Objective: To estimate the impact and cost-effectiveness of treatment as prevention
(TasP), pre-exposure prophylaxis (PrEP) and condom promotion for serodiscordant
couples in Nigeria.
Design: Mathematical and cost modelling.
Methods: A deterministic model of HIV-1 transmission within a cohort of serodiscordant
couples and to/from external partners was parameterized using data from Nigeria
and other African settings. The impact and cost-effectiveness were estimated for
condom promotion, PrEP and/or TasP, compared with a baseline where antiretroviral
therapy (ART) was offered according to 2010 national guidelines (CD4þ <350 cells/ml)
to all HIV-positive partners. The impact was additionally compared with a baseline of
current ART coverage (35% of those with CD4þ <350 cells/ml). Full costs (in US $2012)
of programme introduction and implementation were estimated from a provider
perspective.
Results: Substantial benefits came from scaling up ART to all HIV-positive partners
according to 2010 national guidelines, with additional smaller benefits of providing
TasP, PrEP or condom promotion. Compared with a baseline of offering ART to all HIVpositive
partners at the 2010 national guidelines, condom promotion was the most costeffective
strategy [US $1206/disability-adjusted-life-year (DALY)], the next most costeffective
intervention was to additionally give TasP to HIV-positive partners (incremental
cost-effectiveness ratio US $1607/DALY), followed by additionally giving PrEP
to HIV-negative partners until their HIV-positive partners initiate ART (US $7870/
DALY). When impact was measured in terms of infections averted, PrEP with condom
promotion prevented double the number of infections as condom promotion alone.
Conclusions: The first priority intervention for serodiscordant couples in Nigeria should
be scaled up ART access for HIV-positive partners. Subsequent incremental benefits are
greatest with condom promotion and TasP, followed by PrEP