The cascade of care following community-based detection of HIV in sub-Saharan Africa – A systematic review with 90-90-90 targets in sight

Introduction
We aimed to establish how effective community-based HIV testing services (HTS), including home and community location based (non-health facility) HIV testing services (HB-/CLB-HTS), are in improving care in sub-Saharan Africa (SSA), with a view to achieving the 90-90-90 targets.
Methods
We conducted a systematic review of published literature from 2007–17 which reported on the proportion of individuals who link-to-care and/or initiate ART after detection with HIV through community-based testing. A meta-analysis was deemed inappropriate due to heterogeneity in reporting.
Results and discussion
Twenty-five care cascades from 6 SSA countries were examined in the final review– 15 HB-HTS, 8 CLB-HTS, 2 combined HB-/CLB-HTS. Proportions linked-to-care over 1–12 months ranged from 14–96% for HB-HTS and 10–79% for CLB-HTS, with most studies reporting outcomes over short periods (3 months). Fewer studies reported ART-related outcomes following community-based testing and most of these studies included <50 HIV-positive individuals. Proportions initiating ART ranged from 23–93%. One study reported retention on ART (76% 6 months after initiation). Viral suppression 3–12 months following ART initiation was 77–85% in three studies which reported this.
There was variability in definitions of outcomes, numerators/denominators and observation periods. Outcomes varied between studies even for similar time-points since HTS. The methodological inconsistencies hamper comparisons. Previously diagnosed individuals appear more likely to link-to-care than those who reported being newly-diagnosed. It appears that individuals diagnosed in the community need time before they are ready to link-to-care/initiate ART. Point-of-care (POC) CD4-counts at the time of HTS did not achieve higher proportions linking-to-care or initiating ART. Similarly, follow-up visits to HIV-positive individuals did not appear to enhance linkage to care overall.
Conclusion
This systematic review summarises the available data on linkage to care/ART initiation following community-based detection of HIV, to help researchers and policy makers evaluate findings. The available evidence suggests that different approaches to community-based HTS including HB-HTS and CLB-HTS, are equally effective in achieving linkage to care and ART initiation among those detected. Engagement and support for newly diagnosed individuals may be key to achieving all three UNAIDS 90-90-90 targets. We also recommend that standardised measures of reporting of steps on the cascade of care are needed, to measure progress against targets and compare across settings.