Table 1.

Population-level-and-observational cohorts evaluating expansion of treatment and risk of new HIV infection.

Setting	Time Period	Evaluation	Outcomes	Reference
Taiwan	1984 – 2002	National HIV surveillance data. Transmission rate estimated by use of exponential model.	Transmission rate 0.391 new cases/prevalent cases pre-ART Transmission rate 0.184 new cases/prevalent cases post-HAART. Overall decrease 53%.	(4)
Vancouver, British Columbia, Canada	1996– 2007	Prospective cohorts of injection drug users. Median CVL*. Cox regression model to association with HIV incidence.	CVL associated with time to HIV seroconversion (Hazard ratio 3.32 per log10 increase). After median viral load fell to <20,000 copies/mL, no statistical association with HIV incidence observed.	(40)
San Francisco	2004–2008	HIV/AIDS public health surveillance for new diagnoses and calculated HIV incidence. Mean Community viral load. Poisson models for CVL and new HIV diagnoses.	Significant decline in mean CVL 2004 –2008 (p=0.037). Reduction in CVL associated with decrease in new HIV diagnoses (p=0.003).	(41)
British Columbia, Canada	1996–2012	ART† coverage from centralized registry. HIV public health surveillance for new diagnoses with estimated HIV incidence. General additive models with Poisson regression.	709% increase in ART uptake. 42% decrease in HIV incidence. For every 1% expansion in individuals suppressed on ART, a corresponding 1% drop in HIV incidence was predicted.	(19)
Hlabisa sub-district, KwaZulu-Natal, South Africa	2004–2011	Cohort of 16,667 HIV uninfected individuals. ART coverage and HIV prevalence within the surrounding community assessed, and rate of new seroconversions captured.	As ART coverage within a community expands, risk of acquisition decreases: for communities with 30–40% ART penetration, risk of new infection dropped 38% compared to communities with <10% ART uptake.	(20)

^*CVL = community viral load

^†ART = highly active antiretroviral therapy. Adapted from (42) with permission.