//'Big-data' analysis of HIV viral loads reveals the need for targeted HIV-treatment interventions in HIV hyper-endemic settings

'Big-data' analysis of HIV viral loads reveals the need for targeted HIV-treatment interventions in HIV hyper-endemic settings

Human Immunodeficieny Virus (HIV) remains a public health concern causing severe immunodeficiency in the absence of antiretroviral treatment (ART). Inadequate viral load (VL) suppression increases the risk of HIV transmission and often leads to HIV drug resistance (HIVDR). Having the largest HIV treatment program globally, South Africa like most countries, routinely monitors HIV VLs in people receiving ART, to ensure sustainable viral suppression. However, unlike most countries, South Africa has to consistently perform this imperative task at a massive scale, being home to 1 in every 5 people living with HIV globally. This means routine clinic visits for pharmacy antiretroviral (ARV) drug refills every month and HIV VL tests every 6-12 months. As if that was not enough, the COVID-19 pandemic posed an unprecedented challenge to HIV service delivery, to an extent that had not been realised since the beginning of the HIV/AIDS epidemic in the early 1980s. With the rapid spread of the novel coronavirus disease, countries introduced control measures that included quarantine, social distancing, travel restrictions and total lockdowns, resulting in non-emergency outpatient clinic services being limited or suspended, and disruptions in drug supply and delivery. This heavily impacted HIV-care, with people not able to routinely attend HIV clinic visits, and collect their life-long and desperately needed ARV drugs. During the COVID-19 pandemic, the HIV-world made positive steps in introducing a more potent HIV drug named dolutegravir (DTG). South Africa began transitioning towards DTG-based regimens in public-sector healthcare in December 2019.

To understand the impact of DTG-transition on HIV viral suppression, albeit shadowed by the COVID-19 pandemic, we designed a study that used spatiotemporal analysis of detectable HIV VLs amid DTG-transition in KwaZulu-Natal province, the epicenter of the HIV epidemic in South Africa. To do so, Dr Lilishia Gounder (PhD student) mentored by EDCTP Career Development Dr Benjamin Chimukangara, retrospectively curated a HIV VL database using de-identified routine VL data obtained from the National Health Laboratory Service (NHLS) Central Data Warehouse, at the Department of Virology, University of KwaZulu-Natal, in Durban, South Africa. The NHLS is the largest diagnostic pathology service provider in South Africa, delivering laboratory services to all public-sector healthcare facilities that serve approximately 80% of the population.

Through the EDCTP Career Development grant, the team curated over 7.6 million HIV VL records from 736 public-sector healthcare facilities across KwaZulu-Natal province. Using these data and with the help of collaborators, they analysed trends in HIV viraemia and mapped HIV VLs per facility on geographic maps to identify changes in HIV VLs overtime. This analysis revealed three major findings. First, the team noticed an overall decrease in HIV VLs between 2018 and 2022, suggesting that the majority of people on ART were achieving VL suppression, to levels below 1,000 copies/mL of plasma. Secondly, in as much as HIV VLs were decreasing, it was found that specific facilities in rural northern districts of KwaZulu-Natal province as well as peri-urban and urban coastal districts maintained persistently higher VLs, highlighting regions needing priority HIV-care. Thirdly, it was observed an increase in low-level viremia (VLs between 400 – 999 copies/mL), as well as emergent HIV VL hotspots, demonstrating spatial clustering of high HIV VLs in years following DTG-rollout in South Africa.

Taken together, these findings based on routine HIV-1 VL tests provided real-world estimates showing that, despite DTG-rollout, there is need to direct efforts to known communities with higher levels of viraemia on ART, to strengthen VL re-suppression efforts and HIV prevention activities, and ultimately, to implement activities that curb emergence of HIVDR. These findings also emphasise the need for close HIV VL monitoring in people with low-level viraemia as this could be a marker for emergence of DTG-associated resistance mutations, in a setting where treatment regimens are largely limited. This is especially important in resource-limited HIV-hyperendemic settings where strategic data-driven information, or epidemic intelligence can help appropriate deployment of scarce resources for maximal impact in epidemic control. This study also showed the benefits of using pre-existing data which provides large data-points (“big-data”) at no additional testing cost, making such an approach more attractive for use in resource-limited settings. Therefore, similar studies are warranted, to enable geographically targeted interventions in HIV treatment programmes, including directed improvement of health services and training of health professionals at specific facilities, as we work towards achieving UNAIDS 95-95-95 HIV targets of ending the HIV/AIDS epidemic by 2030.

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