HIV Viral Load Trends in Six Eastern Caribbean Countries Utilizing a Regional Laboratory Referral Service: Implications for Treatment as Prevention

Abstract

ObjectiveSince 2009, seven countries in the Organization of Eastern Caribbean States (OECS), Antigua & Barbuda, Dominica, Grenada, Montserrat, St. Kitts & Nevis, Saint Lucia, and St. Vincent & the Grenadines, have been utilizing a laboratory referral service for HIV-1 viral load (VL) offered by The Ladymeade Reference Unit (LRU) Laboratory, Barbados. The objective of this study was to evaluate 5 year VL trends in the six larger OECS countries participating in this regional referral service.MethodsBlood samples were collected in source countries and transported to Barbados as frozen plasma according to a standardized protocol. Plasma specimens were amplified by RT PCR on a Roche TaqMan 48 analyser (Roche Diagnostics, Panama City, Panama). VL was considered optimally suppressed below a threshold level of < 200 HIV-1 copies/mL of blood. The same threshold was used as a binary indicator in an analysis of the secular change in VL suppression. Montserrat was excluded due to insufficient number of samples.ResultsA steady rise in VL referrals from OECS countries was recorded, rising from 312 samples in 2009 to 1,060 samples in 2013. A total of 3,543 samples were tested, with a sample rejection rate (9.2%) mostly due to breaks in the cold chain. Aggregate VL data showed the odds of VL suppression in the Eastern Caribbean improved by 66% for each additional year after 2009 (Odds Ratio 1.66 [95% CI 1.46 to 1.88]; p<0.001).ConclusionWe demonstrate the feasibility of establishing a regional laboratory referral service for HIV VL monitoring in the Eastern Caribbean. Aggregate VL trends showed a significant year-on-year improvement in VL suppression, implying public health benefits through treatment as prevention in the OECS. VL provides a powerful monitoring & evaluation tool for strengthening HIV programs at country level among the small island states participating in this regional referral network.

Shifting the HIV Paradigm from Care to Cure: Proceedings from the Caribbean Expert Summit in Barbados, August 2017

“… 67 Several of the smaller islands in the Caribbean, that are not equipped to conduct molecular diagnostics, have complained that HIV viral load monitoring through established laboratory referral networks is no longer being supported through international funding partners. 69 …”

Measures of human immunodeficiency virus (HIV) community viral load and HIV incidence among people who inject drugs

“…By including the number of HIV negative people in the denominator of the mean community viral load calculation, we argue that the definition would better reflect community risk and be relevant for monitoring HIV transmission risk and the effectiveness of prevention activities. Despite this concern, studies continue to measure community viral load not accounting for the prevalence of HIV and the CDC guidelines remain unchanged since 2011 [12, 15, 16]. This study seeks to demonstrate the importance of adjusting for HIV prevalence in community viral load measures by comparing the association between community viral load and HIV incidence under two definitions (mean community viral load and prevalence-adjusted community viral load) to evaluate their use in community surveillance and TasP evaluation activities.…”