Background Available HIV prevention interventions are partially efficacious, but might offer the best strategy to control HIV through synergistic combination and targeting. Home-based HIV testing and counselling (HBCT), conducted house-to-house, provides rapid population-level knowledge of HIV serostatus and a means to facilitate access to combined HIV prevention interventions: expedited referral to antiretroviral treatment (ART) for HIV+ persons, counselling for behaviour change, promotion of and referral for male circumcision and topical or oral PrEP for high-risk HIV- persons. Thus, massively conducted HBCT could serve as a platform for achieving high coverage of combination HIV prevention (HBCT-plus).

Methods We used age-sex stratified mathematical model to investigate the impact of HBCT-plus-including population-wide HBCT, behaviour change counselling, initiation of ART for HIV+ persons meeting national guidelines, topical PrEP, and male circumcision-on population-level HIV incidence. Our model was calibrated to data for KwaZulu-Natal province of South Africa. Effects of HBCT and other components of the HBCT-plus intervention package were based on empirical data from African settings.

Results Without major intervention efforts in this province, the model projects HIV incidence to be approximately 2% through the year 2020. In contrast, with high-coverage of HBCT-plus intervention the model indicates that incidence could be reduced by approximately half, to 1%, under assumptions inAbstract O1-S06.04 table 1. Short and long term reductions in HIV incidence are mediated by short and long term behaviour changes following HBCT, respectively, and are manifested by repeated rounds of HBCT every 4 years. Longer-term impacts are supported by a reduction in infectiousness (due to timely initiation of ART as a result of earlier knowledge of serostatus because of HBCT) and susceptibility (due to circumcision) as well as associated ‘herd immunity’ effects.

Conclusions Multiple evidence-based HIV preventive interventions combined and delivered through a platform of periodic HBCT could reduce population-level HIV incidence in South Africa by 50% within 4 years. Fast and slow acting components affecting infectiousness and susceptibility can make combination packages particularly strong. Multiple partially-effective tools for HIV prevention can be combined and if coverage is sufficient, substantial reductions in HIV incidence are potentially within reach.