the top when having anal sex?

Example questions:

Findings: ??? - in progress

• Is the at-risk population homogeneous?
• If not,
  • how much do they differ?
  • how stable are the compartments?

Study 3: Negative cohort

Distinguish between high-risk, low-risk

Different infection rate and testing behaviour

Study 3: Negative cohort

(How often) Do people switch between groups?