Paper # 88LB|
Association of Expanded HAART Coverage with a Decrease in New HIV Diagnoses, Particularly among Injection Drug Users in British Columbia, Canada
Julio Montaner*, E Wood, T Kerr, B Yip, V Lima, K Shannon, R Harrigan, and R Hogg
BC Ctr for Excellence in HIV/AIDS, Vancouver, Canada
Background: We recently described an association
between expanded HAART coverage, decreased “community plasma HIV-1-viral load”
and decreased HIV transmission within two long-standing research injection drug
users (IDU) cohorts in the downtown eastside (DTES) of Vancouver. However,
prospective populational evaluation of this association is lacking.
Methods: We used administrative records to evaluate
the association between expansion of HAART coverage, plasma HIV-1-viral load
and new HIV diagnoses in BC. HAART and medical services are available free of
charge for all British Columbia residents. HIV testing, HAART distribution, and
plasma HIV-1-viral load determinations are centralized in British Columbia. A
targeted effort to expand HAART outreach among IDU was initiated in 2007. Data
for second half of 2009 is preliminary due to delayed reporting, therefore only
the first half of 2009 was used for statistical analyses.
Results: Following the initial HAART roll out in
1996 to 1999, the number of individuals on HAART remained remarkably stable in
British Columbia until 2003 (Fig 1, blue line, left axis). The number of
individuals on HAART increased from ~2500 to ~5000, from 2004 to 2009. As
previously described, the initial HAART roll out was associated with a ~50%
decrease in new HIV diagnoses (first half of top red line, right axis, P =0.027).
The HAART expansion in 2004 to 2009 was associated with a second decrease in
new HIV diagnoses (second half of top red line, right axis slope calculated
quarterly counts until June 2009, P =0.001). Of note, a ~50% a
decrease in new HIV diagnoses among IDU (bottom red line, right axis) was
evident after 2007 and the proportion of HIV infected IDU in BC with plasma
HIV-1-RNA levels above 1500 copies/mL, as a surrogate for high “community
plasma HIV-1-viral load, decreased steadily from ~50% between 2000 to 2004 to
~20% in 2009 (Fig 2 P <0.001).
Conclusions: The results of this prospective
population study demonstrate an association between expanded HAART coverage,
decreased “community plasma HIV-1-viral load”, and decreased new HIV diagnoses,
temporally related to a HAART outreach effort targeting IDU.
1 Figure 2