# Hard-to-Reach Populations: Implications for Ending the AIDS Epidemic

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2021 · $583,117

## Abstract

The Rakai region in Uganda was the initial epicenter of the HIV epidemic in East Africa and continues to be a
high burden area with an HIV prevalence of ~13%. Through the open, population-based Rakai Community
Cohort Study (RCCS), we reported that combination HIV prevention (CHP) decreased population-level HIV
incidence in Rakai by 42% from 1.17/100 person-years (pys) prior to CHP scale-up to 0.66/100 pys by 2016
(Grabowski et al. NEJM 2017). Implications and limitations from this study raise two issues of global
importance. First, mobile persons, typically away for work or school, and, rarely, refusers are a “hard-to-reach”
population that is difficult to survey, reducing RCCS participation rates to ~62%. These populations may
likewise be hard-to-reach for engagement in HIV services. Ongoing cluster-randomized HIV prevention trials
and population-based HIV impact assessments have similar challenges of potential bias due to missing these
hard-to-reach populations. Second, despite reaching 59% male circumcision coverage and UNAIDS 90-90-90
goals with 75% viral suppression of all HIV-positive participants in RCCS, HIV incidence reductions were
moderate and remained well above the estimated rate needed for HIV elimination (~0.1/100py). To address
ongoing HIV transmission in the Rakai region, the PEPFAR program in which RCCS is nested recently began
implementing additional CHP interventions: (i) Pre-Exposure Prophylaxis (PrEP); (ii) assisted Partner
Notification; and (iii) Same-day antiretroviral therapy (ART). This environment provides a unique opportunity to
address the following important questions: (1) To what extent do hard-to-reach populations bias HIV coverage
and incidence estimates? (2) Why do some individuals continue to acquire HIV and from whom? (3) Given
hard-to-reach populations, can state-of-the-art CHP in a programmatic setting reduce HIV incidence to the
levels needed for HIV elimination? Our setting and research infrastructure strongly position us to answer these
highly significant questions and inform current and future HIV prevention trials, evaluations, and programs. We
thus propose a novel study with the following Aims. Aim 1-We will first determine CHP coverage and HIV
incidence among hard-to-reach persons using enhanced surveillance techniques. Aim 2-We will then
characterize ongoing sources of incident HIV infection through partner tracing, viral phylogenetics, and sexual
network analyses. Aim 3-Finally, we will determine if state-of-the-art CHP can engage hard-to-reach
populations and reduce population-level HIV incidence to a level sufficient for HIV elimination by 2030. To our
knowledge, no prior HIV population-based studies have empirically determined the potential effects of
participation bias on HIV epidemiology and incidence due to non-inclusion of hard-to-reach populations. This
study will uniquely address questions on hard-to-reach populations which are critical to understanding the true
state of the epidemic, interp...

## Key facts

- **NIH application ID:** 10114191
- **Project number:** 5R01AI143333-03
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Larry William Chang
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $583,117
- **Award type:** 5
- **Project period:** 2019-04-25 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10114191

## Citation

> US National Institutes of Health, RePORTER application 10114191, Hard-to-Reach Populations: Implications for Ending the AIDS Epidemic (5R01AI143333-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10114191. Licensed CC0.

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