Effect of population viral load on prospective HIV incidence in a hyperendemic rural African community

Abstract

Monitoring HIV population viral load (PVL) has been advocated as an important means of inferring HIV transmission potential and predicting the future rate of new HIV infections in a particular community. However, the relationship between the PVL measures and directlymeasured HIV incidence has not been quantified in any setting and most importantly not in a hyper-endemic sub-Saharan African setting. We assessed this relationship using one of Africa's largest population-based prospective population cohorts, in rural KwaZulu-Natal, South Africa in which we followed 8,732 HIV-uninfected participants between 2011 and 2015. Despite clear evidence of spatial clustering of high viral loads in some communities, our results demonstrate that PVL metrics that are derived from aggregation of viral load data only from the HIV-positive members of a particular community did not predict HIV incidence in this typical hyper-endemic, rural African population. Only once we used modified PVL measures which combined viral load information with the underlying spatial variation in the proportion of the population infected (HIV prevalence) did we find a consistently strong relationship with future risk of HIV acquisition. For example, every 1% increase in the overall proportion of a population having a detectable virus, was independently associated with a 6.3% increase in the risk of HIV acquisition (p=0.001). In hyper-endemic African populations, these modified PVL indices could play a key role in targeting and monitoring interventions in the most vulnerable communities where the future rate of new HIV infections is likely to be highest.

Young people who inject drugs in India have high HIV incidence and behavioural risk: a cross‐sectional study

“…Although earlier multi‐city studies in other countries emphasized the influence of HIV seroprevalence on HIV incidence rates among PWID, more recent studies suggest that community viral suppression, regardless of HIV seroprevalence rate, is a stronger predictor of HIV incidence in high‐risk populations . In this study and previous studies, we show better awareness of HIV status and greater community viral suppression among PWID in the Northeast compared to those in the North/Central region .…”

“…Although the response to injection drug use in India has historically been punitive, the benefits of shifting towards a harm reduction approach is highlighted by the experience of the Northeastern states which were the first to institute widespread HIV prevention and treatment efforts based on harm reduction principles. Although earlier multi-city studies in other countries [59] emphasized the influence of HIV seroprevalence on HIV incidence rates among PWID, more recent studies suggest that community viral suppression, regardless of HIV seroprevalence rate, is a stronger predictor of HIV incidence in high-risk populations [60,61]. In this study and previous studies, we show better awareness of HIV status and greater community viral suppression among PWID in the Northeast compared to those in the North/Central region [19,62].…”

Temporal trends of population viral suppression in the context of Universal Test and Treat: the ANRS 12249 TasP trial in rural South Africa

“…Tanser et al ., using data from another rural community in KwaZulu‐Natal, found that HIV incidence was not directly associated with PVS but rather with population viral load metrics that account for HIV prevalence . As HIV prevalence remained almost stable during the trial, we cannot exclude the possibility that HIV incidence may have been decreasing in both arms.…”

“…In addition, the PLHIV population turnover in the trial area was high, more than one fifth being replaced every year, mainly due to out-and in-migration as well as the continuous inflow of new HIV infections, attenuating the impact of the interventions on the cascade of HIV care and subsequently the differences between arms [26]. Tanser et al, using data from another rural community in KwaZulu-Natal, found that HIV incidence was not directly associated with PVS but rather with population viral load metrics that account for HIV prevalence [27]. As HIV prevalence remained almost stable during the trial, we cannot exclude the possibility that HIV incidence may have been decreasing in both arms.…”

Challenges of HIV diagnosis and management in the context of pre‐exposure prophylaxis (PrEP), post‐exposure prophylaxis (PEP), test and start and acute HIV infection: a scoping review

“…ART has dramatically improved survival for people living with HIV (PLHIV) and globally there has been an improvement in treatment coverage . Viral suppression on ART confers an individual health benefit , and a significant reduction in the risk of onward transmission , with an impact on HIV incidence at a population level . In 2014, the Joint United Nations Programme on HIV and AIDS (UNAIDS) set the 90‐90‐90 targets, whereby 90% of people with HIV will know their status, 90% diagnosed will be on ART and 90% on ART will be virally supressed by 2020 .…”