The ART of war: fast-tracked HIV testing is proving key
Scientists have made even more great strides in the fight against the HIV/Aids pandemic
Hard on the heels of Tuesday’s announcement that stem cell treatment appears to have cured two HIV patients, another huge step forward has been disclosed in the war on Aids.
British scientists working in SA and Zambia reduced new infections by 30% when they offered entire communities voluntary HIV testing and immediately put those who tested positive on treatment in line with local guidelines.
Study leader Prof Richard Hayes, from the London School of Hygiene & Tropical Medicine, said: “Our study found that a combination prevention strategy, including ‘universal test and treat’, may be an effective tool to slow the global HIV epidemic.”
Presenting the research on Tuesday at the Conference on Retroviruses and Opportunistic Infections in Seattle, Hayes added: “People living with HIV who achieve and maintain an undetectable level of HIV in the blood by taking and adhering to antiretroviral therapy [ART], do not sexually transmit the virus to others.
“This is central to ‘universal test and treat’, which aims to ensure that everyone in the community knows their HIV status, with those found HIV-positive linked rapidly to the clinic for treatment.”
The so-called HIV Prevention Trials Network Population ART (PopART) trial, which involved the Desmond Tutu TB Centre in Cape Town, found that new HIV infections were 30% lower in communities where the intervention was introduced alongside other proven HIV prevention measures to those who tested negative, compared to communities that received standard care.
PopART was conducted between 2013 and 2018 in 21 communities of roughly 50,000 residents. Communities were assigned at random to one of three study arms: Arm A received annual door-to-door voluntary HIV testing, linkage to care for those who tested positive, the opportunity to immediately begin treatment and a suite of proven HIV prevention measures for those who tested negative.
Arm B received the same services except treatment was provided according to national guidelines.
Arm C served as a control and received HIV prevention and testing services according to the local standard of care, as well as HIV treatment according to national guidelines. At the beginning of the trial, national guidelines for HIV treatment in Zambia and SA said people living with HIV should start ART when their CD4+ T-cell count – a measure of immune health – had declined to 350 cells per μL. That threshold was raised to 500 cells/μL in 2014.
In 2016, the countries recommended that everyone diagnosed with HIV begin ART immediately, regardless of CD4+ T-cell count. Consequently, arms A and B received the same intervention during the last two years of the trial.
To measure the impact of the interventions, the investigators recruited a random sample of 48,300 adults aged 18 to 44. Members of the study team visited these participants at the start of the trial, and then once a year for three years collected data through a questionnaire and blood testing, including a test for HIV infection.
Investigators found that HIV incidence was 30% lower in arm B than the control arm. By contrast, only a nonsignificant 7% reduction was seen in arm A.
Among those members of the population cohort who tested positive for HIV by the second year of the study, the investigators determined the proportion who had an undetectable level of virus in their blood. Viral suppression was achieved by 72% of these study participants in arm A, 68% in arm B and 60% in arm C.
Prof Sarah Fidler, study co-leader from Imperial College London, said: “The idea behind our study was that if most people living with HIV know their HIV status and take HIV treatment, the risk of passing the virus on to their partners and children will be greatly reduced.
“The results show that this approach was successful, [and] we hope the findings may help to reduce the number of new HIV infections across the world.”
The leader of the Zambian leg of the study, Prof Helen Ayles of the London School of Hygiene & Tropical Medicine, said: “We saw very strong evidence that new HIV infections decreased by a third with a prevention strategy where HIV treatment was started according to country guidelines.
“We did not see a similar reduction when universal HIV treatment was offered from the beginning of the study. Additional analyses are under way to explore the reasons for this finding. However, overall, both strategies improved knowledge of HIV status, uptake of treatment and viral suppression.”
The researchers found that treatment coverage was lower in young people (aged under 30 years) and in men. HIV treatment and prevention programmes will need to address these gaps in coverage to realise the full potential of strategies like PopART.
In 2017, about 37 million people were living with HIV worldwide, with 1.8 million new infections. HIV incidence is declining worldwide, but is unlikely to reach the UNAids target of under 500,000 new infections by 2020. Steep reductions in incidence are needed to curb the HIV/Aids epidemic, especially in southern Africa, where the prevalence of HIV is higher than anywhere else in the world.